q_id
stringlengths 6
6
⌀ | title
stringlengths 3
546
| selftext
stringlengths 0
4.44k
⌀ | category
stringclasses 12
values | subreddit
stringclasses 1
value | answers.a_id
listlengths 1
489
⌀ | answers.text
listlengths 1
4
| answers.score
listlengths 1
4
| answers.text_urls
listlengths 1
489
⌀ | title_urls
listlengths 1
1
⌀ | selftext_urls
listlengths 1
1
⌀ |
|---|---|---|---|---|---|---|---|---|---|---|
csuiqi
|
Why do mountain rivers never run out of water having existed for thousands of years?
|
Other
|
explainlikeimfive
|
[
"exh2ccz"
] |
[
"Rain tends to fall on mountains as the air and clouds flow over them, so the water is constantly replenished from rainfall (or snowfall)."
] |
[
4
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
6my7gz
|
Why does a stream of water only seem to splash when it first contacts the surface of a pool of water?
|
So, the motivation behind this is that I have been cooling down my tea with cold water from a water bottle lately. I have noticed that upon squeezing the water bottle into the tea, a splash occurs when the water first contacts the tea. However, shortly after, the water seems to then smoothly flow into the tea without much splashing. Why is this? Is it a property of liquids, or does it have to do with the mechanics of the water bottle? My guess is that it it is because the stream has higher pressure upon its release from the water bottle and once the valve is opened and some water flows out, the pressure decreases? I would love to hear your explanations!
|
Physics
|
explainlikeimfive
|
[
"dk5ap4p"
] |
[
"Hopefully you find this sufficient but it is because of surface tension. The surface of water is is more elastic than the water in the bulk of its contents. That is, when you pour water into the tea, the first bit of water that hits the surface is pushed away by the surface tension of the tea. After the water splashes from the force of the surface tension, the water you are pouring in flows in because the surface layer of tea has been pushed aside by the flowing water. Surface tension occurs because the tea is more so attracted to other tea molecules (really just water molecules) than air molecules that are above them and stick together better. This cause the top layer of tea to be \"harder\" than the liquid underneath and pushes back on things that hit it."
] |
[
5
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
827lxt
|
How do warrants for arrest work?
|
Other
|
explainlikeimfive
|
[
"dv7z0kd",
"dv7zt9c"
] |
[
"That largely depends on the country but in general, a judge decides that someone should be arrested and the police are tasked with enforcing that decision."
] |
[
3
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
izwwl3
|
What's the difference between a novel and a book?
|
Other
|
explainlikeimfive
|
[
"g6lkn5i"
] |
[
"A novel is a subset. Novels are a type of book. All novels are books, but not all books are novels. A novel is a work of fiction, and is usually written in a prose (rather than poetic) form. It is interesting to know that people aren't sure of the difference because it bugs the bananas out of me when I assign nonfiction autobiographies to my students and they refer to them as \"novels\". But maybe they really don't know. (but you know, first world problems.)"
] |
[
12
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
5n9ehk
|
Have Any Technologies Peaked?
|
Technology
|
explainlikeimfive
|
[
"dc9r53o",
"dc9pch0",
"dca43e1"
] |
[
"Firearms. We can keep making them to tighter tolerances by shaving off thousandths of inches here and there, but the fact is the designs are pretty much perfected. You can't do much to alter the basic physics involved in feeding bullets into a gun. Even experts agree that unless a radically new kind of technology shows up (like directed energy weapons) the basic design of a gun isn't going to change much. There have been some innovations like the Kriss Vector, but results have been mixed and the jury is still out on it."
] |
[
4
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
i65rld
|
What exactly is the difference between a powerful pc and a Server?
|
Technology
|
explainlikeimfive
|
[
"g0tkine",
"g0tknxx",
"g0tm5s7",
"g0tl5w9",
"g0up8lq"
] |
[
"Purpose. A powerful pc is used to perform tasks for a single user. A server is meant to facilitate a service for multiple users and stay powered on for a long time. Powerful PC do job for one person real quick. Powerful server do job for many people."
] |
[
35
] |
[
[],
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
nnpi7d
|
Why is shampooing the second time yields more bubbles than shampooing the first time?
|
I'm not sure if that's just my hair but I always wandered about this.
|
Chemistry
|
explainlikeimfive
|
[
"gzvmc4r",
"gzwax9q"
] |
[
"Because the first time, you scrub all the oils and stuff, the micelles in the soap cling the the fat and just wash off. When you shampoo the second time, they cling to the water because the oil is gone. This is how they create bubbles."
] |
[
8
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
o2nb4p
|
Why are diesel car engines so much louder than petrol, they sound like tractors?
|
Engineering
|
explainlikeimfive
|
[
"h279ikt",
"h27aff7"
] |
[
"Diesel engines operate by causing the fuel to ignite by the rapid heating that occurs when the air and fuel is compressed. In a gasoline engine, the mixture is ignited by the spark plugs. To get the fuel/air mix to combust without a spark requires *much* higher pressure than in an equivalent gasoline engine. The result is also a much more powerful explosion, making for more noise, but also more energy released for a given displacement size, which is why diesels tend to have higher horsepower and torque, and somewhat better efficiency than gasoline engines."
] |
[
16
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
6fgbe5
|
What is the purpose of non-discriminatory hiring laws in workplaces if employers/companies reserve the right to hire or turn away anyone they want?
|
Culture
|
explainlikeimfive
|
[
"dihxipt",
"dihyeh4",
"dii03lu"
] |
[
"They aren't allowed to hire or turn away people for those reasons that the law forbids. Proving it is the case in legal action might be difficult though, unless they're clumsy about it."
] |
[
30
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
7z8qrg
|
Why are the words "Yeah" and "Oh" always in pop songs and said for so long?
|
Culture
|
explainlikeimfive
|
[
"dum5dg5",
"duma1xh"
] |
[
"They are used as *filler* where the tune requires a note, but the singer doesn't have anything more to say. An excellent lyricist will try to adjust the wording so that not too many of these are needed."
] |
[
16
] |
[
[],
[
"https://youtu.be/-VsmF9m_Nt8"
]
] |
[
"url"
] |
[
"url"
] |
|
68qw8c
|
How does a the US debt pose a serious threat to the economy? If so, at what point would it realise this threat?
|
Economics
|
explainlikeimfive
|
[
"dh0m7am",
"dh0ok4j",
"dh0n31g"
] |
[
"Next to no threat in all actuality. Most people are in debt and do just fine. Things like mortgages, student loans, and car payments but as long as you can pay them off on time there is no issue. The same thing applies to the government. We might be trillions of dollars in debt, but we have a fantastic credit score. In fact we have never missed a payment, and as long as we continue to pay off our debts when they are due we will be a strong nation."
] |
[
5
] |
[
[],
[
"https://www.reddit.com/r/Bitcoin/comments/67bsnu/this_is_why_i_bitcoin/"
],
[]
] |
[
"url"
] |
[
"url"
] |
|
c9hmmz
|
How does the US prison system work?
|
Other
|
explainlikeimfive
|
[
"esymg6v",
"esyvb75",
"esyw5ab"
] |
[
"Private prisons also have contracts with the state so that is they fall below a certain number of inmates the state has to pay a fine. Incentivizing them to imprison more people. God bless capitalism"
] |
[
7
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
detxh7
|
How does my phone figure out how much to delay video so it matches my Bluetooth headphone delay?
|
When I use my Bluetooth headphones to watch videos on my phone, the phone usually delays the video enough to synchronize it with the delayed sound on my headphones. How does it figure out how much to delay it? (I have other, secondary, questions too: how close does the timing have to be so I don't notice a mismatch? And why does it sometimes mess up?)
|
Technology
|
explainlikeimfive
|
[
"f2z1c0d"
] |
[
"I know that other streaming protocols have round trip time synchronization built into them which might be what your headset is doing. Basically your phone sends a packet of audio to your headset and then the headset sends back an acknowledgement of receiving it and playing it. The round trip time is measured and divided in half. This allows your phone to know how long it takes and offsets your video play back. As for the issue with being out of sync that is probably because the packet turn around time is an average. One bad packet, one extra delay and it's all off and needs to be synchronized again."
] |
[
6
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
6496a5
|
what do wild animals do when they get bored?
|
For example, a lion. It has its prey for the day, is well rested, the cubs are ok and there is nothing to do.
|
Biology
|
explainlikeimfive
|
[
"dg0bc4c",
"dg0pfkn"
] |
[
"Lions sleep like 16 hours a day. They do what people would do if they didn't have all this shit to do. They just hang out, play, sleep a lot"
] |
[
13
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
5pmx4d
|
What makes materials transparent? Can a transparent metal be created in theory?
|
Chemistry
|
explainlikeimfive
|
[
"dcsdiqi"
] |
[
"The electrons in a material have multiple different states they can be in, and each of them requires a certain amount of additional energy to reach from the \"ground state\" (the stable state with the least amount of energy). The distance between these states (measured in energy) corresponds to the energy of light that that material can interact with - mostly absorption and retransmission. Visible light has energies between around 1.65 eV and 2.76 eV. If the electrons in a material can only take on energy in larger packets than that (all the excited states require more than 2.76 eV extra energy) then it allows visible light to pass unhindered - the material is transparent in visible light. Note that it's equally possible for stuff to be transparent in other wavelengths but not in the visible spectrum. Quartz, for instance, is transparent in infrared. Listening to radio transmissions is possible in a decent part because radio waves have little energy and a whole ton of stuff is transparent in the radio spectrum."
