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No Proton Decay Means Grand Unification Must Wait
- goalieca 10y agoModelling is an interesting thing. Our math is such an elegant language that it can describe such amazingly rich abstractions. On one hand, we have category theorists and computer scientists working on the more familiar modelling of computational patterns. On the other, we have physicists coming up with all kinds of equally curious patterns in particle fields. It seems many of the patterns are just abstract nonsense but there are too many coincidences to ignore. To me this hints of some underlying structure that we are completely blind to still. Oh, how i wish to study math from the future.
- HiroshiSan 10y agoStudy math now! With reverse ageing in the future you could potentially become one of the best in the field. There is time.
- CamperBob2 10y agoSounds like an excellent excuse to not study math now.
- HiroshiSan 10y agoAaah...procrastination. "I'll just wait t'ill I'm 150."
- pavel_lishin 10y agoReminds me of some lyrics I like: Throw it away, what's left to need When you’ve got infinity So much out there left to find We'll do that some other time
- nitrogen 10y ago...and an excellent reason to put 100% of available resources into anti-aging research.
- idlewords 10y agoWith reverse ageing, you'll just unlearn all that laboriously learned math.
- HiroshiSan 10y agoBenjamin button was a documentary ahead of its time.
- lkrubner 10y agoSeriously. Real increases in lifespan (I'm thinking about Louis Gridley Wu celebrating his 200 birthday) would have to involve (at least occassionally) revitalizing stem cells to renew the body at rates that would seem normal in a very young person. This would have to include nerve cells. Presumably, this would lead to a reversal of specialization. That implies memory loss ("memory" in all neurological senses: how to write software, but also how to speak English, how to control defecation, how to control urination. Really renewing one's central nervous system would rewind a person back to the unspecialized nervous system they were born with.)
- judahmeek 10y agoSo do it incrementally like the human body does with everything else so that fresh neurons can learn the roles of the neurons they are replacing.
- sbierwagen 10y agoWhy would you think that? Information is stored in the configuration of neurons, not in the neurons themselves. Neurons are constantly being replaced, and you don't wake up one morning not knowing how to bike because your "bicycle neuron" died.
- Typhon 10y agoNeurons are constantly being replaced Are they ? As far as I know, neurons last more or less from before birth to death. There is neurogenesis in the hippocampus but it doesn't replace existing neurons, and the new cells themselves last until death.
- fjdlwlv 10y agoWhat coincidences? Why assume we are blind? Complex numbers are an underlying structure that has unified wide ranging physical phenomena
- chriswarbo 10y ago> Complex numbers are an underlying structure that has unified wide ranging physical phenomena And yet complex numbers are merely a shadow of much deeper unifying structures https://en.wikipedia.org/wiki/Clifford_algebra https://en.wikipedia.org/wiki/Clifford_algebra
- walrus1066 10y agoThe modeling and the maths allow us to make concrete, precise predictions of how nature behaves, that are testable by experiment.
- amelius 10y agoI sometimes wonder if there is a way to automate the generation of mathematical abstractions and reporting the ones that have physical relevance. I guess one of the big problems then (besides tractability) is how to feed it with experimental data. Even if it is not feasible, then it would still be interesting to read how mathematical physicists would theoretically approach this problem (and even how they would define it).
- paulddraper 10y agoAbstraction is almost by definition the information that not-automated (and the automated portion is concealed but the abstraction)
- gus_massa 10y agoSmall technical correction: > For instance, SU(5) groups quarks and antiquarks together with leptons and antileptons into “fiveplets,” which are like the indistinguishable sides of a regular pentagon. The idea is to put the 5 particles in 5 places that are undistinguishable. For that you need to use the vertex corners of an hyper-tetraedrum ( https://en.wikipedia.org/wiki/5-cell https://en.wikipedia.org/wiki/5-cell ). Don't get confused by the bad drawings, if you have one of them in 4 dimensions, you can put each point at the same distance of all the other points. If you use a regular pentagon, then you must select an order for each of the particles/vertex. If you select one, some are more close than the others. (An alternative is to use a pentagon, but consider not only the rotations and flip, but also the operations that mix the vertex/particles in any order. But then the nice identification with the symmetry of the geometric figure is gone. You can use a square with the central point.)
