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Techno-Raver
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If all four fundamental forces were once unified and equal, why is gravity so much weaker than the other three forces?
Techno-Raver said:If all four fundamental forces were once unified and equal, why is gravity so much weaker than the other three forces?
Mindscrape said:This may or may not be on the topic, but does anybody know that since Fermi Labs found that neutrinos have mass how much more of the universe's mass is now accounted for? Is the search for gravitons still taken as seriously?
Farsight said:This is by a science fiction writer so shouldn't be considered serious physics, but it's "open your mind" interesting.
http://www.npl.washington.edu/AV/altvw98.html
Why is gravity so weak? Why are the color forces between quarks so strong? In the standard model of particle physics, why are there so many different energies at which distinct fundamental forces are supposed to "unify", and what determines these widely separated energies? The answers to these questions may be provided by extra dimensions curled into loops a millimeter around. In other words, our universe may be only a millimeter across, in directions we are not yet able to perceive. In this column we'll consider millimeter-size extra-dimensional loops and their implications...
ZapperZ said:You'll notice that this is OLD. The Adelberg's group at U. of Washington has already verified gravity up to sub-micron scales with NO deviation in G. This implies that there are no "extra-dimensional loops" at the millimeter scale.
Zz.
George Jones said:I'm not sure what happened to this
http://cosmicvariance.com/2005/08/12/rumors-of-new-forces
I'll try and take a closer look this afternoon.
ZapperZ said:In any case, it is still NOT at the mm scale that all of these "extra" dimensions for gravity have been predicting.
Yes string theory does have a good idea about why gravity is so weak you might want to watch thesehttps://www.physicsforums.com/showthread.php?t=8241" for more about string theory.In cosmology was gravity soppsed to become sepreate form the other field froces first. Could this have somthing to do with the reason why gravity is so weak.nrqed said:Nobody really knows why. One idea is inspired by string theory/ brane models scenarios. In string theory, gravity is mediated by closed strings whereas the other forces are mediated by open strings. And it turns out that open strings have their ends attached to submanifolds (the so-called branes) whereas closed strings may propagte freely in all dimensions. If our universe is one of those branes, this would explain why gravity appears weaker: the force is "spreading" out in all dimensions and appears to us weaker. The other forces mediators are confined within our brane and do not "leak" out in all the dimensions.
ZapperZ said:And no one is looking for gravitons right now. Gravitons and "gravity waves" as the ones being looked for with LIGO are not the same thing.
Techno-Raver said:If all four fundamental forces were once unified and equal, why is gravity so much weaker than the other three forces?
nrqed said:well, if I knew why I would have a good shot at a Nobel prize!
Nobody really knows why.
DM said:Can anybody ever look for gravitons knowing they're virtual particles?
Can anybody look for any virtual particles for that matter?
ZapperZ said:How did you think we confirmed the existence of the W and Z particles that mediate the weak interactions, the gluons that mediate the strong interactions, etc... etc? Virtual photons are not verified? Let's throw out QED.
DM said:Actually, I don't know.
I've simply read that virtual particles cannot be directly detected, which makes perfect sense to me. Whether there are practical ways to detect them or not is of great interest since theoretically it sounds very difficult.
ZapperZ said:You should know by now that in physics, unless things are experimentally verified, we normally do not award Nobel Prizes for it, especially if it is theoretical work.
DM said:Your previous post perplexed me. It gave me the interpretation that someone actually directly detected virtual particles, or if not, that there were ways of detecting them and therefore enabling physicists to apply the same experimental procedure to detect gravitons.
ZapperZ said:What's perplexing about that?
DM said:You agreed that virtual particles cannot be directly detected.
Are you now implying they can?
Again, I'm left somewhat perplexed.
Farsight said:For the record, I don't think it's weak.
If I might reiterate without boring you guys: Sure it's weak on the local scale, but that's because it's on a bigger scale. Like the two scaffold poles, both bent into a U. One's only ten foot long, so if you're clinging to it, you really notice the distortion. The other one's a million miles long. It's just as distorted, but you don't notice it so much because it's all so much bigger.
rbj said:personally, i would like to know in what sense do you mean that gravity is weak?
why are the masses of the fundamental particles so, so small?
George Jones said:In other words, why does Nature sprinkle an electron so liberally with electric charge and so conservatively with gravitational charge?
The answer could be "That's just the way it is." or it could be due to some profound new physics.
Or it could be that the gravitational charge of an electron is not (relatively) small,
and that, as nrqed oulines, gravity leaks out into other dimensions while other forces don't.
rbj said:not from a POV of natural units. the mass of even a proton or neutron is exceedingly small (in terms of the natural unit of mass).
The four fundamental forces are gravity, electromagnetism, the strong nuclear force, and the weak nuclear force. These forces govern the behavior of matter and energy in the universe.
Gravity is the weakest of the four fundamental forces, but it has an infinite range. This means that it affects all objects, regardless of their size or distance from each other.
Currently, the weakness of gravity is explained by the Standard Model of particle physics. According to this model, gravity is weaker because it is mediated by a massless particle called the graviton, which has a much smaller coupling constant compared to the other fundamental forces.
Exploring the weakness of gravity is important because it could lead to a better understanding of the fundamental laws of the universe. It could also help us develop new technologies and potentially lead to the unification of all four fundamental forces.
Some current research efforts include experiments at the Large Hadron Collider, where scientists are looking for evidence of new particles that could help explain the weakness of gravity. Other efforts include studying the effects of gravity on a quantum scale and exploring theories such as string theory and loop quantum gravity.