Discussion
There is quite a lot of gravity in space.
It does reduce with distance., but there is enough of a gravitational pull between the earth and the moon to stop the moon flaying off into space, and that is something like 240k miles away.
I think the level of gravity at the altitude of the ISS is still something like 90% of that on Earth's surface.
It does reduce with distance., but there is enough of a gravitational pull between the earth and the moon to stop the moon flaying off into space, and that is something like 240k miles away.
I think the level of gravity at the altitude of the ISS is still something like 90% of that on Earth's surface.
Willy Nilly said:
On earth there's loads of gravity, yet in space there's not much. So, when a person goes to space (ignoring the thrust of whatever they're being sent up in) does gravity weaken incrementaly?
Gravity in dependent on the mass of an object - and it's gravitational 'strength' decreases with the inverse square of distance from that object.Gravity is however pretty much infinite in influence. That's why although the Milky Way and Andromeda galaxies are separated by around 2.5 million light years - they are still gravitationally attracted and will collide in around 4 billion years.
You're thinking of orbit and 'microgravity'.
If you go straight up in a space craft and don't maintain thrust you fall back down, even from geostationary orbit altitudes,
In orbit, gravity is still acting, but you don't fall down, because you are going so fast that you don't hit the Earth, but not so fast that you just fly off into space.
Microgravity is the because gravity acts mostly evenly on all mass, so if you are in a space craft, it is falling at the same rate as you and you effectively have no weight (not no mass).
If you go straight up in a space craft and don't maintain thrust you fall back down, even from geostationary orbit altitudes,
In orbit, gravity is still acting, but you don't fall down, because you are going so fast that you don't hit the Earth, but not so fast that you just fly off into space.
Microgravity is the because gravity acts mostly evenly on all mass, so if you are in a space craft, it is falling at the same rate as you and you effectively have no weight (not no mass).
annodomini2 said:
You're thinking of orbit and 'microgravity'.
If you go straight up in a space craft and don't maintain thrust you fall back down, even from geostationary orbit altitudes,
In orbit, gravity is still acting, but you don't fall down, because you are going so fast that you don't hit the Earth, but not so fast that you just fly off into space.
Microgravity is the because gravity acts mostly evenly on all mass, so if you are in a space craft, it is falling at the same rate as you and you effectively have no weight (not no mass).
I had it in my mind that one of the worst things that could happen to an astronaut would be accidentally floating off into space. Are we saying they would fall back towards earth eventually then? I don’t know which is worse!If you go straight up in a space craft and don't maintain thrust you fall back down, even from geostationary orbit altitudes,
In orbit, gravity is still acting, but you don't fall down, because you are going so fast that you don't hit the Earth, but not so fast that you just fly off into space.
Microgravity is the because gravity acts mostly evenly on all mass, so if you are in a space craft, it is falling at the same rate as you and you effectively have no weight (not no mass).
Willy Nilly said:
On earth there's loads of gravity, yet in space there's not much. So, when a person goes to space (ignoring the thrust of whatever they're being sent up in) does gravity weaken incrementaly?
Still plenty of gravity in space. The iss has about 90 percent of the gravity on earth.
They don't feel it because they are in orbit, only experience micro gravity because they are constantly falling to earth and missing because they go so fast.
RobDickinson said:
We have absolutely zero idea what gravity is.
We know it exists, we can easily calculate it etc.
It seems like a fundamental attribute of space time.
So no, no current plans for anti gravity...
Not Anti-Gravity (Luke Skywalker Landspeeder). Artificial Gravity - rotating stations (Space Odyssey 2001, The Martian etc)We know it exists, we can easily calculate it etc.
It seems like a fundamental attribute of space time.
So no, no current plans for anti gravity...
Leithen said:
Not Anti-Gravity (Luke Skywalker Landspeeder). Artificial Gravity - rotating stations (Space Odyssey 2001, The Martian etc)
We understand that perfectly already have accelerators that produce good force to test pilots etc.Doing it in space on a large scale is purely engineering
RobDickinson said:
We understand that perfectly already have accelerators that produce good force to test pilots etc.
Doing it in space on a large scale is purely engineering
And yet, it would appear no proposals to carry out and test such engineering. The effects of microgravity are well known and not good for Homo sapiens.Doing it in space on a large scale is purely engineering
Take Musk's proposals regarding Mars missions. How does he expect crew to cope with landing on Mars and being able to function without the transit craft having artificial gravity?
Leithen said:
And yet, it would appear no proposals to carry out and test such engineering. The effects of microgravity are well known and not good for Homo sapiens.
Take Musk's proposals regarding Mars missions. How does he expect crew to cope with landing on Mars and being able to function without the transit craft having artificial gravity?
By far the largest science experiment on the iss is how micro gravity affects people. Take Musk's proposals regarding Mars missions. How does he expect crew to cope with landing on Mars and being able to function without the transit craft having artificial gravity?
We've had astronauts on the iss for far longer than a trip to Mars. And Mars has lower gravity than earth.
Yes its a problem, one we know about and are thinking about.
Very interesting readup along these lines from Scott Kelly a year after returning from ISS.
https://www.smh.com.au/lifestyle/astronaut-scott-k...
https://www.smh.com.au/lifestyle/astronaut-scott-k...
RobDickinson said:
We have absolutely zero idea what gravity is.
We know it exists, we can easily calculate it etc.
It seems like a fundamental attribute of space time.
So no, no current plans for anti gravity...
Eh? We have a very good idea of what gravity is. It is the attraction of mass to other mass. We know it exists, we can easily calculate it etc.
It seems like a fundamental attribute of space time.
So no, no current plans for anti gravity...
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