Life Beyond Earth --New Possible Habitable Planets!

[dawp]

I used to get car sick all the time when I was a kid, there are still some carnival rides I still get sick on and I'm 50.

 

[Moonbeam]

The fact that we have races proves that evolution has continued in recent (geological) history. I expect it to continue and see no reason to believe otherwise.

Surely the next clearest example is sitting at a desk all day. That WILL force an evolutionary change, but you may not see it in your lifetime.

You mean like having butts shaped like the mold of chairs?

I don't think you quite have the concept of evolution down properly. Change is a natural consequence of having a genetic code that is subject to mutation. Sitting in a chair doesn't create mutations. Some folk may be better suited to sit in chairs than others but unless there is a selective pressure that favors them over those less so, no evolution in the direction of chair sitting facility will take place.

Also, humanity is all one race and have very little in the way of genetic diversity. We are more genetically identical to chimps than the varieties of rats that are found in the same species.

 

[Hayabusa Rider]

The fact that we have races proves that evolution has continued in recent (geological) history. I expect it to continue and see no reason to believe otherwise.

Surely the next clearest example is sitting at a desk all day. That WILL force an evolutionary change, but you may not see it in your lifetime.

There's a Star Trek NG view of evolution where there's a belief that it's a mechanism for improvement. It is, but only if improvement is defined as becoming maximally efficient to survive to breed. It's more about thermodynamics than intelligence. If an organism which is less intelligent but has more offspring it's genes dominate. What this means is if stamina and strength are not as crucial they will go. If relying on computers means thinking less then that quality will diminish.

 

[Emos]

I think the same could happen for space travel. The breakthrough could be in an area we can't even conceive of. Maybe we'll never be able to travel very fast, but we'll be able to store our minds in a computer system and build ourselves new bodies when we arrive. Who knows?

Actually I wouldn't be shocked if that wouldn't turn out to be a method of manned space travel in the distant future. The hardest portion of current space travel and proposed manned missions to Mars, Europa, ect is protecting our delicate bags of protoplasm against an evironment that is immensly hostile to life. Would be much easier to download our consciences into protected computers and machinery and construct our wetware when we arrive at location. Have no idea how to do that (and the subsequent psychological effects of having your sense of self ripped out of your body) but current scifi has started to explore the subject.

 

[Agent11]

The theory of faster than light travel is sound. Just creating a device that an expand space behind you and contract space in front of you with gravity is a bit tricky. Once we develop that technology, we should be able to travel just about anywhere.

How do you 'expand space'?

 

[smackababy]

How do you 'expand space'?

Gravity. It actually bends space.

 

[SMOGZINN]

If we had the technology a trip that far would be about spreading mankind across the stars, and would be a one way venture most likely.

Not just spreading Humanity across the universe, but across time itself. Consider a war with an alien race, if we can send a group of humans at relativistic speed to a distant star, then they will arrive thousands or even tens of thousands of years later. It would be very hard to kill off a race that spread it self in this manner. It would virtually guarantee survival of the species.

I don't think you quite have the concept of evolution down properly. Change is a natural consequence of having a genetic code that is subject to mutation. Sitting in a chair doesn't create mutations. Some folk may be better suited to sit in chairs than others but unless there is a selective pressure that favors them over those less so, no evolution in the direction of chair sitting facility will take place.

There are selective pressures for and against chair sitters. They tend to grow fatter, which might limit their breeding possibilities. These are evolutionary pressures that enough time could cause major changes to our species.

The theory of faster than light travel is sound. Just creating a device that an expand space behind you and contract space in front of you with gravity is a bit tricky. Once we develop that technology, we should be able to travel just about anywhere.

It is not just about finding a way to get round the speed of light. You need a massive energy source that would dwarf even the output of a star. It just does not seem likely that a power source of that magnitude is even possible.

It might very well be that the answer to Fermi's famous paradox is that all the aliens are sitting on their home worlds looking out at all the unreachable stars while their own natural resources dwindle until their civilization eventually falls back into a stone age where it remains until an extinction event comes along to kill them off.

 

[smackababy]

It is not just about finding a way to get round the speed of light. You need a massive energy source that would dwarf even the output of a star. It just does not seem likely that a power source of that magnitude is even possible.

It might very well be that the answer to Fermi's famous paradox is that all the aliens are sitting on their home worlds looking out at all the unreachable stars while their own natural resources dwindle until their civilization eventually falls back into a stone age where it remains until an extinction event comes along to kill them off.

It is not about accelerating to the speed of light. IIRC the amount of energy required to achieve the speed of light increases exponentially and achieving this would require infinite energy. However, with a "warp drive", you don't need to travel faster than the speed of light to go a greater distance than light travels at the same time. This also would remove the time expansion to a degree. If you could reach half the speed of light and compress space half the distance, we could reach it a destination at the same time as light would.

