Gravity Questions

• Are there any massless particles?
• Are there different types of black holes?
• Can gravity form waves?
• Can you go fast enough to get enough mass to become a black hole?
• Do I weigh less on the equator than at the North Pole?
• Does every black hole contain a singularity?
• Does the influence of gravity extend out forever?
• Does the negative mass of antimatter mean that it's gravitationally repelled from stars?
• Does time go faster at the top of a building compared to the bottom?
• How can the heart be strong enough to pump blood up your legs against gravity?
• How can there be anything left in the universe? Don't black holes suck everything in?
• How can you tell a black hole made out of antimatter from a black hole made out of matter?
• How do space ships make artificial gravity?
• How does a cloud fill up with water?
• How does a supernova completely destroy a star?
• How does astrology work?
• How does the expansion of the universe make outer space a vacuum?
• How does wind create all the ocean currents?
• How high does a building have to be for a penny dropped from the top to kill a person on the ground?
• How large would a bucket of water have to be to put out the sun?
• I know that the gravity of the moon causes ocean tides on earth. How does centrifugal force cause the far-side bulge?
• Is a black hole a 2D or a 3D object?
• Is Pluto a planet?
• Since gravity is unlimited, can we use it as an infinite energy source?
• What is the speed of gravity?
• What keeps a bicycle balanced?
• What would happen if you fell into a hole that went through the center of the earth?
• Why are all the stars fixed in space?
• Why did people believe the earth is the center of the solar system when it's obvious the sun is?
• Why does the moon's gravity cause tides on earth but the sun's gravity doesn't?
• Why doesn't the earth fall down?
• Why is gravity not a real force?
• Why is gravity the strongest force?
• Why is physics scale invariant?
• Why is there no gravity in space?
• Why is there no up and down in space?
• Will the night sky eventually end up completely black because the universe is expanding?
• Would a guitar sound the same on a space station?