A fountain of ammonia to look for holes in the Standard Model

Enlarge / Like this, but much smaller, much slower, and far more toxic. (credit: Houston Texas)

All the cool kids are talking about dark energy and dark matter. Why? Because these are things that current physical models don't predict. The hope is that understanding one or both of these concepts will unveil a new world where everyone gets cookies and is born understanding physical concepts like tensors. OK, maybe not everyone will get a cookie.

But dark matter and energy are not the only things that current physical models don't predict. The Standard Model, which describes the behavior of fundamental particles and forces, has a number of physical constants. These constants are measured, and we know them accurately. But there is no theory that predicts why these constants have the values they do.

What can we do about this? One option is to measure these constants under as many different conditions as possible and test to see if they are, indeed, constant. The focus of this effort has mainly been on change with respect to time. Researchers compare astronomical measurements, made on very distant objects, to lab measurements. To within measurement uncertainty, the fundamental constants have not changed in the last few billion years.