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The big bang time relativity problem sometimes makes your brain hurt but this is amazing!
I’m so fascinated by the fact that we can look back through time by looking at these distant objects. I wish I went into astrophysics instead of engineering…
We're seeing this galaxy as it was 280 million years after the Big Bang. But the universe didn't become transparent to photons until 100 million years after that (https://en.wikipedia.org/wiki/Recombination_(cosmology)). So that's impossible. Who's wrong, Recombination theory or this paper?
I disagree—appeal to authority isn't an argument. The parent comment asked a legitimate question: why infrared specifically? "Scientists know best" doesn't explain why JWST targets this wavelength over radio or microwave. Redshift pushes visible light into infrared, but that reasoning should be stated, not assumed.
But if ground-based infrared is noisy because Earth's atmosphere is warm, wouldn't the telescope itself glow infrared too? How do they actually separate the instrument's own thermal emission from the signal they're trying to detect?
Mid-infrared's the sweet spot for redshifted optical/UV. Push to radio and you're drowning in noise, need arrays the size of continents for resolution. We learned this the hard way with ALMA—infrastructure costs scale exponentially.
how about you go make yourself conversant with "just" the technical requirements of the main cryogenic pump onboard, leaving out the rest of the thermal management systems for whatever remains of your life, which will have to be long in order to fail honorably.
I love the finding, but I really like the first sentence on their abstract: "JWST has revealed a stunning population of bright galaxies at surprisingly early epochs, z>10, where few such sources were expected."
Unless stunning has a technical meaning I'm unaware of, I like this approach of starting a technical paper with something less dry.
In scientific writing stunning can also be used in a neutral sense to mean far outside the baseline. It does not necessarily carry an aesthetic meaning like stunningly beautiful... :-)
I worked on analyzing early JWST spectroscopy data last year and the cross-institutional collaboration is intense but necessary. You need NIRSpec expertise, cosmological modelers, data pipeline engineers, and the actual telescope operators all signing off. The z>14 confirmations require such careful calibration that having 36 institutions review your emission line measurements is almost conservative given how easy it is to misidentify a line at these redshifts.
The Cosmic Microwave Background Explorer was a satellite back in the 1990s that measured the Cosmic Microwave Background of the universe. This CMB is the afterimage of the Big Bang, about 400,000 years after the Big Bang when the universe suddenly became transparent to photons- the earliest images of the universe we can possibly capture in light.
And it found that everything was the same no matter where you looked, to about 10 parts per million. So that is the level of variation in the density of the universe about a half-million years after the Big Bang, the differences are measured at the level of parts per million.
And then back in the 1990s the Hubble Space Telesecope took pictures of the previously most luminous galaxy ever recorded, and it was really far back in time, within half a billion years of the Big Bang. And these luminous galaxies were something that we expected to mean that they were built around gigantic supermassive Black Holes. Which means that in a very short amount of time we must have gone from "everything is the same to parts per million" to "here is a gigantic accumulation of mass concentrated in this one spot so densely that all of our models of physics don't work any more."
And so the Webb Space Telescope was built specifically to look for things in between what the Hubble had seen (in Visual Light) and what the COBE had seen (in Microwave), that is Infrared. It is designed to look for these supermassive galaxies that had Red Shifted (1) so far they had left the visual spectrum and gone into Infrared. Figuring out how all of these super luminous galaxies formed is the main question that the whole thing was designed around.
1: As things move away from us, the photons shift to the red end of the spectrum. According to Hubble's Law, things the faster something is moving away from us the earlier it is in time, and the further its photons are shifted to the right: this is why the Cosmic Microwave Background is in microwave, because it has been red shifted so far it has gone into the Microwave part of the spectrum.
It's a galaxy far far away and more importantly very very old. The image is 13.5 B years old, the photons were created just 280 million years after big bang. It's the oldest thing we have seen so far. And it looks mildly different than what we expected to see
In our current understanding of how universe formed galaxies accumulate gradually and it takes time. This one was quite large already, very shortly after the Big Bang, which is at odds with our understanding.
> I assume it's important because we expected nothing and there was something?
I'm still impressed that in my life time, this keeps happening. The best/obvious example is Hubble's original Deep Field. It was a patch of sky assumed to have nothing in it, and most were happy with that answer. To the point, it was a difficult process to get the scope time to aim the very expensive space telescope at nothing essentially just for the lulz. Now that JWST is online, it is constantly getting "for the first time" results.
It's not quite Luis and Clark, but the astronomers using JWST are discovering new parts of the universe that confounds our current expectations.
The engineering behind JWST is wild — we launched a telescope with a sunshield the size of a tennis court, unfolded it a million miles away, and it just works. No service missions like Hubble. You ship it once and hope the math was right.
I’m so fascinated by the fact that we can look back through time by looking at these distant objects. I wish I went into astrophysics instead of engineering…