I have a feeling that this headline will keep repeating itself as more imagery comes in and keeps getting analyzed. The first thing found from Webb that was further than Hubble gets "most distant ever seen", then the next thing from Webb that was further will get "most distant ever seen". We need to just have "most distant ever seen, yet" edit to them all
Eventually, there will be a telescope to be the last to set the record for the most distant galaxy observed, because cosmic expansion will make it impossible to observe things so distant. I sometimes like to imagine what it will be like in the far future when you can only observe things a billion ly away, or a few million.
I think it will take us a long time to map the entire “surface” of the visible sphere. Eventually, telescopes will be able to pick up some of the farthest galaxies, but there will always be one which might be a bit farther away, even if it won’t be orders of magnitude farther.
The expansion of the universe is accelerating. At some point, the number of galaxies in the visible universe will stop growing and the light received from distant galaxies will grow more and more redshifted. However, it's possible that the redshifting will accelerate faster than our technological ability to detect more and more redshifted light.
I think we can fight back against this to some extent. The most distant galaxies are fading due to increasing redshift. If we build larger and larger radio telescopes then we should be able to continue seeing them at longer wavelengths. If in a billion years we manage to colonize a substantial chunk of our galaxy then maybe we could build a gigantic radio telescope out of many small collectors spread out over several light years.
The universe is likely infinite. The part we can observe is finite, and growing smaller.
Outside of our observable universe is probably just more universe. We're stuck in a bubble within that universe due to the speed of light and cosmic expansion. The expansion of the universe is accelerating and that expansion continually pushes more of the universe outside of our local bubble. Relative to our reference point, some parts of the universe are moving away faster than the speed of light.
Supposing you had some sort of mechanism to travel across the entire universe, when you get to what we on Earth would see as the 'edge' of the observable universe, you could see past the boundary to another section of the universe as big as this one. If you could communicate back to earth, you'd effectively increase the size of our observable universe by half.
But while we're still trapped by the speed of light, we can never see beyond the edge of the universe. An edge which grows closer and closer, faster and faster with every passing second.
No matter how big your sensor is, you can't detect photons that don't exist. Once an object passes beyond the boundary of our observable universe, it effectively ceases to exist for us. No photon from that object will ever reach us again.
There may be other cool tricks that we haven't thought of too. No reason that we need to make things bigger and colonize the galaxy if we figure out something neat that is smaller instead! eg: Maybe we figure out that we can accelerate small telescopes to some significant fraction of the speed of light for an observation. Or perhaps we find some other neat physical phenomena to manipulate incoming light.
The cool thing about scientific and engineering progress is that we can't know what we will discover and develop. 200 years ago, we started having electric lamps. In just 100 years time, we have gone from computers being fringe and folly to them being integrated into places they don't even need to be for sheer convenience. Assuming humanity makes it another 100 years and continues to advance technologically, things we only dream of today could easily be so common-place that people can't imagine living in the current dark-ages of technology.
Also, 100 years is a cosmic blip! If we are thinking ahead to the point where we can't see things in the universe that we can see today, humanity itself will likely not be recognizable from our current vantage point... assuming it exists at all.
Based on today a knowledge of the universe, even if humans colonize the entire universe, you would eventually lose contact with humans in certain areas and therefore their knowledge.
I felt like humans were doomed after watching it, despite the vast scales discussed.
Nothing in the universe can travel faster than the speed of light (we think), but the universe can expand faster than the speed of light. There are probably already objects we can't see and at some point in the far far future we will only be able to see objects in our own galaxy no matter how good our telescopes become.
When I learned that the universe is not constantly expanding/compressing with multiple big bang restarts, I was kind of saddened at the fact it's not. Not sure why, but I liked that idea. Maybe the never endingness about it?? The coldness of everything eventually being so far apart and all stars will eventually burn out and just be a dark place is just meh for an ending. Much more anti-climatic that way
Not everyone says the universe comes to a final end. Hindus and Buddhists believe in cycles, and Abrahamic religions believe in eternal heaven. Even scientists wouldn't all say that the universe conclusively comes to an end. It's one religion of many. You don't have to believe that one!
