Severian

Wow! Itsn't that, like, all the world's physicists!? And they are all atheists!?

None whatsoever!

Well, now I have absolutely no motivation to spam.

Let me put it another way. Look at the equations which ajb wrote down. There is no quantum mechanics there - it is simply expanding the metric in terms of small perturbations, and that is well defined and reasonable to do anywhere that gravity is weak (i.e. everywhere except right next to a black hole). So the graviton, as a fluctuation of the metric, most definitely does exist. The question is, is this fluctuation quantized? Can we rewrite the field [math]h_{\mu \nu}[/math] in terms of an operator and apply it to quantum mechanics (the process of second quantization)? Since (as atheist implicity said above) we have been able to do this for every other field we have ever come across, it does not seem much of a stretch that we should be able to do it here too. The difficulty is that this field is intimately linked with the space-time symmetry, rather than an internal symmetry, so things may be a little different...

To me, the most surprising thing about string theory was how long it took anyone to generalize it to branes. I would have though that the 'radical leap' was points to strings. But once your number of dimensions for the object is >0, I would have thought it very natural to increase the dimensionality.

Saying that cosmology is the new theology is, in my opinion, insulting to both cosmology and theology. No matter how flakey you may think certain cosmological ideas and/or cosmologists are, cosmology is still an experimental science. It can make predictions that can be confronted with data and tested.

Were the avatars all different sizes before, or were they stretched to be one size for everyone?

I don't like the avatars on the right, because I used to use them as fast visual identification. Separating them from the name makes this harder. I don't like the boxes and shadows because they create too much unused space between posts, which means I have to scroll a lot more. It seems slower. Too blue. I do like having the data for the posters on the bottom of the post though. And I like the coloured names rather than icons showing their status.

Sounds fair to me....

You are indeed lying. Photons do interact with one another via virtual charged particle loops. This is known as light-by-light scattering. It is very small but it exists. So even in the most literal sense of the word invisible (can't scatter light), light is not invisible. Edit: Bugger. I should read the whole post before replying. Atheist even gave a piccy of it. Bah humbug!

Flip burgers?

If my boss made me do that I would report her to the Academic Senate and have her fired. And then I would have her job.

I was pointing out that 0/10 is a number, so it is a valid number of points. It wouldn't be redundant. All the admins have to do is give 10 points to the people they already trust (ie. themselves) and then they can award points. The people they give points to are more likely to be trustworthy, and if they get enough, they can give points too. Seems like a good system if you ask me. As it is now (or soon) any Tom, Dick or Yourdad can give points out like candy, which can't be good.

[math]\frac{0}{10} = 0[/math] last time I checked.

The most interesting thing to come out of WMAP lately is their evidence for inflation.

What is the point of starting with 10 if you can't take points away? Why not start with 0?

I object to being labelled 'Primate'.

So why is this thread still open then?

I think I prefered the old style.

It hasn't got many hits because it is a lot of rubbish. It is full of trolls who just make outrageous comments to provoke religious people into an argument. It wouldn't be so bad if the trolls knew something about science, but they clearly don't, and there is no point in discussing with them since they have closed minds and are not interested in true debate. They have even had mods leave, publicly declaring that they are leaving because of the amount of religion bashing going on (and that mod was an atheist!).

Well, I find it very discouraging the way people discuss these topics. They start with a statement "The universe has property A" where 'A' is some arbitrary guess or preconception of what they think the universe is like. Then many people explain to them why the universe is not like A at all. They argue for a while, but incontravertable evidence is produced to explain why we say it is not like A. They pipe down and discuss some other sidepoint, and then a few days later say "The universe has property A" again, and the whole process starts all over again. (Usually they make a new thread, but in this case they didn't even do that...). Its a bit soul destroying really,

I must admit, it is threads like this that made me request to have my 'expert' status removed and made me stop posting for quite a while...

I understand what you are asking. The difficulty is quantifying what one means by increasing knowledge of how the universe came into existance. If you mean the actual creation event itself, then there is no scientific observation that can add knowledge since it is an unscientific question. On the other hand if 'how the universe began' includes the first few (micro)seconds, then pretty much all of particle physics and cosmology has added knowledge. For example, the WMAP measurements of the CMBR, or the particle physics measurements of the Standard Model. As for confidence levels, it is interesting that cosmology and particle physics have different standards on what they are willing to report. Cosmology tends to report results at 2-sigma, which is about 95% CL (for example the WMAP exclusion in their plots is all 2-sigma). Particle physics has two 2 levels of confidence it uses. If something is observed at 3-sigma (~99.7% CL) then it is termed 'evidence', so a paper 'Evidence for...' will be reporting a 3-sigma signal. But if they want to use the word 'discovery' (ie. making something a 'fact') then they use 5-sigma (which is 99.999943% CL)

I would also like to add a technical point. Even though theories of quantum gravity, such as supergravity are non-renormalizable, that doesn't make them wrong. It just makes them incomplete. After all, Fermi's theory was also non-renormalizable, and look what that eventually led to...

Or even worse, where to put the USB port.