# A question on those photographs of galaxies from space telesccopes **URL:** \ **Category:** Factual Questions\ **Created:** [July 28, 2022, 4:03pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723 "2022-07-28T16:03:39Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![superwombat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/superwombat/32/16616_2.png) [@superwombat](https://boards.straightdope.com/u/superwombat)\ **Post date:** [July 29, 2022, 3:32am UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/21 "2022-07-29T03:32:50Z")
It’s amazing that the deep field image is contained in an area approximately the same as what would be covered by a grain of sand at arm’s length. And that was a “short” exposure. Then imagine being inside a sphere of sand of an arm’s radius, one grain thick. Each grain having its own population of galaxies and stellar phenomena. Just Wow. ---
**Author:** ![Novelty\_Bobble](https://avatars.discourse-cdn.com/v4/letter/n/a3d4f5/32.png) [@Novelty\_Bobble](https://boards.straightdope.com/u/Novelty_Bobble)\ **Post date:** [July 29, 2022, 6:58am UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/22 "2022-07-29T06:58:32Z")
> [@Sam\_Stone](#): > > That deep field doesn’t come close to showing you all the galaxies that are in the field of view. The JWST image represents a total exposure time of 12.5 hours. If JWST does a 100 hour deep field it will see many more galaxies. well quite, the JWST has captured an image many times better than Hubble at a fraction of the exposure. What on earth are we going to see when she really stretches herself? ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [July 29, 2022, 11:13am UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/23 "2022-07-29T11:13:41Z")
> [@Novelty\_Bobble](#): > > What on earth are we going to see when she really stretches herself? You mean “What off Earth”. Anyway, it’ll likely be a while before JWST does any really long deep fields. There’s too much demand for its time for other things. Note that Hubble didn’t do a deep field until 1995, 5 years after launch. ---
**Author:** ![Novelty\_Bobble](https://avatars.discourse-cdn.com/v4/letter/n/a3d4f5/32.png) [@Novelty\_Bobble](https://boards.straightdope.com/u/Novelty_Bobble)\ **Post date:** [July 29, 2022, 12:01pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/24 "2022-07-29T12:01:05Z")
There’s probably an opportunity to do something that is not as time-intensive as a Hubble deep field scan, but is longer than these initial exposures, that will _still_ be completely mind-blowing. I can’t wait. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 29, 2022, 1:09pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/25 "2022-07-29T13:09:18Z")
> [@dtilque](#): > > Note that Hubble didn’t do a deep field until 1995, 5 years after launch. And when it did, a lot of people were very upset at the STScI director who made the decision (until they saw the results). One of the perks of being director of the Space Telescope Science Institute is that you get two weeks of telescope time each year that you can allocate completely at your discretion. Usually, this is used for what you consider to be worthy projects that slipped through the cracks, doled out bit by bit. But one year, the director decided that he’d use it all for this one project, instead of using it for dozens of different projects. ---
**Author:** ![zimaane](https://avatars.discourse-cdn.com/v4/letter/z/a3d4f5/32.png) [@zimaane](https://boards.straightdope.com/u/zimaane)\ **Post date:** [July 29, 2022, 3:49pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/26 "2022-07-29T15:49:37Z")
Iirc, it was done somewhat on a whim, like, “Let’s point the Hubble at a blank space in the sky for two weeks straight and just see what happens”. And then of course the results were extraordinary… ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [July 29, 2022, 3:58pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/27 "2022-07-29T15:58:09Z")
> [@Novelty\_Bobble](#): > > well quite, the JWST has captured an image many times better than Hubble at a fraction of the exposure. What on earth are we going to see when she really stretches herself? We may not have to wait that long. The JWST is so powerful that its very first image may upend our understanding of the universe’s early days: > **[2207.11558.pdf](https://arxiv.org/pdf/2207.11558.pdf)** > > 26.26 MB This is very early preprint stuff and needs further study, but it appears that the very first JWST image may have found star-forming galaxies as far back as a redshift of 20, corresponding to a time only 180 million years after the Big Bang. This contradicts theory, as does the number of high redshift galaxies they’ve been finding. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 29, 2022, 5:50pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/28 "2022-07-29T17:50:30Z")
> [@Darren\_Garrison](#): > > Dough? The dough is analogous to space; the raisins are analogous to stars. The dough expands equally from each of the raisins’ perspectives. The hard part is picturing the cake with no edges. For fun extra credit, put cinnamon swirl in the dough and make that analogous to gas filaments. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 29, 2022, 5:57pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/29 "2022-07-29T17:57:34Z")
Well, the raisins are more like entire galaxies or even clusters of galaxies, because cosmological expansion is irrelevant on scales at which individual stars would be relevant. But other than that, yeah, that’s the idea. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 29, 2022, 6:05pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/30 "2022-07-29T18:05:56Z")
Like the balloon spot analogy, the raisin analogy can be scaled up and down. Earth is not a star or a galaxy or a cluster of galaxies, but we see the rest of the universe equally to the same microwave background from what appears to be a center. This would hold true from any other planet in the solar system and from every exoplanet that we’re discovered. The raisins could be individual spaceships as well. That there is no center holds at all scales. The cake is therefore fractal. One can zoom down into it and it will have the same appearance no matter the size of what the raisin represents. ---
**Author:** ![wolfpup](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wolfpup/32/10618_2.png) [@wolfpup](https://boards.straightdope.com/u/wolfpup)\ **Post date:** [July 29, 2022, 6:06pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/31 "2022-07-29T18:06:39Z")
> [@zimaane](#): > > “Let’s point the Hubble at a blank space in the sky for two weeks straight and just see what happens”. And then of course the results were extraordinary… The Hubble deep field image is widely considered to be perhaps the most spectacular and scientifically interesting image ever obtained by that telescope. The fact that the JWST could do even better in what could fairly be described as a pretty effortless trial run is really remarkable. And that’s just a taste of what is to come. The Trappist-1 system has been fascinating since its discovery because it may be the first planetary system found with a good chance of harboring life. Some argue that maybe not, because it’s a cool star and the planets in the habitable zone are in close orbits, which means they could be subjected to dangerous stellar flares. Still, JWST will let us examine the atmospheres of some of those planets, which is really exciting science. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [July 29, 2022, 7:25pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/32 "2022-07-29T19:25:32Z")
