Expert: Jayendra Upadhye - 4/6/2009

Question
Do scientists know exactly what gravity is.

Answer
Hi,
It is the best known open secret that scientists rather agree that they know very little.
That keeps them open to modifying their theories to fit to observed facts and measurements.
Scientists dont have pet theories.
Fred Hoyle's continuous creation of matter and a static universe ruled the roost till Panzias and company discovered the Cosmic Background Radiation, or the echo of the big bang.
Out went steady state, and in came the bang.
We know enough about gravity to have predicted frame dragging, explained the orbital anomaly at perihelion of mercury, predicted black holes and neutron stars, and white dwarfs.
But we do not know why gravity pulls and does not repel.
We simply assume that to be its "given" property!
We DO NOT know why G is of the value it is!
We dont know why it follows the inverse square law.
But scientists are pragmatic fellows.
They say.."well without knowing all that, we predicted gravitational lensing, the size limit on white dwarfs, the size of stars that trigger the super novas, we predicted the neutrino flash that precedes the super nova explosion, we are doing just fine.
Hopefully some day we will know, but no point wasting sleep on that.
Our missiles and space ships are doing fime thank you.

See?
No harm in admitting we dont know.
It rather prepares us to know more.
regards
Jayen