] |
[
7
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
akqix4
|
The difference between venomous and poisonous
|
Biology
|
explainlikeimfive
|
[
"ef6zbkn",
"ef7a80b",
"ef73652"
] |
[
"If you bite it and you get sick, it's poisonous. If it bites you and you get sick, it's venomous. Edit: obligatory \"thanks for the gold, kind stranger\""
] |
[
329
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
e0081c
|
What causes trypophobics to fear or be made uneasy by the small holes?
|
I know that usually phobias are irrational, but what is the root of that? Exe: For spiders I have heard things like "it's how they move" or for worms I have heard "it's their wriggling alien look". I'm just curious if anyone here has the phobia or can explain what the base there is.
|
Psychology
|
explainlikeimfive
|
[
"f8b3gbq",
"f8b4t2z",
"f8bleb1"
] |
[
"For me it has something to do with imagining things crawling out of those holes. A lot of times I see the pattern/small hole and my brain imprints that pattern onto some body part and then I can’t help but think of bugs or something crawling in and out of those holes *under and through your skin* and it gets me bad"
] |
[
11
] |
[
[],
[
"https://dangerousminds.net/comments/apparently_trypophobia_a_fear_of_tiny_clusters_of_holes_isnt_a_phobia_but_a"
],
[]
] |
[
"url"
] |
[
"url"
] |
683vak
|
How do erasers work on a molecular level?
|
What exactly is going on with an eraser on graphite in a microscope.
|
Other
|
explainlikeimfive
|
[
"dgvgdym",
"dgvg9mk"
] |
[
"rub eraser on paper. friction roughens the paper fibres and creates heat. Heat makes rubber sticky. Sticky the rubber picks up the graphite"
] |
[
17
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
75hip7
|
Oil is mostly bought and sold in USD. How does this help the American economy?
|
Economics
|
explainlikeimfive
|
[
"do6yj51"
] |
[
"It increases demand for USD, which increases the value of USD. That means that imports are (relatively) cheaper and exports are (relatively) more expensive, so it hurts farmers, forces manufacturers to expand internationally, and benefits purchasers of imports."
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
gxah41
|
how can dolls close and move their eyes side to side?
|
I've seem a lot of doll that close their eyes when they are laying down or that can move their eyes side to side when shaked. I've tried dismantling one to understand it, but l really couldnt make anything of it.
|
Engineering
|
explainlikeimfive
|
[
"ft02ey2"
] |
[
"It is just gravity. For the eyelids imagine a hemisphere of eyelid that goes around more than 90 degrees but less than 180 with a weight on the back edge. That back edge is pulled downward when the doll is upright, keeping the eyelids open. But when the doll is laid horizontal the weight pulls the eyelids shut as \"down\" is now 90 degrees different than before. Similar methods can be used to make the eyes move from side to side."
] |
[
5
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
88wa55
|
How come what we ingest (eat or drink) doesn’t necessarily have to be sterile, but any time we have some sort of surgery or procedure done, everything has to be completely sterile?
|
Biology
|
explainlikeimfive
|
[
"dwnpfsa",
"dwnpctm",
"dwnpaxo",
"dwnpmtb"
] |
[
"Your digestive system isn't really \"inside\" your body in the same way your organs are. It is fully enclosed, end to end, and designed to deal with all the food-like objects the human animal is going to cram into itself. Your gut does a fine and dandy job of handling lots of pathogens and potential parasites by just generally being a pretty unfriendly environment for life. Now obviously some nasties have evolved to survive through that and will make you pretty sick if you eat them. Your gooey innards though? No such defenses. They are warm and wet and a perfect place for even fairly weak bacteria and other nasties to grow and go hog wild."
] |
[
21
] |
[
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
kvw4z7
|
How do they put magnets In iPad cases without fear of damaging the iPad?
|
SSL
|
Technology
|
explainlikeimfive
|
[
"gj0poza",
"gj0qqxt"
] |
[
"Magnets are harmless to electronics. The only exceptions are magnetic based devices, such as: * Magnetic storage. VHS tapes, floppy disk, and hard drives. They aren't that susceptible though, it's not like a magnet anywhere near them is doom. Modern hard drives in a computer or laptop (if not already SSD) are magnetic based, but not exactly easy to wipe with a magnet vaguely near the computer. I wouldn't go rubbing rare earth magnets directly on a drive though. * CRT TVs and monitors, the big, old, heavy ones. A magent near then will temporarily distort the image and colour. Electromagnets aim a beam to make an image, so a magnet alters the beam path. A phone/tablet has none of these. It has solid state storage, and it has an LCD or LED screen. Nothing magnetic based."
] |
[
19
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
c8sv5h
|
Why is it, with all of our technological advances, that we still don’t have cell service in all areas, especially pretty populated areas?
|
Technology
|
explainlikeimfive
|
[
"esphdyl"
] |
[
"Mainly, it's expensive to build more cell towers, and the companies that provide cell service don't see a need to spend more money on that."
] |
[
18
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
8gy6n8
|
why can't we heal personality disorders?
|
well we know dbt or similar for personality disorders like borderline but why can't we heal it?
|
Biology
|
explainlikeimfive
|
[
"dyghs1o",
"dyfjlie"
] |
[
"I didn't see this answer: because we're fairly new to the concept. People were just called \"crazy\" or \"weird\" or even \"lazy\" for symptoms and no doctors were really out there to day, \"oh, this person has this mental health problem we can work on\". The science of mental health is still a relatively young science, so there's a lot to learn before we can really make advances on those issues."
] |
[
3
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
iehfvl
|
How do underground bases in the ocean keep water from entering when someone enters or leaves?
|
Engineering
|
explainlikeimfive
|
[
"g2ggukf",
"g2ggfe5"
] |
[
"Even submarines do this. 2 doors. You open one. Fill the space with water. Close the first and open the second. This a works for all places that regulate pressure. Such as airlocks in space stations."
] |
[
8
] |
[
[],
[
"https://en.m.wikipedia.org/wiki/Airlock"
]
] |
[
"url"
] |
[
"url"
] |
|
f1w0vp
|
What are those mini spasms you get in parts of your body that if you don't touch it it will continue 'pulse' but when you touch or massage it goes away?
|
Biology
|
explainlikeimfive
|
[
"fh8yhwx",
"fh95y5w"
] |
[
"Muscle fasciculations. Can be caused by muscle strain, dehydration or electrolyte (blood sodium, potassium or magnesium levels are out of normal range) imbalances."
] |
[
34
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
b25p3r
|
How does dish soap remove any "dirt" from dishes?
|
Chemistry
|
explainlikeimfive
|
[
"eiqebgk",
"eiqplu6"
] |
[
"Here is a video on YouTube talking about how soaps work URL_0 basically one side of the soap molecule grabs hold of oils and the other side grabs hold of water so the molecule is washed away carrying a little bit of oil"
] |
[
7
] |
[
[
"https://youtu.be/wTuRmwSkuzQ"
],
[
"https://youtu.be/NfzWSdZSSyk"
]
] |
[
"url"
] |
[
"url"
] |
|
a7u13c
|
Why does Wikipedia need money?
|
Economics
|
explainlikeimfive
|
[
"ec5r2ek",
"ec5ql7m",
"ec5vycd",
"ec5sbgv",
"ec5vhsg",
"ec61j85",
"ec5qf6y",
"ec5r3au",
"ec651w2",
"ec5qgr8",
"ec5rhpi",
"ec65it5",
"ec5vbwc",
"ec5uo5q",
"ec5vixb"
] |
[
"Servers are like playgrounds. And even though other people come and do sports or have races and make the playground fun, when you have so many people using the playground, someone has to do some upkeep. The jungle gym needs to be replaced. The grass needs to be mowed. The nets need replacing on the basketball court. So, because everybody is having fun on the playground, there really isn't one kid responsible for fixing these things. So, there's a groundskeeper who keeps the playground fun and safe for everybody. And occasionally, that groundskeeper asks for a little bit of money to help pay for his time and the money he spent on the new equipment."
] |
[
5098
] |
[
[],
[
"https://donate.wikimedia.org/"
],
[
"https://meta.wikimedia.org/wiki/Wikimedia_Foundation_reports/Financial/Audits/2017-2018_-_frequently_asked_questions#What_is_",
"https://meta.wikimedia.org/wiki/Wikimedia\\_Foundation\\_reports/Financial/Audits/2017-2018\\_-\\_frequently\\_asked\\_questions",
"https://en.wikipedia.org/wiki/Wikimedia_Foundation#Staff",
"https://en.wikipedia.org/wiki/Wikimedia\\_Foundation#Staff",
"https://wikimediafoundation.org/about/financial-reports/",
"https://meta.wikimedia.org/wiki/Grants:Start"
],
[],
[
"https://meta.wikimedia.org/wiki/Wikimedia_Foundation_Annual_Plan/2017-2018/Final/Financials#Wikimedia_Foundation_financial_overview_graphics"
],
[],
[],
[],
[],
[],
[],
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
im8snn
|
How does being carsick work
|
An example is like when I’m looking at my phone and my stomach starts hurting
|
Biology
|
explainlikeimfive
|
[
"g3y1u3o"
] |
[
"It’s because of a disconnect between youre senses confusing your brain. Your eyes (especially why you’re reading/staring at a phone) don’t take in any information that shows your moving, but the fluid in your ears that is used to help you balance does move around, and does register that your moving. So your brain gets toe inputs, one saying “we’re moving” and one saying “we’re still”. The brain doesn’t know what to do about this or why this is happening, and the only thing it can think that is causing this is that maybe you are something bad, maybe you ate soemthing poisoness. Maybe we should throw that up. (This is why carsickness and seasickness and airsickness all often come with feeling like you should vomit)"
] |
[
11
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
apc7yd
|
how does electricity work?
|
Physics
|
explainlikeimfive
|
[
"eg7aukf",
"eg7cguw"
] |
[
"Electricity is the flow of electrons. The electrons can be thought of as a stream of water. When talking about electricity, there are two main metrics people talk about. Voltage can be thought of as the pressure of water, how much energy it is carrying. Amperage is how many electrons you have moving in the same direction. Moving electrons produce a magnetic field, which is exploited by motors, and can excite atoms, like in neon lights. LEDs have special materials sandwiched between two pieces of metal that produce light when a current is put throug h them. However, all of these applications require a steady stream of electrons IN ONE DIRECTION. This is called direct current (DC). The outlets on walls have alternating current in them (AC), which means that the voltage flips back and forth, swapping directions 60 times a second in North America. AC is used because it is cheaper to produce and safer afaik. It is also easier to step up and down in voltage for transfer over long distances, through power lines. Transformers (those weird round metal boxes on telephone poles) are used to do this stepping up and down. I am not an electrical engineer, but that is all true to my knowledge. Please correct me if I am wrong."
