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Can you use an infinite line of reflectors to send light to the edge of the Universe?
(Intermediate)
Could someone travel the universe in his or her own lifetime?
(Beginner)
How are photons created and destroyed?
(Advanced)
How do photons from distant objects maintain enough energy to reach us?
(Intermediate)
How do planets capture satellites?
(Advanced)
How do you calculate the lifetime of the Sun?
(Advanced)
How long do supernova remnants last?
(Intermediate)
How much power is contained in a beam of light?
(Intermediate)
How powerful are quasars?
(Intermediate)
Is cosmic expansion happening on microscopic scales?
(Advanced)
Is light of different colors affected differently by gravity?
(Intermediate)
What causes a particle to decay?
(Intermediate)
What is the photoelectric effect? Why can't multiple low-frequency photons free an electron?
(Intermediate)
What type of energy does a black hole have?
(Intermediate)
When the Sun converts mass to energy, do the orbits of the planets change?
(Advanced)
Where did the matter in the universe come from?
(Intermediate)
Where did the Universe come from?
(Intermediate)
Where does the kinetic energy of infalling bodies come from?
(Intermediate)
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Could photons be dark matter? (Intermediate)
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How much does the Earth "wobble" on its orbit due to the Moon's gravity? (Intermediate)
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)
What makes quantum mechanics and general relativity incompatible? (Advanced)
What are we doing about Space Junk?
What what a black hole merger look like from a telescope? (Advanced)
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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)
Why is looking out into space the same as looking back in time? (Beginner)
Can we find the place where the Big Bang happened? (Intermediate)
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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)
How do we know what we observe is x light years away? (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)
But seriously: what was there before the Big Bang? (Beginner)
What is the universe expanding into? (Intermediate)
What makes quantum mechanics and general relativity incompatible? (Advanced)
How much does the Earth "wobble" on its orbit due to the Moon's gravity? (Intermediate)
What are we doing about Space Junk?
What is the difference between a "star" and a "sun"? (Beginner)
How does the position of Moonrise and Moonset change? (Intermediate)
How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
How are light and heavy elements formed? (Advanced)
At what speed does the Earth move around the Sun? (Beginner)
Why is the sun red? During sunset, Northeastern US, Summer 2021 (Beginner)
What is the universe expanding into? (Intermediate)
But seriously: what was there before the Big Bang? (Beginner)
Why is the moon in a different place every night? (Beginner)
What is the difference between a "star" and a "sun"? (Beginner)
How do you measure the distance between Earth and the Sun? (Intermediate)
Why do the planets orbit the sun? (Beginner)
How does the position of Moonrise and Moonset change? (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)
But seriously: what was there before the Big Bang? (Beginner)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
What is the universe expanding into? (Intermediate)
What was the bright, smoothly moving star that I saw? (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)
Is the Moon moving away from the Earth? When was this discovered? (Intermediate)
How do you measure the distance between Earth and the Sun? (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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