Wednesday, June 10, 2009

The Mysteries Of Gravity

New Scientist put out an article on the mysteries surrounding gravity on their online site. I have included a snippet below.


It's the force we all know about and think we understand. It keeps our feet firmly on the ground and our world circling the sun.

Yet look a little closer, and the certainties start to float away, revealing gravity as the most puzzling and least understood of the four fundamental forces of nature.

You can read them in detail here.

Questions are included in the article this go round (no reason to reinvent the wheel).


Timm said...

I'm a fan of the irreducible complexity argument. Gravity is just another piece of the puzzle.

ExPatMatt said...

I thought irreducible complexity was a biology thing - is it applicable to all systems?

Timm said...

It is for me.

ExPatMatt said...

Oh, OK.

B Nettles said...

From the comments that were left on the New Scientist there are a lot of either weirdos or satirists over there.

Here are my answers:
1) Gravity is a phenomenon that, explained by general relativity, is caused by the curvature of space-time. This curvature is caused by masses, and masses respond to the curvature. It manifests by causing masses to accelerate. So we call it a force, but in the most modern picture, it's not really a force. It's a consequence of curvature.

2) Masses don't cause bulges in space-time, therefore there is no repulsion. The nuclear strong force doesn't have an opposite either. Nuclear repulsion might be hypothesized, but hasn't been demonstrated. In molecules, nuclei repulse each other due to electromagnetic forces.

3) a)Why are electromagnetic forces so strong?
b) Maybe curvature of S-T isn't that easy to do
c) Why would anyone suppose that different forces should have equal strengths?

4)Because gravity is built in to the universe. It is not something that is separately imposed, but an integral part. No universe = no gravity (because there would be not S-T curvature). Also, if Jrazz did not exist, the universe as we know it would not exist. Now THAT'S fine tuning.

5)All living things have mass. Mass causes S-T curvature = gravity. This is really an ill-formed question. Might as well ask, "Does life need forces?" Duh!

6) He hasn't asked a really intelligent question....yet.

7)Aha! An intelligent question. Yes, they do seem at odds which says that either one or both are incomplete. Newtonian gravitation works really really well (just ask Neil and Lance), but it doesn't explain a lot of small discrepancies. If we used Newtonian gravitation and dynamics, GPS satellites wouldn't work well at all. Without quantum mechanics, we wouldn't understand lasers or atomic energy and so atomic clocks wouldn't be developed --> no GPS satellites. But the theories aren't compatible either conceptually or mathematically. Never fear. There are a lot of nerdy, super-dedicated people looking to blend them. Why? In the material world, there might as big a difference between now and new as there was between Newton and Einstein. In the spiritual world...well, not even the Newton-Einstein juxtaposition makes a difference. Christ died for sinners. That's really the only thing that's spiritually important.