Interstellar travel
Discussion
I came across this Royal Institute lecture the other day on interstellar travel
https://youtu.be/R3Igzfte8Pc?si=8wiDtcTI8FUoNOFr
It only deals with the propulsion problems as the person giving the lecture works for NASA on solar sails.
What was interesting to me is having set out the (almost overwhelming) size of the engineering (and temporal) problems involved in getting to next nearest star (after the Sun), he was still optimistic it would happen.
The distances involved are hard to grasp. For most of us the fastest we have traveled is around 1000 kmh in a passenger jet. However at that speed it would take 4.5 million years to reach Alpha Centuri.
This will never happen. The US spent a fortune and ten years to get to the moon. Just getting a probe to Alpha Centuri would be orders of magnitude more difficult and more expensive and even in the best case it would be centuries or millennia to know if it had worked. Politicians struggle to think long term when long term is more than the next election cycle. Who would pitch something like: we are going to spend 10% of global GDP on a project that will take decades or centuries, has no pay back beyond intellectual curiosity and you and everyone you know will be dead when or if it works. Good luck with that.
https://youtu.be/R3Igzfte8Pc?si=8wiDtcTI8FUoNOFr
It only deals with the propulsion problems as the person giving the lecture works for NASA on solar sails.
What was interesting to me is having set out the (almost overwhelming) size of the engineering (and temporal) problems involved in getting to next nearest star (after the Sun), he was still optimistic it would happen.
The distances involved are hard to grasp. For most of us the fastest we have traveled is around 1000 kmh in a passenger jet. However at that speed it would take 4.5 million years to reach Alpha Centuri.
This will never happen. The US spent a fortune and ten years to get to the moon. Just getting a probe to Alpha Centuri would be orders of magnitude more difficult and more expensive and even in the best case it would be centuries or millennia to know if it had worked. Politicians struggle to think long term when long term is more than the next election cycle. Who would pitch something like: we are going to spend 10% of global GDP on a project that will take decades or centuries, has no pay back beyond intellectual curiosity and you and everyone you know will be dead when or if it works. Good luck with that.
LunarOne said:
Even if we could travel at light speed, Alpha Centauri is still nearly 4.5 years away. The only way we could keep humans alive for that long would be to have them comatose and fed intravenously and when they got to the other end their muscles and bones would have wasted away to the point where they would never be able to survive in the gravity of any sort of planet. At more realistic speeds, it would take centuries to get there. Human interstellar space travel is never going to happen until we figure out replicators, artificial gravity, particle deflectors, shields and warp drive. Basically we need most of the fictional tech in Star Trek to be able to go anywhere outside our solar system.
The only way around this is by finding a way to download our consciousness into a robotic body which can survive for decades with few resources.
If you could get close to light speed then it wouldn’t take 4.5 years for the occupants of the ship owing to time dilation. Unfortunately getting close to light speed not realistic.The only way around this is by finding a way to download our consciousness into a robotic body which can survive for decades with few resources.
thegreenhell said:
I don't think it will ever happen with any sort of propulsion we can conceive of currently for the reasons others have stated. The distances are simply too great at even a meaningful fraction of light speed for a human lifetime.
It's going to take a literal quantum leap into warp drives or worm holes, or something equally far out of our current, even theoretical, capabilities.
I watched another RI video last night on the topic of black holes, worm holes and warp drives. Unfortunately conclusion was that the latter two are more fantasy than science - fun to look into but not something observed to exist and reliant on “exotic” materials ie ones with negative energy (which have never been observed and not consistent with our current understanding of the universe). It's going to take a literal quantum leap into warp drives or worm holes, or something equally far out of our current, even theoretical, capabilities.
I think what is a bit depressing but needs to be kept in mind is that despite our knowledge of science and technological abilities having advanced massively since the 1960s, our space faring abilities haven’t really moved on and even with today’s technology it wouldn’t be much easier to put people back on the moon.
Eric Mc said:
deckster said:
Mr Whippy said:
I was considering the other day the cost of just making a huge hill so you can basically traverse “along the ground” to about 100,000ft or 200,000ft, or wherever it gets a bit tricky.
Once you can get stuff up there super cheaply (assuming you ignore initial cost), and bring stuff back down, it’d seem pretty easy to start building some big equipment for getting out and about.
This is, broadly speaking, the thinking behind the Space Elevator, as popularised by Arthur C. Clarke. But whilst the concept is sound, the engineering remains way beyond us. But it's a good idea.Once you can get stuff up there super cheaply (assuming you ignore initial cost), and bring stuff back down, it’d seem pretty easy to start building some big equipment for getting out and about.
Apart from inventing new materials which can withstand the enormous dynamic forces acting on the cables, there are also issues around heat loads and electromagnetic effects as well. It's a very, very difficult thing to do in reality.
I nice idea to chat about over a pint (like most of the other stuff about warp drives) but hardly serious engineering
Mr Whippy said:
Artificial gravity seems an easy fix if you just spin your occupants around?!
On travelling interstellar, I’m sure when the time comes we’ll have no need to for the reasons we think we do now, and to travel there will be like travelling to the local shop on foot… a case of opening and closing a few doors.
