> We can only see a finite volume—a finite number of galaxies. That’s essentially because there’s a horizon, a shell around us, delineating the greatest distance from which light can reach us. But that shell has no more physical significance than the circle that delineates your horizon if you’re in the middle of the ocean.
No, that's not true. You can rise above the surface of the ocean. Barring some major unforeseen revolution in our understanding of physics, you cannot transmit information faster than light. The oceans horizon is grounded in a technological limit, but the cosmological horizon is grounded in a fundamental physical limit.
According to current cosmological thought, the laws of physics at that shell are very close to if not identical to the laws of physics here. And yet, that shell is retreating from us faster than the speed of light. The shell is ever expanding, but we shall never see what that current shell will look like when it is 10 billion years.
How can that be, you ask? It is quite simple. The speed of light is a limit on how fast light can travel through the universe. But the universe is expanding. Light trying to get to us is like a bug crawling over an expanding balloon. If the balloon is expanding faster than the bug is crawling, it can crawl forever but never reach the point it is trying to crawl to.
So there is a fundamental epistemological limit - we can't actually know that our current models are correct. But within existing theory, the location of "the farthest we can see" is not particularly meaningful physically.
i don't understand what you are "no, not true"-ing. it's just analogy. you pointed out a flaw if one happens to take the analogy too far, but i don't see the point when the original analogy was clear enough what they are getting at.
>Barring some major unforeseen revolution in our understanding of physics, you cannot transmit information faster than light.
There's been a significant amount of research done in the recent years into quantum entanglement. Although we're not there yet, it wouldn't surprise me if we eventually manage to pass information via entanglement.
> At first sight, the concept of parallel universes might seem too arcane to have any practical impact. But it may (in one of its variants) actually offer the prospect of an entirely new kind of computer: the quantum computer, which can transcend the limits of even the fastest digital processor by, in effect, sharing the computational burden among a near infinity of parallel universes.
I'm far from an expert on quantum computing, but this seems inaccurate to me. There may be an explanation for a quantum computer's operation that invokes parallel universes, but I don't believe that they are actually required for the systems to function. Quantum mechanics is sufficient.
I think the allusion is quantum mechanics -> many worlds interpretation -> quantum computers are executing in parallel universes. But quantum computers get their abilities from the quantum states and quantum operators, neither of which require any particular interpretation of quantum mechanics.
Similarly, by the copernican principle, wouldn't our "local" quantum computer also then be burdened by the work being sent from a near infinity of parallel universes?
> if the universe stretches far enough, everything could happen <
The article says this. Is this an assertion that the number of things that could happen is finite, or is it an assertion that the number of elements in one infinite set is greater than or equal to the number in another infinite set? Which infinity is equal to the number of things that could happen? How many dimensions would the universe need so that the number of things that would happen in it would equal the number of things that could happen in the most inclusive case?
> “The long-term future probably lies with electronic rather than organic ‘life.’”
I guess this is the standard transhumanist position, but it strikes me as both pessimistic and overconfident. Pessimistic because it doesn’t see the life that arose against all odds on this rock as fit for or worthy of continuation on a solar timescale, and overconfident in its implication that we will inevitably create something in our image that will succeed us.
The last question was asked for the first time, half in jest, on May 21, 2061, at a time when humanity first stepped into the light. The question came about as a result of a five dollar bet over highballs, and it happened this way...
What exactly would be "copernican" about it? Also 3 of the 4 "copernican" revolutions outlined have nothing to do with copernics. Even copernicus's "revolution" was just a rehash of ancient greek idea of heliocentrism ( aristarchus of samos ).
Proving our multiverse is one among many will be the fifth Copernican revolution. Proving this sequence of Copernican revolutions is one among many will be the aleph one Copernican revolution.
> if the universe stretches far enough, everything could happen
This means, I presume, that in an alternative universe, children-like creatures are being boiled alive forever with no hope of dying (since they are immortal), there exists creatures being tortured alive forever, although they have evolved to be a million times more sensitive to pain, and a God-like being exists... the possibilities are truly endless.
If other universe contain all logical possibilities, then yes. David Lewis talks about this and points out the moral issue is that even if you choose to do good things in this universe, in some universe your alternate is a psychopathic torturer, so decisions to do good don't actually lessen universal suffering, if calculated across all alternate universes. I think his conclusion was that it's still desirable to locally decrease suffering anyway.
[+] [-] lisper|7 years ago|reply
No, that's not true. You can rise above the surface of the ocean. Barring some major unforeseen revolution in our understanding of physics, you cannot transmit information faster than light. The oceans horizon is grounded in a technological limit, but the cosmological horizon is grounded in a fundamental physical limit.
[+] [-] btilly|7 years ago|reply
How can that be, you ask? It is quite simple. The speed of light is a limit on how fast light can travel through the universe. But the universe is expanding. Light trying to get to us is like a bug crawling over an expanding balloon. If the balloon is expanding faster than the bug is crawling, it can crawl forever but never reach the point it is trying to crawl to.
So there is a fundamental epistemological limit - we can't actually know that our current models are correct. But within existing theory, the location of "the farthest we can see" is not particularly meaningful physically.
[+] [-] empath75|7 years ago|reply
[+] [-] nikofeyn|7 years ago|reply
[+] [-] parliament32|7 years ago|reply
There's been a significant amount of research done in the recent years into quantum entanglement. Although we're not there yet, it wouldn't surprise me if we eventually manage to pass information via entanglement.
[+] [-] excalibur|7 years ago|reply
I'm far from an expert on quantum computing, but this seems inaccurate to me. There may be an explanation for a quantum computer's operation that invokes parallel universes, but I don't believe that they are actually required for the systems to function. Quantum mechanics is sufficient.
[+] [-] jcranmer|7 years ago|reply
[+] [-] jbattle|7 years ago|reply
[+] [-] kgwgk|7 years ago|reply
[+] [-] lucas_membrane|7 years ago|reply
The article says this. Is this an assertion that the number of things that could happen is finite, or is it an assertion that the number of elements in one infinite set is greater than or equal to the number in another infinite set? Which infinity is equal to the number of things that could happen? How many dimensions would the universe need so that the number of things that would happen in it would equal the number of things that could happen in the most inclusive case?
[+] [-] Phrodo_00|7 years ago|reply
[+] [-] mortenjorck|7 years ago|reply
I guess this is the standard transhumanist position, but it strikes me as both pessimistic and overconfident. Pessimistic because it doesn’t see the life that arose against all odds on this rock as fit for or worthy of continuation on a solar timescale, and overconfident in its implication that we will inevitably create something in our image that will succeed us.
[+] [-] unknown|7 years ago|reply
[deleted]
[+] [-] hprotagonist|7 years ago|reply
The last question was asked for the first time, half in jest, on May 21, 2061, at a time when humanity first stepped into the light. The question came about as a result of a five dollar bet over highballs, and it happened this way...
http://www.multivax.com/last_question.html
[+] [-] kurthr|7 years ago|reply
[+] [-] dullroar|7 years ago|reply
[+] [-] qubax|7 years ago|reply
[+] [-] jvanderbot|7 years ago|reply
[+] [-] yters|7 years ago|reply
[+] [-] davesque|7 years ago|reply
[+] [-] marmaduke|7 years ago|reply
[+] [-] prmph|7 years ago|reply
This means, I presume, that in an alternative universe, children-like creatures are being boiled alive forever with no hope of dying (since they are immortal), there exists creatures being tortured alive forever, although they have evolved to be a million times more sensitive to pain, and a God-like being exists... the possibilities are truly endless.
[+] [-] _emacsomancer_|7 years ago|reply