String Theory

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I don't know if this is the right place to ask this question and I've never seen anyone ask this kind of question before, but:

Could someone who is better informed than I please explain what String Theory is? Then the rest of us can ask questions or add information and have a little scientific discussion here. I am curious and clueless. (Please, no smart a** remarks about violins or spaghetti, etc.)

http://en.wikipedia.org/wiki/String_theory

It's way over MY head.

Thanks for the link, Serissa. It's over my head, too. That is why I was hoping someone who understands it well could explain it in terms that could at least bring it into my grasp.

Understand it well? No, but I might just be able to see where it's coming from. What follows is a very broad brush depiction.

The basic continuing thread (no pun intended) is finding phenomena, scientific events, that the existing view of physical substance cannot account for.

In trying to understand the nature of the world, we might start with the idea of the four elements "Earth, air, fire, water" (centered around a fifth element? No, that was a film!)

The limitations here were soon apparent, but the idea that heat was a "substance" that flowed from one object to another (Phlogiston theory) lasted quite a long time.

Then came the first ideas of atoms: little hard balls of matter that could be combined in different ways. A model that is almost instinctive now, and still works at a basic level in chemistry.

The discovery that there was a structure inside an atom, a nucleus and electrons, was the next development. (Bouncing radiation off material showed it was *mostly* empty space) This led to the familiar "solar system" models, developing into electron shells which gave a better understanding of the periodic table of elements. A very good working model. But there were problems.
One, the ultraviolet catastrophe, (http://en.wikipedia.org/wiki/Ultraviolet_catastrophe) was a major factor in realising that the fine nature of the unverse was not divisible into finer and finer parts (the old idea that the atom was indivisible having long been abandoned) but came in definiote lumps, "quanta". This was first applied to electromagnetic energy, but was soon found to be useful elsewhere too, for example with wave-particle duality. Quantum theory became essential, down among the small stuff.

It didn't tidy everything, quite. In finding particles and forces making up the subatomic world, variant theories predicted different numbers of elements, "The quantum zoo", some of which had never been found, or did not behave as might be expected. The more particles that were uncovered, or predicted, the more there was a desire, and a hope, to find the fundamental particle behind fundamental particles. The one lego brick from which all bigger blocks could be made up, especially if the nature of this "brick" predicted and limited the variety of subatomic particles that can be seen.

It currently looks as though something which, mathematically, has the properties of a vibrating string may fulfill this concept. Down at this level there is only the maths, and the predictions.


Offered only subject to improvement by those knowing better.

*42*

"What do you get if you multiply six by nine?"

Ahhhhhh........ "Six by nine. Forty-two."
"That's it. That's all there is."


The Ultimate Question


The Ultimate Answer

it is 6 times 7, 6 times 9=54

lol yep. I don't think he tryed to work it out before he posted it.


Anyway about the string Theory. The string theory is a confusing piece of work that I am not even sure if there are on the right track with. The String Theories (its a plural because there is actually 6 string theorys not just one) are a attempt to try and merge the theory of relitivity with the Quantium theory.

The Quantium theory deals with the universe at a very small scale and the theory of Relitivity deals with the univerese on a very large scale. The theory of relitivity says that Time and Space can be bent where as the Quantium theory requires time and space to be stable.

I didn't realise I had forgotten so much about this stuff.

Sorry, as Liorda can confirm, the answer is "42", the question IS "What do you get if you multiply six by nine?" (The answer comes first, if that's any help)

"I always said there was something fundamentally wrong with the universe."


But you are right about the other. One theory, understanding, which reconciles quantum and relativity, is much sought, because it leaves a gaping hole in our understanding. It did not trouble previous generations of scientists, because they did not know it was there.
The same still holds for the vast majority of the public.
"If you are not shocked by quantum theory, you have not understood it."

If time and space are bent, does that affect the calculations of distances between stars and galaxies and the time it takes to travel to them? Do scientists already take this into consideration?

How much would string theory affect long-established theories?

(I am very curious about science, but a real "science dummy") Someone should write a book, "Science for Dummies"!

Yeah, it does - it's called Special Relativity and it means you can't go faster than the speed of light, but you could still travel to planets lightyears away in a few months (to you) if you went fast enough because the distance to them would contract. But if you came back everyone else would've aged more than you. General Relativity is even twistier

Technologies like GPS have to include relativistic effects to keep their clocks so accurate. So while you aren't going to use it to calculate the path of a bouncing ball (that isn't going near light speed), where it's needed, it's used.

All I know about String Theory is that it sounds very cool and uses lots of dimensions. But since it extends existing theory, it shouldn't contradict previously tested parts.

Steven Hawkin has written a few books which are supposed to introduce modern physics ideas without involving much math.

Quite fun, but with a lot of real science packed into it is "The Cartoon History of Time" by Kate Charlesworth & John Gribbin (ISBN: 0747406804)


It's a few years out of date on cosmology now, but will get you within striking istance of the latest stuff. Hmm. It has some value: starting at $30-40 dollars on
http://dogbert.abebooks.com/

Hey, thanks for the leads, Drizzle and Emmet men. My "must read" list is growing ever longer. I wish that I had been taught better in high school.

There's a readable and comprehensive brief intro to quantum physics and string theory here.

And there's news this week of awesome discoveries about so-called dark matter, the 95% of matter in the universe about which up to now we have known only that it is there. Dark matter, it seems, is not cold and dark at all (at 10,000C it is far hotter than the sun's surface); it is made of particles which are not slow and sluggish as had been thought, but zoom around at 9km/sec; and ! it clumps together in "building blocks" with a minimum size of 1000 light years across, with 30 million times the mass of the Sun. Large galaxies are built by combining these blocks and the stars they contain - but this process doen't work for small galaxies.

State-of-the-art cosmology which will change our understanding of the universe and ourselves, and change our lives in the future in ways we can hardly begin to imagine... read about it here and here.
_____________________________
it's the global warming gonna getya

I read Steven Hawking's book, "A Brief History Of Time", when I was 22. I was just coming to terms with the idea that I'd never be a professional footballer (!). That book, along with "Unweaving The Rainbow" by Richard Dawkins, made me wish I'd been a scientist.

I looked at the Hawking book a few years later, and I really couldn't work out what had so inspired me originally.
I had studied maths at university, so I knew what an asymptote was, and what a singularity was. But I knew nothing about physics, and many of the facts in the Hawking book are presented without any background or explanation.
And that's what I find frustrating about a lot of popular science. It might make a person look good at dinner parties (not that I go to any), but often doesn't provide a very deep understanding.

One of the best books I've read recently was "The Big Bang" by Simon Singh. It starts off explaining how the ancient Greeks managed to measure the circumference of the earth, the size of the moon, the distance to the moon, the distance to the sun, and the size of the sun. How they did this was something I never learnt, and something I might never have figured out for myself (some scientist, huh?). Anyway, reading this I felt it was something I should probably know before I started reading about String Theory. The book then goes on to cover Copernicus, Kepler, Galileo, Newton, Michelson-Morley, Einstein, Hubble and much more.
I would recommend it if you can put up with all the biographical information (which I personally found very interesting).

There is a book on The Standard Model of particle physics that I've started (and intend to finish one day!) called Deep Down Things by Bruce A. Schumm. There's almost no biographical information, and it looks far more informative than the Hawking book.
Even this book only gets round to devoting one page to String Theory!