Slashdot Mirror
Physicists Discover Geometry Underlying Particle Physics
New submitter Lee_Dailey sends this news from Quanta Magazine:
"Physicists have discovered a jewel-like geometric object that dramatically simplifies calculations of particle interactions and challenges the notion that space and time are fundamental components of reality. 'This is completely new and very much simpler than anything that has been done before,' said Andrew Hodges, a mathematical physicist at Oxford University who has been following the work. The revelation that particle interactions, the most basic events in nature, may be consequences of geometry significantly advances a decades-long effort to reformulate quantum field theory, the body of laws describing elementary particles and their interactions. Interactions that were previously calculated with mathematical formulas thousands of terms long can now be described by computing the volume of the corresponding jewel-like "amplituhedron," which yields an equivalent one-term expression."
Almost there....
Is secretly a complex distributed particle physics computation!
Isn't this similar to the geometric structure that the 'surfing physicist' came up with - the one that predicts a bunch of undiscovered particles? Or is this completely different?
Roll for initiative...
God is playing dice with the universe
Guys, we've been down this road about a million times in physics. Just because a mathematical model simplifies certain calculations, does not mean that the actual underlying physical geometry matches the theoretical model. Mathematicians have been adding extra dimensions to equations and finding they simplify things for years. It doesn't mean we live in a 27 dimension manifold. All direct observations to date point to a 3D universe.
#fuckbeta #iamslashdot #dicemustdie
I have an impressions that the wall of fundamental laws is reached and further research of particles is useless. This is it. No way further. The impasse.
http://en.wikipedia.org/wiki/Amplituhedron
Since the N=4 supersymmetric Yang-Mills theory is a toy theory that does not describe the real world, the relevance of this theory to the real world is currently unknown, but it provides promising directions for research into theories about the real world.
xkcd's Purity. In the other hand, can't take out of my head that Kepler originally tried to match that the orbits of the 6 known planets at that time with the shapes of the platonic solids, and this could face the same risk.
EARTH HAS 4 CORNER
SIMULTANEOUS 4-DAY
TIME CUBE
WITHIN SINGLE ROTATION.
4 CORNER DAYS PROVES 1
DAY 1 GOD IS TAUGHT EVIL.
IGNORANCE OF TIMECUBE4
SIMPLE MATH IS RETARDATION
AND EVIL EDUCATION DAMNATION.
CUBELESS AMERICANS DESERVE -
AND SHALL BE EXTERMINATED
Modern physicists have studied all of that, and more.
In fact the physicists I know are also the best read on the classics and have a tremendous breadth of knowledge about many subjects other than physics. Perhaps you should actually get to know them.
And incidentally, most Physicists don't use Cartesian corrdinats. Physicists use whatever coordinate system they need to use depending on the geometry, and the real world is far from Euclidian.
This is either a major breakthrough or utter bullshit. It's too early to tell which. If it's real, it's a Nobel Prize in physics.
The publisher, the Simmons Foundation, is a project of a rich weirdo from Texas.
It looks like Wolfram was onto something in A New Kind of Science with his approach to replacing complex equations with simple rules.
I'd say Plato (perhaps Pythagoras) was onto something when he basically said that math is the fundamental everything of everything. Yep, the guy was wrong on the details, but what damn fine intuitions he managed to have 2400 years ago. No matter what we do we always end up referring back to him...
Conservatism: (n.) love of the existing evils. Liberalism: (n.) desire to substitute new evils for the existing ones.
One of the things the article says is that space and time may not be fundamental properties of nature, but properties that emerge (i.e., are the result of) a more fundamental reality.
Warning: IANAP. But with some axioms, it is possible to reach the same conclusion.
Imagine a simple experiment with an electron source and a detector. An electron is emitted in the direction of a detector. The experiment is set up such that while travelling towards the detector, the electron does not interact. More precisely, in between the emitter and the detector, the electron does not exchange any energy. Then, the electron hits the detector and becomes detected (interaction two).
Has the electron physically travelled in the space between the electron source and the detector? May it be assumed that in between the interaction with the emitter and its subsequent interaction with the detector the electron is physically present?
Obviously, it is impossible to establish that the electron is present between the emitter and the detector without actually interacting with the electron. It is therefore herewith observed that any assumptions about physical presence of the electron in between the source and the detector can not be experimentally verified. More generally, it is observed that the assumption of physical presence of any elementary particle in between two interactions can not be falsified.
Equally impossible to falsify is the assumption that in between the emitter and the detector, the electron in the experiment was not physically present. This assumption implies that (in the reference frame of the observer) the electron disappeared at the emitter and reappeared at the detector, and did not take up any physical space at any time in between. In between interactions, the representation of the electron disappeared and became unobservable. For as far as an observer can tell, the electron disappeared from the universe completely in between interactions.