The biggie is getting out into our solar system in the short term while we’re undeveloped enough to need it’s resources and safety (eggs not all in one basket)
I was considering the other day the cost of just making a huge hill so you can basically traverse “along the ground” to about 100,000ft or 200,000ft, or wherever it gets a bit tricky.
Once you can get stuff up there super cheaply (assuming you ignore initial cost), and bring stuff back down, it’d seem pretty easy to start building some big equipment for getting out and about.
Also lots of scope for a geostationary ring full of solar panels and stuff to variably shade the Earth and provide energy.
I assume someone has done some quick scribbles on this already?
Ie. Will the plate you build it on just sink/split apart under the weight?
Assuming your “hill” has a pyramid shape, even if you had a steep angle of 45 degrees, a hill of 65,000 m (proper unit equivalent of 200,000 ft) then the base of the pyramid would be a square 65,000 m x 65,000 m with a volume of 13,672 cubic kilometres. For reference Mount Everest is about one cubic kilometre…On travelling interstellar, I’m sure when the time comes we’ll have no need to for the reasons we think we do now, and to travel there will be like travelling to the local shop on foot… a case of opening and closing a few doors.
The biggie is getting out into our solar system in the short term while we’re undeveloped enough to need it’s resources and safety (eggs not all in one basket)
I was considering the other day the cost of just making a huge hill so you can basically traverse “along the ground” to about 100,000ft or 200,000ft, or wherever it gets a bit tricky.
Once you can get stuff up there super cheaply (assuming you ignore initial cost), and bring stuff back down, it’d seem pretty easy to start building some big equipment for getting out and about.
Also lots of scope for a geostationary ring full of solar panels and stuff to variably shade the Earth and provide energy.
I assume someone has done some quick scribbles on this already?
Ie. Will the plate you build it on just sink/split apart under the weight?
Whoozit said:
Mr Whippy said:
It’s still a bit 2D trying to understand 3D here isn’t it?
I suppose we need aliens that are very advanced but are constrained by lots of physical things that we find ourselves constrained by.
[snip]
I think we’re pretty much going to be alone until we evolve to not see the universe the way we do.
And when we can see it all for what it truly is, we will realise we don’t need to travel around it in machines… we’ll just travel around it in our minds… peeking in at stuff from our extra dimensions of perspective.
Ah well yes. God mode. Somewhat of a cheat code answer to this thread, don't you think I suppose we need aliens that are very advanced but are constrained by lots of physical things that we find ourselves constrained by.
[snip]
I think we’re pretty much going to be alone until we evolve to not see the universe the way we do.
And when we can see it all for what it truly is, we will realise we don’t need to travel around it in machines… we’ll just travel around it in our minds… peeking in at stuff from our extra dimensions of perspective.
Talk or warp drives and folding space seem to me not much different than saying you will invent magic and then create a spell to teleport yourself anywhere in the universe.
glazbagun said:
Skeptisk said:
Whoozit said:
Mr Whippy said:
It’s still a bit 2D trying to understand 3D here isn’t it?
I suppose we need aliens that are very advanced but are constrained by lots of physical things that we find ourselves constrained by.
[snip]
I think we’re pretty much going to be alone until we evolve to not see the universe the way we do.
And when we can see it all for what it truly is, we will realise we don’t need to travel around it in machines… we’ll just travel around it in our minds… peeking in at stuff from our extra dimensions of perspective.
Ah well yes. God mode. Somewhat of a cheat code answer to this thread, don't you think I suppose we need aliens that are very advanced but are constrained by lots of physical things that we find ourselves constrained by.
[snip]
I think we’re pretty much going to be alone until we evolve to not see the universe the way we do.
And when we can see it all for what it truly is, we will realise we don’t need to travel around it in machines… we’ll just travel around it in our minds… peeking in at stuff from our extra dimensions of perspective.
Talk or warp drives and folding space seem to me not much different than saying you will invent magic and then create a spell to teleport yourself anywhere in the universe.
Before the enlightenment and the development of science lots of people believed in magic and so there was magic - surely not all the witches burnt were innocent!
To allow us to use magic to get to the stars we just need to make people believe again. I’m sure my grant application of £10 million to get people to believe is cheap compared to NASA…
Eric Mc said:
Unless affected by a gravity field in which case it will follow a curve. In fact, genuine straight line trajectories are rare.
And of course, if you're David Beckham (or Rivelinho if you are old enough to remember him).
I think that under general relativity the ball is following a straight line (geodesic?) and it is us who are following a curve as the surface of the earth is accelerating us from the path we would travel in spacetime.And of course, if you're David Beckham (or Rivelinho if you are old enough to remember him).
Sending people is a non starter. How would you keep them warm, feed them and provide electricity to power all functions on a spacecraft? People survive on space stations because of solar power and occasionally supplies from earth. There is no energy source in the deep space between solar systems so you would have to send an energy source with them. Either you would need to send all the food or have enough extra space and equipment to somehow grow it all. All that extra mass would make it more difficult to accelerate and decelerate.
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