What life could be like for civilizations 1 trillion years from now • Hacker News Board

Re: What life could be like for civilizations 1 trillion years from now

#61

Post by alf-pogz » Sat, Jun 30, 2018, 2:09 PM UTC

losteric wrote: post #49

alf-pogz wrote: post #46

Earlier quoted context omitted.

I don't get it. I mean this is the premise of many sci-fi stories, but humanity has made pretty steady civilized progress since its inferred inception. There isn't much of a reason to believe this pessimism.

Prior civilizations collapsed after over-exploiting their environment, and we're making the same mistake on a global scale. Our complex supply chains based on fossil fuels are rather fragile - we will likely survive a collapse at reduced quality of a life, however total recovery may be slow or impossible depending on remaining resources.

We can produce more food than ever with less energy. Knowledge transfer is always improving, and with computer programs it will be even easier to transfer knowledge.

You guys need to clarify what "a collapse" is. Not eating as much meat? Do you really think that we would not be able to power our computers or not be able to produce rice/wheat on any industrial scale?

The amount of FUD spread without any foundation for it is maddening.

Re: What life could be like for civilizations 1 trillion years from now

#62

Post by ben_w » Sat, Jun 30, 2018, 2:13 PM UTC

gaius wrote: post #9

montrose wrote: post #6

Earlier quoted context omitted.

How could they be moving faster than the speed of light?

And if they can, why can’t we and catch them? I mean we are in spacetime. If it stretches we stretch too!

Right now the only serious effort to consider how to do so is the Alcubierre metric and its variations. Nobody knows how to build one, or what matrials could build one, or how to turn it on or off. Unless you have a cunning way to cheat, such as making the inside bigger than the outside, it requires in excess of minus the rest mass of the observable universe for a plausible sized object. There are further objections, but above my level.

Re: What life could be like for civilizations 1 trillion years from now

#63

Post by novalis78 » Sat, Jun 30, 2018, 2:14 PM UTC

How would this scenario change, if there was a Big Bounce? And how would we potentially recognize alien civilizations preparing for that? And finally: in order to find out which of the two cosmological models is actually the correct one, we just set up SETI to find signs as to which of those two hyper-engineering projects have been undertaken - by civilizations that are a bit further in their cosmological understanding ;-)

Re: What life could be like for civilizations 1 trillion years from now

#64

Post by Findeton » Sat, Jun 30, 2018, 2:17 PM UTC

chii wrote: post #13

hsk wrote: post #11

Earlier quoted context omitted.

Because while matter cannot move faster than the speed of light the universe itself is allowed to expand faster than the speed of light. Think of the spacetime fabric stretching so fast light cannot cover the increased distance. The universe is essentially creating more distance between objects. Another way to think of it is velocity of an object is derivative of position in space over time. If space itself is moving…

I still can't intuitively understand this. If two objects ar stationary relative to each other, the expansion implies that at some point, the distance between those two objects will increase (without either of those objects having moved). So space is being somehow created?! What if i have a large object, will the length of that object increase? Or will it break up?

I think you are using a concept of space-time that is quite limited. You are at most using concepts from Einstein's Special Relativity. Everything changed with General Relativity.

Space is not "created", space-time is warped. Gravity is the deformation of space-time by mass/energy. The distance from point A to point B is measured by the time it takes for a light ray to get from A to B using the shortest path. But if you move objects with mass (or with energy) near A and B, the shortest path will change. Also, it's easy to measure distance in seconds when you know the speed of light.

Re: What life could be like for civilizations 1 trillion years from now

#65

Post by Findeton » Sat, Jun 30, 2018, 2:18 PM UTC

maxerickson wrote: post #31

criddell wrote: post #21

Earlier quoted context omitted.

So would the light from those stars also be moving outward faster than the speed of light?

No. It's color shifted though. https://en.wikipedia.org/wiki/Relativistic_Doppler_effect

Just like the sound of an ambulance.

Re: What life could be like for civilizations 1 trillion years from now

#66

Post by ben_w » Sat, Jun 30, 2018, 2:18 PM UTC

ekianjo wrote: post #29

oooooof wrote: post #17

Earlier quoted context omitted.

The idea that humanity will ever travel even to the nearest star is pure fiction. Anyone who thinks otherwise just fails to grasp the distances involved. They are so large as to be beyond understanding.

thats pretty accurate as far as current technology goes, but then again with a few additional centuries of research we never know what we end up achieving.

We could just about do interstellar now if an existential threat called for it. Project Orion or a nuclear salt water rocket are both possible already.

Re: What life could be like for civilizations 1 trillion years from now

#67

Post by [deleted] » Sat, Jun 30, 2018, 2:19 PM UTC

nabla9 wrote: post #54

OscarCunningham wrote: post #20

This goes together nicely with the Aestivation Hypothesis ( https://arxiv.org/abs/1705.03394 ). If a civilisation puts itself on hold for a trillion years, just waiting around doing nothing, then when it wakes up the universe is much colder and it can do computations 10^30 times more efficiently. If the civilization consists of minds running on computers then they've increased their own lifespans by the same factor.

The background temperature of the universe now an trillion years from now is not significantly different. It's 2.73 Kelvins today. Even if it goes very close to zero, that's not a big difference.

[deleted]

Re: What life could be like for civilizations 1 trillion years from now

#68

Post by ben_w » Sat, Jun 30, 2018, 2:22 PM UTC

senorjazz wrote: post #59

akie wrote: post #24

Earlier quoted context omitted.

400 years is nothing. I mean, climate change is real and could be very damaging, but what aside from that and war - why do you think we’ll be living amongst ruins? That seems overly pessimistic to me.

Water is already running out in many areas of the world. Rains are failing worldwide. No water = no food. Where millions perhaps billions of people are on the move, societies will break down. Look what is happening on the European and US borders and the hysteria it generates when the migration is but a trickle of what is to come. Yes humanity and technology is moving forward at record speeds, but at what cost to the…

Fresh water is running out. If you have enough cheap energy, desalination solves that problem.

Re: What life could be like for civilizations 1 trillion years from now

#69

Post by OscarCunningham » Sat, Jun 30, 2018, 2:23 PM UTC

oooooof wrote: post #17

wavedingo wrote: post #15

Earlier quoted context omitted.

Due to the big bang the universe is expanding... but you’d expect the expansion to be slowing down due to the drag of gravity. However, since the 1990s we’ve observed that the universe’s expansion is accelerating - the theory is that a force called “dark energy” is causing this acceleration. If the acceleration continues, there will be a point where distant galaxies will be accelerating away from each other at the sp…

The idea that humanity will ever travel even to the nearest star is pure fiction. Anyone who thinks otherwise just fails to grasp the distances involved. They are so large as to be beyond understanding.

The distance to the moon is already beyond intuition, but you can still understand how to get there by doing calculations. If the numbers say that it's possible then it's possible.

Re: What life could be like for civilizations 1 trillion years from now

#70

Post by akvadrako » Sat, Jun 30, 2018, 2:24 PM UTC

tomrod wrote: post #55

By this time in the future I hope we have worked out wormholes.

Highly unlikely. Unless wormholes are setup with strange restrictive configurations they allow sending messages back in time, without needing any new physics.

Once you have a wormhole, if you use gravity to accelerate one of the ends away then bring it back near the other end, they will have a time difference, due to general relativity. If you bring them close enough, that time difference will be greater than it takes to travel between them in normal space, allowing you to travel to your own past.

This video gives a quick explanation of the problem:

https://www.youtube.com/watch?v=sUqxzH0652w&t=186s