] |
[
6
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
ghmzbu
|
Why is it called "non-small" with like cancers and stuff? Why not like "large?" "Non-small" doesn't seem very descriptive. You don't go to McDonald's and order "non-small" fries. They'd be like "Ok then, what fucking size do you want?"
|
Biology
|
explainlikeimfive
|
[
"fq9m4zl",
"fqa6lfo"
] |
[
"There are 4 types of lung cancer, for example: oat cell carcinoma, adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. The treatment of oat cell is different, it's what's called a small cell cancer. The treatment for the others is very similar, so they are called non-small cell cancers. Since large cell is a specific type, that would be a bad name to use for the group."
] |
[
22
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
aswfpp
|
Why is Sisyphus happy with his punishment?
|
According to Albert Camus
|
Other
|
explainlikeimfive
|
[
"egxbft5",
"egxbipn",
"egxatvu",
"egx5yoj"
] |
[
"It isn't that he *is* happy with his punishment, but that *we must imagine* him happy with his punishment; it's a metaphor suggesting that in order to be at peace with the absurdity of a meaningless universe we must embrace it's futility and find satisfaction in it's banality."
] |
[
8
] |
[
[],
[],
[],
[
"https://www.youtube.com/watch?v=ZsaFUEq5UEo"
]
] |
[
"url"
] |
[
"url"
] |
aa2cy0
|
Why does pushing on/massaging sore muscles mke them feel better?
|
Biology
|
explainlikeimfive
|
[
"ecoeo8u"
] |
[
"It helps to break up the build up of lactic acid, as well as helping to separate the fascia from the muscle. The fascia is the \"casing\" of tissue around the muscle that helps it slide back and forth. It can get \"attached\" to the muscle and create discomfort. You can see the \"silver skin\" on chicken breasts - this is the fascia. The real thin membrane around the meat. It also increases blood flow to that area. Source: Wife owns a massage clinic and is a therapist."
] |
[
19
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
e86rad
|
Why are not all gloves touch screen friendly?
|
Technology
|
explainlikeimfive
|
[
"fa9jst6",
"fa9kazy",
"fa9jtw0"
] |
[
"There are different ways the touch screen itself works... The 2 main ones are resistive and capacitive touch. Resistive works of of pressure, you could use any glove you want. Capacitive uses your body or the stylus to complete a circuit to tell the screen where you pressed. So most insulators will interfere (rubber, plastics, things like that)"
] |
[
6
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
l6vx6w
|
when someone walks in the snow, how come those footprints disappear when it snows again? Why aren’t the footprints always there, just with more inches of snow?
|
Other
|
explainlikeimfive
|
[
"gl2ytaf",
"gl4vrkz"
] |
[
"If the snow falls straight down sometimes you’ll still see the outline of the footprints. Usually snow is accompanied by wind though, and the drifting snow fills in gaps and smooths out the surface layer again."
] |
[
35
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
851b3c
|
How did we decide peppermint was the smell of good breath?
|
Other
|
explainlikeimfive
|
[
"dvugqtn",
"dvunpzy"
] |
[
"because good and bad breath comes from digestion. peppermint was good for the stomach when we didn't have anything else, like 1900 or something. now there are alot of available plants and differents things to help your digestion and have a good breath, but we just use peppermint because we're used to it and commercials keep showing it. it's because it sells."
] |
[
9
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
9xb1wp
|
Could Space X Patent Reusable Rockets?
|
So I work in software and there are so many news stories about software patents being used to sue developers for basic things like "using Internet to send mail" level of obviousness. Why couldn't Space X have a patent to demand royalties / licensing fees from other rocket companies for any future attempts to make reusable rockets? Note that I'm asking "could" they, not "should" they... I don't want to see innovation or competition stifled.
|
Technology
|
explainlikeimfive
|
[
"e9qt7cp",
"e9qswve",
"e9qsscd"
] |
[
"> Why couldn't Space X have a patent to demand royalties / licensing fees from other rocket companies for any future attempts to make reusable rockets? The basic concept of wanting to reuse parts of a rocket for multiple launches isn't novel enough to be considered patentable. They can patent a specific implementation of a reusable rocket but they cannot patent the goal no matter how it is achieved."
] |
[
7
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
ft0vhh
|
Why does the arm of octopus move after it is cut?
|
Biology
|
explainlikeimfive
|
[
"fm4died"
] |
[
"Tissue doesn't die as soon as it is severed, the tissue doesn't actually die until the lack of blood flow carrying fresh oxygen causes the cells to die. Being severed does cause the nerves to start firing off more or less randomly though. That is why octopus tentacles squirm after being cut off, fish heads still move their gills and chickens run around after their heads are cut off."
] |
[
6
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
6oa7qo
|
Does thinking hard, or concentrating on a particularly difficult analytical problem burn more calories than normal?
|
Another way to say this whether some mental states burn more calories than others? If so, why? And how does that work? Also, do two people burn the same amount of calories to do same mental task?
|
Biology
|
explainlikeimfive
|
[
"dkfzi5o"
] |
[
"I'd say probably not. Neurons that aren't firing use ATP (biological energy; calories) to maintain their \"resting potential\". As far as I understand this doesn't take any more calories than a neuron firing, and if anything it uses less. Edit:. Shortened"
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
a8gxih
|
Why do people get nauseous when they see blood?
|
Biology
|
explainlikeimfive
|
[
"ecanq8z"
] |
[
"It’s a defense mechanism. A person’s body is saying “get the hell away from the blood, there could be danger” so it makes one uncomfortable. Part of the “flight” response"
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
bu41jb
|
How does muscle memory work?
|
For example: being stressed out before a concert because you don't know the notes/chords in memory, but once you start playing, your hand just knows whats to do.
|
Biology
|
explainlikeimfive
|
[
"ep6rp8c"
] |
[
"\"Muscle memory\" is a bit of a misnomer, since your muscles don't actually remember anything at all. The memory is still entirely neurological, and isn't really that different from other kinds of memories. You can think about a certain sight or smell, sound, or smell and call it to memory. Likewise, you can do so with skills. When I think \"throw a punch\" my brain acts it out as if it is preparing to do it. And because I've got a little bit of boxing training, what it acts out incorporates that training and my experience throwing punches, making the punch I throw in my head a more skillful one than that of someone who has never practiced."
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
7s0riy
|
Why does a helmet-to-helmet hit only hurt 1 player?
|
Just saw the hit on Rob Gronkowski. Just wondering why he has to leave with a concussion while the other guy is unharmed? What’s happening here?
|
Physics
|
explainlikeimfive
|
[
"dt11vm4",
"dt15cos",
"dt17dq6"
] |
[
"The defender is usually in a position in which they can deliver that blow with the crown (forehead) of the helmet. The neck is strongest against being bent backwards and the defender is prepared for impact in that region. On the flip side, the offensive player’s neck is going to snap one way or the other. There’s really no way to prepare for and lessen this impact. This is how concussions and spinal injuries occur."
] |
[
26
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
ikddh8
|
Battery sizes
|
What do the different sizes of batteries mean???
|
Physics
|
explainlikeimfive
|
[
"g3jydxq"
] |
[
"Size is not always equivalent to the contents. The chemistry of the battery is important as well. Lithium, nimh,nicd, alkaline, SLA etc. So a lithium that is smaller than an alkaline may hold more energy for example. An nimh of the same size as a nicd may hold more energy as well. Also some nicd have multiple capacities that are equal in size as well, same for nimh. What's important is the capacity rating, the number on many batteries (besides alkaline) Also some batteries can vary in size for other reasons such as voltage, a 1.2volt nimh or nicd, or even alkaline battery may be soldered to another of the same type and capacity to create a 2.4volt battery (this is a small example) In this scenario the size is relevant to the voltage need of the device. For alkaline alone size matters more, the bigger they are the higher the capacity because the battery can hold more chemicals. For example a , AA battery has less capacity than a D battery. A D battery had less capacity than a 6v lantern battery ( which essentially houses 5 D batteries each are 1.2v, x5= 6v) **So size can, but does not always, suggest capacity compared to other batteries of the same chemestry.** Is there more specific battery type you were wondering about ? Or anything I can clarify ?"
] |
[
6
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
iynz8y
|
why are the Pirate Bay and other torrent sites able to still exist?
|
Technology
|
explainlikeimfive
|
[
"g6dmye3",
"g6dnrx8",
"g6dnpvv",
"g6dnekm"
] |
[
"International law is complicated and the sites are careful to not break local laws - the users share the data, not the site."
