The Principle of Relativity (in the restricted sense)
Word of the day – Anisotropic – having different values when measured from different directions.
Albert is trying to be as clear as possible, but I don’t get it. Perhaps it is the language of the early 1900s that is perplexing me or I am just plain dumb as a box of rocks. But I am not daunted.
Something that moves in a straight line at a constant speed is said to move in a uniform translation – imagine the old train car jugging along --------
Now if a raven is flying overhead while we are on the train it will have a different uniform translation than if we saw it flying overhead while standing on the ground. I get that, but then Albert has to start in with this math crap —“If a mass m is moving uniformly in a straight line with respect to a co-ordinate system K, then it will also be moving uniformly and in a straight line relative to a second co-ordinate system K1, provided that the latter is executing a uniform translatory motion with respect to K”. What happened to the raven??
SO –If the Train is moving in a straight line in relation to the guy on the ground, and the raven (m) is moving in a straight line with respect to the train, then the raven will also be moving uniformly in relation to the guy standing on the ground.
So Albert’s brilliant principle of relativity (in the restricted sense) is –If the raven maintains a uniform translation it will follow the same general laws as the train in relation to the guy on the ground. I thought we already kind of knew that.
Oh crap – there is a BUT. But in view of the recent development in electodynamics and optics things might be more difficult - of course.
If a man (w) is walking inside a train car (v) (in the same direction as the train car) his distance (W) traveled is the combination of his walking (w) and the train’s movement(v)
W = v + w
Then we have the speed of light – 300,000km per second in a vacuum – and this, Albert says threw physicists into a tizzy. Because if light (c) is moving through a train car (v) instead of a man it is now W = c- v. It is subtracted. It is not the same equation and that screwed things up. But I’m not sure why? Is it because the light is so fast that the train in essence traps it and slows it down? Like catching a flying hummingbird in a net. Okay. I’m good with that. However – since these two equations don’t fit, one of the founding theories was thought to be flawed - It couldn’t be relativity, no, not Albert’s brilliant idea. Perhaps it is the idea of the constant speed of light.. No. That can’t be it either. Some other guys proved that. So – we need another theory to explain the inconsistency.
At this point my book exploded – literally.
I guess I’ve been too rough on Albert.
Welcome to Theoretical Thursday!
Today I start a new journey of expoloration and learning. I will endeavor to learn Theoretical Physics. For as long as I can remember I have loved science – the idea that things are discoverable and understandable largely just by being observant. The life cycle of an insect, the growth of mold on bread, the magic of a healing cut, etc. And in physics class - A ball in a wagon is set in motion when the wagon is pulled. When the wagon stops, the ball keeps moving… etc. I get that. After all, I was the girl who scored the highest in all things mechanical on some Junior High assessment test (you had to follow the cogs and wheels of a machine and draw the direction of movement for each.)
But then I hit a road block – theoretical explorations where things like quirks, quarks and the Higgs-Boson particle are spoken about as if they too were sitting in a wagon. As I type this sentence, I realize that my ignorance may be showing and these things are real and observable and I just haven’t understood the conversation. And that is the impetus for this experiment – I want to understand the conversation. I want to understand how very smart men and women can earn a living by making stuff up. At least that is what it seems to me, right now, in my theoretically-challenged brain.
So, who better to teach me Theoretical Physics than the great man himself – Albert Einstein. And I just happen to have his book –
RELATIVITY: The Special and the General Theory, A Clear Explanation That Anyone Can Understand. (Wanna bet?) Even Einstein appears to have misgivings as he peers at me with raised eyebrows from the photo on the cover. He holds his hands in pre-wringing motion as if to say, “This job may be harder than I thought.” And I think he may be right.
This book, written in MCMLXI, includes a preface. “The present book is intended, as far as possible, to give an exact insight into the theory of Relativity to those readers who, from a general scientific and philosophical point of view, are interested in the theory, but who are not conversant with the mathematical apparatus of theoretical physics.” I fit that bill – I am interested. And I am not conversant. So far so good.
His next sentence (Don’t worry, I’m not going to go through the whole book sentence by sentence. I think.) presumes I have an education of a standard “corresponding to that of a university matriculation examination.” I have a Masters in Anthropology, but that probably isn’t what he meant. I suspect that exams in MCMLXI might have been more rigorous than they were when I graduated, but I can’t be sure, so I press on.
The book also presumes, “…a fair amount of patience and force of will on the part of the reader.” Hmmm. Might have a problem there. I didn’t have much force of will last night when I ate 4 bowls of popcorn and a couple glasses of wine. (Note: it was “Smart Popcorn”) However, Albert promises that he has written the book in a ‘step-motherly-fashion” (and I’m hoping that doesn’t mean evil Cinderella’s step mother) and he hopes the book may bring someone “a few hours of suggestive thought!” (Albert, you dog! I don’t know about a few hours worth, but I like a suggestive thought now and then.)
That preface was written in December 1916. The edition I have is the 15th edition and on June 9th, 1952 (8 years before I was born) he wrote a short note about the addition of a 5th appendix about the “problem of space in general and on t
