Weightlessness in space and the 1960's?

The first man in space was Yuri Gagarin in 1959.

You do have weight in space, but that is more momentum than force. Astronauts are weighed even nowadays.

Actually, it's very sensible to weigh people getting on a spaceship because in space we still have MASS. And the amount of fuel the spaceship carries determines how much MASS it can take off with (and PS, we still have weight during take-off!) and carry to its destination.

The physics was of course known back then. It's not true that you don't have weight in space, if we're talking about being in orbit around Earth for example. The ISS is 400 km above the Earth, which is further away from the Earth's centre of mass than we are, but not so far that it's not unaffected by Earth's gravity. The reason why the astronauts feel weightless is because they are in orbit, in free fall. Alan Shepard was launched on a suborbital trajectory which gave him a few minutes of free fall, which is what the SpaceShipTwo will offer its passengers. He was in space but the capsule fell back to Earth again, because of the Earth's gravity. Had he been in orbit like Yuri Gagarin (1961), he would have felt weightless.

Xelebes said:

You do have weight in space...

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No, you don't. You have mass. Weight describes the relationship between mass and gravity.

As for the original question, I couldn't say, because I wasn't alive. Scientifically known, yes. Commonly known? :: shrug ::

LOG said:

Was it common knowledge that one did not have actual weight in space in the 1960's?

I'm writing a review of 'To Serve Man' (Twilight Zone episode) in which, at a certain point, you see the Kanamit's weighing people before they get on the spaceship. No one seemed to think that was strange. I was wondering if the audience at the time would have been aware of that.

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Yes, I was taught about it in elementary school science in the 1960's.

However, weight is a factor in getting off the ground since it determines the amount of fuel needed for the thrust to escape atmosphere.

However, given the twist of that episode, I never thought that it was odd at all. Just a different kind of price per pound, as it were.

LOG said:

I'm writing a review of 'To Serve Man' (Twilight Zone episode) in which, at a certain point, you see the Kanamit's weighing people before they get on the spaceship. No one seemed to think that was strange.

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Aren't they weighing them because ... they're going to EAT them?

It may be more about them being "fattened for the slaughter" than the physics of space travel.

[Without wanting to hijack the thread, can I ask a question with the same title?

If we're weightless in space ... does anyone know at WHAT ALTITUDE / distance from Earth we start to become "weightless" ?
Not weightless in an airliner, weightless in space ... where's the weightlessness kick in if you're not moving (disregarding acceleration, etc)?

And I have a scene where an astronaut is in his spaceship, in orbit.
Does "in orbit" by definition make you "weightless" regardless the size of the planet you're orbitting?]

dempsey said:

No, you don't. You have mass. Weight describes the relationship between mass and gravity.

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It depends. If you are close to Earth, you will have weight even if you are in space.

TMA-1 said:

It depends. If you are close to Earth, you will have weight even if you are in space.

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Fair enough, though astronomically speaking this is an insignificant portion of what "space" means (though likely more relevant as it's what we have easier access to).

LOG said:

Yes they were. But the people didn't know they were going to be eaten. That's why I was wondering if they thought it would be odd.

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I thought you meant wouldn't the home viewers think it was odd (but then that's explained in retrospect because they were being weighed fer eatin')

But yeah, my bad, I missed you meant the people as they were being weighed.

On the other hand, some airline recently threw movie director off a plane because of his porkitude:

http://www.nydailynews.com/gossip/2...hwest_clerks_writerdirector_tweets_rage_.html

So I guess the aliens were just "ahead of us" on ALL aspects of flight!

small axe said:

If we're weightless in space ... does anyone know at WHAT ALTITUDE / distance from Earth we start to become "weightless" ?

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As soon as you're falling, you're 'weightless', as weight doesn't matter until you encounter a surface to exert force against (splat). The glib answer, then, is "1 millimetre". But that's not completely true, because when you fall in the atmosphere, air resistance is exerting a force against you, however slight. So a more correct answer might be "at the top of the atmosphere".

Earth's gravitational field itself extends to infinity, but attenuates by inverse squares.

And I have a scene where an astronaut is in his spaceship, in orbit.
Does "in orbit" by definition make you "weightless" regardless the size of the planet you're orbitting?

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If you are falling around the planet at the same speed the ship around you falls, you are weightless. This state only occurs when the ship's engines are off. The planet's size doesn't matter unless it's so dense (like a neutron star) and so close to you that the tidal forces acting on your body become significant.

Um. Don't ask me why a sad face appended itself to the top of my post.