I'm just glad that this isn't in the Physics forum or I would have been seriously pissed! :)
dgoodpasture2005 said:
I think I've done a good job of that... no one here admits they know what gravity is.
DEFINE what you mean by "know".
I will put it to you that what you accept as something that YOU know has less certainty than what physicists describe gravity with. Think about it - we can use gravity and predict the constellation, send spacecraft to planets, predict motion of celestial bodies, etc. We have qualitative AND quantitative predictions that agree with observations. Compare that with what you can predict of the things that you "know"?
You and every one need to keep in mind what physicists mean when they say "oh, we don't know about so-and-so". These are the same people who would say that there is a small, but non-zero probability that if I throw a broken vase onto a floor, it can reassemble itself. The high standards that we have to finally be able to say "yes, we know about so-and-so" is why many keep saying we don't know ENOUGH about gravity. But please, don't mistaken it by assuming that we DON'T KNOW about gravity. This is not only wrong, it's hysterically funny and contradicts what we have done and can do.
And no one seems to notice of what exactly is meant by "anti-gravity" here. For example, is a repulsive force considered as an "anti-force"? If it is, then someone needs to do a lot of explaining. We have repulsive force in EM interaction, yet, I see no one calling that as an "anti-EM" force. Do we have an "anti-EM" concept? Sure we do. EM forces are mediated by photons. We have anti-photons. They are the same as the photons themselves.
So, are these "anti-force" defined strictly as the anti-particle carriers, such as anti-gravitons? Or are we simply talking about a "repulsive" gravity, something that is already contained in GR?
When you don't have ample knowledge of what we already formulated, and then start making all these statements and "accusation", then you can't help but make a series of ambiguities. When this occurs, there's more uncertainty in your question, then there is in the issue that the question asked.
We understand gravity ENOUGH to make it work. It may not have the same degree of certainty as some areas of physics, but it has more than enough to hold its own.
Zz.