Science a GoGo's Home Page Forums General Discussion Physics Forum The Hierarchy Problem, or why gravity so weak?

The other day I promised Bill S. that I would look into this and see if I can come up with something about it. So here is what I have found.



The Gravitational coupling constant is related to the Planck Mass.

That is from http://phys.wordpress.com/2006/05/10/a-problem-of-hierarchy/

There is also a list of the coupling forces at http://hyperphysics.phy-astr.gsu.edu/hbase/forces/couple.html#c1 This one does have some more esoteric formulas in it.

Anyway the problem is that there is such a large gap (33 orders of magnitude) between the gravitational force and the rest of the forces. Physicists just don't like that. They keep thinking that there must be some profound explanation of this huge difference. There have been a number attempts to explain it using such things as String Theory and Supersymmetry. The biggest problem with these and other theories that attempt to explain the gap is that they are so far untestable, and considered by many to be purely speculative.

This then is one of the huge unanswered questions in physics. It is hoped that if we can come up with a theory of quantum gravity it will help to explain the hierarchy problem.

Bill Gill

Thanks Bill. It's 3am here so I shall leave following the links for tomorrow.

Haven't dropped through in ages and not much has changed but this is the only thread I feel real discussion and thought is going on so I will prompt you guys to think a bit more.

I asked Bill a question he hasn't got back to which was "Is energy real?".

So lets join that concept up with your discussion here and consider what if energy isn't real what do we end up with

>>> http://en.wikipedia.org/wiki/Zero-energy_universe <<<

As a final thought provoke even in QM we have those on the fringe who challenge stuff. This has not passed peer review yet but it is probably worth having a look at

>>> http://www.newscientist.com/article/mg21...ntum-trick.html <<<

Keep up the thinking and questioning guys.

Orac asks "Is energy real?". I think he is the one that has a better grasp of that than I do. But I'm not sure how it couldn't be real. Unless of course we go to a Descartian universe where it is all in our minds. Descartes is the one that came up with the phrase "I think, therefore I am". He reached this conclusion after a lot of thought about what he could absolutely know to be true. He realized that people have dreams and hallucinations that are not real, but they seem real, so we can't actually know that what we see as the world around us is real, it may be a dream or hallucination. But he knows that he is real, because he is thinking. So in a Descartian universe there might not be any energy since it is all in our mind. That of course pushes the question back a step. If all we perceive around us is a product of our mind, where does our mind exist?

Then he has the link to the article about a zero-energy universe. Essentially that says that the total sum of the energy in the universe is zero. That doesn't say there is no energy. There is positive energy, mass, and negative energy, gravity. But that leaves the fact of energy alive and well, it is just that at the end of the day the books have to balance.

Bill Gill

It pushes the question of the locus of the mind back, but does nothing to the question of the reality of energy. Presumably, even if there is only one mind thinking it is using energy, so energy must still be a reality.

As I see it, there is only one way in which energy could be unreal. Sorry to bring infinity into the discussion yet again, but in an infinite cosmos everything "is", there is no change and no use for energy. Our perception of change is an illusion.

Not really sorry.

I need to make a change in that quote.

If all I see around me is a product of my mind, where does my mind exist?

After all if it is all in my mind, then there is no reason to suspect that any other minds exist. That should make it easy for me to get rid of all those irritating people that don't agree with me.

Bill Gill

I actually am sitting on the fence on this one I have seen no compelling answers either way and hence my interest in the question.

How you answer that fundemental question puts the settings in place for what the universe is and how it works.

A zero energy universe can only be flat but unfortunately we can't falsify the idea on that because the universe is measured to be sort of flat with an error either side.

When you look at any modern QM discussion you sort of end up at this sort of thing.



To put this in perspective I was taught in my student days energy was real and it's only when you started doing QM studies that you realise the question has never really been settled or even really tested.

In some ways even the past greats never really asked the question because like me they were taught it was real and never thought to question it. It was only the weirdness of QM that brought the whole question of what energy is into debate.

What is interesting in QM is that you can "borrow energy" because it encapsulates that other big unknown TIME and hence the question is very very important.

Trying to settle what the universe is and how it works without settling this question is ridiculous because anything you measure and any theory you setup is based around an assumption that you haven't really thought about.

And thats the memo for today :-)

Bill, I think the first thing you would have to clarify here would be: Is your mind finite or infinite?

You might also consder; if the universe is all that exists, where does it exist? If this question has any relevance, so might the question about your mind; otherwise, you're on to a loser!

I think that would be completely irrelevant. If the whole universe is in my mind I don't really have to have the whole universe. All I have to have is my interface with it. And that consists of what I can see, hear, and feel. That means that anything that I am not actually in contact with doesn't have to "exist". Everything that "exists" is what I am imagining. So it basically is a simulation. If you every played with a flight simulator on your computer then you realize that all of the things you see out the cockpit window aren't real. They are imaginary constructs built in the computer software. So the universe is the same way, it just exists as a simulation built in my mind.

So in a Descartian universe nothing exists that isn't imagined in the mind of the observer. Which then leads on to other philosophical conundrums. And it makes a lot more sense to decide to act completely as if the universe is real, not a construct of my mind.

Bill Gill

Bill, I agree with all that, except the idea that my question was irrelevant.

If your mind is all that exists and is finite, where is it?
If it is infinite, it is everywhere; so deciding if it is infinite or finite is very relevant.

I was suggesting that the same reasoning might be applied to the universe.

I think your problem here is that you are trying to apply a scientific attitude to a philosophical question. According to Wikipedia "Philosophy is the study of general and fundamental problems, such as those connected with reality, existence, knowledge, values, reason, mind, and language.[1][2] Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational argument.[3] The word "philosophy" comes from the Greek &#966;&#953;&#955;&#959;&#963;&#959;&#966;&#943;&#945; (philosophia), which literally means "love of wisdom."

The problem here is that philosophy is asking the really difficult questions, questions for which there are no hard answers. In fact this discussion is really NQS. I'm not sure where I picked it up, but I remember this. "If you laid all the philosophers in the world in a row they wouldn't reach a conclusion." So trying to discuss a philosophical concept in a physics group is kind of a dead end.

Bill Gill

Once again I find myself in general agreement, but would have to add that the infiniteness, or otherwise, of the universe is a physical question rather than a philosophical one.

Bill, I realize that you have an interest in infinity, but for my case I just can't get particularly interested in it. I know generically what infinity is, but the fact is that it doesn't really enter into anything that I am particularly interested in. As far as I am concerned everything that is within the scope of my interests can be counted. That includes such things as: rocks, planets, minutes, miles, degrees of temperature, megaparsecs, the age of the universe, and the size of the visible universe. The universe in and of itself may or may not be infinite. But since I can't observe anything beyond the visible universe it is of no consequence to me. I'm sure that there are some theorists who are very interested in the total size of the universe, but to me that is all philosophy, at least until somebody comes up with a way to measure it.

Bill Gill

As usual, you continue to make excellent sense. However,you say you can count, or measure all these things. Let’s take the megaparsec for example. Presumably you would measure this as about 3.26 million light years; but only if you are stationary relative to the Earth would you measure light as taking 3.26 my to cover the distance, or, indeed, measure the distance as 3.26 mly. At some point the question arises as to whether the time taken for the journey, or the distance between the two points, becomes infinitely small.