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Can anyone explain to me what 'string theory' is?
I know this is a stupid question, but I've heard about string theory many times, but have no clue what it really is. Please understand I have very little background in physic. Do you have a good explanation about what it is and why it matters a lot in our universe? Thanks!
Paul Mullins
lo xueyu
Enrico Petrucco 20+
The first thing one learns in Quantum Physics is that matter is merely constructive interference of energy. M-Theory exhibits the case for all particles and attempts to rigorously describe each manner of energy interaction.
It only matters insofar that humans wish to understand the Universe and to do so in the most elegant manner possible. M-Theory is the mathematical means to that end and may aid human exploitation of the Universe.
Non-mathematical means seek to understand the Universe less explicity, yet are equally relevant.
Benjamin Liu
http://en.wikipedia.org/wiki/String_theory
http://superstringtheory.com/
And...you can actually watch the entire "Elegant Universe" here!
http://www.pbs.org/wgbh/nova/physics/elegant-universe.html
Benjamin Liu
http://www.pbs.org/wgbh/nova/physics/conversation-with-brian-greene.html (If you like Brian Greene, check out this interview)
Also, you should watch Brian Greene's "The Elegant Universe" which seeks to educate the general public on the mysteries that physicists such as Stephen Hawking try to solve.
If you want to understand the universe you will encounter two branches of theoretical physics:
1. Quantum Mechanics
2. General Relativity
Quantum Mechanics seeks to understand the smallest particles in the universe, even smaller than the atom. In this realm, there is something called the "Uncertainty Principle." It says the closer you get to a particle, the less you know about its motion. Strange? Definitely--the quantum mechanics realm is perhaps as strange as you can get! Particles literally teleport from place to place all the time. In this realm, unreality blends with reality in a strange way. Unfortunately, you really do have to have a mathematical background to truly appreciate the phenomenon you see here.
General Relativity is a realm totally opposite of quantum mechanics, as it deals with objects in our universe. Partial differential equations are able to predict space and time of objects. Einstein is perhaps the pioneer of this study. General relativity introduces what Einstein called the 4th dimension known to us as time and made the amazing claim that gravitation is actually the curvature of space and time.
String theory tries to unite these two concepts into one theorem as part of the search to find "The Ultimate Equation," which I particularly doubt we will find. It's hypothesis is that electrons and the quarks that make up an atom (which make up elements, which then make up chemical structures, then cells) are 1-dimensional "strings" rather than simply points. As xkcd jokes, the theory does not have a useful stance...yet. But this IS the future of physics.
Enrico Petrucco 20+
;-)
Daxesh Degdawala
Felippa Amanta
Daxesh Degdawala
Dan F 50+
String theory is a creative and theoretical attempt to reconcile how the General Theory of Relativity and Quantum Mechanics can be incorporated into a single unifying theory.
I have found understanding physics gets acceleratingly wild as you work backward toward the fundamentals in an attempt to understand why our physical world behaves the way it does, or seems to.
I find youtube especially helpful because it often offers graphics with someone explaining some esoteric part of physics. It makes difficult ideas easier to grasp for me. The Hadron Collider (see youtube) is beginning to produce more information about this subject. You may want to check it out if you haven't already.
You possess one of the most fundamental gifts of all - curiosity. Welcome to TED.
Felippa Amanta
It is really wild, but at the same time very exciting. Even when I know so little about physics, the broad possibilities of our universe is just mind-blowing!
Oh, and thanks for the recommendation :)
Derek Young 30+
The additional understanding I have realized it that music's effect on you is evidence enough to find that each Quark vibrates to a similar vibration, which is similar to the effect of listening to music we love or hate. Music tunes into our vibrations which connect with us deeply and the lyrics adds a bigger impact in addition to the music you find so catchy. =)
Thanks for reading my thoughts. Hope that helped. =)
Felippa Amanta
And now you got me thinking about music too!
Thanks a lot :)
Derek Young 30+
No problem. =)
TED 10+
It's not a stupid question. We're glad to see you use TED Conversations for learning purposes!
Thank You,
TED Conversations team
conversations@ted.com
Felippa Amanta
I'm glad I stumble upon TED. TED has really change the course of my life. :D
Vidyardhi Nanduri
multi-Universe concept is introduced by me dec 1999- Cosmologyreview [dot] com -available through
www [dot]scribd[dot]com/doc-27460496/THE-COSMIC-VISION-OF-THE-UNIVERSE-PART-1-BASIC-APPROACH-Dec-1999
Daxesh Degdawala
Daxesh Degdawala
Classical physics describes the universe as made of small particles (points) which are static (not moving) and unchanging. In contrast, string theory describes the particle as a string or line (not a particle or point). The string forms the four different forces by vibrating in different ways.
Orlando Hawkins 20+
also from what I read from Kaku, string theory may have some relation to explaining what dark matter is, so if you understand string theory it may give you some insight to the nature of and structure of dark matter...
I'm not sure if this answered your question
Felippa Amanta
And one more question, what's a dark matter?
Orlando Hawkins 20+
As for dark matter, in a nutshell it is unseen matter that seems to be attracted to gravity. As mentioned before, no one can see dark matter but you can see its effects or influence on other bodies from the universe. For example, light cannot pass through dark matter. it can only go around dark matter. Also without it, many things in space would just fly off randomly. Galaxies would also break apart. Many astronomers and physicist realized that the bodies on the outer parts of galaxies were moving just as fast as those closer to the center part of the galaxies. This was quite odd because the outer bodies, moving at such a fast speed should have flown off into unknown space but they didn't and this concluded that there was something keeping the galaxies together and calculations showed that there was more mass than what people could actually see.