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As a layman it always amazes me when reading such news that what we see now actually _happened there_ n years ago (in this case: 3.5 billions years ago). Not that it matters, but it is mind boggling nevertheless.
Well, due to the massive gravitational lensing from the intermediate galaxy a few billion years away, I guess it's not actually a perfect 13½ billion light year sphere right... It's a fair chunk of the photons in the 10 billion light year sphere swept up and focused over a vast area and pointed in our direction.
I get the same amazement when I think about an ant I see on a tree five feet away. A photon was born somewhere in the middle of the Sun thousands (or more) years ago. It eventually made its way to the surface and—at extreme improbability—it traveled directly toward Earth. With more extreme improbability, it found itself on an intercept course with a tiny little ant on a tree.
Layer on yet another high improbability, that photon-ant collision just so happened to send it directly toward me. Wait, not just me, but the tiny little pupil in one of my eyes!
Tremendously large numbers and crazy minuscule fractions can be found in your backyard. Don't even need to leave the Solar System.
Well, it's a good point no? If the universe is expanding as the photons propagate they are spread out into that larger sphere. So for the purposes of light gathering, a galaxy 13 billion years in the past has its photons spread over that much larger sphere into even greater invisibility. Although I guess in this case they were spread out into the larger sphere at the point of the expansion of the universe of a few billion years ago before being focused towards us - so. Some value significantly smaller than 46 but a lot larger than 10. Which makes it even more amazing to think about.
I just ate a bunch of food. I am now more massive. So I have stretched space around me a bit more than I did before I ate. You just need to make an instrument sensitive enough to detect it.
But still - it unveils the "present" to just as well be an illusion of human categorical thinking, an abstract concept, not more. It is super useful to have none the less, just interesting to know its fragility.
Should we ultimately be able to develop relativistic rockets, and it seems there is no inherent reason why we shouldn't, then everything is just going to be so unbelievably weird. Traveling on a rocket to friendly distant planet, except the planet you land on may be millions of years in the future from when it was first settled. Or imagine living on said planets and occasionally seeing relics thousands, millions, or even further back in history approaching for landing.
Time, life, death, technology, and everything will be just so unimaginably alien. It will be basically impossible to have a normal linear view of time when it's violated constantly, even though your body itself will yet still almost certainly be insistent on linear time - and steadily marching towards its expiration date. Even evolution itself will be weird. Humans over millions of years will probably scarcely resemble ourselves today, yet you'll regularly have 'old' species humans regularly reintegrating with 'new' ones?
Such a bizarre reality we live in, unless perhaps somehow the views we have today end up being as quaint as those of times past.
Maybe it will be a quaint, and ultimately solved, problem in that time but if the present is any indication, I can’t imagine how old and new might interact.
We already have enough problems with conflicts arising between people born in either side of an imaginary line. How will that work with humans born in different eons?
>It will be basically impossible to have a normal linear view of time when it's violated constantly, even though your body itself will yet still almost certainly be insistent on linear time - and steadily marching towards its expiration date.
Why do you think humans will stage undergo the aging process at that time? With that level of technology, the idea that humans won't have cured the disease we call "aging" seems absurd.
>Even evolution itself will be weird. Humans over millions of years will probably scarcely resemble ourselves today, yet you'll regularly have 'old' species humans regularly reintegrating with 'new' ones?
Humans haven't been evolving due to natural selection for thousands of years. Any changes in humans in the future will be due to genetic engineering.
Every single thing in this universe dies, even stars. Every single thing we're made of dies, and breaks down. I see no reason to think aging and death will ever stop, for anything. And to reject natural selection, especially at a time like now, is something I find even more odd. Natural selection basically comes down to the truism that traits which are productive for fertility tend to become more dominant in the following generations.
