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Q & A: Physics Questions? Ask the Van

Physics Questions? Ask the Van

Question of the Day

"The earth revolves round the sun because the sun attracts the earth. The sun also attracts the moon and this force is about twice as large as the attraction of the earth on the moon. Why does the moon not revolve round the sun ?"
-Kelvin (age 19)

See the answer

About Us

7409 questions have been answered online since 1998 by volunteers from the Department of Physics at the University of Illinois' Physics Van outreach program. We've tried hard to make this the most reliable physics Q&A site on the Web, but no site is perfect, as we explain on this note. Our Baloney feature provides examples of how shaky many other sites are.

If you'd like to ask us a new question, not already covered, please read our answering guidelines first. We try to answer as many questions as we can, but it's not always possible to answer them all. Questions from kids are especially welcome.

Although we recommend not using our informal site as a cited reference, students who are in a rush and can't find a more proper peer-reviewed source can check our citation information section.

Questions from kids are especially welcome!