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…
Truly, only those who think about nothing but (astro)physics can bear it.
I still love thinking about fundamental problems and upcoming research however. That will never be gone.
I used to love engineering but with AI I feel like all the passion (learning things, making brain squeeze) is gone and I’m just managing another resource.
Don’t get me wrong, I like building things. I also like solving challenges and hard problems and I haven’t done that in a few years now.
Note: I like arXiv links anyway, but in this case something about the page was killing my browser, had to reload a few times.
[Angular Diameter Turnaround](https://xkcd.com/2622/)
(Note: the reason to measure in red shift rather than light years is that when this comes up it suddenly gets very important to be very careful about what exactly you even mean by "how far away is that thing?")
So if I understand this correctly, the galaxy above in the paper is at Z=14.4 and that means it appears in the sky about as big as if it were a very small Z or roughly 350 megaparsecs away?
Or have I missed something?
As per your own link:
Solving for z_rec gives value around 1100, which converts to a cosmic time value around 400,000 yearsUnless stunning has a technical meaning I'm unaware of, I like this approach of starting a technical paper with something less dry.
It sounds like JWST found a galaxy where one wasn't expected to be for the time in which it takes light to reach where JWST is?
I assume it's important because we expected nothing and there was something?
But I am just guessing, honestly
For far IR/submillimeter observations we had Herschel in space, SOFIA in the stratosphere (flying on a 747), and several large terrestrial telescopes at very high altitudes can also observe at FIR/submm wavelengths. But sure, there are likely many astronomers who would love nothing more than a new spaceborne FIR telescope, given that it’s been more than a decade since Herschel’s end of mission, and SOFIA was also retired in 2022.
For microwave we’ve had several space telescopes (COBE, then WMAP, then Planck), mainly designed to map the cosmic microwave background. That’s the farthest and reddest that you can see in any EM band, 300,000 years after the big bang.
Past microwave, that’s the domain of radio astronomy, with entirely different technology needed. We have huge radio telescope arrays on the ground – the atmosphere is fairly transparent to radio so there’s no pressing reason to launch radio telescopes to space, and their size would make it completely infeasible anyway, at least until some novel low-mass, self-unfolding antenna technology.
Though not the same thing, you may be interested in https://en.wikipedia.org/wiki/Laser_Interferometer_Space_Ant...
One would need to go to space for that of course.
But you can also use multiple, much smaller antennas to synthesize a narrow beam, and those little antennas are often dishes but can also be very simple and rather small antennas.
The longest wavelengths of light are generally classified as "radio".
So radio telescopes have been tasked to explore the very early universe.
https://en.wikipedia.org/wiki/Reionization
If I understand it correctly, the "Period of Reionization" is first light we can see from processes like stars and galaxies.
There was ionized plasma at the beginning but the universe was like a really thick fog everywhere, and that first light was scattered around and you can't really see stars. As the universe expanded, that fog cooled down, and you could see, but cold matter doesn't emit much light, so there wasn't much to see. It took a while for gas clouds to collapse into the first stars, heating up the gas to ionized plasma once again, so it's re-ionized matter.
The Low Frequency Array, LOFAR, has been used to study this "Cosmic Dawn".
The Square Kilometer Array was designed to explore this era.
But! Not a radio telescope JWST has revealed unexpected, huge globs that seem to be galaxy-sized gas clouds collapsing into (maybe) black hole cores; the thermal emission from the collapse isn't nuclear fusion, so I don't know if those are "stars". But it's very early light.
Honestly, every time a new class of telescope is built, it discovers fundamentally new phenomena.
https://duckduckgo.com/?q=LOFAR+square+kilometer+array+reion...
https://news.ycombinator.com/item?id=44739618
https://news.ycombinator.com/item?id=46938217
I searched "Reionization" and "Cosmic Dawn" plus some favorite telescopes via web and here using the Hacker News search (Agolia).
(Certainly you know the difference between radio and infrared, but I had to look into how those choices of telescope have observed different aspects of Reionization Era, got nerd-sniped, and just had to write it down in a couple of sentences.)
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.
So to 'catch' a certain frequency with a receiver the size of the receiver gets proportionally larger as the frequency drops. Focusing light can be done with relatively small gear. Focusing radio waves, especially when the source is distant requires a massive structure and to keep that structure sufficiently cool and structurally rigid is a major challenge. It is already a challenge for the JWST at the current wavelengths, increasing the wavelength while maintaining the sensitivity would create some fairly massive complications.
In the end this is a matter of funding, and JWST already nearly got axed multiple times due to its expense.