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Q & A: Physics Questions? Ask the Van

Physics Questions? Ask the Van

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Question of the Day

"I have heard it stated by renowned scientists, for example Stephen Hawking, that the macroscopic world is completely deterministic from a theoretical if not practical perspective, while the quantum realm is probabilistic. My question concerns the interaction of atomic radiation with the macroscopic world. The emission of a particle from a particular nucleus at a particular time is, as I understand it, purely probabilistic. If that particle hits a DNA molecule and causes a mutation resulting in cancer how can that cancer be said to be theoretically deterministic?"
-Jack Stephens (age 70)

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6847 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.

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Questions from kids are especially welcome!