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Physics/space questions



Why astronauts feel weightlessness in space? A free falling body will have accelaration of g downward but  I read that accelerometer will read zero in free falling objects, is that true and why?

How ancient people were aware of planets even before telescope were discovered. Did the people came to know that saturn have rings only after telescope discovery or earlier. If earlier, how they know?


An accelerometer will accelerate with the same speed as a falling only reads acceleration relative to itself.  If everyone is falling, the accelerometer will read zero of course.

Ancient people named them "planets" which means "wanderer" in Greek.  They didn't stay in the same position as other stars in the night sky but wandered in strange patterns through it.

The rings of Saturn did wait until telescopes.  You can't see them with the naked eye.


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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