Since obviously, properties about the electron are preserved in between interactions, the electron must still somehow being represented – i.e., the representation of the electron has clearly not disappeared from the universe.
The notion “observable universe” is therefore being introduced to make the distinction between interactions which can be observed, and the herewith theorized part of the universe that is apparently capable of at least holding a representation of an elementary particle and which can not be observed.
Observable universe: The part of the universe in which an interaction manifests itself.
Let us formulate the following two axioms:
Axiom 1: An interaction is instantaneous, i.e., it lasts for an infinitely small amount of time.
Axiom 2: An elementary particle only exists in the observable universe at the moment of its interaction.
Notice that axiom 1 and 2 are unfalsifiable. Consider the reverse of axiom 2:
Reverse of Axiom 2: An elementary particle physically exists in the observable universe in the time that passes (in the reference frame of an observer) between two interactions.
This axiom is equally unfalsifiable, since physical presence of an elementary particle can only be proven by interacting with it. The reverse of axiom 1, which would postulate that an interaction lasts a non-zero amount of time, is equally unfalsifiable.
Elementary particles have no internal structure and are considered point particles. In other words, an elementary particle does not take up any physical space. If we assume that everything in the observable universe consists of elementary particles, then it follows that all particles that exist in the universe do not take up any space. The aggregate volume of all elementary particles is zero.
Combined, axioms 1 and 2 state that in between two interactions, an elementary particle is not present in the observable universe. A particle only manifests itse
My karma ran over your dogma
The Slashdot headline, not the physics.
http://www.math.columbia.edu/~woit/wordpress/
My question is - does this get humanity any closer to the point at which I can build my own interstellar spacecraft? If not... why I should care?
An enigma, wrapped in a riddle, shrouded in bacon and cheese
This doesn't necessarily invalidate Feynman's approach. His problem was that he assumed a limitless supply of graduate students to calculate the various reaction path probabilities.
Have gnu, will travel.
But I'm hoping we never actually prove that souls exist. That's one door I'd prefer to remain closed. If science determined that souls exist, then we'd be figuring out ways to harness souls for energy. And then that'd bring up the whole question of what else is out there in that sphere of reality--and I'd really rather not draw a Nyarlathotep-analogue's attention.
Here's to hot beer, cold women, and Glaswegian kisses for all.
If one assumes that Special Relativity and Quantum Mechanics are correct, and there is no observational evidence that they are not, then Yang-Mills theory, or something very much like it, is inevitable. It arises from the need for conservation of the various charges each force.
A Yang-Mills theory, based on {pick-your-favorite-group}, may be inevitable. Whether it would be the N=4 supersymmetric Yang-Mills theory is another matter; it won't be.
The amplituhedron, or a similar geometric object, could help by removing two deeply rooted principles of physics: locality and unitarity.
...And unitarity holds that the probabilities of all possible outcomes of a quantum mechanical interaction must add up to one.
I'm probably being very naive attempting to understand this article that has probably already been massively dumbed down, but, how can the probabilities of all possible outcomes of an interaction not add up to one? Surely they add up to one by definition, otherwise they are not probabilities? For example outcome X having a probability of 1/3 means, on average, you can multiply the number of times you observe the interaction by 1/3 and get the expected number of times you would see outcome X. If the probabilities in your statistical trials didn't add up to 1, doesn't that mean adding up the numbers of individual outcomes observed would give a number bigger (or smaller) than the total number of interactions observed? Obviously it cannot mean that, as that fails basic arithmetic.
I can imagine tossing a fair coin - heads has probability 0.5, tails 0.5, total 1. So now how about a 3 sided coin without unitarity? Let's say the probability of heads is still 0.5, tails 0.5 but it has a third side, bodies that also has probability 0.5 of occurring. That sounds mathematically impossible. It could be a mind-reading coin, where you pick heads and find that then occurs on half your coin tosses. Later you pick tails, and that occurs on half your coin tosses, but when you pick bodies, that also occurs on half of those coin tosses. OK, I give up! Can anyone who really understands unitarity enlighten me please? Is this anything like the uncertainty principle?
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Quantum computation won't make a dent in any NP-HARD problem.
The fact that nature (basically THE quantum computer) can fold a complex protein in a fraction of a second seems to demonstrate that at least some of these problems are solvable by QC in P time.
Is this because the problem wasn't NP-hard to begin with (but it sure seemed that way)?
Or don't we yet have the right QC algorithms to do this (it's a growing field)?
Or maybe nature cheats and doesn't solve the same problem (but finds some local minimum in the energy landscape)?