Expert: Tom Whiting - 1/10/2008

Question
What would happen if only gravity were operating on Earth? and What do you think would happen if Earth were not moving?

Answer
Hi melissa,
What do you mean by the Earth "not moving"?
Not rotating, or not revolving around the sun?
Actually in real life, the Earth, and everything else,
is always moving, relative to something else.
There is no such thing as ABSOLUTE REST, as everything
in the Universe is moving, relative to everything else.
In fact, it is impossible NOT to be moving.  Even if the earth was not rotating, and not revolving, we would still be moving relative to the center of the Milky Way Galaxy, and of course, the Milky Way is moving relative to the Local Group of Galaxies, and the Local Group is moving around the Virgo Supercluster of Galaxies out there 65 million lightyears in Virgo.  So it is impossible not to move in our Universe. Everything moves, relative to something else....nothing can ever be, at "total rest".

Gravity is simply a curvature of space due to the presence of a mass. If there is a mass, then there is gravity.  {So basically, matter tells space how to curve (= gravity), and space tells matter how to move.}

If gravity was only operating on Earth, and not the sun,
then obviously we, the Earth,  would depart from the sun's vicinity rather quickly, so in a matter of hours we'd all freeze to death, as the temperature would drop to near absolute zero (-460 degrees F) rather quickly once we were removed far from the sun.  But that can't happen, so don't lose any sleep over it. Everything has worked fine for the
past 4.6 billion years since formation of the Solar System,
and I would guess things will work fine for the next 2 or
3 billion years too.
Hope all this helps,
Clear skies,
Tom Whiting
Erie, PA