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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?
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How can the Universe expand faster than the speed of light during inflation?
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If gravity is a "curvature of space" rather than a force, why do a ball and bullet follow different paths?
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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?
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Does Mt. Everest cast a shadow on the moon? (Intermediate)
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Is speed of light the same everywhere ? (Beginner)
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Earth's Bow Shock (Advanced)
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Why is the sun red? During sunset, Northeastern US, Summer 2021 (Beginner)
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But seriously: what was there before the Big Bang? (Beginner)
How far can photons move freely in the early universe (Advanced)
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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)
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Can we find the place where the Big Bang happened? (Intermediate)
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How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
What are constellations used for? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
What's going to happen on December 21st 2012? (Intermediate)
How does the location of sunrise and sunset change throughout the year? (Advanced)
Which planet is most similar to Earth? (Intermediate)
How are light and heavy elements formed? (Advanced)
How do you measure the distance between Earth and the Sun? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
Why do the planets orbit the sun? (Beginner)
Which planet is most similar to Earth? (Intermediate)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
At what speed does the Earth move around the Sun? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
What's going to happen on December 21st 2012? (Intermediate)
How does the position of Moonrise and Moonset change? (Intermediate)
What are constellations used for? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
Are there telescopes that can see the flag and lunar rover on the Moon? (Beginner)
How big is the Hubble Ultra Deep Field image? (Intermediate)
Which planet is most similar to Earth? (Intermediate)
Why do the planets orbit the sun? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
What are constellations used for? (Intermediate)
Why do we not have eclipses every month? (Beginner)
How long could life on Earth survive if the Sun stopped shining? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
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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