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8 votes
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Explaining gravity assist to a 6-year old

I like the trowing a ball against a speeding train analogy. The important factor is that Jupiter is moving, quite fast. About 13 km/s. The other important factor is that Jupiter is very massive,...
userLTK's user avatar
  • 24k
7 votes
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In zero gravity - I'm floating inside a torus as they spin it up, do I float do the "ground"?

Yes... In the scenario you describe, you (and the air) will remain at rest, while the torus speeds up. One hopes there are no radial partitions, or, if there are, one comes along to pick you up ...
DJohnM's user avatar
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4 votes
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Orphaned star systems and intergalactic travel (in fictional context)

The Canis Major dwarf galaxy is about 8 kpc from the Sun, but is only 8 degrees below the Galactic plane (and further out than the Sun). So it is about 42,000 light years from the Galactic centre and ...
ProfRob's user avatar
  • 152k
4 votes

Explaining gravity assist to a 6-year old

I tend to think the best explanations are the simple ones which explain the core concepts of the concept without getting too fancy or detailed. That being said, I'd just explain what happens during a ...
zephyr's user avatar
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3 votes

Was NASA's moon mission completely fake?

While "was the Moon landing a hoax?" is starting to be a tiresome genre, the points you make is somewhat legitimate. I am not going to address the issue in general, (Best to go here if you want that) ...
SE - stop firing the good guys's user avatar
3 votes
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Farthest Orbit around the Earth?

The farthest Orbital Point from Earth is regulated by the fact that at what point the gravitational pull of the Sun overcomes the gravitational pull of the Earth. I found a post for this on Quora ...
Sushant Gurjar's user avatar
2 votes
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How fast does a spacecraft have to be to enter a primordial black hole without being torn apart?

Let's try a crude back of the envelope calculation to get orders of magntitude: The tidal force near the event horizon is of the order of $G M/r^3$ which is something like $10^{18} g/m$. So a probe ...
Steve Linton's user avatar
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2 votes
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What would happen if you jumped out of a moving spacecraft?

If the spacecraft is not accelerating, the astronaut leaves the airlock and just floats outside, not moving relative to it. If the rocket is accelerating they "fall" down towards the stern from the ...
Anders Sandberg's user avatar
1 vote
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Food in outer space

Short answer: No. A bit longer explanation: You only have what you bring and grow on your way in your own vessel. Recycling is essential, like exercised already today on the ISS. But you might have ...
planetmaker's user avatar
  • 19.4k
1 vote

Explaining gravity assist to a 6-year old

I might modify Zephyr's answer just a hair -- and I have not tried this on a 6-year old, let alone the average adult, who is much more difficult to explain things to than any child is. Gravity is ...
Carl Witthoft's user avatar

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