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But seriously: what was there before the Big Bang?
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Can you see the future as you fall into a black hole?
(Intermediate)
How can the Universe expand faster than the speed of light during inflation?
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How do gravitons escape black holes to tell the universe about their gravity?
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If gravity is a "curvature of space" rather than a force, why do a ball and bullet follow different paths?
(Intermediate)
If gravity isn't a force, how does it accelerate objects?
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If light has no mass, then what draws it into a black hole?
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If spacetime is curved, is it possible for us to look into space and see light from Earth from long ago?
(Intermediate)
Is there any possibility that the Solar System or the Universe is in a black hole?
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What are "curled" dimensions?
(Advanced)
What happens to spacetime inside a black hole?
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What is a wormhole?
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What would an "open geometry" for the universe look like?
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Why does the Earth tilt back and forward once a year? (Beginner)
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Is speed of light the same everywhere ? (Beginner)
How does Venus have sulphuric acid in it's clouds? (Beginner)
Earth's Bow Shock (Advanced)
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Why is the sun red? During sunset, Northeastern US, Summer 2021 (Beginner)
Why do rays from Sun appear to converge at a point? (Beginner)
But seriously: what was there before the Big Bang? (Beginner)
How far can photons move freely in the early universe (Advanced)
How likely is it that the Solar System has had or will have a close encounter with another star? (Intermediate)
How do we know what we observe is x light years away? (Beginner)
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What is the universe expanding into? (Intermediate)
What do I need to do to become an astronomer? (Beginner)
What's the difference between astronomy and astrology? (Beginner)
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Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How far is each planet from Earth? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
What kind of eyepieces do I need to look at planets? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
Does the Mediterranean sea have tides? (Intermediate)
Why do we not have eclipses every month? (Beginner)
Is it possible for amateurs to do optical interferometry? (Intermediate)
Why do the planets orbit the sun? (Beginner)
What would happen if the Moon fell out of its orbit around Earth? (Intermediate)
What was the bright, smoothly moving star that I saw? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How far is each planet from Earth? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
What would happen if the Moon fell out of its orbit around Earth? (Intermediate)
Earth's Bow Shock (Advanced)
Which planet is most similar to Earth? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
Why do the planets orbit the sun? (Beginner)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How are light and heavy elements formed? (Advanced)
How do you measure the distance between Earth and the Sun? (Intermediate)
How far is each planet from Earth? (Intermediate)
Which planet is most similar to Earth? (Intermediate)
What was the bright, smoothly moving star that I saw? (Beginner)
Why is the moon in a different place every night? (Beginner)
What would happen if the Moon fell out of its orbit around Earth? (Intermediate)
Earth's Bow Shock (Advanced)
How does the position of Moonrise and Moonset change? (Intermediate)
What's going to happen on December 21st 2012? (Intermediate)
What color is each planet? (Intermediate)
At what speed does the Earth move around the Sun? (Beginner)
How far is each planet from Earth? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
Why do the planets orbit the sun? (Beginner)
What is the significance of the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle? (Beginner)
When was the last time all of the planets were aligned? (Beginner)
How long does it take for the Sun's light to reach us? (Beginner)
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