] |
[
13
] |
[
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
htqe95
|
When a man pumps 1 million sperm into a woman from one wad, are each of those sperm a different person if it fertilizes an egg, or do they repeat?
|
Biology
|
explainlikeimfive
|
[
"fyiccd0",
"fyibwp4",
"fyidz1t",
"fyij87x",
"fyie9xy"
] |
[
"Each sperm is different. They do not repeat.... at least the odds are astronomically small that one spermatozoa is exactly the same as another. > can one man populate an entire planet with unique offspring? \"Unique\" offspring yes. But ones that are related like any other brother and sister. A society built on only one man will soon die off of genetic abnormalities."
] |
[
40
] |
[
[],
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
8toywi
|
What makes the earth rotate on its own axis ?
|
Hey, i've read something about gravity and space-time, didn't understand.
|
Physics
|
explainlikeimfive
|
[
"e1947cp",
"e194711",
"e196yam"
] |
[
"Newton’s First Law An object in motion will stay in motion and an object at rest will stay at rest unless acted upon by an unbalanced force. This applies to rotation as well. It continues to rotate because there is nothing stopping its rotation. It originally was spinning mainly because during its creation, the matter which makes up our planet was spinning slightly and when it was pulled together. Some may answer “conservation of angular momentum” which is also correct but that is ultimately a consequence of other laws including Newton’s. It has nothing to do with space time."
] |
[
4
] |
[
[],
[
"https://www.youtube.com/watch?v=Yhtr2hbg9Rs"
],
[]
] |
[
"url"
] |
[
"url"
] |
5t1w3x
|
Why do members of the Senate state 'My colleague the senator from _____' instead of stating their name?
|
Other
|
explainlikeimfive
|
[
"ddjjd5e",
"ddjq0fu",
"ddjvznu"
] |
[
"Edit: See the bellow top level replies. I think, all things considered, they're more accurate than mine. Because people know their state's name and most know what a senator is, not so many know their senator's name. \"My colleague, the senator from Nevada is against kicking puppies!\" Is going to have a lot bigger impact than \"Dean Heller is against kicking puppies!\" Very few know who their senator is, mentioning senator+state resonates more. Heck, they may even bother to learn about this Nevada senator who doesn't like to kick puppies! Note: I made the puppy part up, I have no idea what the senator from Nevada's stance is on puppy kicking."
] |
[
7
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
9rffcm
|
Why is it possible for our bodys to radiate heat to a point we don't need protective clothing? I.e. joggers in winter
|
Biology
|
explainlikeimfive
|
[
"e8ggdka"
] |
[
"The heat is regulated by sweat. Even in the winter, extreme exercise may heat the body beyond its limits if it didn't have the capability of sweating."
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
6vfr4l
|
How do construction workers deal with bad weather? Aside from slowing progress, doesn't it have a chance to majorly destroy the work they've done?
|
Engineering
|
explainlikeimfive
|
[
"dlzxe8x",
"dlzxd3y",
"dlzwn1c"
] |
[
"I work in the residential construction industry in NC. There are many factors but planning and timing play a big part. What I see is lots of building in the fall, a good bit in spring. Some in summer and just a little in winter. Each season has its advantages and disadvantages. Winter is cold with hard ground, spring has a lot of rain. Summer gets hot. Fall is great. But you still have to watch the weather to see what's going on. If the slab is supposed to be poured and it has been a hurricane in the past week, you are going to be delayed. Working with professionals, they can get the house up quick. Once the house is dryed in it's mostly fine. Weather can still mess with the schedule but not as bad as it can in the beginning."
] |
[
5
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
harmer
|
If dust is made up of mostly dead skin cells, would a black persons dust be darker than a white persons?
|
Biology
|
explainlikeimfive
|
[
"fv4fyfy"
] |
[
"No. The dead skin cells leaving your body do not possess the pigment. So the color of the dust doesnt depend oon it."
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
c5gmy9
|
Why can some animals cross breed between them, while others cannot. For example, donkeys and horses can breed to give a mule, but nothing comes out if your breed humans and chimpanzees.
|
Biology
|
explainlikeimfive
|
[
"es1pe0t",
"es1onfr",
"es1qiq4",
"es1slrn"
] |
[
"There may be different reasons. For humans and chimpanzees we have differences in the chromosomes that don't allow us to breed. it's like trying to plug a USB cable into a micro USB port, they're similar, but the differences don't allow for the mix. Now, with donkeys and horses they can have a mule, but consider that the mule can't breed, it's sterile. So while some animals can breed, they aren't meant to, and are still to some extent incompatible."
] |
[
67
] |
[
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
bndvtv
|
Why do Starbucks and Dunkin Donuts make you load their store cards when ordering from the app?
|
Why doesnt it let you order using a debit card or credit card where the money is taken out from your bank account? Rather, they make you fill up a card that you use to order online that always ends up having spare change at the end. I'm asking cause I have $1.10 cents in the account and can't get my money back or buy something that I want? My only option is to add more money to my account and keep repeating the cycle. Why do they have such a douchebag design? Its so frustrating I don't even want to use the apps anymore
|
Other
|
explainlikeimfive
|
[
"en4oett",
"en4p76x"
] |
[
"That’s exactly why. So you feel obligated to spend the remaining balance on your store card, which means you’ll add more money to it. It also allows them to better track the metadata associated with your purchases, like the loyalty cards at grocery stores."
] |
[
6
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
hvymr2
|
Why does moving faster through space cause time to slow down for you.
|
I've heard the concept on movies like interstellar and videos of scientists talking about it in general but I really don't understand how it works. Please help.
|
Physics
|
explainlikeimfive
|
[
"fyw8w4h",
"fyw913x",
"fywryb1"
] |
[
"What time dilation is not: --- In order to explain time dilation, let me fist explain what it is **not**. A popular, but entirely wrong notion of time dilation states, that time passes slower the faster you move. A quick examination of this claim, however, reveals that it cannot be true. There is no absolute velocity, so velocity only makes sense with respect to a frame of reference. That means, velocity only makes sense if we state relative to what we are measuring. Thus, if this version of time dilation were true, time on your spaceship would magically speed up and slow down depending on the frame of reference you measure your spaceship's velocity against. Thus, the statement that the rate at which time passes depends on your velocity (relative to an arbitrary frame of reference) cannot be true. Now, let's get started with actual time dilation: Why does time dilation happen? --- To understand how time dilation can happen, let's consider the following thought experiment: A clock is any object that does an action periodically. As such, a light beam bouncing off two mirrors can be considered a clock, with each period of the photon bouncing up and down again being one tick. Let's now consider a train with such a clock in one of the compartments, as seen [here]( URL_0 ). Imagine a person in a resting train with a flashlight. They shine the beam of the flashlight to the ceiling of the carriage and time how long it takes to return to them. Very simply it is just the distance the light travels (twice the height of the carriage (d)) divided by the speed of light (c). Someone on the embankment by the train will also agree with the measurement of the time that the light beam takes to get back to the person with the torch after reflecting from the mirror. They will both say that the time (t) is 2d/c. Now consider what happens as the train moves at a constant speed along the track. The person in the train still considers that the light has gone from the torch, straight across the carriage and returned to them. It has still traveled a distance of 2d and if the speed of light is c the time (t) it has taken is 2d/c. However to the person on the embankment this is not the case. For them, the train has been moving during a tick of the clock, and the photon has to travel a longer distance accordingly. Instead of a straight vertical path up and down, the photon now follows a triangular path, like [this]( URL_2 ). As we know, the beams of a triangle are longer than the straight line, so the photon now has to travel a longer path. Now in classical physics, pre relativity, we would now say that since the light beam has moved further in the same time it must be moving faster, in other words we have to \"add\" the speed of the train to the speed of the light. But the theory of relativity does not allow us to do this. It says that the speed of light is constant. Thus, the photon will take longer to reach its destination from the point of view of the observer on the embankment. Hence we know that it takes the photon longer to complete this journey from the point of view of the observer on the embankment than it does from the point of view of an observer resting in the train. And we know that the time it takes the photon to complete its journey up and down again corresponds to one tick of a clock. Thus, it follows logically that the observer on the embankment sees clocks on the moving train as ticking slower than someone resting in the train. Which is exactly what special relativity is all about. The twin paradox: --- One of the central claims in special relativity is, that all inertial frames of reference are equally valid to describe a phenomenon. That is, the laws of physics are the same in all frames of reference that are not being accelerated. This is called the equivalence principle. Consider an inertial frame of reference I and another inertial frame of reference I' that moves at a constant velocity v relative to I. Time dilation states, that an observer O resting in I will measure clocks resting in I' as ticking slower than their own clocks. According to the equivalence principle, the same statement has to be true for an observer O' resting in I' as well, since they are both in inertial frames of reference. Thus, the observer O' resting in I' sees clocks resting in I as ticking slower than their own. **Time dilation is a symmetrical effect. Both observers see clocks in the other observer's frame of reference as ticking slower.** \"But wait\", you might interject at this point, \"what about the [twin paradox]( URL_1 ). The twin making a trip to space ages less than the twin remaining on earth. Doesn't that contradict what you are saying?\" While that seems true on the first glance, this is actually not a contradiction. In order for the twin paradox to work, the twin traveling in the space ship has to return to earth. In order to do that, he has to change direction at some point. This change in direction implies acceleration, and acceleration breaks the symmetry of the problem. Remember, that we stated that all *inertial* (un-acclerated) frames of reference are equal. By accelerating, the space traveling twin breaks the symmetry of the equivalence principle, thus leading to the observable difference in passed time. **In Summary: Interstellar works because the characters are in a strong gravitational field, and according to General Relativity, clocks tick slower in strong gravitational fields than clocks in weaker gravitational fields. This has very little to do with special relativistic time dilation, which is symmetric and reciprocal.**"
] |
[
55
] |
[
[
"http://www.schoolphysics.co.uk/age16-19/Relativity/text/Time_dilation/images/1.png",
"https://en.wikipedia.org/wiki/Twin_paradox",
"http://galileo.phys.virginia.edu/classes/109/lectures/photclk0.gif"
],
[],
[]
] |
[
"url"
] |
[
"url"
] |
fzty97
|
what makes a code language work
|
Like I get that scripting and code = working OS. But why does that jumbo of words and numbers and shit make a working system and how is that even recognized
|
Technology
|
explainlikeimfive
|
[
"fn63sqh",
"fn64u1c"
] |
[
"Computers store billions and billions of ones and zeros in specific order: ``` 1010 0101 0101 0001 1010 0000 1010 ``` We have made computers in such a way that we can give them simple instructions to change the values of these ones and zeros. These instructions look something like this: 0x 60 01 00 84 0x A4 01 02 00 0x 60 02 00 00 As you can see, this is not very easy for a human to understand. It is possible to learn this kind of machine code, but it would take a very long time to learn and making a modern app with machine code would take something like a thousand years. To make coding simpler, we have made coding languages that are easier for people to understand. These languages usually have many instructions written in English. For example, you can probably figure out what this code prints even if you don't know how to code: let x = 6; if(x < 5) { print(\"x is less than 5!\") } else { print(\"X is more than 5!\") } We can write the code in a way that is easier for people to understand and use a special thing called compiler to turn that code into the machine code and then tell the computer to do what the code says. Edit: Typo"
] |
[
3
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
gsamjw
|
How do our eyes/brains perceive depth?
