### "The Essence of Physics" - Sumiswald, Switzerland, 3/31/16

The essence of physics, hmmmm, seems hard, but I'll take a stab at it and say it's the concept of momentum.

The basic equation is p=mv.  "p" stands for momentum (I guess because m was taken), "m" is mass, and "v" is velocity.

So momentum is mass that is moving.

Starting with the fundamental machines that we heard about in elementary school (lever, inclined plane, etc) all the way to the motion of the stars, galaxies, and clusters, and even the energy flows at the surface of a black hole, that's what physics is about: moving things.

There's a lot left unexplained in this, e.g. what is mass, why does it move, and where does it go?

Starting with "where does it go?" the answer has to do with space. If something moves from one place to another there is a distance between those places and a direction from one to the other.  My mathematical model of the creation of space was less than satisfying, maybe physics can do better.

So physics says that the universe had a beginning. This seems to mean it didn't always exist. Space, mass, motion---all this started at some point in time. But wait! It turns out that time is part of the universe, so time...what did time do? It began? But a beginning is a point in time, without time how could time begin? Actually, how could anything begin without time?

I guess we need to know what time is. First how do we measure it? We measure it with clocks. There are many kinds of clocks but they all count periods of moving things. A clock goes around or digitally progresses through 12 or 24 hours and then repeats. Atomic clocks count the number of pulses or cycles of certain atoms.

Of course, this measures time in units of time. That's like measuring feet in units of feet, like telling you that a distance of 4 and a half feet is exactly 4 and a half feet long. You should think about that some. It's subtle. If the rate of time were changing we would never know it. All the clocks would speed up or slow down together, including all the human thought processes, so we would never be aware of any change. This kind of thing is commonly known today as part of Einstein's special theory of relativity, that time is not constant under certain conditions. These conditions have to do with motion. You can't have motion without mass, and mass in motion is momentum.

I'm going to jump to my fundamental definition and say that for us, time is the motion of mass, which is momentum. Time is momentum.

So the "beginning" (I'm very leery of that term) of time is the beginning of momentum, which is the beginning of mass and motion.

Was space already there? I don't see how it could be without time for a lot of reasons. (I'll come back to this later.) So add space in there too.

We're looking for the beginning of time, mass, motion, and space all together.

Since we have to have mass in order to have motion, maybe mass is the fundamental concept of the universe.

More on this next time.

----- Hugh