Our Future Among the Stars

[Eddi]

In general, what do you think of space travel and living in space or on other heavenly bodies other than earth?

I think such endeavours are futile distractions from things that are more important (and much easier to solve)

We only have one Earth, the idea of expanding outwards into space is I believe a convenient distraction from this sad fact

I think this is the only planet we will ever have, and that we are trashing it, even though it sustains our lives!

Personally, when I look up at the night's sky I imagine I am looking up at God, not at aliens, or whatever

 

[Mock Turtle]

This is a spin-off of "end times". Our discussion about space travel has become off topic there, so we'll continue here.

In general, what do you think of space travel and living in space or on other heavenly bodies other than earth?

Unless we eventually find a way of travelling faster than the speed of light, like warping space and time, wormholes, and such, we will likely only be mining the objects in our solar system and perhaps forming colonies on such. We might send probes to some of our nearest star systems, but any colonisation might only be done by advanced machines, perhaps together with an eventual influx of human life but not in the frozen humans form. We have to face the fact that the life of the Earth is limited, even if it is very long, and there is always the possibility of a catastrophic event to end us all anyway. We would be extremely foolish in my view not to look for ways to expand into space, given the latter probability (which is an unknown in all reality). Getting to other galaxies seems to be an impossibility, given the distances and the speed at which they are all receding from ours - although one is approaching ours apparently.

 

[ChristineM]

@ChristineM wrote in "end times":

Interstellar flight is the problem. Moving a ship to close to the speed of light will require a way to counteract the massive increase in mass.

The alternative is slow (relitively) speed taking some time, a 10 light year journey will take around half a million years
​

Using only known physics and technology that has been shown to work at least in principle, 20% of c seems possible. Using nuclear fusion while capturing interstellar hydrogen overcomes the rocket problem.
I.e. a trip to proxima centauri takes about 20 years.
Take extended life span into account and interstellar travel becomes interesting.

Working in principle is not working in practice. A lot of work is needed to make such sustainable speeds commercially viable, and more importantly, reaching them safely!

To a human being speed it not the problem (we are after all moving through space at around 650km/s) assuming interstellar speeds do become commercially viable. Humans can handle speed, the problem is acceleration and deceleration. A typical human can handle about 5g (around 50 m/s2) for a short time (seconds to less than 2 minutes) and even a sustained 1g can be uncomfortable, think being in a car breaking hard for a few years.

I am sure the required speed can be attained assuming the world is willing, and it will need to be a world endorsed project. And maybe the technology to overcome acceleration and deceleration can be developed.

A nice idea but i just don't see it happening.

 

[ChristineM]

@ChristineM is right. Just think about the impacts from space dust and other matter that regular spacecraft incur requiring continual maintenance and repair.

Imagine what those impact's would be like hitting them at the speed of light.

I was going to add that interstellar space is not empty to the post above but though it to negative to add to other problems

 

[ratiocinator]

A typical human can handle about 5g (around 50 m/s2) for a short time (seconds to less than 2 minutes) and even a sustained 1g can be uncomfortable, think being in a car breaking hard for a few years.

Think about subtracting the earth's gravity and then standing on the windscreen. We all cope very well with 1g throughout our lives. In fact, the ideal (from a human comfort and health perspective) would be to accelerate at 1g to the midpoint and then decelerate at 1g to the destination. You then have "artificial gravity", equivalent to the surface of the earth, throughout the journey. You just have to make sure your ship points in the right direction throughout, so "down" is in the opposite direction to the acceleration.

 

[Thief]

Think about subtracting the earth's gravity and then standing on the windscreen. We all cope very well with 1g throughout our lives. In fact, the ideal (from a human comfort and health perspective) would be to accelerate at 1g to the midpoint and then decelerate at 1g to the destination. You then have "artificial gravity", equivalent to the surface of the earth, throughout the journey. You just have to make sure your ship points in the right direction throughout, so "down" is in the opposite direction to the acceleration.

not quite

During acceleration....you feel the 'weight' of your body in the chair
During flight.....you would feel weightless
during deceleration...you again feel your weight in the chair

artificial gravity is gained by rotating some portion of the ship
centrifugal force holds you to the shell of the craft

if you move yourself to the center of the craft.....you become weightless again

but hey
the distance from here to there exceeds your life span
freezing your meat is not yet a known science
recovery from the hardship of the journey seems unlikely

what I'm saying is
getting there …...is the trick
and in this human form...…..nope

so if someone can stuff your brain in a metal robot
and you somehow keep your sanity......you might get there
see the movie Robocop

or clone yourself every few decades.....and somehow not forget who you are

or......wait til you die and go there in mind and awareness
as God might do

 

[ChristineM]

Think about subtracting the earth's gravity and then standing on the windscreen. We all cope very well with 1g throughout our lives. In fact, the ideal (from a human comfort and health perspective) would be to accelerate at 1g to the midpoint and then decelerate at 1g to the destination. You then have "artificial gravity", equivalent to the surface of the earth, throughout the journey. You just have to make sure your ship points in the right direction throughout, so "down" is in the opposite direction to the acceleration.