|
For example take a tree. How can our brains tell that it is a big tree far away instead of a smaller tree which is just closer to us?
|
Biology
|
explainlikeimfive
|
[
"fs3zmod"
] |
[
"Your brain gets two images, one from each eye and uses that information to triangulate depth more or less. There are different degrees of depth perception: first your brain has a simultaneous perception of an image coming from both eyes, your brain then overlaps those images so that you don’t see double, with that overlap comes the actual sense of depth. However, it is a highly manipulable sense. You can talk yourself into seeing all sorts of oddities very easily. Here’s an experiment: hold up a single pencil and look at a blank wall behind it. You should notice you see two pencils. If you don’t, blink a lot and hold the pencil a little close or further from your nose. Grab a second pencil, hold it about an inch or two away from the first pencil and you should see four pencils while looking at a wall between (behind) them. If you merge the middle two pencils you just created into 3, you will perceive the third pencil in the middle slightly behind the pencils on either side of it. There’s a real life demo for you, right there!"
] |
[
9
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
hi1uwl
|
What is that tingling feeling you sometimes get when you think about eating sour, spicy, or ‘vinigary’ foods?
|
I was driving home when I thought about Kim chi, you know, the usual. My mouth instantly flooded with saliva and I got a sort of tingling feeling under the back of my tongue. What causes this, and what is it?
|
Biology
|
explainlikeimfive
|
[
"fwdkoph"
] |
[
"Our nervous system is divided into the central nervous system (CNS), the brain and spinal cord, and the peripheral nervous system (PNS), the rest of the nerves throughout the body which control your senses, muscle movement, etc. A part of the peripheral nervous system is the autonomic nervous system, which in turn consists of the sympathetic and the parasympathetic nervous systems. The sympathetic NS is the one controlled by adrenaline, activated when you have to work, exercise, are scared i.e. the \"fight or flight\" response. The parasympathetic one is controlled by a neurotransmitter called acetylcholine which activates the \"rest and digest\" response. This occurs when you have eaten and are feeling safe and relaxed. Symptoms of this are slower heart rate, relaxed muscles, and yes, increased salivation. (TLDR) So all of this to say that I THINK that when you think about eating food you like you start preparing by salivating more (as saliva is part of the digestion process), and this is triggered by acetylcholine. And the tingly sensation might be your salivary glands, which produce and release saliva?"
] |
[
7
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
as5ngs
|
How do airlines determine the collective weight of passengers on board any given flight?
|
Mathematics
|
explainlikeimfive
|
[
"egs4awb",
"egsn9g0"
] |
[
"For the largest jets it's basically just a guess, they choose an average number and assume that every passenger is approximately that weight. For smaller regional Jets and turboprops, you might actually see cabin crew ask passengers to move to more evenly distribute the weight, but for planning purposes they still just use a guess as to what the average passenger weighs. For the smallest planes you might even see people get weighed individually before getting on the plane because the margins for the weight and balance and center of balance are much smaller the smaller an aircraft is. Basically they need to know exactly how much weight passengers and luggage will be so they know how much fuel they can take on. If you're interested in the subject you can search for \"aircraft weight and balance\". It's a very important part of planning a flight."
] |
[
15
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
b8kryg
|
what is a magnetic monopole?
|
Physics
|
explainlikeimfive
|
[
"ejyt5ny"
] |
[
"Every magnet we know and you know has two sides: north and south. Opposite sides attract, likes repel. If you break a magnet into two - every piece will now have a north and south poles. Even if you continue to break it, you won’t get a magnet that’s only south or north - which is what we mean by magnetic monopole. We think they don’t exist. We kind of assume that actually. But we haven’t actually proven they can’t exist."
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
az6i0f
|
If a medication has a half life of 6 hours, (we can use montelukast for this examples) but say it’s effective for 24 hours? How can that be true?
|
Chemistry
|
explainlikeimfive
|
[
"ei5m3o9"
] |
[
"Nurse here. Medication is like the porridge in Goldilocks, too much in the body (a lot of side effects, OD), too little in the body (no effect) or juuuust right amount (the desired effect). The just right is called the therapeutic window. Now, the therapeutic window is different for different medications. Let's say that you take Montelukast, the therapeutic window is quite broad.. so even if you take a high amount it doesn't hit the levels where it would do damage, but can also go down half and still be in the therapeutic window. There are also other reasons, for example slow release tablets that make the uptake of the body to be more spaced out. There are many different reasons for this. Hope that helps."
] |
[
7
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
n9m38k
|
Why is there sometimes like a black sheen/shadow across the road that goes away as you drive closer?
|
Other
|
explainlikeimfive
|
[
"gxokdaa"
] |
[
"It's a mirage. It's caused by the heat of the road heating up the air above it, which changes the air's refractive index and the layer of air above the road bounces the light from the sky at you. Sometimes it looks like water, which is why the common idea of a mirage is people seeing \"water\" in the desert. Same mechanism can create the same effect in a hot desert."
] |
[
16
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
8ag1wq
|
What goes on when government/military does a check on someone before giving them Secret/Top Secret clearances?
|
Other
|
explainlikeimfive
|
[
"dwygcnl"
] |
[
"The two are different, but not totally. Secret requires a background investigation that covers usually 7-10 years of employment, travel, and living arrangements. Current and past financial history also covered, as is mental health. You provide individuals who can corroborate all of these things. It also covers a variety of factors since birth including your family history and propensity for criminal or illicit behavior. Drug use falls in this category. The process starts when you fill out the investigation form. That form is usually reviewed by a security specialist who will determine if you’re an automatic No-Go (got a rape conviction or a handful of recent DWI??) You can review this form online, it will explain everything required and it’s called the SF-86. If cleared by the specialist, it’s referred for a full background investigation. The investigator sends out contact letters or makes face to face calls on the individuals you have listed on your form. They also usually sit down with you and go over the entire form in detail with you to ensure everything is there and accurate. Investigator then investigates all of the form. If no discrepancies are found, the information is forwarded to the agency sponsoring your BI. Agency then determines whether your history allows for you to get a clearance. If there are discrepancies between what you put and what the investigator finds out, you usually will get reinterviewed. The investigator than forwards to adjudicator at your sponsor agency. Top Secret goes further back, but covers the same information. I believe there can be some additional questions about your personal life i.e. sexual or marital history. You may also be subject to a polygraph regarding the info you provide, depending on the agency taking you on. This can take several months to several years, unfortunately. There is ample information about this subject online, you can check the Federalsoup forums for specifics, likely your questions have been asked and answered there. DO NOT LIE OR OMIT ON YOUR SF-86 (but do not add more than exactly what is asked in the time frames requested). Good luck!"
] |
[
4
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
ju077e
|
Why is it "I'm from the < country name > " for some countries, while "I'm from < country name > " for the others?
|
Other
|
explainlikeimfive
|
[
"gc8sbzg",
"gc8slb3"
] |
[
"It’s not a perfect answer, but it helps if you remember that some place names are referring to plural entities (the United States, the Philippine Islands) and some are using a singular form (America, Corregidor)."
] |
[
3
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
7ij4ww
|
Free market
|
The concept of what ‘free market’ is confuses me. What is it? Why is it good/bad?
|
Economics
|
explainlikeimfive
|
[
"dqz5wwj",
"dqzjnpd",
"dqze8t8"
] |
[
"My basic understanding is that it lets people or groups of them exchange any goods and services for whatever price they choose . However it can only be free up to a point when it conflicts with the freedom and well-being of others which is also a market on its own. An extreme example would be someone offering a service to kill people for a fee. Well that can't happen because the law limits that market to only a few people or under specific circumstances. The reason this example is limited by law, or regulated, is because a majority of people with relatively good ethics don't want to be killed. They value their lives and the ones they love so they would not give it up at any price they also value their time and don't want to spend their lives barricaded and armed to the teeth to defend themselves. So they choose people to represent their values and give them powers and money to try to prevent this from happening with discouragements like jail time and other punishments. I think that in that case our society with its laws is still a free market. You can still offer that killing service, the price and risk is just much higher, because a contract has been made by a majority of people to prevent it."
