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James Webb Telescope

arthwollipot said:
NASA isn't about exploitable resources any more. The current policy is that NASA and other governmental agencies will concentrate on deep-sky exploration and research, and commercial interests will take care of exploitation. SpaceX opened that door, but they will not be the only ones to go through it.
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As far as I know, NASA has never been about exploitable resources in the sense you mean. They've always handed off to private enterprise whenever possible. They have, however, been involved in projects that have immediate benefits for humanity on Earth. Landsat, for example.

You're talking about commercial profits. I'm talking about benefits to humanity and NASA having limited resources. If NASA is going to do pure science with no immediate benefit, I'd rather they tackle some of the big questions. I'd rather they do missions that help us develop a better model of galaxy evolution.

That tell us more about black holes and what happens in high gravity, high energy scenarios we can't create here.

That help us refine the competing predictions of cosmological redshift and converge on an agreed value.

That better sift the interstellar energies for signs of intelligent life.

Looking more closely at exoplanets does none of this. Looking specifically at "habitable" exoplanets just seems like a human interest mission. An appeal to emotion. I'm not a fan. If we're going to throw a new telescope up there, I'd rather it do serious fundamental research into the nature of our reality. Not inspect rando rocks orbiting rando stars.
 
How is studying black holes any more "useful" than finding habitable exoplanets?

Both are interesting science questions but without any immediate practical value.

Assuming that it works as planned it could find lots of exoplanets that aren't findable by methods like the transit method, which only works for a tiny subset of exoplanets that just happen by chance to orbit at an angle that makes them transit from our perspective. Mostly planets with very short orbital periods, orbiting closer to their stars than Mercury orbits our sun. I think it's a great mission.

If we do find extraterrestrial life, that would be amazing. I suspect life is more common but technological civilizations like our own are probably rather rare. I also don't believe in Dyson spheres.
 
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Puppycow said:
How is studying black holes any more "useful" than finding habitable exoplanets?

Both are interesting science questions but without any immediate practical value.

Assuming that it works as planned it could find lots of exoplanets that aren't findable by methods like the transit method, which only works for a tiny subset of exoplanets that just happen by chance to orbit at an angle that makes them transit from our perspective. Mostly planets with very short orbital periods, orbiting closer to their stars than Mercury orbits our sun. I think it's a great mission.

If we do find extraterrestrial life, that would be amazing. I suspect life is more common but technological civilizations like our own are probably rather rare. I also don't believe in Dyson spheres.
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Spectral lines from atmospheres will be the proof of life elsewhere, I thought this was uncontroversial.
But early black holes are fascinating. And logical, I wonder if JWT might find an exact time when there were two points in the early universe that were isolated by the speed of light. Was this as early as Alan Guth's inflation proposition? Is inflation under major attack? These are the questions JWT can advance beyond thought experiment.
Or not, I have no idea, but if the universe cannot transition from finite to infinite, a given, can it transition from communication by photon to non communication?
 
Puppycow said:
How is studying black holes any more "useful" than finding habitable exoplanets?

Both are interesting science questions but without any immediate practical value.

Assuming that it works as planned it could find lots of exoplanets that aren't findable by methods like the transit method, which only works for a tiny subset of exoplanets that just happen by chance to orbit at an angle that makes them transit from our perspective. Mostly planets with very short orbital periods, orbiting closer to their stars than Mercury orbits our sun. I think it's a great mission.

If we do find extraterrestrial life, that would be amazing. I suspect life is more common but technological civilizations like our own are probably rather rare. I also don't believe in Dyson spheres.
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Fair enough. I'm not saying we shouldn't look for exoplanets. I just think they should be a lot farther down our priority list.

To me, exoplanets are like Kuiper Belt objects. We know they're out there, we know we can find more if we look harder. But nobody is prioritizing any missions to discover and catalog them all. To me, finding more exoplanets is merely a technical exercise. Let the ESA do it, or JAXA. Or the Chinese, if they want to show off their skills.

As I understand it, there are two big questions in cosmology today. One is, we have two competing models for spacetime expansion, that predict two different and incompatible expansion rates. Observations that helped us converge on one of those models, or develop a superseding model, would be a breakthrough in cosmological physics. I would prioritize a mission aimed at that goal.

The other question is, how do we get better galaxy formation models. The current ones involve a lot of guesswork, partly because we don't have a good view of very young galaxies. JWST has improved that view, and shown that a lot of our guesswork is wrong. Figuring out a better galaxy formation model would also be a breakthrough in cosmological physics. I would prioritize a mission aimed at that goal.

As for black holes: We're limited in the amount of energy we can put into particle collisions. We're pretty sure there's interesting things going on, at much higher energy levels than we can current command. The accretion disks around black holes are a high energy environment. The energies they release create quasars, some of the brightest objects in the sky. If we could figure out a way to get a better look at what happens to matter in the vicinity of black holes, it might teach us a thing or two about particle physics that we can't learn here on earth. I would prioritize a mission aimed at that goal.

Generally, I would prioritize the Hubble-West trend: more advanced telescopes looking further and further back, towards the beginning of the universe as we know it.
 
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It seems odd to criticize the JWST for not answering the questions you're admitting it's helping to answer.
 
Beelzebuddy said:
It seems odd to criticize the JWST for not answering the questions you're admitting it's helping to answer.
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It seems odd to me, too. Which is why I wasn't doing it.

I like JWST. I like that it took us beyond what the Hubble telescope could show us. I like that it took us further back towards the beginning of the universe. I like that it's already telling us new things about what's back there. I absolutely love that it's already helping us falsify our current galaxy formation models.