- deleted 10y ago[deleted]
- lambdasquirrel 10y agoThe talk of simple geometry reminds me of the Ptolemaic universe for some reason. Layman's comment, I know, but I just couldn't resist.
- jayajay 10y ago"If a and b do not agree, begin your search for letter c."
- gus_massa 10y agoIn some sense, yes. I remember the class were my physics professor explained why the SU(5) could be The Group of the universe and why it failed (IIRC the predictions were 1% off with the experiment, a good try, but enough to be discarded.) You could feel how sad he was that SU(5) has to be discarded. :( In some sense, no. The SU(5) group includes all the symmetries of the hyper-dodecahedron, were you can rotate it in the 4-dimmensional space to exchange one of the vertex/particles with another. But it also includes more strange things, like half mixing two particles. a -> (a+b) / srqt(2) b -> (a-b) / sqrt(2) This is more difficult to explain. Technically, it's a rotation in the plane x-y of 45 degrees. And you can rotate another angles, for example in some particles decays the important rotation is 13 degrees. And you can mix three or four or five particles. All of this is more difficult to imagine, but it's easy to write analytically. The use of geometric shapes like the hyper-dodecahedron is more a nice visualization technique. It's easier to explain than the details of the SU(5) group and it provides a good intuition, even after studding the theory with more details. So I prefer to ignore this technical detail, specially for a popular science article.
- maxander 10y agoThe thing that pop-science stories about GUT always seem to fail to explain is- what does it mean for a symmetry to break at a certain point in time? In the present day physical symmetries (isotopy of space, say, or conservation laws) are just static laws of nature; what was going on in the first microseconds that could mess with the laws of physics itself? ...I'm sure my question contains within it at least several misconceptions, but let that just be an illustration of how confused this kind of article leaves laypeople.
- cohomologo 10y agoThe symmetry breaking should be thought of as a phase transition that occurs as the temperature of the universe changes, like liquid freezing and becoming ice. The universe was initially very hot, but rapidly cooled down as it expanded and went through phase transitions when it passed the "freezing temperature", i.e the temperature at which the laws of physics prefer to spontaneously break the symmetry.
- rwallace 10y agoI've always been curious about that as well. Suppose you took a small region of the universe and reheated it to be unification temperature today, presumably you would restore the symmetry, but presumably when you let it cool down, the symmetry would not randomly break in a different way, but deterministically in the same way; isn't that a way the analogy does not hold? To get random breaking in a different way, presumably no amount of mere heating of matter would suffice; you would have to somehow restore the high-energy false vacuum of the Big Bang itself? I don't suppose there's any way to do that in today's universe, even in principle?
- JumpCrisscross 10y ago> Suppose you took a small region of the universe and reheated it to be unification temperature today...I don't suppose there's any way to do that...? You're describing a particle accelerator. When we talk about the LHC accessing "higher energies" than the Tevatron [1] we are saying it is "baking" small parts of the universe to higher and higher temperatures. [1] http://blogs.discovermagazine.com/cosmicvariance/2009/11/30/the-lhc-surpasses-the-tevatron-in-energy-but-what-about-power/ http://blogs.discovermagazine.com/cosmicvariance/2009/11/30/...
- xefer 10y agoThis is an question I've always had about proton decay: if virtual particles can spontaneously appear anywhere at anytime, why couldn't some virtual quark appear in the midst of the three that make up the proton causing it to fall apart? What keeps The constituent components of a proton immune from this behavior?
- walrus1066 10y agoYou can't have a single virtual particle appearing, it's always two, due to conservation of momentum, charge etc So it'd be a quark-antiquark pair popping up. The proton is the lightest Baryon (3 quark particle), there is no lighter Baryon it could decay into. The decay products have to be lighter than the original proton, by at least the mass of the virtual quark pair, to repay the energy 'borrowed' from the vacuum to create the virtual quark pair (because energy is always conserved). So the proton remains unaffected by the virtual particles popping in and out of existence around it. The virtual particles have no choice but to effectively to annihilate with one another and disappear, to pay back the energy debt. Heavier Baryons (Sigmas, Lambdas) are indeed destabilized by virtual quark pairs, that is the mechanism by which they decay, almost instantaneously, on their own. You could have an up-anti up quark pair that pops up close to the up quark of the proton, the up quarks could 'swap places', and then the up of the proton annihilates with the anti up of the virtual quark pair, but the the result is still a proton.