] |
[
4
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
bwnbcl
|
What makes a continental breakfast, “continental”?
|
Culture
|
explainlikeimfive
|
[
"epyog8t",
"epyp1wc",
"epzspts",
"epyvlv4"
] |
[
"It's a British term where the \"traditional\" English fried breakfast is large with eggs, bacon,fried bread, fried tomato, and a few other things. The \"continental\" breakfast is traditionally served cross the channel (I.e. on \"the continent\") which is a smaller fare just to get you going. This is something like coffee/hot chocolate, croissant/toast, etc. The true European continental breakfasts I experienced may also include sliced meat or cheese. But it's a lot smaller that the bigger breakfasts we tend to have in North America."
] |
[
1012
] |
[
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
brr1re
|
how do radio signals (4G, WiFi etc.) manage to retain their information after passing through trees, buildings and other obstacles? And how are they not mixed up, intertwined?
|
Technology
|
explainlikeimfive
|
[
"eofwcqn",
"eofv3m0"
] |
[
"They are, the key is there are error correction and detection algorithms that work to counter the problem. In bad environments they don't always work. Also, many newer devices actually utilize the attenuation and reflections to improve signal quality. Take a look into [MIMO]( URL_1 ) technology. They do what is called [beamforming]( URL_0 ) where they vary the signal being output on multiple antennae to create hot spots in the signal at the receiving antenna(e) to improve reception. When multiple devices are connected it will actually change the beam forming per device moment to moment depending on the destination. It's really cool stuff. Edits: Links, typos. Edit 2: Figured I could expand as well. When you're dealing with reflections or other signals that could potentially interfere, they are usually a bit weaker than the main signal. This means that a receiver can filter them out by simply ignoring signals that are weaker than a certain level. This is called the noise floor of the radio. Think of it like being in a room full of people talking and ignoring all the background conversations because they're harder to hear and focusing on your current one. Attenuation of the main signal works similarly. As long as the signal isn't attenuated below the noise floor, it will work. If the operating environment for the radios is bad enough, it may be impossible to get a strong enough signal to overcome the noise floor, and then nothing works."
] |
[
7
] |
[
[
"https://en.wikipedia.org/wiki/Beamforming",
"https://en.wikipedia.org/wiki/MIMO"
],
[
"https://i.dailymail.co.uk/i/pix/2014/08/27/1409153044123_wps_3_How_To_Perfectly_Locate_Y.jpg"
]
] |
[
"url"
] |
[
"url"
] |
|
j9ax18
|
How can you check how ripe a watermelon is just by knocking on it?
|
Do you knock somewhere specific? What do you listen for? This has been bothering me for years, so I'd really appreciate an explanation.
|
Biology
|
explainlikeimfive
|
[
"g8ikx12",
"g8ik2q7",
"g8iibp4"
] |
[
"It should sound like you are tapping on something hard and hollow (\"tok\"). The sound should not be dull (\"dup\"). A better tell is to check the light spot. If the light spot is white, it is under ripe. If the light spot is light yellow, its probably a good one. If it seems a bit dark, you can tap it to check that it isn't overripe. This really comes with practice. There's a right shade of yellow and a right sound but you'll have to buy a lot of watermelons to get consistently good at picking them."
] |
[
14
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
mwez7y
|
Death caused by Hypertensive And Atherosclerotic Cardiovascular Disease?
|
Biology
|
explainlikeimfive
|
[
"gvhzld6"
] |
[
"your blood goes through a bunch of tubes called vessels. They died because their blood vessels got tighter(less blood can flow) and their cholesterol created a blockage. Hypertension means your blood pressure is high because the vessels are tighter, atherosclerosis is when plaque builds up in the arteries. Plaque is sticky, so it can stick to the sides of the vessel and stick to other plaque When you have both, your blood has very little room to flow through until eventually somewhere gets blocked entirely. It happens a lot in capillaries which is bad, but generally won't kill you, but if it gets bad enough it can block the bigger vessels. Then a large part of your body won't get blood, and if that part is a major organ you will die without serious interventions."
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
bshhws
|
Why does our voice sound different to us on recordings?
|
Biology
|
explainlikeimfive
|
[
"eonaeks"
] |
[
"Since sound is just vibration, so is your voice. When you speak, the air you exhale isn't the only thing that vibrates. The bones in your head, your skull, vibrate as well. This vibration of your skull makes the air in your ears move too, but since bones are a lot denser and harder than air, what you speak sounds a good tad lower. When you hear your own voice on a speaker, you don't have that effect and it sounds kind of awkward because that's not what you're used to."
] |
[
7
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
jt9idm
|
if a torpedo blew up a nuclear submarine, would there be a risk of a major nuclear meltdown type situation?
|
Physics
|
explainlikeimfive
|
[
"gc4bbc3",
"gc4aj72"
] |
[
"Believe it or not, it's actually very difficult to cause a meltdown in a modern nuclear reactor. A meltdown occurs when a reactor core overheats and burns off its coolant, causing it to \"melt down\" inside the reactor housing. To do that you need a self-sustaining, uncontrolled nuclear reaction- something that all modern reactors have layers upon layers of safeguards to prevent the remotest possibility of occurring. Even if a nuclear sub was torpedoed, destroying the reactor, the nuclear reaction inside would instantly stop as the core broke apart and terminated all fission reactions. There would certainly be the issue of radioactive contamination from the reactor fuel, but definitely not a meltdown."
] |
[
7
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
g39kae
|
Why is it easier for a lot of people to read from paper over a computer?
|
Biology
|
explainlikeimfive
|
[
"fnq8uau"
] |
[
"When you read from paper, you're reading light reflected (and diffused) off that paper. What this means in practice is that the reflected light from one part of the paper hits all across your eye in a smooth continuum. When you read off a computer monitor, you're looking directly into the light source. This means the light is focused on one particular part of your eye and you're forced to over-use that part of your eye. It's a bit like the difference between a pillow fight and a fist fight. The same force is involved in both cases, but spreading it out makes one a lot more pleasant than the other."
] |
[
4
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
g6zwe4
|
Why do I need to start/run my car every once in a while when it's not in use?
|
A *certain situation* has brought me back home to my parents house, but my car is across the country at my school, not being used until \~September. Why does everyone keep insisting it needs to be turned on/driven every once in a while? (Which it is, my landlords a pretty cool guy and offered to do it!
|
Engineering
|
explainlikeimfive
|
[
"foe24vf"
] |
[
"Cars that sit fall apart. Al;l the parts that need oil and grease on te=hem dry up and start to rust. Driving the car spreads the oil and grease where it belongs in the engine, the wheel bearings and on the seals that sotp the oil and grease from leaking out. If they sit for a long time those seals dry out and crack and start to leak. Also the brakes rust, and the brake seals dry out. And so on and so forth. The worst thing you can do to a car is let it sit for a long time. That is before we even talk about the battery going dead over time so if you left it until September it would not even start. And the battery likes a little exercise too. Your landlord is a good chap, take him a small token of appreciation, preferable beer."
] |
[
8
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
67p20e
|
Why we can have so many diferences between humans but when we reach +37ºc we all get fever?
|
Why is so standar to get fever at that point? Every human is so different than the other like bones sizes, genetic, etc.. but when it comes to fever we all get it at that temperature.
|
Biology
|
explainlikeimfive
|
[
"dgs30gn",
"dgs33p1"
] |
[
"A fever is simply defined as abnormally high body temperature. Normal human body temperature is often expressed as 37 degrees C, but it fluctuates throughout the day and from person to person. Your temperature can be higher without necessarily having a fever, and a temperature slightly over 38 degrees is not a particularly unusual reading for an oral thermometer."
] |
[
3
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
kk4r29
|
Why are some old sound effects used so much?
|
Technology
|
explainlikeimfive
|
[
"gh0en2e"
] |
[
"Mostly because they are free. Think of them like stock photos but for sounds. Its easier and cheaper to use public domain sound effects than record new ones."
] |
[
4
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
g8qsw2
|
Why do psychiatrists focus more on the chemical component of people's emotions than the external influences?
|
Biology
|
explainlikeimfive
|
[
"fop0ssb",
"fop1acw",
"fop15lv",
"fop1ga1",
"fop1gh5"
] |
[
"Psychiatrists focus on the bodily functions that alter your mental faculties, such as hormones and the like. Psychologists focus on the external influences."
] |
[
9
] |
[
[],
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
g00rvi
|
Why do professional singers, such as Elvis Presley and Andrea Bocelli, have a vibrato on every note? Is it learned/does it make singing easier in some way?
|
Biology
|
explainlikeimfive
|
[
"fn74fp1"
] |
[
"Vibrato might make the sound a little more pleasant, and it also covers up tiny imperfections or discrepancies in pitch."
