ajb

Isn't the question how may ways can you arrange 6 objects?

suppose we have no numbers on the dice.

pick a number. how many sides can we attatch this number? The answer is 6.

pick another number. This can now only be placed in one of the remaining 5 sides.

pick another number. we now only have 4 sides to place it.

etc...

so we have the number of possible ways os assigning {1,2,3,4,5,6} to the six sides of a dice is

6.5.4.3.2.1 = 6! = 720

relativists use commas.

Isn't it the number of permutations of 6 objects?

I am a physicists and I feel a little uneasy about fine tuning.

On a technical note, I always wonder about the renormalisation of fine tuned parameters. Generally you could set it classically to a number and then quantum effects could alter this value.

So, Severian what symmetry protects the Higgs mass? As I am no expert at phenomenology, I guess it is gauge symmetry?

Maths can even be done in infinite dimensional space' date=' although that is quite beyond me.[/quote']

 

In physics infinite dimensional spaces occur very naturally. In deed I use them all the time.

abskebabs;

Mathematically you can have spaces of any (integer) dimension. [you can also have fractal dimension but that is a different story]. A 26-dimensional space if fine. In fact (bosonic) string theory insists on 26 dimensions. We can talk about that somewhere else if your interested.

As for the Rubik cube, the mathematics of the problem is group theory.

Can you explain exactry what you mean by vacuum force? Do you mean somthing like the Casimir effect?

I am having the same problem.

I don't quite understand your question. do some more examples in full.

All I can suggest is that you search the archives

http://www-spires.dur.ac.uk/spires/hep/

http://xxx.soton.ac.uk/

My fav has to be maxwells equations written using differential forms. It goes straight to the heart of modern physics; physics does not care about the coordinates.

Thats my point exactly Atheist, the equations are just Gobble-Dee-Gook.

I am sure you have "good intentions" elas, but without careful explanation of where these equations come from (they may be empirical of course) and the units involved no one will be able to follow your logic.

I am thinking you don't mean "force" but work done, by something or on something. Work has the same units as energy.

Majid does quantum groups and related stuff if I remember rightly.

I know about loop quantum gravity, but it is not my research topic. My understanding (not being an expert) is that including matter was an issue.

My supervisors are Hovik Khudaverdyan and Ted Voronov. I would call their work supermathematics and supergeometry. Recient work of interest has been on odd-symplectic geometry and odd Laplacians. These things are all connected with the antifield formulism.

Topological field theory was something that we might look at also. Not sure exactly what, but probabily something to do with exactly solvable models and gravity in 3 and 2 dimensions.

I expect my research will be something related to this.

I have come across Freidel, but i have never actually read any of his papers.

I take it you are talking about the noncommutative geometry workshop at the Newton Institute. I won't be going, but i do know some of the participants.

Also as a side note, my supervisor did his PhD under A. Schwarz, who is one of the invited speakers.

The title of my PhD topic is "geometric constructions in quantum field theory".

I was told to go away and read up on fibre bundles and gauge theory, which I have done now, up to a few proofs etc. So thats why I want to be VERY clear on trivial bundles etc.

We are also interested in the BRST symmetries, these are a clever way of dealing with gauge theories by promoting the gauge parameter to be a dynamical anticommuting field. It is particulary useful when dealing with gauge fixed actions and quantum gauge theory. There is a lot of (super)geometry behind this which is of interest.

you wrote

r = F/M

so provided I am reading your equation right, the units are

[meters] = [Newtons]/[kilograms]

= [meters][kilograms][seconds]^{-2}[Kilograms]^{-1}

= [meters][seconds]^{-2} ???????

which is just wrong. Unless your F is not a force, but some other constant with units [meters][kilogram]^{-1}. Im not sure what that would physically correspond to.

Thanks Martin, I will have a look at the PDF you suggest.

I know how to prove it using the homoptopy axiom, it is quite simple really. I have no idea how you would prove the axiom.

AJB

With the USA I keep thinking about CSI, Law and Order, NCIS, things like that. So america is full of pedophiles, murderers, gangsters and gun carrying nuts! It can't be true?

AJB

I was thinking about R^n as I had manifolds as the base space in mind. Once I assume the homoptopy it is easy to prove. Basically, it allows you to identify a bundle over a contractable space with a bundle over a point, which is trivial.

I will look at the website you suggest Matt.

Cheers

Rocket man is talking about the Athena project at Cern.

http://athena.web.cern.ch/athena/

All the theory points to the fact that matter and anti-matter behave the same. This is due to some deep theorems of quantum field theory like the CPT theorem. It is a good test of quantum field theory and the standard model.

However, these ideas need to be tested and so Athena was born.

On a personal note, Mike Charlton is head of the physics department at the university of swansea. I did my undergrad studies at swansea. I think he joined in my final year.

I am not convinced by the basic formula you wrote down. Check the units carefully.

The following site will helpyou

http://units.nist.gov/cuu/Units/units.html

Does any one know who to prove that fibre bundles over contractible spaces are trivial?

One method woud be to use the Homoptopy axion for bundles. Do you know how easy that is to prove?

I was wondering if there is a more geometric method of proving it. It seems obvious that on say R^n we could use the global coordinates of R^n as a local trivialisation. Thus only one trivialisation would be needed and hence we have a trivial bundle. Can this be proved?

Any ideas and references welcome.

Cheers

AJB:confused:

It is not something I have thought much about. Everett to me seems a "waste of space", the number of so called parallel universes would be huge. The Copenhagen interpretation relies on the obsever to much, it is difficult to think about quantum mechanics of the whole universe in this way.

So I really don't know what one to vote for, both have pros and cons. Yet again maybe the answer is something else....

I will vote for the Copenhagen interpretaion. I think it is the most useful when dealing with most quantum systems in which you can define a classical observer.

To understand something I think you should have both a "mental picture" and be able to understand the mathematics and compute things.

Without the mathematical framework, you cannot say that you understand something. Most crackpots and people with "new theories" simply do not understand the mathematics of current thinking and hence dispute them.

But at the end of the day, physics (to me at least) is an attempt to describe the natural world using mathematical models. Some of these models are hard to describe, such as quantum mechanics.

I have also been able to make it compatable with the add-on "VariationalMethods" by adding a few more lines of code.

By doing so, I have been able to get the equations of motion for (N=2) one dimensional supersymmetric quantum mechanics. I am sure more complex systems could be studied, of personal interest are BRST symmetries in (pseudo)clasical mechanics.