String theory relates to this because many believe (or at least used to believe) that the constituents of dark matter, were actually sub-atomic, so seem theory in relation to dark matter is breaking down dark matter (or matter in general) to its molecular and basic constituents.
Ric Shanahan
Felippa Amanta
Robert Winner 50+
Paul Limbers
Thomas Reddy
1) It hasn't been observed experimentally, nor are there any experiments which have been conceived that could verify or falsify it. It is currently a mathematical framework that does a decent job of describing phenomena we know, and may tell us something about why certain things are the way they are.
2) String Theory is about the smallest of scales. Atoms are made up of Protons, Neutrons, and Electrons. Protons and Neutrons are made up of a range of Quarks. And the whole mess of them are theoretically made of tiny little vibrating strings.
3) Sting Theory may provide physicists with a way to unify all of the forces of nature into one basic force that just behaves differently in different situations... This is like how Electricity, Magnetism, and Light can appear to be three very different things, but when viewed in the correct way can be represented as different expressions of a single electro-magnetic force. In this way, scientists hope that string theory will be able to combine Gravity & electro-magnetism into one force. (It would also combine the Strong and Weak Nuclear forces which are the two other known fundamental forces.) This may not seem like a big deal, but it's huge.
4) In addition to understanding "HOW" the universe works the way it works, it could help us begin to answer some of the "WHY" questions... Or if not answer those questions, at least correctly frame the "why" questions. Why are there X fundamental particles, and why do they have the values they have? Why is value of the speed of light the value that it is? Why is gravity as strong/weak as it is? etc... String Theory probably won't answer many of these questions, but it's an attempt to try.
5) The mathematical framework of String Theory is really complex and un-intuitive, that doesn't mean it's wrong. But it is the source of much of the criticism of String Theory.
Felippa Amanta
That actually explains a lot for me, I think I might have just the simplest idea of this very complicated concept.
I may not understand the whole String Theory, but it gives me a realization that our universe is beyond mind-blowing!
Thanks for the video too, I'll definitely take a look at that after my finals. :)
peter lindsay 30+
Krisztián Pintér 200+
Thomas Reddy
It wouldn't be enough for a person to make predictions, or really use the theory in any way, but it would be sufficient to understand the concepts in play.
Krisztián Pintér 200+
i have a BSc degree in chemical engineering, and i work as a computer programmer, so math is kind of my my thing. i managed to somewhat understand special relativity, and i have a clue what general relativity is about. they tried to teach me quantum mechanics with little success, but i passed the exam. i watched the talk of brian greene here:
http://www.ted.com/talks/brian_greene_on_string_theory.html
but all i got is i don't get it. i understand the metaphors, but i have no clue how this theory actually works. i also read some book of stephen hawking, as he explained some new way to describe spacetime in order to get rid of the specialness of the time dimension. the guy struggled to make it available to the reader, but but basically he said what i described, and nothing else. everything else would be hopelessly abstract postgrad math.
einstein said: everything should be as simple as possible, but not simpler. i believe for these advanced theories, as simple as possible is way more complex than we can grasp.
Thomas Reddy
http://www.youtube.com/watch?v=nvaRlPCWCcM&feature=related
I guess, the question is, what level of mastery are you actually looking for? I would hazard to guess that you have the insight into the matter that Felippa was looking for in here original question. You could probably give her an answer that satisfies her curiosity. The problem I think you have is that you have enough knowledge to know that your own knowledge on the subject is inadequate to sate your own curiosity (a problem I too suffer from).
I had a B.E in Chemical Engineering, and I too took courses in Quantum and Relativity. I've also done some reading into String Theory, and what I can say is this... If you're in over your head in Quantum, you're not going to understand the math and concepts that are really deep at the heart of String Theory, because it's just as loony. That's not meant as an insult, it's just a very difficult subject, and to make matters worse, String Theory isn't a complete subject. For the most part, we know how Quantum works. We can make predictions and test the theories... String theory is one step removed from a graduate level math class, and that's about as esoteric as it gets.
If you have 15 hours to kill, and you're interested, I'd also recommend Leonard Susskind's lecture series on the development on String Theory. It requires a good deal of advanced Math, and some understanding of Quantum, but I found it to be informative. It's on You Tube:
http://www.youtube.com/watch?v=25haxRuZQUk&feature=list_related&playnext=1&list=SPA2FDCCBC7956448F
Krisztián Pintér 200+
Paul Limbers
Felippa Amanta
It makes a lot of sense to me. I can start to imagine the idea of it.
Funny thing is, I just came out of my physic class which still explains how atoms are the smallest of all. This new revelation about the String Theory changes the way I think! Once again, thanks :)
Thomas Reddy
Get a handle on whatever physics class you're in. After you get through Mechanics and E&M, you'll be better equipped to start looking into some of this other stuff, but String Theory is really the end of the line on this stuff. Pick up Hawking's "Brief HIstory of Time", it's a good read and it goes a long way to introducing you to the more exotic stuff. Or go and find anything and everything by Neil DeGrasse Tyson when he's talking, he's electric. Brian Cox is also good at explaining things, take a gander at his stuff on here, or a 1 hour special he did in Britain: http://www.youtube.com/watch?v=4f9wcSLs8ZQ
Felippa Amanta
Thanks for the recommendation :)
How about Hawking's The Grand Design? Which is better for a starter?