Interstellar travel
Discussion
LimaDelta said:
The fastest human-made object to date travelled at around 157,000mph, which is 0.0002c, so at that speed a journey of 4.2 ly would take 21,000 years.
For context, 21,000 years back in human history, was the first use of pottery, and about the same time this was drawn:
We were literally living in caves. Imagine how much human technology could advance in the next 21,000 years while our little spacecraft makes it's theoretical journey to our nearest neighbour. We would almost certainly catch it up and pass it. We might not even recognise it as being of our own creation.
You're gonna need abigger faster boat.
I think it's infinitely more likely that Humans as a species will be extinct in 21000 years. For context, 21,000 years back in human history, was the first use of pottery, and about the same time this was drawn:
We were literally living in caves. Imagine how much human technology could advance in the next 21,000 years while our little spacecraft makes it's theoretical journey to our nearest neighbour. We would almost certainly catch it up and pass it. We might not even recognise it as being of our own creation.
You're gonna need a
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?
Would be easier to lasso a space rock and install a lift. 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?
Bannock said:
Gonna reveal my utter ignorance of physics here, and I know it's a bit off topic, but as you mentioned it...I always wonder how it is that the matter our planet is made up of got to this point of space, before all that light from the birth of the Universe? Given that nothing can travel faster than light, wouldn't all that light have passed by here long before the matter arrived which would form our planet?
No doubt there's an explanation, and no doubt I won't understand it, but I hope you get the premise of my question?
Does this help?No doubt there's an explanation, and no doubt I won't understand it, but I hope you get the premise of my question?
https://www.skyatnightmagazine.com/space-science/d...
otolith said:
Bannock said:
Gonna reveal my utter ignorance of physics here, and I know it's a bit off topic, but as you mentioned it...I always wonder how it is that the matter our planet is made up of got to this point of space, before all that light from the birth of the Universe? Given that nothing can travel faster than light, wouldn't all that light have passed by here long before the matter arrived which would form our planet?
No doubt there's an explanation, and no doubt I won't understand it, but I hope you get the premise of my question?
Does this help?No doubt there's an explanation, and no doubt I won't understand it, but I hope you get the premise of my question?
https://www.skyatnightmagazine.com/space-science/d...
Probably need to give myself a
until I've done a it more 
Bannock said:
Thanks. So matter can travel faster than light, when it's being propelled by expanding space, which is expanding faster than light can travel. Which begs another question in my mind, how does the expanding "space" have any way to drag matter with it? How come the matter doesn't just stay where it was as space expands past it? Does space have some kind of sticky property? And how isn't the light getting dragged along with the expanding space, if matter which can form planets is?
Probably need to give myself a until I've done a it more
The space is expanding, the things in it don't need to be dragged, they just stay in the same place, but those places get further away. If the space between us were to expand, you'd see me moving away from you, and I'd see you moving away from me, but neither of us would perceive any movement ourselves. Think of it like drawing a pattern on an elastic band and then stretching it. Probably need to give myself a
until I've done a it more The bit I don't get though is that if you were to then point a laser at me, presumably the light would move away from you at faster than light speed?
RizzoTheRat said:
Bannock said:
Thanks. So matter can travel faster than light, when it's being propelled by expanding space, which is expanding faster than light can travel. Which begs another question in my mind, how does the expanding "space" have any way to drag matter with it? How come the matter doesn't just stay where it was as space expands past it? Does space have some kind of sticky property? And how isn't the light getting dragged along with the expanding space, if matter which can form planets is?
Probably need to give myself a until I've done a it more
The space is expanding, the things in it don't need to be dragged, they just stay in the same place, but those places get further away. If the space between us were to expand, you'd see me moving away from you, and I'd see you moving away from me, but neither of us would perceive any movement ourselves. Think of it like drawing a pattern on an elastic band and then stretching it. Probably need to give myself a
until I've done a it more RizzoTheRat said:
Bannock said:
Thanks. So matter can travel faster than light, when it's being propelled by expanding space, which is expanding faster than light can travel. Which begs another question in my mind, how does the expanding "space" have any way to drag matter with it? How come the matter doesn't just stay where it was as space expands past it? Does space have some kind of sticky property? And how isn't the light getting dragged along with the expanding space, if matter which can form planets is?
Probably need to give myself a until I've done a it more
The space is expanding, the things in it don't need to be dragged, they just stay in the same place, but those places get further away. If the space between us were to expand, you'd see me moving away from you, and I'd see you moving away from me, but neither of us would perceive any movement ourselves. Think of it like drawing a pattern on an elastic band and then stretching it. Probably need to give myself a
until I've done a it more So space is expanding between galaxies (or galaxy clusters) faster than light can move through space.
Bannock said:
OK. Thanks. So how come the light isn't coming with us, and then takes billions of years to arrive where we are?
I think you might be under the impression all the light and matter started from a single 'place' in the universe. That is not how the big bang works.SpudLink said:
RizzoTheRat said:
Bannock said:
Thanks. So matter can travel faster than light, when it's being propelled by expanding space, which is expanding faster than light can travel. Which begs another question in my mind, how does the expanding "space" have any way to drag matter with it? How come the matter doesn't just stay where it was as space expands past it? Does space have some kind of sticky property? And how isn't the light getting dragged along with the expanding space, if matter which can form planets is?
