What advantage does a flatbed scanner have over a polaroid camera? They both capture light, but with different optics and for different purposes. Copy and past

What advantage does a flatbed scanner have over a polaroid camera? They both capture light, but with different optics and for different purposes. Copy and pasting a previous comment: https://news.ycombinator.com/item?id=36558940 https://news.ycombinator.com/item?id=36558940 Euclid is a deep sky survey space telescope. Like many space telescopes, it's designed to run cold (-140C) to extend viewing into infrared bands ground telescopes can't access. Being a sky survey instrument, it has a wider field of view than Webb, 0.5 square degrees versus 0.0025 sq deg. It's something of a follow-on to ESA's Gaia astrometry space telescope, which surveyed the entire sky out to visual magnitude 20 and in 320–1000 nm light, while Euclid will specifically examine the 15,000 square degrees of the sky the Milky Way doesn't cover, out to magnitude 24.5 and in 550-2000 nm light. Both dimmer and more redshifted. (Fun fact: both Gaia and Euclid are made largely out of silicon carbide, including the optical bench and mirrors, which has become a ESA specialty.) For another comparison, the first Sloan sky survey (using a 2.5m ground based telescope much bigger than Euclid) took 5 years to image 8,000 square degrees down to magnitude 22.2 and only out to 893 nm. Again, Euclid can see objects dimmer and more redshifted. These press photos are of large, interesting objects, like nebulae and nearby galaxies. Amusingly enough, though, for Euclid's mission these are obstructions, which are getting in the way of all the dim smudges in the background that it's actually supposed to be capturing. A cloud passing in front of a mountain you're trying to take a picture of. We'll either need to send another telescope a thousand light years away to image them, or wait thousands more for Sol to travel along its orbit in the Milky Way and move them out of the way. >Also, the Lagrange point is where Webb and some other stuff is located — is it getting crowded up there? For stability reasons, spacecraft orbit around L2 rather than sitting at its center. Here's a diagram of JWST's orbit: https://i.stack.imgur.com/sBH2i.png https://i.stack.imgur.com/sBH2i.png It's a bent ellipse that's 1.6 million km in length along the long axis, considerably larger than the orbit of the moon. You could put three million telescopes on that orbit and they'd each be a kilometer apart.