text: 218,57,1374923106905698309,838066124,Jeff Filippini,"New paper: Constraint on primordial gravitational waves from the first flight of SPIDER, a balloon-borne CMB telescope: <LINK> <LINK> SPIDER is an ambitious instrument: six millimeter-wave telescopes containing &gt;2000 superconducting detectors, housed in a 1300 liter cryostat, hanging from a string at 35 km altitude. Ballooning lets us observe in space-like conditions, largely free from the fluctuating glow of the atmosphere that plagues even the best Earth-bound observing sites. This pristine vantage point brings challenges: strict mass and power constraints, and a horrifying inability to fiddle with your instrument after launch. It has to basically run itself, with minimal communication, its first time out. Ballooning is also a key way we flight-qualify technologies for future space missions. And incredible training for new crops of space scientists and engineers. This has been a long road, and I've been privileged to work with a fantastic team. Here's to further adventures with new instruments, on the ground and in the air! The view from the stratosphere over Antarctica: looking down with an optical camera on the gondola, and looking up with SPIDER itself. <LINK> While I'm here, I should advertise: we have postdoc positions open, in cosmology from balloons and ground! <LINK>",https://arxiv.org/abs/2103.13334,"We present the first linear polarization measurements from the 2015 long-duration balloon flight of SPIDER, an experiment designed to map the polarization of the cosmic microwave background (CMB) on degree angular scales. Results from these measurements include maps and angular power spectra from observations of 4.8% of the sky at 95 and 150 GHz, along with the results of internal consistency tests on these data. While the polarized CMB anisotropy from primordial density perturbations is the dominant signal in this region of sky, Galactic dust emission is also detected with high significance; Galactic synchrotron emission is found to be negligible in the SPIDER bands. We employ two independent foreground-removal techniques in order to explore the sensitivity of the cosmological result to the assumptions made by each. The primary method uses a dust template derived from Planck data to subtract the Galactic dust signal. A second approach, employing a joint analysis of SPIDER and Planck data in the harmonic domain, assumes a modified-blackbody model for the spectral energy distribution of the dust with no constraint on its spatial morphology. Using a likelihood that jointly samples the template amplitude and $r$ parameter space, we derive 95% upper limits on the primordial tensor-to-scalar ratio from Feldman-Cousins and Bayesian constructions, finding $r<0.11$ and $r<0.19$, respectively. Roughly half the uncertainty in $r$ derives from noise associated with the template subtraction. New data at 280 GHz from SPIDER's second flight will complement the Planck polarization maps, providing powerful measurements of the polarized Galactic dust emission. ","A Constraint on Primordial $B$-Modes from the First Flight of the SPIDER