• We’re currently investigating an issue related to the forum theme and styling that is impacting page layout and visual formatting. The problem has been identified, and we are actively working on a resolution. There is no impact to user data or functionality, this is strictly a front-end display issue. We’ll post an update once the fix has been deployed. Thanks for your patience while we get this sorted.

Gravity

Page 2 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.
Our schools suck.

Gravity = LAW - mathematically proven beyond doubt, rare exceptions do not demote it as it still consistently exists in 99.999% of all circumstances. It is a force of nature. That we do not completely understand it does not take away from the fact that we can predict it with great accuracy.

Evolution = theory - hypothetically proven but (until we invent time machines) not beyond doubt
 
Originally posted by: Legendary
Originally posted by: DrPizza
There are 4 forces in nature.
Of those 4: gravity, strong, weak, and electomagnetic,
gravity is the LEAST understood.

(and the weakest of the 4 forces)

Weakest, but greatest distance of travel

Actually, that's not true. We just feel gravity from large distances because there is no (known) negative gravity charge. All mass/energy has attractive gravity so it's cummulative. EM is infinite in range as well, but EM has +/- charges which usually completely cancel each other out.

The weak force is practically limited in range due to the mass of the W/Z bosons. They decay before they can get very far, but I guess you could have one reach as far as you want.

The strong forces is really messed up. The potential decreases from r=0 out a very short distance, but then it increases rapidly again (ie, the strong force gets stronger the farther out from a colour charge you go). Basically, the strong force between two infinitely separated colour charges is infinite! This never happens though as the potential energy stored in the field is large enough that the field spawns new particles. A drawing:

legend:
r : red colour charge particle
R : anti-red colour charge particle
= : gluon

A pion:

r=R

Try to pull the pion apart:

r====R

The gluons contain energy. As you stretch them, the field they make up increases in energy to the point where they "pinch off" and form new particles:

r========R -> r==R r==R

quantum electrodynamics (electromagnetism + electroweak) is VERY well understoood

quatnum chromodynamics (strong) has a theory written out, but the problems you end up writing down are so difficult to do that no one in the world has been able to solve many of them algebraically

quantum gravity doesn't even exist as a theory yet.
 
Originally posted by: Descartes
It is similar to evolution in that it's both theory AND fact. Newton derived a law that established unequivocally its quantitative footing; however, it wasn't until Einstein actually determined the mechanism of gravity: ripples in the fabric of spacetime.
GREAT SCOTT!
 
Back
Top