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Comment by yalogin | Hacker News Reader

So the universe is just biding it’s time to die? This is it, no more creation, no more new platforms for biological miracles. Interesting, so while humans figure out how to navigate the universe, many planets/stars would simply die and we will not even know.

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I mean the universe is so incredibly vast that even if we figure out how to travel at the speed of light, we'll only ever get to see a small fraction of it. I don't think we'll have to worry about running out of places to explore.

So, about that. One of the weird things about General Relativity is that if we COULD travel at or near the speed of light, then time dilation and length contraction will conspire to enable a trio to the end of the observable universe in 30 years.

So we could definitely explore the universe, we just have no way to share what we discover with our friends back home.

This is forgetting to account for the accelerating expansion of the universe. Even if one were to depart from Earth today, traveling at light speed, 94% of the observable universe is already impossible to reach. See this excellent video for more detail: https://m.youtube.com/watch?v=uzkD5SeuwzM

Still, the observable universe is only a small fraction of the whole universe (we believe, based on spacetime curvature, I think).

For the timelines we are discussing here, sure there will lots of new discoveries in physics. And who knows may be somebody will toss out what we know today and come up with something new, where none of these limitations we know today apply.

> we'll only ever get to see a small fraction of it

True, but on the other hand, due to relativistic time dilation, a very fast traveller could visit very far away destinations if they get closer and closer to the speed of light.

Remember, this is from our current understanding. 500 years from now, who knows what we’ll discover. Or maybe our whole theory is wrong.

Or the effect of conscious intelligence is so great, we will have to rewrite some of the laws of cosmology. After all, when a human being with a death star can simply change the angle of the beam to destroy one planet instead of another, clearly the impetus is that weakly energetic states (state of the brain) are extremely potent in the evolution of the universe. Normally we think that the magnitude of energy is what matters. However, when it comes to conscious entities, it is the structure that matters. Kinda throws a wrench in just using total energy as a measure of the effect that an object can cause. Brains use hardly any energy and yet cause absurdly strong effects that we still don't know the full extent of.

One peculiarity about quantum mechanics is that even the lowest energy particles still require the universe to compute their paths and wavefunctions. This has commonly been a target of ways to verify if we are living in a simulation - looking for screen door effects in the interference patterns of extremely low energy particles. The hypothesis was that perhaps the universe attempts to save computation on low energy particles. We did not find any screen door phenomena though. So the current stance is that the universe provides full fidelity wavefunctions to particles independent of the magnitude of their energy. A low energy particle or system can have a wavefunction of seemingly limitless quantum complexity.

Cosmology currently revolves around magnitude of energy, not the butterfly effect or intelligence. Expect this to change as we further our understanding.

Conceptually I have a hard time imagining that the universe could not 'restart' ... otherwise how could it 'start' at all.

The same way the universe could be finite and there be no boundary or outside.

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