Hacker News Reader

Comment by schiffern | Hacker News Reader

> we can't grow exponentially forever!

We can't grow exponentially forever in space either. Somehow this gets forgotten.

  O(N^t) > O(t^3), for all N > 1

Here t^3 is the future light-cone of Earth, ie this assumes [trans]humanity expands at the speed of light and instantly colonizes all matter. This is an optimistic upper bound IMO.

View on HN

Something something heat death of the universe.

I do hope that our civilization starts someday putting substantial research funding into moonshot bets to escape this limiting ending.

For example, if we eventually have multiple star systems' worth of resources at our disposal, then I hope we put at least a trillion dollars per topic into long-shot research topics such as time travel, the multiverse, FTL travel, methods of creating new universes via an artificial Big Bang, applied theology (trying to find evidence of a God so that we can communicate with them), methods of achieving infinitely positive states of qualia such as something like nirvāṇa, and so on.

Each bet might be 1 in a million - but I'd much rather that we try every possible chance at escaping what we currently see as the inevitable, and not go gentle into that heat death night.

This goal, to break through the wall at the end of the universe, was what Asimov called for in his inspiring short story The Last Question.

https://users.ece.cmu.edu/~gamvrosi/thelastq.html

One in a million FTL and time travel?

No, there's not another tree. We just happen to be rather efficient in dissipating free energy.

Keep in mind that anything is possible if the Cosmological Principle turns out to be false, and if we can travel far enough to escape our local zone.

For example, there might turn out to be particle types which don't exist at all in our zone, but which are force carriers for forces that enable time travel or other violations of causality. We might have evolved in a zone with zero of these particles simply because it's hard for life to evolve in a zone without causality. Our zone might be a life-friendly little bubble beyond which things get truly strange, but where with appropriately designed nanotechnology, we might achieve incredible things we've never before observed, including changing the past or even stepping entirely outside of the fabric of spacetime into someplace with more or fewer spatial dimensions.

https://en.wikipedia.org/wiki/Cosmological_principle

So, 1 in a million is my approximate a priori estimate of the odds of the Cosmological Principle being false in a useful way.

For a fun example of fiction that takes place in a setting where the Cosmological Principle is false, check out A Fire Upon the Deep by Vernor Vinge. The zone where Earth is situated, and where the laws of physics are the same as in our observed reality, is called the Slow Zone. There are three other types of zones with other laws, called the Beyond, the Transcend, and the Unthinking Depths.

Science fiction is great and all, but I'd rate this probability more like the inverse of stupid large numbers brought to us by Knuth's up-arrow notation.

Could be! Your estimate is as valid as mine.

I suppose that to approach a topic like this, we can reason in the classical-logic manner of the ancient Greeks and others who sought to understand their universe without yet having the instruments to make necessary observations. What I mean is, without our civilization having seen evidence either way yet, the question of what is a good prior probability is only able to be informed through non-empirical means, such as the philosophy of science (e.g. https://en.wikipedia.org/wiki/Sunrise_problem ), philosophy of knowledge (e.g. https://en.wikipedia.org/wiki/Anthropic_principle ), and theology (e.g. https://en.wikipedia.org/wiki/Best_of_all_possible_worlds ).

Another similar topic about which we must reason without having yet made any applicable observations is the question of whether our universe is a simulation. If it is, then it is possible that a sufficiently well-constructed prayer (message to the system administrators) could have causal effects.

Sorry, I can't help but perceive this as intellectual cowardice. "There has to be something that'll make our collective life not as finite and pointless as the evidence we have suggests!".

The two are apples and oranges, by a factor of a billion.

The heat death of the universe is trillions of years off. However even assuming a modest 3% annual growth, humanity runs out of matter in only a few thousand years.

What's nine orders of magnitude between friends? ;)

Reply on news.ycombinator.com