> [@Exapno\_Mapcase](#): > > The dough is analogous to space; the raisins are analogous to You said the view from each rasin in the expanding bread is similar. The view is dough. ---
**Author:** ![filmore](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@filmore](https://boards.straightdope.com/u/filmore)\ **Post date:** [July 29, 2022, 7:38pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/33 "2022-07-29T19:38:51Z")
> [@wolfpup](#): > > The Hubble deep field image is widely considered to be perhaps the most spectacular and scientifically interesting image ever obtained by that telescope. The fact that the JWST could do even better in what could fairly be described as a pretty effortless trial run is really remarkable. For the public support, a JWST deep field should be one of the first projects it takes on. I’m sure there are more important science applications, but a deep field would be one that would capture the public’s imagination and help with support for future projects. If you asked the general public to name one picture from the Hubble, I’m guessing the deep field would be the top pick by a wide margin. Don’t make the public wait 5 years for a JWST picture that they resonate with. Take the pic now so the public immediately feels the project was worth it. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 29, 2022, 8:06pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/34 "2022-07-29T20:06:11Z")
> [@filmore](#): > > If you asked the general public to name one picture from the Hubble, I’m guessing the deep field would be the top pick by a wide margin. I’d expect it to be the Pillars of Creation from the Eagle Nebula. And anyone who’s inclined to be awed by astronomical pictures is already pretty well awed by what we’ve got already. We don’t need to go pandering to public interest just yet. > [@Darren\_Garrison](#): > > You said the view from each rasin in the expanding bread is similar. The view is dough. So the raisins obviously need to develop telescopes that work in wavelength ranges where dough is transparent. ---
**Author:** ![filmore](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@filmore](https://boards.straightdope.com/u/filmore)\ **Post date:** [July 29, 2022, 8:09pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/35 "2022-07-29T20:09:52Z")
> [@Chronos](#): > > I’d expect it to be the Pillars of Creation from the Eagle Nebula. As a member of the general public, I have no idea what picture that is. I’m sure if I saw it I would recognize it as a picture I’ve seen before, but I wouldn’t know the name or what it’s a picture of. The deep field is one that people know the name and know something about what it’s a picture of. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [July 29, 2022, 8:28pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/36 "2022-07-29T20:28:55Z")
> [@filmore](#): > > For the public support, a JWST deep field should be one of the first projects it takes on. I’m sure there are more important science applications, but a deep field would be one that would capture the public’s imagination and help with support for future projects. I think it’s the opposite. Deep Field imagery goes to perhaps the prime mission of JWST - to better understand the very early universe. As I pointed out above, even that first semi-deep field is providing huge scientific dividends. We are getting to look at an epoch we have never seen before - the earliest stars and galaxies emerging out of the darkness. This has the potential to turn cosmology upside-down in an area where current theories are still pretty shaky. Hubble has generated lots and lors of pretty pictures, and that’s what the public sees. Web will provide more, but because its angular resolution isn’t really better than Hubble’s, they aren’t going to be THAT much prettier. Just different, because it’s looking at different wavelengths where different things glow and where dust and gas can be seen through. The thing I’m most excited about are JWST’s spectroscopic capabilities. But unless they discover life signatures around other planets, the general public probably won’t care. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 29, 2022, 8:41pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/37 "2022-07-29T20:41:47Z")
Yeah, it’s really difficult to get the general public interested in a spectrograph, even though that’s where most of the meaty scientific data comes from, with any telescope. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 29, 2022, 8:56pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/38 "2022-07-29T20:56:28Z")
Over-literalizing analogies defeats their entire purpose. As I said, the dough is analogous to expanding space, not literally identical to it. The raisins are analogous to matter. Just as we see other matter in the universe despite the intervening space, a raisin in an expanding cake would see other raisins despite the intervening dough. And would consider itself to be in the center with no way to tell otherwise. If you were just whooshing us, though, please let us know now. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [July 29, 2022, 9:02pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/39 "2022-07-29T21:02:21Z")
> [@Exapno\_Mapcase](#): > > If you were just whooshing us, though, please let us know now. I’m _pretty_ sure that you were the only one whooshed by the obvious joke. Now you are just nerdsplaining to me: > [@Dark matter/energy, and the Big Bang](https://boards.straightdope.com/t/dark-matter-energy-and-the-big-bang/769743/53): > > In the entry-level general science book I’m (eternally) attempting to write, I’m describing the expansion of space with a “big bread model.” Imagine that you are cooking a loaf of raisin bread. You take a piece of dough that is 4 inches long and put it in a 12-inch bread pan, and it takes one hour to bake. In that hour, the piece of dough triples in length to fill the pan. Now imagine that you measure the distance between some of the raisins before and after baking the dough. Two raisins that s… (BTW, I’ve long since abandoned the book idea, along with my buggywhip factory plans.) ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [July 29, 2022, 9:53pm UTC](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723/40 "2022-07-29T21:53:51Z")
Poe’s Law at work. Sorry/not sorry I didn’t remember a six-year-old post. [Previous page](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723.md?page=1) [Next page](https://boards.straightdope.com/t/a-question-on-those-photographs-of-galaxies-from-space-telesccopes/968723.md?page=3)