Previously answered questions by Dave Rothstein

(in order of times viewed)

What is the universe expanding into?
What is apparent magnitude?
What is the observational difference between a star and a planet?
Is the universe expanding faster than the speed of light?
Can we feel the Earth spin?
How long does a solar eclipse last?
What is the physical difference between a star and a planet?
How do you calculate the lifetime of the Sun?
How can we see the Milky Way if we are inside it?
Why doesn't the length of each day change much around the solstices?
Does your weight change between the poles and the equator?
What would happen if the gravity on Earth was suddenly turned off?
What happens to a substance if its speed is more than the speed of light?
What is the density of a black hole?
How do astronomers use math in their jobs?
Could there be life in the galaxies nearest to the Milky Way?
Do most astronomers believe in God based on the available scientific evidence?
When the Sun converts mass to energy, do the orbits of the planets change?
Does gravity vary across the surface of the Earth?
How long would it take the Earth to fall into the Sun?
Why hasn't NASA gone back to the moon?
How do astronauts use math in their jobs?
Why is the moon in a different place every night?
What is a star's "spectrum"?
What can we learn from the color of a star?
Does evolution contradict the second law of thermodynamics?
When we look back to the Big Bang, why don't we see the universe as a tiny speck of matter?
Can you see the future as you fall into a black hole?
How can we distinguish a star's "real" color from the change in color that we observe due to the star's motion?
How does the brightness of a star depend on its distance from us?
What is the difference between the "Doppler" redshift and the "gravitational" or "cosmological" redshift?
How do we define distance in an expanding universe?
What companies or businesses can astronomers work for?
How do we know that nuclear fusion is still going on in the Sun?
How does astronomy benefit humankind?
If gravity is a "curvature of space" rather than a force, why do a ball and bullet follow different paths?
Will the Moon be invisible in 500 million years?
How do astronauts communicate with their families from space?
Why isn't the sky bright at night if the universe has so many stars?
Will we ever stop having solar eclipses because of the moon's motion away from the Earth?
What does the term "visible universe" mean?
Why do clocks turn in the opposite direction from the Earth and Moon?
What process would bring about a quark star?
Why do astronauts in space need to exercise?
What are "blue stragglers" in globular clusters?
How close does a supernova need to be to damage the Earth's environment?
Would extraterrestrial civilizations know that there is life on Earth?
How can we see galaxies if their stars are so faint?
How can we compare dark matter and dark energy?
What happened to all the black holes that were around in the early universe?
How long do supernova remnants last?
Could there have been multiple Big Bangs at different places in the universe?
Is the universe really like an expanding balloon?
Can gravitational lensing from intervening galaxies cause the observed ripples in the Cosmic Microwave Background?
Why do some eclipses take longer than others?
Could dark energy come from matter anti-matter pairs forming spontaneously and then annihilating?
Have astronomers observed any phenomena that could be produced by extraterrestrial civilizations?
Is light of different colors affected differently by gravity?
Do we see the same stars from above and below the equator?
Why are accretion disks flat?
How can we understand the meaning of large numbers like "a million million?"
What is the farthest in space that we have gone?
Why do spacecraft need heat shields coming back to Earth but not leaving?
Why aren't accretion disks around giant stars as hot as accretion disks around black holes?
When measuring the expansion of the universe, do astronomers consider that they're seeing how galaxies moved long ago, not today?

URL: http://curious.astro.cornell.edu/authorlist.php?number=4
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Last modified: November 19, 2007 11:28:35 AM

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