Closest exo planet

sooey said:
Scientists think they've found an Earth sized planet in the habitable zone (where liquid water, and hopefully life, can exist) around the nearest star to the Sun. Proxima Centauri, only four light years away, if we sent a rocket there now it would only take about ten thousand years or so to get there. what are we waiting for? :LOL:
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http://www.extremetech.com/extreme/...will-eventually-power-interplanetary-missions

According to a science programme i was listening to yesterday, if humans ever create a working fusion drive, we will be able to reach 10% of the speed of light.
At a steady 1g of acceleration (which we experience most of the time on earth anyway), we would only have to maintain that acceleration for 34 days to reach that speed. Putting Proxima Centauri a "mere" 40 yrs away.

Interstellar travel might be closer than we think..........
 
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sooey said:
We'd have too make contact with them by carrier pigeon, they wouldn't have got round to inventing anything better yet.
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Wow, the anti-Muslim handful can drag their obsession into even this topic.

Who could have seen that coming?
 
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Brigadier said:
sooey said:
Scientists think they've found an Earth sized planet in the habitable zone (where liquid water, and hopefully life, can exist) around the nearest star to the Sun. Proxima Centauri, only four light years away, if we sent a rocket there now it would only take about ten thousand years or so to get there. what are we waiting for? :LOL:
Click to expand...



http://www.extremetech.com/extreme/...will-eventually-power-interplanetary-missions

According to a science programme i was listening to yesterday, if humans ever create a working fusion drive, we will be able to reach 10% of the speed of light.
At a steady 1g of acceleration (which we experience most of the time on earth anyway), we would only have to maintain that acceleration for 34 days to reach that speed. Putting Proxima Centauri a "mere" 40 yrs away.

Interstellar travel might be closer than we think..........
Click to expand...

But what would people do when they got there? The astronauts would be too old to have children, even if many couples made the journey.
If they had kids on the way, say 10-years out from lift-off, it would condemn those children to half a lifetime in space.
 
That depends on why 'we' went.

If for exploration, then it would be a very long time for a little knowledge.
Possibly could even be overtaken by newer technology.

If for repopulation because of a dying earth, then completely pointless.
It does not matter if we become extinct.
 
tony1851 said:
Brigadier said:
sooey said:
Scientists think they've found an Earth sized planet in the habitable zone (where liquid water, and hopefully life, can exist) around the nearest star to the Sun. Proxima Centauri, only four light years away, if we sent a rocket there now it would only take about ten thousand years or so to get there. what are we waiting for? :LOL:
Click to expand...



http://www.extremetech.com/extreme/...will-eventually-power-interplanetary-missions

According to a science programme i was listening to yesterday, if humans ever create a working fusion drive, we will be able to reach 10% of the speed of light.
At a steady 1g of acceleration (which we experience most of the time on earth anyway), we would only have to maintain that acceleration for 34 days to reach that speed. Putting Proxima Centauri a "mere" 40 yrs away.

Interstellar travel might be closer than we think..........
Click to expand...

But what would people do when they got there? The astronauts would be too old to have children, even if many couples made the journey.
If they had kids on the way, say 10-years out from lift-off, it would condemn those children to half a lifetime in space.
Click to expand...


If we advance science such that we can reach 10% the speed of light, what is the chances of extending the typical human lifespan beyond 120 or 130 years?
 
If the nearest star which might have planets with some life forms on them is 4 light years away, surely it must
be practically impossible for us as a species to visit them?
 
EFLImpudence said:
That depends on why 'we' went.
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EFLImpudence said:
If for exploration, then it would be a very long time for a little knowledge.
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Completely agree.

EFLImpudence said:
Possibly could even be overtaken by newer technology.
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Space tech tends to favour proven reliable technology, over cutting edge stuff, where it can. So, practically (given the current modus operandi of those who do this sort of thing), i think that's unlikely to be the case.

EFLImpudence said:
If for repopulation because of a dying earth, then completely pointless.
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That makes no sense; repopulation of some other planet because our Earth is dying, makes sense.

EFLImpudence said:
It does not matter if we become extinct.
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To who? You? The Earth?
 