I want more of that. I want our next priority to be something that goes even further, that takes us beyond what JWST can show us. I don't want NASA to spend its limited budget on shifting our attention away from that goal.

And in the meantime, I am super happy that JWST finally got off the ground, and I'm super happy about all the things it has shown us and has yet to show us.

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It seems odd that you'd interpret my previous posts as criticism of JWST. I thought it was pretty clear that I consider it a huge step in the right direction, and that I want to continue taking big steps in that direction. Can you quote the passage from my posts that gave you the impression I was criticizing JWST?
 
With my highlighting.

theprestige said:
As I understand it, there are two big questions in cosmology today. One is, we have two competing models for spacetime expansion, that predict two different and incompatible expansion rates . Observations that helped us converge on one of those models, or develop a superseding model, would be a breakthrough in cosmological physics. I would prioritize a mission aimed at that goal.
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I don't know what theprestige thinks those two competing models might be.

Historically, we once had steady state models competing with Big Bang models, but observations pretty much ruled out the steady state models decades ago.

So far as I know, all currently viable models for spacetime expansion are variations of the ΛCDM models.

Another thread's most prolific poster has been going on and on about the so-called Hubble tension. The Hubble tension concerns two complementary (not competing) general techniques for estimating the Hubble constant, which is a dependent parameter of ΛCDM models. Those two techniques give estimates that differ by up to 10%, which is a big improvement over the factor-of-two uncertainty that prevailed from the 1930s through the 1990s. Those two techniques are not competing models of spacetime expansion, although it seems likely that research aimed at understanding why those techniques give different estimates will improve our models of spacetime expansion.

Amusingly, the poster who's been making the most noise about the Hubble tension recently directed our attention to an essay that refers to people who make "so much noise and commotion surrounding Hubble tension" as "sheep-cosmologists" who have succumbed to "groupthink".

theprestige said:
The other question is, how do we get better galaxy formation models. The current ones involve a lot of guesswork, partly because we don't have a good view of very young galaxies. JWST has improved that view, and shown that a lot of our guesswork is wrong. Figuring out a better galaxy formation model would also be a breakthrough in cosmological physics. I would prioritize a mission aimed at that goal.
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Yes.

theprestige said:
As for black holes: We're limited in the amount of energy we can put into particle collisions. We're pretty sure there's interesting things going on, at much higher energy levels than we can current command. The accretion disks around black holes are a high energy environment. The energies they release create quasars, some of the brightest objects in the sky. If we could figure out a way to get a better look at what happens to matter in the vicinity of black holes, it might teach us a thing or two about particle physics that we can't learn here on earth. I would prioritize a mission aimed at that goal.
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Yes. I would add that recent studies of black holes have confirmed several of general relativity's most spectacular predictions (e.g. gravitational waves, the Kerr metric) and given us our first truly detailed photographs of a black hole and its dynamics.

theprestige said:
Generally, I would prioritize the Hubble-West trend: more advanced telescopes looking further and further back, towards the beginning of the universe as we know it.
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Yes.
 
I missed that you were rustled about the next telescope plan to study exoplanets, and not the exoplanets being studied by the present telescope. Mea culpa.

If you look at the pdf though, you'll note it's a general purpose space telescope, not JUST an exoplanet thing.
 
This mission is not just looking for exoplanets. It's looking for exoplanets with the conditions suitable to support Earth-like life. There's only one planet we know of with those conditions. Finding another one would be stunning.
 
W.D.Clinger said:
With my highlighting.


I don't know what theprestige thinks those two competing models might be.

Historically, we once had steady state models competing with Big Bang models, but observations pretty much ruled out the steady state models decades ago.

So far as I know, all currently viable models for spacetime expansion are variations of the ΛCDM models.

Another thread's most prolific poster has been going on and on about the so-called Hubble tension. The Hubble tension concerns two complementary (not competing) general techniques for estimating the Hubble constant, which is a dependent parameter of ΛCDM models. Those two techniques give estimates that differ by up to 10%, which is a big improvement over the factor-of-two uncertainty that prevailed from the 1930s through the 1990s. Those two techniques are not competing models of spacetime expansion, although it seems likely that research aimed at understanding why those techniques give different estimates will improve our models of spacetime expansion.

Amusingly, the poster who's been making the most noise about the Hubble tension recently directed our attention to an essay that refers to people who make "so much noise and commotion surrounding Hubble tension" as "sheep-cosmologists" who have succumbed to "groupthink".


Yes.


Yes. I would add that recent studies of black holes have confirmed several of general relativity's most spectacular predictions (e.g. gravitational waves, the Kerr metric) and given us our first truly detailed photographs of a black hole and its dynamics.


Yes.
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Thank you for the correction.
 
arthwollipot said:
This mission is not just looking for exoplanets. It's looking for exoplanets with the conditions suitable to support Earth-like life. There's only one planet we know of with those conditions. Finding another one would be stunning.
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My understanding is that everything we currently know about planets and stars leads us to the reasonable conclusion that there must be thousands of such planets in the Milky Way, at least. What would be stunning is if we kept looking and looking, but never found one. And finding one won't do much to advance our knowledge. Not in the same way that resolving the Hubble Tension, or getting a better galaxy formation model would.

NASA has limited resources, which I would prefer they prioritize on the biggest questions of cosmological and particle physics. Let ESA or JAXA or CMSA look for planets we totally expect to be found sooner or later. If it comes to later, and still none have been found, then we can maybe revisit the question. That's my opinion, anyway. I'm well aware that there are people who believe that NASA needs to prioritize this. I disagree with them, for the reasons stated. I want more of JWST, and less of whatever takes resources away from the next JWST.
 
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