] |
[
5
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
8y3e1x
|
Why cant our brains correct/adapt to poor eyesight without the use of glasses?
|
From reading an earlier post about the upside down goggles, which take X long to readjust to seeing "properly" again, would it be possible to regain good eyesight given enough time without glasses?
|
Biology
|
explainlikeimfive
|
[
"e27tg49",
"e27tk2d",
"e28mte3",
"e27tk3q",
"e288ij1"
] |
[
"Your brain can't process unfocused images that it receives into focused images, it can only interpret them. So your brain won't adjust to poor eyesight by figuring out how to sharpen your vision, it'll adapt by making it easier for you to understand what you're seeing, even if it's blurry. This won't overcome things like being unable to read fine print at a distance, but you will be able to recognize things that someone who just took their glasses off a minute ago wouldn't. **Edit:** fixed typo"
] |
[
15
] |
[
[],
[],
[],
[],
[
"https://en.wikipedia.org/wiki/Anton%E2%80%93Babinski_syndrome"
]
] |
[
"url"
] |
[
"url"
] |
8e5b3j
|
So we are always taught to "save water" to protect the environment. But using water isn't destroying the water it goes back into the environment because the water cycle. So why are we taught to save water if it doesn't actually go away?
|
Other
|
explainlikeimfive
|
[
"dxsh85l",
"dxsh9h4"
] |
[
"The amount of *water* on the planet is basically unlimited, but what is limited is clean, fresh water. Water you can actually use for the vast majority of things you actually use water for. Making clean water takes time, energy, and money, and in some places climate or political factors make a water problem even worse. Simply desalinating sea water is expensive and moving that water across large distances is even more expensive. So we don't have an unlimited supply of *clean* water because it takes money and effort to make clean water."
] |
[
7
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
6ajm7z
|
films often play a distinctive 'clicketty' sound when someone just raises a gun, even if they aren't cocking it or drawing the hammer back. do guns actually make any noises like this in real life? if not, why is it added to films?
|
Culture
|
explainlikeimfive
|
[
"dhf0awo",
"dhf0bod",
"dhf23v8"
] |
[
"Foley is sound effects added to movies. Foley artists sometimes overdo a sound for more effect. Another sound that is overdone is tires squealing on pavement . A B-movie from Mystery Science Theater 3000 showed tires squealing on gravel . Foley is overdone a bunch, but most of the time it is barely noticeable."
] |
[
4
] |
[
[],
[],
[
"https://www.youtube.com/watch?v=dtPnRRxuOuc",
"https://en.wikipedia.org/wiki/Colt_Single_Action_Army"
]
] |
[
"url"
] |
[
"url"
] |
|
ch74o9
|
how a blister is formed.
|
Biology
|
explainlikeimfive
|
[
"euq448c",
"eusf4t4",
"euql756",
"eurrqbi"
] |
[
"Something causes a break between the layers of the skin - like heat that breaks connections between layers, or movement that mechanicaly tears it. The inner layers are living tissue, and so contain 'lumph'- the fluid that surrounds all living cells. This lymph pushes open that break made between layers, pushing the layers apart. This is fine, however - left alone, the lower layer will seal over and become strong skin, the lymph will slowly be reabsorbed or leach through the skin, the top layer will dry up and flake off, leaving new, healthy skin. As long as the blister is left in tact."
] |
[
296
] |
[
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
b54wfg
|
how is it possible to become so zoned out when driving a route you frequent, that you don’t recall part of the drive there?
|
Biology
|
explainlikeimfive
|
[
"ejb8ba4",
"ejbkkbb"
] |
[
"The former consensus was that people could “microsleep” or sleep for very short periods of time but now the leading theory is that you are fully awake the whole time but you’re brain isn’t putting anything into long term memory. Imagine a computer with no cache. As soon as you leave the website your computer completely forgets you were there."
] |
[
4
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
7d5nno
|
What causes dandruff & why are some people more susceptible to it than others?
|
Biology
|
explainlikeimfive
|
[
"dpvizsm"
] |
[
"Causes : -Dry scalp -Not washing your hair often, not combing /brushing your hair often causes dandruff . New skin cells are forming on the scalp regularly while the old ones die . These dead skin cells then accumulate to form white flakes which is known as dandruff . -Another cause for dandruff is a condition (seborrheic dermatitis) in which the scalp is oily and itchy. It causes excess of oil production. The oil causes the dead skin cells to clump together and form dandruff. People with seborrhoeic dermatitis and those who have dry skin can be more susceptible to it then those who don't. But it can be avoided by cleaning /washing and combing the hair regularly as you will be getting rid of the of the dead skin cells before they have the time clump together to form dandruff"
] |
[
5
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
73t5iy
|
why do people care about the difference between shaken and stirred?
|
Chemistry
|
explainlikeimfive
|
[
"dnsvhvg",
"dntmxg9",
"dnsvlwy"
] |
[
"Without getting into personal opinions, which are subjective, there's a difference between shaking and stirring. Shaking agitates the ice in the drink more, which causes it to melt faster. This results in a colder, more diluted drink. It also introduces air into the drink, which can make it frothier or fizzier, especially if there's something in there like dairy or egg. Stirring mixes the ingredients together in a calmer manner, so less ice melts and air isn't introduced. Stirring results in a slightly warmer, but less diluted drink without foam or froth. For most drinks that are just liquor and mixers, you probably want to stir so you don't dilute them (they'll still be pretty cold). For most drinks that involve dairy or egg or are supposed to be light and frothy, you'll want to shake to aerate them. For drinks that you want to be really cold and don't mind if they get diluted some (e.g., a martini for some people), you can also shake."
] |
[
37
] |
[
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
71pef6
|
Why is the Catalan separatist movement not a bigger news story?
|
Other
|
explainlikeimfive
|
[
"dnch83v"
] |
[
"It's pretty big news here in Europe, but it's not a new thing, so everyone's already pretty familiar with the story. There are a few protests, but tourists are still flocking to Barcelona as normal - it's not like the whole of Catalonia is up in arms. Assuming you're in the USA, Catalan independence would have little impact on the USA, so it's not news there."
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
axm5py
|
If Iron, Nickel, and Cobalt are the only magnetic elements, then how/why do rare earth metals make stronger magnets?
|
Chemistry
|
explainlikeimfive
|
[
"ehufy59",
"ehug754"
] |
[
"The rare earth metals are magnetic, but only at lower temperatures. By combining them with iron, nickel, and cobalt in alloys, you can raise the temperature at which their magnetism would normally disappear. The stronger magnetic field comes partly from the high number of unpaired electrons they have."
] |
[
34
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
f2kb18
|
How can a scale be both sensitive enough to weigh light items, like dollar bills, accurately, yet also handle weighing heavy things, like rolls of coins?
|
Engineering
|
explainlikeimfive
|
[
"fhd3wt5"
] |
[
"I think that‘s the thing, you focus on very small things, where you need to be accurate on floating points, or you can measure heavy things. That‘s why you normally need to use a different weigh if it comes to very light things."
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
7j7geu
|
What is the purpose of joker cards in a deck of cards?
|
Other
|
explainlikeimfive
|
[
"dr48px8",
"dr47kv0"
] |
[
"Jokers were originally introduced as the highest Trump as a variant in the game of Euchre in the 1860's, and it caught some popularity with card players and manufacturers at that time. Poker later adopted the Joker as a wild card, resulting in the legendary \"five of a kind\" which beats the royal flush. Finally, jokers started becoming standard in the 1940's for the game of Canasta. Now jokers are used in all sorts of card games, including Pitch and Rummy."
] |
[
4
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
k4cf3i
|
why does everything get extremely funny at a certain point of being tired
|
Biology
|
explainlikeimfive
|
[
"ge83ufl"
] |
[
"Fatigue lowers your inhibitions and self-control. So you start to overreact to things, humorous things become hilarious. Perhaps there is something to be said once you start laughing, you can also become giddy. So being tired can jumpstart that process."
] |
[
9
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
75thfa
|
How is that extremely spicy foods can cause coughing?
|
Biology
|
explainlikeimfive
|
[
"do8tpfb"
] |
[
"Spicy foods (aside from wasabi) contain a chemical called capsaicin, and this chemical is what we interpret as \"spicy.\" Capsaicin mimics \"heat,\" but it's also an irritant. It activates receptors associated with temperature and pain, and in high concentrations can be damaging to tissue, resulting in inflammation. When your upper airway (throat, mainly) gets irritated, the body's response is to cough, which may forcefully clear the irritant from the body. More broadly, the cough reflex can be activated by any abnormal sensation, including that of capsaicin. Pretty much any strong stimulus will trigger the cough/gag reflex, including pressure (mostly gag reflex), pain, temperature, and even strong tastes or smells. The farther down you travel towards the lungs, the more sensitive the response becomes."
] |
[
4
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
lje7of
|
Why does the Northern Territory and THE Australian Capital Territory have self-government arrangements?
|
So I'm currently working on a project for my Legal Requirements unit of my course I am doing. I've only just now discovered that NT and ACT have self government arrangements. I don't need to know why for my course but I am highly intrigued and I can't make sense of any of the information I've found on google.
|
Other
|
explainlikeimfive
|
[
"gnc0r18"
] |
[
"Australia is a federation. This means that it is made up of federal states which are automatically self governing. The Northern Territory and Australian Capital Territory are not federal states. This means that they are not automatically self governing, rather, they are directly controlled by the federal government. The federal government has passed laws, which create a government in these territories, and lets those governments run those territories. So, it’s kind of like a state, but those powers come from federal law, and not the status of statehood. You see something very similar in the US with Puerto Rico and DC. You also see the same thing in Canada, with the provinces being like states and the territories being like... well, like territories hahah In a different way, you also see this in the UK. The UK is NOT a federation — which means that all parts of the UK are by default, run by the British government. However, the British government has created governments for some parts of the UK, and allowed those governments to self govern those parts. By the way, this process is called devolution. It’s found in pretty much all non-federations, and, in some cases, federations (ie, US, Canada, Australia, etc)"
] |
[
7
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
locvzs
|
Why do liquids get even colder when shaken with ice? It seems even colder than the ice itself.
|
Physics
|
explainlikeimfive
|
[
"go57aea"
] |
[
"Shaking the mixture will pretty quickly bring it all into thermal equilibrium (bring the liquid down to ice temperature), since heat is exchanged by contact and circulation of the liquid and the ice. Shaking speeds that up. That's why the liquid is *as cold as* the ice. Why does it *feel* even colder? Well since it circulates, it can can also exchange heat with your body faster than a solid can. Your body doesn't really sense the temperature of things you touch, what it really senses is how fast heat is being transferred from you into them. A block of styrofoam that's been cooled in the freezer, doesn't feel as cold as a metal signpost that's just been outside in the shade on a cool day. The styrofoam might have a much lower temperature, but its very low thermal conductivity keeps it from feeling all that cold."