Ig in one direction, add another plane and it becomes uncomfortable. But yes, a constant 1g in one direction is an answer but if will take considerably longer to traverse the distance.

 

[Messianic Israelite]

This is a spin-off of "end times". Our discussion about space travel has become off topic there, so we'll continue here.

In general, what do you think of space travel and living in space or on other heavenly bodies other than earth?

Humans may attempt it, but the scripture remains true, it's not going to work out. Amos 9:2 clearly tells us that none can escape the judgment, even if one were to go to the utmost part of the heavens. I seriously doubt that they are any habitable planets out there in the universe anyway, although some planets like TOI 700 d have been discovered, we simply do not know whether they would support life. It's guesswork. Look at the planets in our solar system. They are a wasteland. Earth was also a wasteland until Yahweh chose to make it habitable in Genesis 1.

 

[Quintessence]

In general, what do you think of space travel and living in space or on other heavenly bodies other than earth?

I think humans need to knock it off with the escapist mentality and start making the necessary sacrifices of this age.

But that's rather like asking an ice cube to voluntarily cast itself into a pit of magma, unfortunately.

 

[ratiocinator]

During acceleration....you feel the 'weight' of your body in the chair
During flight.....you would feel weightless
during deceleration...you again feel your weight in the chair

Try reading what I said again. I was suggesting accelerating for half the journey and decelerating for the other half, so you don't spend any time at constant speed (weightless).

 

[ratiocinator]

But yes, a constant 1g in one direction is an answer but if will take considerably longer to traverse the distance.

But don't forget that the further you're travelling, the higher your maximum speed and the closer you'll get to light speed so, from the point of view of the passengers at least, it might not take as long as you think:-

Source: Space travel using constant acceleration - Wikipedia

 

[Thief]

Try reading what I said again. I was suggesting accelerating for half the journey and decelerating for the other half, so you don't spend any time at constant speed (weightless).

distance is of great length.....out there

and you did the math?....acceleration to maintain 1g

 

[Thief]

it takes 18g to escape earth's gravity
44g to escape the solar gravity

1g is a crawl

 

[ChristineM]

But don't forget that the further you're travelling, the higher your maximum speed and the closer you'll get to light speed so, from the point of view of the passengers at least, it might not take as long as you think:-

Source: Space travel using constant acceleration - Wikipedia

Time is relative to the individual. It may seem quicker to the observer but for the traveler if remaines constant (i think, not quite got my head around the nuances of relativity)


Edit, time would seem slower to the observer but remain constant for the traveler

 

[Thief]

our future in space.....

there seems to be two lines of thought

time slows down
but we age......no matter how fast we are moving

 

[ratiocinator]

Time is relative to the individual. It may seem quicker to the observer but for the traveler if remaines constant (i think, not quite got my head around the nuances of relativity)

You can actually look at it in several different ways, but basically if the ship gets close to light-speed, then the journey time will be shorter in the reference frame of the travellers (the proper time of the journey) than in that of people observing from Earth. From the point of view of the travellers, the distance between the Earth and the destination actually gets smaller the faster they go, due to relativistic length contraction (because, from their point of view, the universe is moving past at close to light-speed).

 

[Heyo]

Ig in one direction, add another plane and it becomes uncomfortable. But yes, a constant 1g in one direction is an answer but if will take considerably longer to traverse the distance.

At a constant acceleration of 1G we will reach 20% c in less than 2 years. With an estimated travel time of over 20 years to the nearest other star system (Proxima Centauri) it adds about 10% to the travel time.

 

[Heyo]

We haven't even figured out how to live on the Earth, yet. We don't deserve to presume the right to infect and exploit anywhere else.

Imagine living in a tin can with only the resources you have on board. People will learn to live with what they got fast - or die fast.

 

[Thief]

At a constant acceleration of 1G we will reach 20% c in less than 2 years. With an estimated travel time of over 20 years to the nearest other star system (Proxima Centauri) it adds about 10% to the travel time.

and the other 80% of c...?

 

[Heyo]

it takes 18g to escape earth's gravity
44g to escape the solar gravity

1g is a crawl

Acceleration is irrelevant. It is called escape velocity for a reason. (And that is ~11000 m/s for earth and ~16600 m/s for the solar system (when you are already at earths distance from the sun)).