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Why Is Gravity the Weakest Force?
StartsWithABang writes: If you calculate the forces between two fundamental particles separated by subatomic distances, you find that the strong, electromagnetic or weak nuclear force could all be the strongest, dependent on the particulars of your setup. But throw gravity in there, and it turns out to be weaker by some 40 orders of magnitude. This discrepancy, that gravity is such an oddball, is known as the hierarchy problem, and is by many measures the greatest unsolved problem in theoretical physics. Yet the new, upgraded run of the LHC has the potential to uncover any one of four possible solutions, some of which we have hints for already.
Theoretical particle physicist here. These claims are hype. Pure wishful speculation to entice funding agencies via the general public. They should be ashamed of themselves. Best to ignore them. Cui Bono.
Because. That's all. There doesn't have to be a reason. The mystery is the puzzlement.
Unlike the other three forces, gravity neither cancels out because of negative and positive versions, nor peters out beyond subatomic distances. Its effects are therefore cumulative over huge swaths of the universe.
If gravity were much stronger, the entire universe would collapse into a singularity, and we wouldn't be here to gaze at our navels about the issue.
We are dragged along by four dimensions as they expand, but we can still move freely in the other three, but not time. Coincidence? Yeah, probably, but maybe not.
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I tried reading that article on my mobile device (doesn't support ad-blocker). Got ten ads. The first was a full-screen block that, after I clicked through, didn't even take me to the article. The other 9 all caused the article to "repaginate" under my fingers when I reached them (or at least, recalculate vertical spacing) and all blocked further text until they'd spent their 1-2 seconds loading.
What a terrible experience. So sure that I never got to the actual substance of the article before I gave up.
Oh, also a permanent title bar that takes too much of my small device's limited screen real estate.
Forbes is a disaster on mobile.
Why Is Gravity the Weakest Force?
Entropy? If there are other universes some of them may have a different set of physical laws due to their big bangs or their aftermath playing out in a subtly different way than in the case of our universe. If some of these other universes have strong gravitational forces they will presumably pass into something resembling the upcoming black hole era of our own universe before developing any intelligent life so let's just be happy our universe has weak gravity.
Redirects to forbes.com/welcome, which is an empty page.
Stop linking sources with crude javascript, please.
if you think about it for a moment in terms of the weak anthropic principle, gravity has to be very weak, because it is cumulative. The Weyl curvature of spacetime, which is the metric tensor that governs the propagation of gravity in free space, acts across the entire Einstein manifold, i.e., everywhere at the same time. If gravity were any stronger, it is pretty unlikely that matter as we understand it would be able to exist long enough to produce objects like humans capable of asking that question.
With that said, it is not really an important question question on its own, as the over-hyped intro suggests. The important questions pretty much are looking for explanations as to why the universe behaves so differently at different scales and velocities. Important questions in physics and cosmology are more along the lines of "Why are our two most successful theories about the nature of the universe, quantum mechanics and general relativity, incompatible with each other?"
We know the theorists want to be able to describe gravitation in terms of Quantum Mechanics. This will necessarily involve hypothetical "virtual gravitons" as "exchange particles" between interacting masses. So:
How do gravitons, even virtual ones, escape a black hole?
How do gravitons from the Sun pass through the Earth to affect the Moon (and artificial satellites) when eclipsed by the Earth, as if the Earth was a zero-size object? That is, the orbits of those bodies don't change just because the Earth sometimes eclipses them from the Sun's perspective.
In a way, just one proposal can answer both those questions, plus the one in the title of this page's article. If gravitons interact very rarely with other particles, including each other, then they can't stop each other from escaping a black hole, the Earth would be mostly transparent to them --AND gravitation would be the weakest force.
Some force has to be the weakest. And perhaps there's some other force 40 orders of magnitude smaller yet. maybe there's some inter multiverse quantum repulsion that causes multiverses to diverge. We just don't know about it.
Likewise it's possible there's some force 40 orders of magnitude stronger than the strongest forces we know of. perhaps quarks have sub particles that are held together by this but it's so string we've never seen them unbounded.
Some drink at the fountain of knowledge. Others just gargle.
Progress is insanely expensive, funding is all but non-existent, it's hard to find talented scientists who actually want to study it, and the general public just isn't interested anymore.
I completely disagree, funding still exists although it is being squeezed by governments who want to fund building better widgets rather than understanding the physics which will let you continue to do this 50-100 years in the future. Given the article it is clear that the public are interested in it - so much so that they will listen to someone like 'startswithabang' who, when it comes to particle physics, doesn't really know what he is talking about since the heirarchy, or fine tuning, problem is all about trying to explain the difference between the mass of the Higgs and the scale of gravity and not just why gravity is so weak. For example in SUSY you still end up with gravity incredibly weak and there is still no explanation as to why.