The idea of 10 dimensions might sound exciting, but they would cause real problems if you forget where you parked your car.

Observations indicate that the universe is expanding at an ever increasing rate. It will expand forever, getting emptier and darker.

The intelligent beings in these regions should therefore not be surprised if they observe that their locality in the universe satisfies the conditions that are necessary for their existence. It is a bit like a rich person living in a wealthy neighborhood not seeing any poverty.

One might think this means that imaginary numbers are just a mathematical game having nothing to do with the real world. From the viewpoint of positivist philosophy, however, one cannot determine what is real. All one can do is find which mathematical models describe the universe we live in. It turns out that a mathematical model involving imaginary time predicts not only effects we have already observed but also effects we have not been able to measure yet nevertheless believe in for other reasons. So what is real and what is imaginary? Is the distinction just in our minds?

A lot of prizes have been awarded for showing the universe is not as simple as we might have thought.

Science predicts that many different kinds of universe will be spontaneously created out of nothing. It is a matter of chance which we are in.

The boundary condition of the universe is that it has no boundary.