How much longer will life on earth last?

Originally posted by sonhouse
Andromeda colliding with our galaxy won't have much effect on any one solar system since it is mainly the gasses that interact with each other not the stars.

But isn't the collision potentially catastrophic? It seems that one day, the human race (assuming it actually achieves interplanetary travel and successfully colonizes a planet) would have to face leaving the galaxy. As I said, I read that there's a possibility that nothing will happen, because of the massive amount of space in the galaxy, and that Andromeda could pass through. However, it could still be (as far as a know) a monstrous event.

This does bring up one question. How much force would be needed to leave the Milky Way for intergalactic travel? A certain amount of force is needed to leave the earth's orbit, so I'd assume that leaving our galaxy would needed even more force...or am I just completely and hopelessly wrong?

Originally posted by vivify
But isn't the collision potentially catastrophic? It seems that one day, the human race (assuming it actually achieves interplanetary travel and successfully colonizes a planet) would have to face leaving the galaxy. As I said, I read that there's a possibility that nothing will happen, because of the massive amount of space in the galaxy, and that Andromed ...[text shortened]... leaving our galaxy would needed even more force...or am I just completely and hopelessly wrong?

The Andromead galaxy and the Milky way galaxy will collide in some bilions of years from now. Is this really a big problem? I'd say the humanity will go extinct by several different reasons long before that.

Originally posted by vivify
But isn't the collision potentially catastrophic? It seems that one day, the human race (assuming it actually achieves interplanetary travel and successfully colonizes a planet) would have to face leaving the galaxy. As I said, I read that there's a possibility that nothing will happen, because of the massive amount of space in the galaxy, and that Andromed ...[text shortened]... leaving our galaxy would needed even more force...or am I just completely and hopelessly wrong?

Andromeda and the milky way, indeed, all or most galaxies, are mainly empty space. Look at our neighborhood. Nearest star 4 odd light years away. Some 24 TRILLION miles. Them is a lot of miles! You could fit a hundred stars in a line 24 trillion miles and they would STILL be a quarter trillion miles apart.

1000 stars in that space and they would be 24 billion miles apart. If you convert that to a volume, you could put 1 billion stars in a space 4X4X4 light years and they would still be 24 billion miles apart. Even with that many stars in one volume, there would be little chance of a collision. And what we have now is TWO stars in that same volume of space. Probability of Alpha Centauri and Sol colliding, essentially zero. So if and when Andromeda collides with the milky way, it would only double the amount of stars in a given volume, now in our neck of the woods there would be 4 instead of 2. Get the picture?

I think the escape velocity of our galaxy is about 5000 miles per second, a decent fraction of c. Close to 3 % of the speed of light. I imagine we could do that propulsion wise within 1000 years assuming continued growth of science and technology and we don't get sidetracked with stuff like major wars, bad climate change and so forth.

The problem there is even to get to Alpha Centauri at 3% c would take over 150 years.

If the order of the day was to avoid getting clobbered by Andromeda, you would want to go to a galaxy that was way away from ours or And.

So that would mean a trip of say, 10 million odd light years.

Now even if somehow we got a craft to go at the speed of light, you are talking a trip time of 10 million years but at 3% c you are talking about 370 MILLION years, about 1/3 of a BILLION years to get to that galaxy and then suppose you had to go the the far side, say another 100,000 light years where you say, spot a nice habitable planet, you get to travel yet another 4 million years to get from the edge of that galaxy to the other side where your nice juicy planet resides.

So you better have some REALLY good hibernation technology otherwise the entire human race would have gone extinct in 1/3 of a billion years.

To say nothing of a spacecraft capable of self repair for that long a time also.

I suppose anything is possible but it would be more in the line of possibility if mankind came up with a space drive that goes a billion times the speed of light. That would mean a trip of only a couple months. Think about that.

Going one BILLION times the speed of light you still have to be in your spacecraft for MONTHS to get to the nearest galaxy.

Suppose you had to go 50 BILLION light years, a journey of 50 years duration even at one billion times the speed of light.

Originally posted by sonhouse
Andromeda and the milky way, indeed, all or most galaxies, are mainly empty space. Look at our neighborhood. Nearest star 4 odd light years away. Some 24 TRILLION miles. Them is a lot of miles! You could fit a hundred stars in a line 24 trillion miles and they would STILL be a quarter trillion miles apart.

1000 stars in that space and they would be 24 bi ...[text shortened]... LLION light years, a journey of 50 years duration even at one billion times the speed of light.

Excellent feedback. Thank you for this post.

I guess scientists also need to look at ways to exploit wormholes.

Originally posted by vivify
Excellent feedback. Thank you for this post.

I guess scientists also need to look at ways to exploit wormholes.

Well... First we should discover if they actually exist in reality...

😉

Originally posted by sonhouse
Andromeda and the milky way, indeed, all or most galaxies, are mainly empty space. Look at our neighborhood. Nearest star 4 odd light years away. Some 24 TRILLION miles. Them is a lot of miles! You could fit a hundred stars in a line 24 trillion miles and they would STILL be a quarter trillion miles apart.

1000 stars in that space and they would be 24 bi ...[text shortened]... LLION light years, a journey of 50 years duration even at one billion times the speed of light.

I think if mankind manages to travel for millions of years through space, our descendants may not even be particularly interested in "settling down" on a planet. They will no doubt have adapted to life between the stars. There's a lot more to explore there, and exploration comes naturally for us.

About the galaxies passing through each other, even if stars don't likely collide immediately, won't they tug at each other, possibly causing stars to collide as an after effect?

Originally posted by C Hess
They will no doubt have adapted to life between the stars.