Natural selection doesn't require you to be out in the wild fighting against the elements, it's no different than what's happening socially at an extreme level today. Certain groups have certain characteristics driving them to have large families. Others lack those characteristics. Whatever these characteristics may be, they're going to be far more dominant in the generations that follow ours. It's evolution.
You're making a couple of extremely common misconceptions here. Look more into 'biological immortality' and you'll find the examples range from plainly false, to controversial and almost certainly false. For instance lobsters are one of the most typically cited (largely because the other stuff is microscopic), but it's about as true the old 'humans only use 10% of our brains' stuff:
"Lobsters grow by moulting which requires considerable energy, and the larger the shell the more energy is required.[28] Eventually, the lobster will die from exhaustion during a moult. Older lobsters are also known to stop moulting, which means that the shell will eventually become damaged, infected, or fall apart and they die.[29] The European lobster has an average life span of 31 years for males and 54 years for females." [1]
As for evolution, we all learn about Darwin's finches, and so people think of it in terms of things like a bird gradually evolving a more adaptive beak for what's available on an island. But natural selection and evolution is not about evolving your body to fit your environment, unless that would provide a benefit to fertility. If there was endless food on the Galapagos islands for said finches, then said beak would provide 0 fertility benefit and would not, in any way, be evolutionarily selected for.
The reason we, as a species, exist today is because higher intelligence enabled higher successful fertility rates. It's not because intelligence is inherently better. So, for instance, if it turns out that lower intelligence, in modern times, is more productive for fertility when we as a species will gradually become less intelligent. All evolution cares about is fertility, and whatever it takes to achieve it.
There are other species that are effectively immortal. And those are natural things: with artificial treatments, it's certain that biological immortality could be achieved. Stars can be immortal too, if you make changes in them to replace their fuel, for instance.
Why do detractors always think that biological immortality shouldn't require some kind of external treatments occasionally, and then argue from that assumption? Most people don't expect their car to work forever without new fuel, maintenance, repairs, etc.
Because the evidence completely rejects biological immortality for anything vaguely resembling 'advanced' life (in so much as a lobster is 'advanced'). As the snippet above mentions, even with interventions lobsters would eventually die. Older lobsters not only expend more energy moulting, but eventually cease the process altogether resulting in their inevitable death.
So you're left with a mish-mash primarily of weird little microscopic asexually reproducing creatures, that have essentially nothing in common with advanced lifeforms. And as more evidence on these species is collected, it invariably trends towards the rejection of biological immortality rather than the confirmation of such. For instance the hydra once thought ageless, has been shown to decrease asexual reproduction as it ages - clearly demonstrating an active and detrimental aging process.
The entire field is even more dysfunctional with the obsession on telomere length, even though we know that telomere length is correlated with aging, and not causal. Lobsters are an example, as they actively regenerate their telomeres, yet age and die. As are mice - where telomere lengths remain roughly the same as they age, and die.
Nobody wants to die, and so it creates a strong motivation for us to set aside our logic and rationale, and imagine we might live forever. I simply refuse to do that. I believe it will lead to a happier and healthier life for myself than for a man like Ray Kurzweil who will certainly die in the coming years, after spending a lifetime trying to convince himself he could live forever, using logic he could trivially refute in 5 minutes if he actually wanted to.
The idea that it's physically impossible is simply ridiculous, and a religious belief. We're able to effectively be immortal now, simply because of reproduction: cell lines continue forever, just not in the same organism. Can we achieve this anytime soon? Perhaps not. But to say it's impossible is silly, it's like saying you can't transmute elements (like lead to gold), when it's been done countless times in stars. Of course, there's a way, but it might involve very advanced tech like nanomachines and genetic engineering.
Are you sure you're not projecting there? The idea we might live forever turns technological development into a path that might one day lead to 'salvation.' And, most tellingly, that day of salvation invariably tends to lie just within one's life expectancy, again as with Ray Kurzweil - though there are endless other examples. By appealing to advanced tech you can convince yourself anything is possible, when that's obviously not the case.
