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JWST spots giant black holes all over the early universe

quantamagazine.org

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Re: JWST spots giant black holes all over the early universe

#11

Post by pdonis »

whiw wrote: post #2

> Galactic spectra, which JWST started to send back in earnest at the end of last year, are useful for two reasons. > First, they let astronomers nail down the galaxy’s age. The infrared light JWST collects is reddened, or redshifted, meaning that as it traverses the cosmos, its wavelengths are stretched by the expansion of space. The extent of that redshift lets astronomers determine a galaxy’s distance, and therefo…

> Won't a photon climbing out of a huge gravity well have a huge redshift

It depends; the key factor is not how "huge" the gravity well is (in terms of how massive the object is), but how close to the black hole horizon the light is emitted. The vast majority of the light JWST is seeing from black holes is not from very close to the horizon. It's from the accretion disk, which is much further from the horizon and so the gravitational redshift is much smaller.

Re: JWST spots giant black holes all over the early universe

#12

Post by r2_pilot »

ijidak wrote: post #8
javajosh wrote: post #3

This is super cool. I think it's funny how Quanta writes, "It is expected because JWST was built, in part, to find the ancient objects." "Ancient" is equivalent to "distant" because of special relativity. It's an odd thing, astronomy - it's a real world time-traveling observation, except we're limited in resolution and we can't look here only there . If it was a game mechanic I'd call it a cunning way to impose inter…

> internally consistent limits on what the player can know Interesting thought. Can you expand? What do you mean by this?

Not the original author but my first interpretation is that this means, if it were in a video game, it would be a way to self-reinforce "fog of war" where you can only have extremely local information and you don't want extra information to leak to the players.

Re: JWST spots giant black holes all over the early universe

#13

Post by marcosdumay »

ben_w wrote: post #4
whiw wrote: post #2

> Galactic spectra, which JWST started to send back in earnest at the end of last year, are useful for two reasons. > First, they let astronomers nail down the galaxy’s age. The infrared light JWST collects is reddened, or redshifted, meaning that as it traverses the cosmos, its wavelengths are stretched by the expansion of space. The extent of that redshift lets astronomers determine a galaxy’s distance, and therefo…

> Won't a photon climbing out of a huge gravity well have a huge redshift, Yes > thus confounding estimates of distance from us and estimated age? Not if you know, or can get a good estimate of, the potential well it's climbing out of. That said, Brian Cox does sometimes joke that astronomers round π to 1; while I wouldn't know about the reality, it's probably safe to infer at least some frustration on his part about…

The joke was way more true at the 20th century. There were many really important measurements where we got unprecedentedly precision, enough to say it's X, 100X, or something in between.

Nowadays astronomy got a lot more precise. But there are disagreements on how much confidence to put on that extra precision.

Re: JWST spots giant black holes all over the early universe

#15

Post by blueprint »

mkoubaa wrote: post #5
whiw wrote: post #2

> Galactic spectra, which JWST started to send back in earnest at the end of last year, are useful for two reasons. > First, they let astronomers nail down the galaxy’s age. The infrared light JWST collects is reddened, or redshifted, meaning that as it traverses the cosmos, its wavelengths are stretched by the expansion of space. The extent of that redshift lets astronomers determine a galaxy’s distance, and therefo…

My understanding is that a particles, like photons, don't have wave shifts. That's an emergent property of many particles

Your comment is a bit strange. Light doesn't travel as photons. Photons exclusively exist at the site and instant of detection of the wave of probability of detection that light really travels as.

When light is redshifted, it loses energy, therefore the wavelength becomes longer.

Re: JWST spots giant black holes all over the early universe

#16

Post by andai »

mvdtnz wrote: post #14

I wish stories like this were a more straight forward counting of the interesting facts and relevant input from experts. I don't really need the origin story of the conference this finding was discussed at.

You can ask GPT to rewrite it according to your preference. (Not being facetious: I often ask it for bullet points or "explain like I'm 13.")

Re: JWST spots giant black holes all over the early universe

#17

Post by louislang »

andai wrote: post #16
mvdtnz wrote: post #14

I wish stories like this were a more straight forward counting of the interesting facts and relevant input from experts. I don't really need the origin story of the conference this finding was discussed at.

You can ask GPT to rewrite it according to your preference. (Not being facetious: I often ask it for bullet points or "explain like I'm 13.")

the problem with GPT is that you're not guaranteed to get something that's _accurate_. I'd definitely prefer some input from an expert over GPT.

Re: JWST spots giant black holes all over the early universe

#18

Post by burnished »

andai wrote: post #16
mvdtnz wrote: post #14

I wish stories like this were a more straight forward counting of the interesting facts and relevant input from experts. I don't really need the origin story of the conference this finding was discussed at.

You can ask GPT to rewrite it according to your preference. (Not being facetious: I often ask it for bullet points or "explain like I'm 13.")

I'm not sure this is good advice, especially considering the context is around novel material.

Re: JWST spots giant black holes all over the early universe

#19

Post by ajross »

mvdtnz wrote: post #14

I wish stories like this were a more straight forward counting of the interesting facts and relevant input from experts. I don't really need the origin story of the conference this finding was discussed at.

The stuff you're complaining about seems limited to a little bit of POV text in the first seven (!) sentences of a rather long article. Does it really bug you so much that they gave you just a tiny taste of the perspective of a woman who works on this stuff? That seems a bit much. This kind of text is everywhere in science journalism.

Re: JWST spots giant black holes all over the early universe

#20

Post by ajross »

whiw wrote: post #2

> Galactic spectra, which JWST started to send back in earnest at the end of last year, are useful for two reasons. > First, they let astronomers nail down the galaxy’s age. The infrared light JWST collects is reddened, or redshifted, meaning that as it traverses the cosmos, its wavelengths are stretched by the expansion of space. The extent of that redshift lets astronomers determine a galaxy’s distance, and therefo…

> Won't a photon climbing out of a huge gravity well have a huge redshift, thus confounding estimates of distance from us and estimated age?

Of course it will. It will also have a redshift related to the expansion of the space it's been travelling through. Both of those corrections are absolutely part of the model. It's not nearly as simple as "Astronomers forgot about General Relativity!".

But I guess it's true (to be clear: I'm just an amateur in this field) that the ΛCDM model for cosmological evolution that we've all been looking at for the past decade or two isn't holding up well at all. It looked like it was pretty much there and just needed some fine tuning. Then we got a bunch of new data and everything's a mess.

That's kind of exciting all by itself, though it's also leading to a bunch of nattering from the existing iconoclasts (MOND nuts in particular) whose theories are also not working very well to explain JWST observations.

New insight needed, basically. We're all watching for updates.

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