Now, how to achieve this seems to be immense gravity, like that of a star. The sun bends space around it, which is evident because light bends around the sun. That is a particularly tricky device to build.

 

[DrPizza]

http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html

At a constant 1g you would be surprised how fast we could get moving.

On earth a long time would pass, but for the people traveling near the speed of light much less would be experienced.

That's a great page, I've been there before. To put it in terms of technology that we don't quite have yet (and no guarantees we'll have it), let's look at fusion for the source of energy. The mass of fuel is based on 100% efficiency, which is physically impossible in the first place (Damn you, Entropy!) We know that fusion >>> fission when it comes to energy density. But, in fusion, what percentage of the mass is actually converted to energy (E=mc²)? The answer is starting: only .61% So, to get to the nearest star, assuming 100% efficiency, you need 38 kg of fuel for every kilogram of payload. The amount of mass of fuel per kilogram of payload becomes absolutely enormous. Keep in mind that the mass of the International Space Station is nearly half a million kilograms - and that keeps only a handful of people alive - people who need to constantly be resupplied with food, etc. Make it large enough to provide food & you're looking at at least triple the size. Until we can bend space, we're not going anywhere beyond our solar system.

For what it's worth, and IIRC from a calculation I did within the past year either here or for a class, the amount of energy required for a 100 year trip to the nearest star is greater than the total amount of nuclear, wind, solar, and fossil fuel energy used by humans on the entire Earth in one year. (I can repeat the calculation later in the thread if someone wants to see it & critique it.)

From what I've read, it would take about 82 years AT LIGHT SPEED to reach the center of the Milky Way, let alone other galaxies!

Yeah, I think the best we could humanly do is watch and wait for another "WOW" signal.

"At" light speed, it would take zero time to reach the center of the Milky Way, in the traveler's frame of reference. However, the traveler would have to be massless, since anything with rest mass cannot accelerate to the speed of light. However, as your percentage of the speed of light gets larger, your time decreases. The 82 year figure could *not* be in the Earth's frame of reference, since it takes light longer to get to the center of the galaxy. We're 26,000 or so light years from the center.

Do you have any idea how many stars are in the milky way? There would be no reason to have to leave our galaxy, except for the fact that andromeda will collide with the milky way in the distant future, but thats a problem so very far in the distant future we may as well not even think about it.

You could cross the milky way in 12 years of experienced time at 1g of constant acceleration.

Even then, there would be little to worry about. The galaxy isn't that dense. It would be like having a dozen blind birds leave Europe toward the US, and a dozen leave the US (from random locations along the coast) headed toward Europe, and worry about the birds colliding with each other somewhere over the Atlantic.

 

[SMOGZINN]

It is not about accelerating to the speed of light. IIRC the amount of energy required to achieve the speed of light increases exponentially and achieving this would require infinite energy. However, with a "warp drive", you don't need to travel faster than the speed of light to go a greater distance than light travels at the same time. This also would remove the time expansion to a degree. If you could reach half the speed of light and compress space half the distance, we could reach it a destination at the same time as light would.

Now, how to achieve this seems to be immense gravity, like that of a star. The sun bends space around it, which is evident because light bends around the sun. That is a particularly tricky device to build.

I understood that, but to bend space in that manner also takes a huge amount of energy. And mattering just what gravity turns out to be it might not be possible at all.

 

[Agent11]

Even then, there would be little to worry about. The galaxy isn't that dense. It would be like having a dozen blind birds leave Europe toward the US, and a dozen leave the US (from random locations along the coast) headed toward Europe, and worry about the birds colliding with each other somewhere over the Atlantic.

If humanity is still around to see it happen I hope we can model how the super massive black holes at the center of the two galaxies will behave during such an event.
That's what I would be concerned about.

If they had more matter falling into them then they could begin to quasar, 2 quasars going off at the same time as they orbit each other wouldn't be something I would want to be anywhere near...Even in a cosmic sense.

 

[Agent11]

Gravity. It actually bends space.

Right, I know of no mechanism for gravity to expand space however.

 

[Kadarin]

As part of my work I've been researching and documenting the evolution of early computers. All of the early digital electronic machines used vacuum tubes, and they were massive. ENIAC weighed 60,000 pounds, took up 1800 square feet and used 150 kW of power. But the machines were improving steadily, so people thought that maybe one day they might be able to get the machines down to, say, 1,000 pounds, so they'd be more practical.

And then came the transistor. And shortly after that, the IC. If you had told the men who designed ENIAC that 50 years later someone would duplicate its capabilities on a device smaller than a fingernail, using 0.00000003% as much energy, and also running 200 times faster, they would have thought you were insane.

Reminds me of this scene from Iron Sky: https://www.youtube.com/watch?v=_wK3LogJvJE

Alternatively, the opening chapter (prologue?) from Peter F. Hamilton's novel Pandora's Star, from the point of view of the commander of the first manned mission to Mars where they landed only to find a couple of graduate students had opened a wormhole to their landing site.