I think that would be rather difficult given the lack of sources of energy between the solar systems and matter between the solar systems being rather sparse. It would always be easier to exploit the energy and matter in solar systems than between them so it would be a very strange choice indeed to choose to live in the much less easy place to adapt to of between the solar systems -a bit like choosing to live in the middle of Antarctica when you could choose to live on one of the the more pleasant tropical islands.
If humans traveled for millions of years between the stars (I don't know how likely that would be ), most likely they would first create the technology to go into frozen hibernation so they don't exactly 'live' between the stars but stay dormant until they finally reach their destination. That way, the lack of energy and resources between the stars would be rendered pretty much irrelevant because they wouldn't be needed for life support.

Originally posted by humy
I think that would be rather difficult given the lack of sources of energy between the solar systems and matter between the solar systems being rather sparse. It would always be easier to exploit the energy and matter in solar systems than between them so it would be a very strange choice indeed to choose to live in the much less easy place to adapt to of betwe ...[text shortened]... stars would be rendered pretty much irrelevant because they wouldn't be needed for life support.

So you're saying the same generation of humans that leaves our solar system will be the one waking up so many millions of years later? Who steers the ship and deals with all the unforseens in between?

Originally posted by vivify
But isn't the collision potentially catastrophic?

It may be catastrophic for some stars/planetary systems. We would however probably have plenty of warning and be able to jump between stars or move off in a space ship, or simply keep our spaceship in orbit around the star even if the planets are thrown off. Leaving the galaxy is way way overkill and has no benefits.

Originally posted by C Hess
So you're saying the same generation of humans that leaves our solar system will be the one waking up so many millions of years later? Who steers the ship and deals with all the unforseens in between?

artificial intelligence or at least advanced computers. Surely, by then, they would be much more advanced than they are now with greater intelligence and thousands of times more energy efficiency (probably by using spintronics ) and more reliable and more than up to the job.

Originally posted by humy
most likely they would first create the technology to go into frozen hibernation

I am not sure what the limit is on frozen embryos but its at least 20 years:
http://singularityhub.com/2010/10/14/embryo-frozen-for-20-years-is-now-a-bouncing-baby-boy/

It would certainly be the easiest and safest way to do it.
Send off hundreds of frozen embryos and have them raised by computers at the destination. To some extent that reduces the loss of adult lives should something go wrong in transit.

Originally posted by C Hess
I think if mankind manages to travel for millions of years through space, our descendants may not even be particularly interested in "settling down" on a planet. They will no doubt have adapted to life between the stars. There's a lot more to explore there, and exploration comes naturally for us.

About the galaxies passing through each other, even if stars ...[text shortened]... immediately, won't they tug at each other, possibly causing stars to collide as an after effect?

It would be more likely for that future mankind to have created a drug or some other means to hibernate for millions of years so the same generation that left is the same generation that gets there.

If you just had a permanent living spacecraft with people living in it generation after generation, if the flight was to last, say, 10 million years, well, humans would evolve to something quite different in all that time if they didn't just go extinct on the ship after a few hundred thousand years.

I imagine you would have to have a situation where you could every few thousand years or so, get close enough to a star system to refuel, get materials, repair damages and so forth.

It would probably be more like just information that is sent on such a journey, where the means to create the proper DNA and so forth would be built in to the ship and nothing living is actually on board. Then say, 10 million years later, the ship, being intelligent, sees the destination, starts the process of making the DNA and builds the sperm and eggs and so forth, to start humanity going again, where the first humans decanted in that way would be educated by the computer to foster the next batch of humans. That way no DNA or frozen egg deterioration happens.

Originally posted by twhitehead
I am not sure what the limit is on frozen embryos but its at least 20 years:
http://singularityhub.com/2010/10/14/embryo-frozen-for-20-years-is-now-a-bouncing-baby-boy/

It would certainly be the easiest and safest way to do it.
Send off hundreds of frozen embryos and have them raised by computers at the destination. To some extent that reduces the loss of adult lives should something go wrong in transit.

I was thinking more in terms of genetically modifying whole humans, including adult humans, to make them ready for the frozen hibernation so they can, like the wood frog, simply be frozen solid and then be revived just by thawing. That kind of GM, of course, is still a long time off. Perhaps ~200 years time?

Alternatively, to reduce both the mass and volume of the payload, just the human brains could be so genetically modified and then frozen and then cut out, discarding the body. Then only the frozen brains are transported and are given new bodies once they reach their destination. That kind of GM, I assume, would be even more a long time off. Perhaps ~400 years time?

Originally posted by humy
I was thinking more in terms of genetically modifying humans, including adult humans, to make them ready for the frozen hibernation so they can, like the wood frog, simply be frozen solid and then be revived just by thawing. This, of course, is still a long time off. Perhaps ~200 years time?

It will probably never happen. For a start, its not just the human that needs to survive but all the bacteria etc inside him/her.
I doubt that even wood frogs can remain frozen indefinitely. There must be some decay over time. Hundreds to a few thousand years is probably feasible, but probably not much more than that.
Of course humans will have evolved considerably long before we are ready for interstellar travel, and technology will have progressed too.
Maybe it is only the brain that needs to be sent and the rest of the body will be robotic anyway. Maybe the brain can be downloaded to a computer? So many possibilities.

Originally posted by sonhouse

It would probably be more like just information that is sent on such a journey, where the means to create the proper DNA and so forth would be built in to the ship and nothing living is actually on board. Then say, 10 million years later, the ship, being intelligent, sees the destination, starts the process of making the DNA and builds the sperm and eggs ...[text shortened]... omputer to foster the next batch of humans. That way no DNA or frozen egg deterioration happens.

Okay, but, for the sake of humanity we better "forget" to download the Bible, Koran, Talmud, and other religious texts onto the ship's hard drive, eh?