] |
[
9
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
jysz47
|
How come we see weird patterns when we close both our eyes?
|
Biology
|
explainlikeimfive
|
[
"gd728ek",
"gd7hbs2",
"gd7d6mt",
"gd7au3e",
"gd7iszo",
"gd7jqgh"
] |
[
"The cornea or outer transparent layer of eyes are made up of living cells. They have nucleus, which along with scratches and dirt leads to the patterns you see in the dark. There is also the aspect of blood vessels in the eyelids which are visble with eyes closed in certain conditions."
] |
[
19
] |
[
[],
[],
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
gdaewr
|
why do artists draw on canvas to cover it up?
|
Theres been a lot of times I’m watching videos of people doing art and they sketch out the entire thing on the canvas but then immediately paint over it with the background color. why draw it out if you cant see it for reference?
|
Other
|
explainlikeimfive
|
[
"fpg4v6s",
"fpg5jac"
] |
[
"Usually you can still see the lines through the background color. At least enough to use it as a guide"
] |
[
8
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
62c4cl
|
How did we first find out about the difference in gravity in space?
|
Physics
|
explainlikeimfive
|
[
"dflf9rz",
"dflezmr"
] |
[
"Take my answer with a grain of salt. I'm not a scientist. EDIT: There is a difference in gravity depending on how far away from the body (earth) you are. A person on a mountain will feel less gravity than a person at sea level. But it's such small amounts until you get far away from the planet. **First of all, gravity is not different in space.** What you're talking about is weightlessness. Which means we feel like there are no outer forces acting on our body. Let's take the ISS as an example. The ISS is constantly affected by gravity. HOWEVER, it is traveling super fast across the earth. So it's constantly \"falling\". I wish I could draw on my phone/reddit, then I could visualize the forces. There is one force dragging the ISS down towards earth. And there is another force (\"centripetal force\") F=m*v^2*r These create the orbit. [Here]( URL_0 ) is a good link to read on orbits. > > How Do Objects Stay in Orbit? An object in motion will stay in motion unless something pushes or pulls on it. This statement is called Newton's first law of motion. Without gravity, an Earth-orbiting satellite would go off into space along a straight line. With gravity, it is pulled back toward Earth. A constant tug-of-war takes place between the satellite's tendency to move in a straight line, or momentum, and the tug of gravity pulling the satellite back. An object's momentum and the force of gravity have to be balanced for an orbit to happen. If the forward momentum of one object is too great, it will speed past and not enter into orbit. If momentum is too small, the object will be pulled down and crash. When these forces are balanced, the object is always falling toward the planet, but because it's moving sideways fast enough, it never hits the planet. Orbital velocity is the speed needed to stay in orbit. At an altitude of 150 miles (242 kilometers) above Earth, orbital velocity is about 17,000 miles per hour. Satellites that have higher orbits have slower orbital velocities. Orbiting is basically infinite freefall. There is still gravity in space (if close to a dense body). I've tried to explain it, but I don't have the tools to make it easy."
] |
[
5
] |
[
[
"https://www.nasa.gov/audience/forstudents/5-8/features/nasa-knows/what-is-orbit-58.html"
],
[
"http://gnomeexperiment.com/"
]
] |
[
"url"
] |
[
"url"
] |
|
fhi0ey
|
Why the chance of hitting at least one of two 20% chances equals around 36% and not 40%
|
Ok so I know most of the reasoning but I just need it explained a bit better because thinking about it is hurtng my brain. So you have 2 chances of 20% rolls to hit your goal at least once, 2 D5 dice, win condition need one of them to land on 5 would be an example, the chances of either one hitting isn't 40%, it's actually more like 36%. I THINK this is because you are hitting 2 out of 2 in some realities so that's wasted potential, therefore your odds of hitting at least one are lower than 40%... But I really don't get that last bit at all.
|
Mathematics
|
explainlikeimfive
|
[
"fkb64v1",
"fkb80xr",
"fkb6pmq",
"fkbl7lh",
"fkb9dy3",
"fkb6r3f"
] |
[
"There is a scenario where you hit the goal the first time (20%) There is a scenario where you hit the goal the second time (20%) If you just add them up, you get 40%. The problem is the scenario where you hit *both* goals. This happens in both the first scenario *and* the second scenario. So if you add up the odds, you are double counting that specific occurrence. So you need to subtract one instance of it. The odds of hitting both goals is 20%\\*20% = 4%. And 40% - 4% = 36%"
] |
[
32
] |
[
[],
[],
[],
[],
[],
[]
] |
[
"url"
] |
[
"url"
] |
bw8hqb
|
How come you can go for days without eating and not feel hungy when you're sick?
|
Biology
|
explainlikeimfive
|
[
"epvvlke",
"epvzbte"
] |
[
"Your body usualy has \"reserves\" that can sustain you for a while. When you're sick, it can prioritize healing, not \"waste energy\" digesting and to avoid chances of ingesting more contaminants (more things to fight off). So it doesn't send you hunger signals. (Ofc that can go wrong, especialy if you don't have much reserves to start with, and you can require an IV, but generaly a few days shouldn't be a problem)"
] |
[
6
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
|
6ns4h6
|
teaching/learning robots
|
How much groundwork programming does it take to let a robot know that "stand up" shouldn't look like a topsy-turvy turtle? Is it like: these are the rules, now bring it to a usable order? How does the robot know what makes an order usable?
|
Technology
|
explainlikeimfive
|
[
"dkbz025"
] |
[
"imagine you have some inputs (sensors, energy), some internal nodes (stuff that can be connected together), some outputs (motors) and a simple test to \"score\" the result, f.e. how close you are to the desired result. now a computer connects everything randomly, and uses it as start state. now it keeps repeating 2 things 1) scoring; check how close we are 2)random changes and scoring again; if we got somehow better, use that as new start state... and repeat that until you are within an \"error margin\", aka, your are close enough to the target. this can take a few cycles or billions, it depends on how you choose inputs/nodes/outputs, how you \"randomly change\" stuff (what changes how much?) and how good your score function is. tl;dr: learning here is just \"random\" trial & error until you are within a defined goal setting, the pro is also the con, in that you dont need to or can know \"how\" it solves the problem, just how reliable (test alot)"
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
g2isve
|
If Radio Waves have a lower frequency than visible light, how can radio waves penetrate through surfaces that visible light can't penetrate through?
|
Physics
|
explainlikeimfive
|
[
"fnlqbvq",
"fnlqrmh",
"fnlq432",
"fnlpgxn",
"fnmtqn5",
"fnmq1e5"
] |
[
"Hey! Photovoltaics lab scientist here. Light of any sort (radio, visible, xrays, etc) will keep moving until it interacts with something. The thing is, light has funny rules for how it interacts with objects. Each object (really, each different type of material) basically has an “energy toll” that the light must “pay” in order to interact. Radio waves, like you say, have much less energy than visible light (lower frequency = lower energy). In fact radio waves have so little energy, they can’t afford to pay the energy “toll” of any material out there. Can’t pay the energy toll? Can’t interact. No interaction? You’ll never stop. So, radio waves are very good at traveling long distances without being stopped."
] |
[
916
] |
[
[],
[],
[],
[],
[],
[
"https://jerseyir.com/infrared-windows-101-basics-need-know"
]
] |
[
"url"
] |
[
"url"
] |
|
5w7kub
|
Why are some mothers unable to produce milk for their offspring?
|
Biology
|
explainlikeimfive
|
[
"de7xcvj"
] |
[
"Bad luck, genetics. Duct blockage/infection. They formula fed early, and during formula time weren't also pumping their own milk. Like a cow, the boob stops producing milk if it thinks there's no demand. Going too long an interval between pumping/feeding will also cause demand to drop. I'd recommend hitting the various mom subreddits."
] |
[
3
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
|
egeqff
|
What keeps our bodies from sneezing while we’re sleeping?
|
I’ve had a cold for a few days and I start sneezing as soon as I wake up but never in the middle of the night.
|
Biology
|
explainlikeimfive
|
[
"fc6bjp5"
] |
[
"You sneeze because it tickles in your nose. When you sleep, the part of your brain that receives this signals is \"shut down\" so it ignores them. Therefore, it doesn't tickle in your nose before you wake up. But no part is actually fully shut down, just less sensitive. That way you \"MAY\" be able to tickle someone that's sleeping. However, the part of the brain that receives pain is still active so that you wake up in case of a attack."
] |
[
13
] |
[
[]
] |
[
"url"
] |
[
"url"
] |
nvqdya
|
I just noticed if I stand in front of two diagonal mirrors that meet, the vertical line between the mirrors will always be on whichever eye is closed. However, my friends noticed it goes to a single eye by default if both are open. How does it choose this?
|
Physics
|
explainlikeimfive
|
[
"h14nwr9",
"h14nxq5"
] |
[
"Surely you mean whichever eye is open? If you are looking with both eyes open then they will actually see different reflections, and which eye appears (in your brain) to be on the centreline will depend on which eye is dominant (at that moment)."
] |
[
5
] |
[
[],
[]
] |
[
"url"
] |
[
"url"
] |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.