Brigadier said:
tony1851 said:
If the nearest star which might have planets with some life forms on them is 4 light years away, surely it must
be practically impossible for us as a species to visit them?
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Currently, yes. But who knows, in the future?
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In my very layman's understanding mass increases with velocity. The faster you go the more massive you become, so the more energy is required to accelerate. Those effects aren't noticeable at the kind of velocities we can achieve, but the closer you get towards the speed of light the more your mass increases, and the more energy is needed to go faster. As I understand it an objects mass becomes infinite at the speed of light and would require infinite energy to accelerate past that limit.
That's why Einstein said nothing can go faster than that. And nothing will get anywhere near it because of the mass increase effect.
But time also slows down for objects moving faster so anyone on a spaceship which could travel at light speed for four years would only experience a journey that passed in the blink of an eye. And when they got back from their journey they would have hardly aged at all while everything else back on earth had aged 8 years.
 
sooey said:
A bit of education for you giant brain.:rolleyes: If there are any stars or galaxies moving away from us at the speed of light we would never be able to see them. Because their light would never be able to reach us.
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That's incorrect, light travels at a fixed constant speed relative to the universe, it's not being dragged along with the Star, it will reach us eventually.
We can see Galaxies almost up to 13.8 billion years ago, the beginning of the universe.
 
I don't claim to be an expert on this but it's right I think, distant objects are moving away from us because of the expansion of space between us and them. The further away they are the more space between us to expand, and the faster they move away. If the space between us is expanding at a fast enough rate the light travelling this way can never reach us, that's why astronomers refer to the ""observable universe". A lot of them say the actual universe is much larger than we can ever observe. There was a guy who used to be on here called spacecat who was great at understanding and explaining this kind of stuff, hasn't been on here for ages though.

Both popular and professional research articles in cosmology often use the term "universe" to mean "observable universe".[citation needed] This can be justified on the grounds that we can never know anything by direct experimentation about any part of the Universe that is causally disconnected from us, although many credible theories require a total universe much larger than the observable universe.[citation needed] No evidence exists to suggest that the boundary of the observable universe constitutes a boundary on the Universe as a whole, nor do any of the mainstream cosmological models propose that the Universe has any physical boundary in the first place, though some models propose it could be finite but unbounded, like a higher-dimensional analogue of the 2D surface of a sphere that is finite in area but has no edge. It is plausible that the galaxies within our observable universe represent only a minuscule fraction of the galaxies in the Universe. According to the theory of cosmic inflation and its founder, Alan Guth, if it is assumed that inflation began about 10−37 seconds after the Big Bang, then with the plausible assumption that the size of the Universe before the inflation occurred was approximately equal to the speed of light times its age, that would suggest that at present the entire universe's size is at least 3x1023 times larger than the size of the observable universe.[18] There are also lower estimates claiming that the entire universe is in excess of 250 times larger than the observable universe[19] and also higher estimates implying that the universe is at least 101010122 times larger than the observable universe[20]
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https://en.wikipedia.org/wiki/Observable_universe
 
From your link, Sorry....

The observable universe consists of the galaxies and other matter that can, in principle, be observed from Earth at the present time because light and other signals from these objects have had time to reach Earth since the beginning of the cosmological expansion.

".....have had time to reach the Earth......"
 
Don't forget when you look at a distant galaxy you see it as it was. i.e. The light you see left it many billions of years ago at a time when it was close enough not to appear to be travelling away faster than light. If the space between us since then has expanded enough for that galaxy to now be travelling away faster than light then there will come a time when that galaxy will fade away and never be seen again by us even though it still exists.
For any galaxies that are far enough away there will never be enough time for their light to reach us and we will never see them.

You might be wondering how we could possibly see a galaxy that is moving away from us faster than the speed of light! The answer is that the motion of the galaxy now has no effect whatsoever on the light that it emitted billions of years ago. The light doesn't care what the galaxy is doing; it just cares about the stretching of space between its current location and us. So we can easily imagine a situation where the galaxy was not moving faster than the speed of light at the moment the light was emitted; therefore, the light was able to "outrun" the expansion of space and move towards us, while the galaxy moved away from us as the universe expanded. Keeping in mind what we learned above -- that farther objects recede faster in a proportionally stretching universe -- we can immediately see that right after the light is emitted, the galaxy is moving away from us faster than the point at which the light is located, and that this disparity will only increase as time goes on and the galaxy and light separate even more. Therefore, we can easily have a situation where the galaxy keeps on moving away faster and faster, eventually reaching or exceeding the speed of light relative to us, while the light which it emitted billions of years ago leisurely coasts on, never having to move across a region of space that was stretching faster than the speed of light, and therefore reaches us eventually.
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