Question about Cavorite


So this substance screens out gravity. That would mean that if you want to go to the moon, a sphere like the one they built could use Cavorite to prevent the Earth's gravitational pull from keeping it on the Earth.

In order to reach the moon, though, wouldn't you still need a source of propulsion to push the sphere in the right direction?

I do understand the idea of how they could open and close Cavorite screens on the sphere's surface to avoid Earth's gravity and use the moon's gravity to attract the sphere. But in the movie it looks like the sphere takes right off quickly and starts shooting towards the moon. Given the distance between the sphere, sitting on the surface of the Earth, and the moon, and the mass of the sphere and the moon, I don't think the Moon's gravity would make the sphere move that fast even if the Cavorite "cut off" the effect of Earth's gravity on the sphere. It is more likely the sphere would just gently float around, perhaps pushed by forces other than gravity like air currents.

That's what I think, anyway.

Of course, I'm no physicist - to be honest, I struggled a bit with some physics topics in school(then again, that's not too uncommon, it's a challenging subject!) so maybe there's some simple explanation I missed.

Thoughts, anyone?

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I mentioned an explanation in a recent thread.

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Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it.

Once in space they need no propulsion.

As for the trajectory - They had the minds of M.I.T. figuring out the precise moment to take off and the exact window shade on the sphere to close so they would head straight for the moon. Then Einstein called Cavor to make sure he had everything he needed in the way of figuring out the amount of shade to open or close at any given moment. They also figured out that the Cavorite would be stronger when 1st applied so it would overcome the Earths gravity but, even though it was weakened, it would still have enough oomph to lift them off of the moon and slow them down when they returned to Earth.


It's a fantasy... who cares if it's accurate? Just watch it and enjoy it for what it is.

(edited for spelling)

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Make me a sargeant and charge the booze!

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[deleted]

Using an app I found and some arithmetic, I calculated that an object free-falling towards the Moon from the distance of the Earth would only travel 0.00165738043212890625 meters in the first ten seconds. This is either exactly correct or way off. May have dropped a few decimals.

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... I calculated that an object free-falling towards the Moon from the distance of the Earth would only travel 0.00165738043212890625 meters in the first ten seconds.
Keep in mind that the initial velocity of the sphere is provided mainly by the suction of the Earth's atmosphere escaping above it. Remember how fast the roof of the house ascended?

The real problem is in getting back from the moon where that boost is unavailable.

How long will it take to free fall to Earth from the moon? It's important to calculate the acceleration. There is no terminal velocity in the vacuum of space. Another problem is the initial momentum of the sphere which would be orbital and not towards Earth. Breaking out of that orbit doesn't seem to be achievable with Cavorite alone. It would require all the earthward blinds to be open just to maintain an orbit without flying further out into space.

Even separating from the moon without propulsion seems to be an impossible task as they are moving together. Painfully slow progress might be made in these problem areas if the sun is blinded out.

--
Drake

FYI



[spoiler][/spoiler]

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I still don't get the opening and closing of the screens. Why does Cavorite stop working depending on the position of the screen? Shouldn't it always be in effect? If so, what difference does the position of the screen make?

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[deleted]

The Moon gravity is what gives us our ocean tides.

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