# What do these Physicists “do” anyway?

Before we start any Physics problem post, let’s define its parameters physicists. A physicist is someone who gains knowledge about Nature. He’s curious to define the phenomena of nature (like how something works) by a bunch of his laws. He doesn’t care about (nor believe in) any omnipotent being out there defining the laws of nature. He just goes on his own way…

## Unity of Physicists & Philosophers

At the start, physicists and philosophers were tangled. For instance, Aristotle was a philosopher, whereas Kepler, Galileo and Newton were physicists. How did we classify that? Once, Aristotle formulated a law for the motion of objects, expressed as $F=mv$, and everyone believed in his words. According to him, an object moves only when there’s a force acting on it. It’s necessary to investigate how this is wrong. He went wrong because his world was dominated by friction (resistance to motion when two “stuff” are in contact, which still ruins our world). So, his law was apparently right, that you need to keep forcing the object to maintain some velocity. What did Newton’s $F=ma$ say? It says that there’s a change in velocity (for now, let’s ignore mass) when a force acts on an object. He’s right in a physical point of view, that an object stays at rest, or keeps going (due to inertia) as long as the total forces are balanced (unless a force acts on it). This has been widely observed.

And this was the main reason, they both got separated (so did all other sciences). Observation. Any consistent theory in Physics has a need that it should fit with observations. If it doesn’t, it’s simply philosophy. There’s no reason to talk about it.

## What have people done so far?

(I ‘m making this precise. If you’re interested in the whole story, go read “The Elegant Universe” by Brian Greene. Or, try watching his video series)…

During the 16th century, observations done by Galileo (the concept of inertia and that objects fall at same rate, not really) and Kepler (elliptical orbits of celestial objects) was enough to prove Newton’s laws of motion and gravitation. Thus, he united apples and celestial objects. In the 18th century, two sets of magical equations, formulated by Maxwell was enough to concrete electricity and magnetism (based on observations done by Faraday, Lenz, etc.), which were different aspects of exactly the same thing. Later, in the 19th century, Einstein unified the concept of space & time using light and finally theorized a general law for both gravity & light. What do we see here? Physicists are trying to unite the basic forces of nature. They’re just doing the knitting job (by means of some guesswork) to define nature. As a result of these successive unification, we found the existence of four fundamental forces – Gravity, Electromagnetism, Strong & Weak nuclear forces.

## The “Breakthrough”…

Einstein’s quest for unifying all the forces of nature failed, because he believed in absolute predictions. His phrase was “God does not throw dice” (despite of his contributions to the field) But in the 1920s, a new theory arose to explain the phenomena happening at quantum scales. It was based on one & only fact – “Nature speaks in the language of probability, to which humans’ knowledge & instruments are limited to”. Can we predict the result of a coin toss? or a die? NO..!!!

By following this guess, people (a lot of ’em – Dirac, Bohr, Planck, etc.) were able to predict the results of observations quite accurately. But, QM didn’t make predictions directly. It just showed likeliness that “in how many ways one can solve a particular problem”. Along the way in the 1930s, the interest in the universe grew up spontaneously, by solving Einstein’s equations for gravity (people came up with different solution each time), which gave a gentle tap to astrophysics & cosmology.

Well, the interest in universe  was already there, with Astronomy being the starter of Physics, which was smoothly growing (for centuries). But, the theorizing part came out with the magic explanations of quantum mechanics (how stars burn) and general relativity (how the universe was born).

In the 1960s, Standard Model was found and a lot of new particles were observed. Then, physicists had a problem of fitting these new particles into SM and also in explaining the weak force. A lot of assumptions were made so that the theory fits with observation. Somehow, quantum mechanics managed to unite light with the nuclear forces. But, there was one last unification left. General relativity (one that theorizes extremely large scale structure of universe – gravity) and Quantum mechanics (which deals with extremely small scales). Thus, quantum theory of gravity was formulated. More than four decades have gone. But still, physicists aren’t able to unify gravity along with QM and succeed in arriving at the ultimate “Theory of Everything“…

But, quantum mechanics solved a lot of mysteries and helped its daughter sciences like Chemistry, Biology and even lead to the  development of a new era – Electronics. Both got separated out from our family. Well, there’s a valid reason. Because, you don’t have to go around and learn about the wave function collapse, Eigen states and stuff deeply to understand how an NPN transistor works or how sulfuric acid reacts with zinc. Useful successive approximations are far enough. But still, we’re quite proud that the theoretical insides of both still need Physics…

## On the Quest to reveal Science Fiction…

For more than a century, physicists were using zero dimensional point particles for their theories. Now, they’ve to develop theories to fit to observations, instead of making predictions from theories. Due to their existing unsatisfactory models which are clinging out incomplete, they set out developing a new theory for unification. String Theory, which made an unique assumption that all particles in their heart (in the deepest scale) are made of one-dimensional vibrating strings, which maybe open or closed, and that each kind of oscillation represents a new particle…

But, this unification comes at a price. 6 extra dimensions in addition to 3D space, Multiverses, new supersymmetric particles etc. There was a suggestion that these extra dimensions are curled up so tightly (within 3D) that we’re not able to observe them. Another major issue is that, the theory has a lot of predictions, but none can be observed yet..!!! Even a single false observation can prove it wrong. String theorists, having resolved the five different kinds of string theories and other anomalies, thereby unifying into a single M-theory, are trying to achieve the unification by means of their math magic.

So, Is string theory Science (or) Fiction ? We just don’t know (at least till now)…

I think Philosophy has cursed Physics for not believing in its dreams. That maybe a reason why the unification takes quite a long time. Even in Wikipedia, whatever you search, click on the first link and crawl on links continuously, it finally leads you to Philosophy

## Fate of Physicists…

In addition to these, physicists have a lot of problems in real world, because they apply “Physics” in their everyday life. They see & visualize things in a very different perspective and go crazy sometimes.

Just like dark matter, that doesn’t like to interact with normal matter particles or photons, but prove its existence only by gravity, physicists have the difficulty that they won’t be able to interact with normal people, but prove their existence only by means of Physics.

A guy at Stack Exchange, once told a quote, which I can never forget…

“Once you become a physicist, there’s a risk that you won’t be able to talk with normal people”

______________________________