I think this was an issue, even in the distant past. The Fountain of Youth would have been being 'thought up' about the time mankind was discovering all sorts of strange wonders in the world, like what happens if one chews on the bark of the willow tree. You will feel a bit odd, but all of your pain and discomfort will just magically fade. Of course that is where Aspirin comes from. And similarly for all other sorts of other seemingly magical discoveries. In this context it's easy to convince oneself that even the waters of immortality are just one more discovery away, but really there's no reason to really think it was, or is.
The "waters of immortality" are certainly more than just one discovery away; they won't be easy or simple at all, because they require re-engineering human biology.
However, the idea that aging is somehow necessary is purely a religious belief. There's absolutely no physics-based reason why it has to be this way.
> Should we ultimately be able to develop relativistic rockets
Aren't all rockets relativistic? In the sense that "there's no inherent reason", I take it to mean "near to c", for some value of "near". that is, it's a "relative" term.
Contrary to what many people think, the speed of light isn't like a speed limit. Imagine you're on a ship with near infinite fuel. And there's a button that each time you press will generate enough thrust to gain 1km/s of velocity. It's not like the 300,001st time you press that button (with the speed of light being around 300k km/s), it just won't work anymore somehow, nor will it require any more thrust than the 50th press required. No you'll keep accelerating, to no limit.
What relativity does is change things in a way relative to who's observing. From your perspective distances would begin to physically contract, time everywhere else would begin to accelerate, and things would probably start looking a bit odd. But you could keep hitting that button to your heart's content, and continue going faster and faster.
By contrast for a relatively at rest observer, looking at you, they would see your relativistic mass start to approach infinity as you approached the speed of light. And so they would see you slowing down (as accelerating an infinite mass object would be impossible), and the movement of time for you (relative to them) would begin to slow dramatically, hence why time for them (relative to you) seems to accelerate dramatically.
The calculations for relativistic rockets are quite remarkable [1], because it's an exponential system. For instance, here are some times it'd take you to travel to various points in a typical relativistic rocket that continues to accelerate at 1g (you go half way to a target at 1g, and then half way in reverse):
- Proxima Centauri - 4.3 light years away - 3.6 "real" years of travel
- Vega - 27 light years away - 6.6 "real" years of travel
- Center of our galaxy - 30,000 light years away - 20 "real" years of travel
- Andromeda Galaxy - 2,000,000 light years away - 28 "real" years of travel
With a relativistic rocket, if you wanted to see what the end of the universe looked like in a single human lifetime, you could. It's really really weird. So basically a relativistic rocket is more about creating a rocket that can just keep accelerating for years at a time, rather than reaching any specific speed. They're certainly similar in effect, but framing it in terms of years of acceleration makes it a pretty well defined problem.
But if information can only travel at the speed of light shouldn’t we consider the events being observed way out there as “now”? For all intents and purposes information couldn’t have gotten here any sooner so it might as well be “now”.
Yes, “surface of simultaneity”, but you have to keep in mind that it's inherently relative: your “now” at best only approximately corresponds to anyone elses, and is a weird cross-section of history and future for _most_ reference frames.
What I can't get my head around is that the Milky Way either formed around the same time, 13 billion years ago, or it formed from stuff produced by galaxies that did. But we can't see the primordial Milky Way by pointing our telescopes at z=13. These old, faraway galaxies must have been formed just faraway enough from where our galaxy formed, that the expansion of spacetime has prevented their light from reaching us until "just now".
So I wonder what distances apart the places where the primoridal Milky Way, and these two distant galaxies, must have been for the light to take so long to reach us. Like, the Universe was a lot smaller then; galaxies were much closer together.
Galaxies at z=13 must have formed shortly after the Dark Age ended, and the Universe became transparent - like a few tens of millions of years - less than the time since the dinosaurs were knocked out (I'm assuming galaxies can't form in a plasma Universe, but maybe I'm wrong).
When I saw this I thought it was a "water is wet" type story, because this telescope is supposed to see further than all the other ones we've made. The gravitational lensing aspect of it makes it cool though.
