Forecasting The Fate Of Mysteries

What will be completely satisfying will be to show that there was only one kind of nature that was logically possible and derive the laws of nature in the same way that we derived the principles of arithmetic. I don't think that will be possible, because we can already imagine logically consistent laws of nature that don't quite describe the world we see. We will always be somewhat disappointed. But people who believe in God have the same problem. They will never be able to understand why the God that they believe in is that way and not some other way. All human beings, whether religious or not, are caught in a tragic situation of never fully being able to understand the world we are in.

I don't believe in God, but I don't make a religion out of not believing in God. It is logically possible that something could be discovered that will make me change my mind, and it will be interesting to see if that happens. But I don't expect it. It is always possible that we will discover something in nature that cannot be explained in the naturalistic way that we've gotten used to in science and that will really require divine intervention. That hasn't happened. I don't know of any religious people who say that the breaking of the symmetry between the weak and the electromagnetic interactions requires divine intervention. Discovering the Higgs boson, or confirming the theory of electroweak symmetry breaking, is not going to upset people's religion.

Possible evidence of a 4th dimension
Brian Greene, Columbia University, string theorist
The one insight that we are most confident or hopeful about is supersymmetry. It's a little complex to describe in detail, but I can describe an implication: for every known particle species in the world—electrons, quarks and so on—we should see a partner particle that is as yet undiscovered. We find this possibility exciting because supersymmetry is an intrinsic quality of string theory. If you discover supersymmetry, it doesn't prove string theory right, but it does prove one of its central attributes to be right.

What Einstein did with general relativity, in terms of its role in theoretical physics, is give us an understanding of certain symmetries or qualities of space and time. Supersymmetry in essence is taking that to the next level. If supersymmetry is right, it's telling us that space and time have qualities that Einstein couldn't have dreamed of but naturally fit into the same progression that he started. There are other things beyond supersymmetry that again would tie into Einstein in a deep way that could also be found.

The LHC could provide evidence for more than three dimensions of space. One of the ways that we have formulated string theory in the last five or 10 years suggests that the following might happen at the LHC. What happens there is you slam one proton against another proton traveling in opposite directions near the speed of light. And there are literally trillions of protons going around the LHC at something like 11,000 times a second. And then you have these collisions. What might happen is there will be some debris created in the collision that gets ejected out of our three dimensions of space into a higher dimensional space, dimensions that we don't have direct access to. How would you notice that? If some debris gets rejected, it will carry some energy with it, which means that if you measure the energy just before the protons collide and you measure what's left over just after, you should have a little less at the end than you had at the beginning. That would be indirect evidence that energy had been lost to more dimensions.

[The follow up to the LHC is] already being planned: the International Linear Collider. You can think about the LHC as a very powerful microscope, but it's likely to reveal just the gross features of the new physics. The ILC is a machine of a different design that has the capacity to then take the gross road map that the LHC can provide and begin to really go down the little alleyways and enchanting avenues, to really explore the terrain with the kind of detail and precision that the LHC likely can't. Let's say some new particles are discovered at the LHC. The ILC would have the capacity to study the very fine detailed properties of those particles, to really produce them copiously and understand with great precision their mass, election charge, interactions, things of that sort, which the LHC may be able to roughly say. The ILC is one that really can get in there and describe the properties with fantastic precision.

No, it won ' t swallow up the Earth
Stephen Hawking , Cambridge University, mathematician
The large Hadron Collider will allow us to study particle collisions at energies three times greater than previous particle accelerators. We can guess at what this will reveal, but our experience has been that when we open up a new range of observations, we often find what we had not expected. That is when physics becomes really exciting, because we are learning something new about the universe.