What’s “Physics” doing?

You all probably know that Physics is the science to understand Nature. Take any science field – biology, chemistry, psychology, electronics whatever. Go to the deepest chasms of it. It boils down to Physics. This is because, the spontaneous breakthroughs in Physics over the last two centuries (especially quantum mechanics) paved the way for fruitful development of other daughter sciences…

Language of Nature

You can’t enjoy the enrichment of something completely without the use of a proper language. Nature is our best opponent (as far as knowledge is concerned), in a way that its lot smarter than us. It has been designed in a clever way to play its tricks around and fool our expectations.

So, if you have an idea of learning something about Nature, you should get a nice grasp on the language she speaks to us. From simple arithmetic and geometry, all the way down to calculus and probability, she communicates via mathematics. Whether it’s implicit or explicit, is our way of understanding the seemingly complex phenomena.

“To those who do not know mathematics, it is difficult to get across a real feeling as to the beauty, the deepest beauty, of nature… If you want to learn about nature, to appreciate nature, it is necessary to understand the language that she speaks in…”                                        – Richard P. Feynman

What’s the necessity for “WHY”?

People often ask, “why is something the way it is?”, without knowing the fact that it is not the aim of Physics (nor the physicists). Asking yourselves, “why should I do this, why to do that, etc.?” can help you lead a better life. But, please don’t ask “why” to us. Because, physicists always try to unravel how something in nature can be explained by means of the available consistent physical laws. Not why something works..!!! Because, a “why” question has infinite depth, that no one can solve it. Asking, “Why gravity is always an attractive force?” is equivalent to asking, “Why humans ever evolved at all?”

To such questions, the only answer we have, “Because, that’s the way nature has been designed..!!!”

(Feynman addresses the same issue with why questions in one of his “Fun To Imagine” videos. I suggest everyone watching it. At least, in that way, people can understand how it’s infinite…)

But no matter how many times you repeat, repeat & repeat, people don’t really stop asking why questions, as they’ve been brought up from their childhood asking such questions (Duh… Curiosity, you too suck sometimes..!!!). At least they can control shooting these questions towards a physicist.

So, what does Physics do anyway?

I cannot really explain it well. Go read the Feynman lectures if you’re interested for more. The nice usual analogy (always being followed) is a chessboard. That we’re all watching the Gods playing a chess game, we don’t know the rules completely (due to our limitation of knowledge), but we can try to figure out what are the common events and when they occur (i.e) when a common move is made. Then, we’ll try to bring a theory from it. For example, “the rook always moves straight”. We don’t know why it does that way (Ugh.. I’ve already told you “why“). But, we do know how it moves. Now, we apply this to other pieces and find if that works right. We find that it works for all the rooks, until we see the other pieces (pawn or bishop) moving differently. Now, we’ve to modify our existing theory (which is what’s always happening in Physics). And these are the places where physicists get interested – the places where some theory fails, so that they can discover some new consistent theories that (may) explain it.

So, at first, we do the guess (maybe good or bad) – it’s all about guesswork in science. We make sufficient assumptions for our guess and put that to analysis. We analyze what the results would be? if such a law is followed (I mean, the consequences) and finally surrender it to nature (i.e) compare the theory with observations. Like I’ve told (in the previous post), an observation is what differentiates science from philosophy.

Approximations as Nukes…

First, we should must digest the fact that our knowledge is limited. We cannot “always” expect Nature to give an outcome that agrees with our theoretical prediction. We’re not the one to say what Nature should do. She’ll do all her dirty tricks and we’re just here to find out what they’re and how they work. One simple question is far enough to overcome the belief in absolute prediction. Why do we rely on chances? Don’t get it? I’ll rephrase it. Why can’t you predict the exact number for the result of a die? Or, why can’t you say whether it’s head or tail for a coin toss? So, why do you rely on chances?

If you’ve got a wonderful theory (the theory hasn’t arrived yet, and it won’t..!!!), then you can predict the result. You can’t even rely on a single number. Truly speaking, approximations are weapons of Physics. When things seem to appear more complex to us, we just approximate it…

(And, I didn’t know that failure is success rounded down..!!!)

For instance, what’s the speed of a car covering a distance of 19 meters in 7 seconds? It’s really 2.7142857…… (and goes on). But, we approximate it to 2.7143. Is that exact? Nope. Why? Because, we don’t need our calculations to be so much accurate. We can just satisfy ourselves by rounding-off the value and apply to macroscopic problems. Keep in mind, we still have the uncertainty. (Make this issue bigger). Is such an approximation enough for predicting the motion of clouds in the atmosphere, and thereby “weather”? NO..!!! It’s not enough…

The predictions will be somewhat accurate only if you include the next 20 or so digits along. That too, will be true for 6 hours or say, a day. Then, you’d have to recalculate things again.

Here’s a rough analogy on what we do while experimenting & developing stuff...

Are you developing a theory?

Roughly, these are the steps…

  • Guess the theory
  • Approximate the model
  • Compute & analyze the consequences
  • Compare with observations and
  • Satisfy yourselves that it’s not so much accurate…

But, always keep in mind while developing your theory: It should be consistent with the existing theories and, it should be simple. Nature is simple, but the intertwining of “stuff” over and over is what makes it appear to be complicated. That’s why we follow the Occam’s razor and eliminate unnecessary things…

“Plurality must never be posited without necessity”                                         – William of Occam

What it says? We should always go with the easier ones, and then add complications step by step, when things don’t add up to the result. Well, he himself hasn’t stated the rule simply

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