Probably need to give myself a until I've done a it more
The space is expanding, the things in it don't need to be dragged, they just stay in the same place, but those places get further away. If the space between us were to expand, you'd see me moving away from you, and I'd see you moving away from me, but neither of us would perceive any movement ourselves. Think of it like drawing a pattern on an elastic band and then stretching it. Probably need to give myself a
until I've done a it more So space is expanding between galaxies (or galaxy clusters) faster than light can move through space.
Bannock said:
OK. Thanks. So how come the light isn't coming with us, and then takes billions of years to arrive where we are?
I think you might be under the impression all the light and matter started from a single 'place' in the universe. That is not how the big bang works.And yes, I am under the impression that all light and matter started from a single place in the Universe. I take it that's wrong, so I'll go and do some reading on it. Thanks.
SpudLink said:
I think you might be under the impression all the light and matter started from a single 'place' in the universe. That is not how the big bang works.
That's a very good point, the universe was created in the big bang and then expanded, so the big bang actually took place across the entire universe right?RizzoTheRat said:
SpudLink said:
I think you might be under the impression all the light and matter started from a single 'place' in the universe. That is not how the big bang works.
That's a very good point, the universe was created in the big bang and then expanded, so the big bang actually took place across the entire universe right?Note: I am not an astrophysicist.
Bannock said:
On your first nested statement, the bit I don't get is that you can't compare it to water - water is matter with properties which can move other things with it. Space is not, it is, by definition nothing. So how does it take things with it?
And yes, I am under the impression that all light and matter started from a single place in the Universe. I take it that's wrong, so I'll go and do some reading on it. Thanks.
The more common analogue is the inflating balloon. Draw some dots on a balloon and then blow it up. The dots move apart from each other without moving on the surface of the balloon.And yes, I am under the impression that all light and matter started from a single place in the Universe. I take it that's wrong, so I'll go and do some reading on it. Thanks.
RizzoTheRat said:
The space is expanding, the things in it don't need to be dragged, they just stay in the same place, but those places get further away. If the space between us were to expand, you'd see me moving away from you, and I'd see you moving away from me, but neither of us would perceive any movement ourselves. Think of it like drawing a pattern on an elastic band and then stretching it.
The bit I don't get though is that if you were to then point a laser at me, presumably the light would move away from you at faster than light speed?
Light is a slippery bugger to wrap your head around. The speed of light is always constant, no matter how or where you measure it. The light from the headlights of a moving car isn't moving at the speed of light plus the speed of the car. What appears to happen is the apparent wavelength of the light stretches or shrinks if the light source and the observer are moving relative to each other. This is how we can deduce that the universe is expanding - because the light from far off galaxies is stretched more into the red wavelength (red shift).The bit I don't get though is that if you were to then point a laser at me, presumably the light would move away from you at faster than light speed?
That plus the double slit experiment combine to blow my mind and make me wonder if this all just an illusion.
Bannock said:
On your first nested statement, the bit I don't get is that you can't compare it to water - water is matter with properties which can move other things with it. Space is not, it is, by definition nothing. So how does it take things with it?
And yes, I am under the impression that all light and matter started from a single place in the Universe. I take it that's wrong, so I'll go and do some reading on it. Thanks.
I think inflation is the key bit, could be wrong.And yes, I am under the impression that all light and matter started from a single place in the Universe. I take it that's wrong, so I'll go and do some reading on it. Thanks.
thegreenhell said:
I think the closest we'll get to a space elevator is to use the moon as a base and launch pad for longer missions, especially if we can find minable resources there that can be used to construct and fuel such a mission.
The moon's a long way away and it moves around.... Even if it didn't, its not necessary to go that far to minimise the cost of lifting out of the gravity well. If - and it's a big if - heavy industry can move into space and asteroid mining is commercially viable, then the first steps may be to build a few space elevators around the equator, then join them up into a single hab ring. It might take a hundred years. But then humanity has a way of not just getting into space, but staying there with cheap-ish resupply.
I think interstellar travel is waiting for a shift in the understanding of the human brain, not an imaginary propulsion system.
I think a true understanding of how to create a gooey brain from scratch or an artificial one and implant consciousness in it is not as far away as people would like to believe. I suspect no more than another 1-200 years.
When that happens interstellar travel will happen because time won't be a barrier to the human condition.
Go to some world a gazillion miles away sit an artificial head on top of a body designed for its environment and presto. Humans will be created on distant planets without the need to travel to them.
It'll be like the worlds slowest teleporter.
I think a true understanding of how to create a gooey brain from scratch or an artificial one and implant consciousness in it is not as far away as people would like to believe. I suspect no more than another 1-200 years.
When that happens interstellar travel will happen because time won't be a barrier to the human condition.
Go to some world a gazillion miles away sit an artificial head on top of a body designed for its environment and presto. Humans will be created on distant planets without the need to travel to them.
It'll be like the worlds slowest teleporter.
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