 

[Hayabusa Rider]

Right, I know of no mechanism for gravity to expand space however.

Gravity is confined by space, well probably. This may be what he's talking about though.

Alcubierre drive

The problem is that this technique isn't dependent on just power but there being negative mass, which has a crapload of theoretical problems to even exist. As far as we know it's unobtaniam in the truest sense of the world.

 

[Paratus]

Right, I know of no mechanism for gravity to expand space however.

Inflation theory says this happened right after the Big Bang. In fact space-time appears to be expanding right now. This where the term "dark energy" comes from.

Gravity tends to contract space-time.

So it theoretically and physically possible to both expand and contract space-time.

How we do that is currently the hard part.

 

[Agent11]

Yea i wouldn't hold my breath on that one.

Antimatter annihilation as an energy source would be much simpler to figure out comparatively.

 

[werepossum]

Gravity is confined by space, well probably. This may be what he's talking about though.

Alcubierre drive

The problem is that this technique isn't dependent on just power but there being negative mass, which has a crapload of theoretical problems to even exist. As far as we know it's unobtaniam in the truest sense of the world.

I thought the general consensus today was that dark matter holds negative mass, at least in that it is repelled rather than attracted by gravity, as that is required to explain the universe's expanding acceleration?

 

[Hayabusa Rider]

I thought the general consensus today was that dark matter holds negative mass, at least in that it is repelled rather than attracted by gravity, as that is required to explain the universe's expanding acceleration?

Dark matter weakly interacts with what we consider ordinary matter. It would feel gravity just like any other. You are thinking of dark energy, which is a horse of a different dark color

 

[Retro Rob]

Make it large enough to provide food & you're looking at at least triple the size. Until we can bend space, we're not going anywhere beyond our solar system.

Well, we're close to leaving the Solar System in the sense of a 35-year Voyage which, according to NASA, has about 10 more years of communication left.

Just thinking though, while typing this post: Why would anyone want to leave this planet anyway? All the other "worlds" are hostile to human life, and there's no liquid water anywhere out there (that we've found, anyway) - this is essential and necessary.

I agree with the effort -- space travel helps make new technologies (like Artifical Gravity) and drives innovation here on Earth, but sending a man to Mars for instance, is another story.

 

[Jaskalas]

Why would anyone want to leave this planet anyway?

Not sure if serious...

Limiting ourselves to a single planet is just asking for an extinction level event. Like having all our eggs in one basket, which we literally do.

 

[Retro Rob]

Not sure if serious...

Limiting ourselves to a single planet is just asking for an extinction level event. Like having all our eggs in one basket, which we literally do.

The Earth is fine - humans are the problem.

That being said, I don't think there's a world out there that will not kill us the very second we remove our spacesuits.

 

[Jaskalas]

The Earth is fine - humans are the problem.

That being said, I don't think there's a world out there that will not kill us the very second we remove our spacesuits.

I think the goal is to live in contained environments that we would engineer.

 

[Retro Rob]

I think the goal is to live in contained environments that we would engineer.

Ahhh... like Total Recall (1993)?

 

[Jaskalas]

Ahhh... like Total Recall (1993)?

Yeah. I mean, if the Atmosphere wasn't the right mixture, or the right density... if the temperature was wrong... the sun for that system thew out too many flares / radiation. If the ozone was missing. So many factors go into making Earth just right for us - you're correct in thinking other planets are by and large uninhabitable. If only because our biology demands the specifications of this one.

So to solve that problem, we bring our environment with us. We hide ourselves within it. Which creates a metric ton of new challenges, of having to both manufacture and maintain it.

Alternatively we might bio engineer changes to ourselves to help us survive those environments.

 

[Retro Rob]

Yeah. I mean, if the Atmosphere wasn't the right mixture, or the right density... if the temperature was wrong... the sun for that system thew out too many flares / radiation. If the ozone was missing. So many factors go into making Earth just right for us - you're correct in thinking other planets are by and large uninhabitable. If only because our biology demands the specifications of this one.

So to solve that problem, we bring our environment with us. We hide ourselves within it. Which creates a metric ton of new challenges, of having to both manufacture and maintain it.

Alternatively we might bio engineer changes to ourselves to help us survive those environments.

That sounds good, but I'm sorry... I can't make the connection. There are places on earth that aren't real suitable for long-term human habitation (like Antartica or Siberia because of the extreme cold), so colonizing another planet, likely one further away from the Sun than Earth, doesn't sound very feasible to me, personally.

I cannot even imagine what the situation could be here on Earth thousands of years from now, but I do believe, though as smart as humans are, that we have limitations that can't be overcome -- like transporting our cilvilization as we know it to another planet.. again, to one further away from the Sun. We wouldn't be able to move closer to any star.

The only thing that I can see threatening our survival is us, outside of our Sun eventually making iron billions of years from now and self-destructing.