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# Physics/Earths rotation and revolution

Question
Hi,

What are the evidences for earth's rotation and revolution around sun? Is earth's rotation observable from space station? Is there any video that captures earth's rotation, kindly share.

What are the evidences for moon's rotation in its own axis? Why there are no dusts, wind in moon?

Hypothetically, if sun were to revolve around earth, will the lengh of day and night be constant through out earth?

There's a ridiculous amount of evidence for the Earth's rotation.  The Earth is 6370 km wide and the space station orbits it every 90 minutes from just 200-400 km above its surface, so it's very difficult to put together a video at that speed of the Earth rotating.  However, the Galileo spacecraft did a flyby of the Earth from much further out, there's a video here: https://www.youtube.com/watch?v=UVuqcEuIRgs

The Moon is gravitationally locked to the Earth, because it is so close.  The fact that we observe it going around us once a month is plenty of proof of that.  It also has no atmosphere (too small to hold one with gravitation), so what would there be to make wind?  There's plenty of dust, just no air to blow it around.

Look, we have satellites.  We landed people on the Moon.  GPS works just fine.  We understand these things ridiculously well, if our understanding were so wrong, none of our satellite technology (satellite phones, satellite data networks and television) would work at all.  The Sun does not revolve around the Earth, it can't.  It's too massive.  That would be like you swinging something that weighed less than a gram around on a string and you asking if you were really swinging around it instead.  The day would be whatever length you wanted, since you're violating the basic physics of gravitational attraction and orbits that have been understood for a few hundred years now.  Also, here's a video of the Sun rotating, taken by a NASA satellite.  Yes, it rotates, too... https://www.youtube.com/watch?v=7dfKoPsA8KQ

Physics

Volunteer

#### Dr. Stephen O. Nelson

##### Expertise

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.

##### Experience

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.

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