Seven Brief Lessons On Physics

Seven Brief Lessons On Physics is your guide to getting up to speed with current theories on how the universe works by explaining general relativity and quantum mechanics, the two pillars of modern physics.

The two pillars of modern physics are general relativity and quantum mechanics. Relativity is Einstein’s theory of how time and space relate to one another. Quantum theory, on the other hand, zooms right down to the atomic level to explain things. The problem is, although these two are widely accepted as plausible, they contradict each other.

The rules of relativity declare that space is continuous and curves. In contrast, quantum mechanics paints a picture of it being flat, using quanta, or finite packets, to describe how energy works. But this is what gives physicists the opportunity to develop theories that work better.

A leading contender is loop quantum gravity (LQG) that says that microscopic loops make up space. Think of these as the “atoms of space” that are the makeup of space itself. This means that space and time aren’t continuous. Space is comprised of tiny grains and time has a differing rhythm for every system in nature.

The other crazy part about this theory is what it says about the big bang, which many believe to be the beginning of our universe. LQG sets up the start of everything as more of a “big bounce” instead. This idea comes from the thought that a universe before ours now collapsed then exploded in what we think of as the big bang.

Thermodynamics sounds like a big word, but breaking it down it’s just simply the science of heat. The whole study of it comes from a simple question: what is heat? In the nineteenth century, it was thought to be under the roof of fluids, or calorics. We now know that heat isn’t a fluid but simply friction causing the atoms of an object to move faster. Atoms are always bouncing around all over the place and vibrating. And it’s simple to see that quicker vibrations make for hotter objects. It’s easy to see why heat happens, but how it moves around is a little more difficult. Take a hot cup of coffee for example. Putting a cold spoon into the cup will heat the spoon up, right? But what about the spoon adding some extra heat to the coffee? Shouldn’t it also become hotter from whatever heat the spoon has? In the eyes of Ludwig Boltzmann, this is because heat transfer happens just by pure chance. The way we see time is another thing that heat affects. Thinking of a pendulum, it slows because of the air it contacts as it swings. This friction causes…