Which disciplines would you call Hard Sciences vs. Soft Sciences ?

[humanino]

Where does the idea that we're going to get 'the answer' in the next few years come from?

I did not say we are close in time. We have achieved during the previous century a convincing unification of 3 out of 4 fundamental interactions. We are close logically to complete this process. It appears the last step is more difficult.

 

[rewebster]

I did not say we are close in time. We have achieved during the previous century a convincing unification of 3 out of 4 fundamental interactions. We are close logically to complete this process. It appears the last step is more difficult.

century? I guess 'close' has a different time span for 'logically close' to me.

I think it was Hawking who said something about 20 years, but I can't remember what year he said it.

 

[cronxeh]

I did not say we are close in time. We have achieved during the previous century a convincing unification of 3 out of 4 fundamental interactions. We are close logically to complete this process. It appears the last step is more difficult.

You've got to admit that the unification attempts are more of philosophy than science. In any event, who came up with the idea that there is a need for a unifying theory? Was there some pattern to suggest that perhaps that which applies to magnets will apply to the nucleus and to the planetary motion?

 

[Klockan3]

century? I guess 'close' has a different time span for 'logically close' to me.

I think it was Hawking who said something about 20 years, but I can't remember what year he said it.

That got to have been an estimate assuming that the standard model where correct. However as it is now I bet that the standard model is wrong, that would be the most interesting thing that could happen in my opinion.

 

[humanino]

You've got to admit that the unification attempts are more of philosophy than science.

No I do not have to admit that. Theoretician groups do they best to come up with tests and experimentalists do they their best to find deviations from the standard model. I know literally dozens of highly dedicated individuals who work on unification and I think deserve the title of scientist.

In any event, who came up with the idea that there is a need for a unifying theory? Was there some pattern to suggest that perhaps that which applies to magnets will apply to the nucleus and to the planetary motion?

Yes, there is an obvious pattern. Unification has definitely been the most successful path in physics.

Maybe you need to remember that it was not obvious at all planets and stars would obey the same dynamical laws as rocks and apples. That was the first major unification : universal gravitation.

Then electricity and magnetism. Why would a magnet be anyhow related to Sun light ?

Then electromagnetism and weak interactions are actually two inseparable faces of the same electroweak coin. Radioactivity and magnets stem from the same electroweak interaction, we already know that. Besides, strong interactions are also unified in the same gauge scheme, and you cannot renormalize the standard model of particle physics (given its flavor and charge structure) without SU(3) of strong interactions (cancellation of anomalies).

We do have reasons to believe it does not stop here, and includes gravitation as well. For instance, weak interactions know of spacetime symmetries, they are chiral : they like left-handed particle and right-handed antiparticles. Another reasons is simply that gravitation knows of everything : there is no regime where gravitation "decouples" from the the standard model interactions. Yet another reason comes from supersymmetry : the almost perfect match in the running of the couplings becomes perfect with supersymmetry, and this includes gravitation.

So there are very general, historical reasons to believe in unification, and there are very specific, technical needs for it.

 

[humanino]

century? I guess 'close' has a different time span for 'logically close' to me.

Again : it is not close in time. It could be thousand of years from now, it could be a billion years, it is irrelevant : we logically close because we completed 3 steps out of 4.