- walrus1066 10y agor.e. Heavy baryon decay, here is a feynmann diagram showing a delta baryon decaying into a proton and pion. The down + anti-down quark pair that appears in the middle of the diagram are virtual particles: https://ned.ipac.caltech.edu/level5/Cottingham/Figures/figure1_3.jpeg https://ned.ipac.caltech.edu/level5/Cottingham/Figures/figur...
- gbrown 10y agoAt a guess, probability.
- cynicalkane 10y ago
- jeebers 10y agoThe article can be summarized by this line: "Japan is considering building a $1 billion detector called Hyper-Kamiokande, which would be between eight and 17 times bigger than Super-K and would be sensitive to proton lifetimes of 10^35 years after two decades." All this to possibly detect a single proton decay in 20 years. Now that's some serious commitment!
- sanxiyn 10y agoIf it were solely to detect proton decay, yes, I agree it would be very impressive. The reality is a bit more prosaic though, as the article suggests in passing: "In the meantime, a Nobel Prize has been won for a different discovery in the cathedral-esque water tank pertaining to particles called neutrinos." Hyper-K is a dual-purpose detector, a neutrino detector as well as a proton decay detector. Substantial part of Hyper-K funding should be interpreted as investment to a neutrino detector.
- hashhar 10y agoI would like to take a moment to praise Quanta Magazine. They really are the one magazine that got me reading all forms of long form articles about science which if it were written plainly would go high above my head and/or would seem boring.
- bvv 10y agoQuanta Magazine has also a good reputation among many theoretical physicists including myself. They of course do suffer from the occasional misconception, but as a whole the accuracy of their reporting is leaps and bounds above many other popular science sites or blogs.
- hashhar 10y agoLifehacker introduced me to them and I've been a happy reader since then. The thing I like the most is that don't play the "analogy game" too much and instead generally teach a small concept and then build up on it. While other popular media outlets like Wired or Verge simply dumb it down too much or are factually incorrect. I do like WIRED's Science Blogs though even though they are a little bit inactive.
- Manglano 10y agoAssume the physical universe takes the form of a set of axiomatic systems whose statements are elementary particles and whose interactions are logical operations; i.e., metals in the presence of ions will form salts. Matter creates the gravitational interaction as a function of mass. Why do we assume the theories are unifiable?
- just2n 10y agoI think in an effort to understand exactly how the mechanics of the big bang worked and how you can go from an infinitesimal point of incredible energy to an enormous and expansive universe with the diverse laws we observe today. From the article: > If the forces were indeed one during the “grand unification epoch” of the universe’s first trillionth of a trillionth of a trillionth of a second, then particles that now have distinct responses to the three forces would then have been symmetric and interchangeable, like facets of a crystal. As the universe cooled, these symmetries would have broken, like a crystal shattering, introducing distinct particles and the complexity seen in the universe today.
- Manglano 10y agoWe assume the precondition that the Universe we experience and observe originated in a vacuum of...existences, for lack of a better term. This seems myopic, why should it be so? What if the universe we experience is the product of interactions between distinct universes, which circumscribed by different physical laws, and the only universe we can sufficiently experience and observe is that which is governed by the Strong Nuclear Force?
- bmh100 10y agoIt could very well be that way, but what is the evidence for that origin? Why not any number of other plausible explanations? It is not myopic to accept the explanation best supported by available evidence, until sufficient new evidence supports a different explanation. Right now, the Universe coming into existence as a solitary singularity is the best available theory.
- 10y ago
- peter303 10y agoCross out the Third (of five) Age of the universe in the 1999. Book of that name. That was era dominated by degerate stars untils all bayrons decay. Then the universe would be dominated by evaporating black holes. https://en.m.wikipedia.org/wiki/The_Five_Ages_of_the_Universe https://en.m.wikipedia.org/wiki/The_Five_Ages_of_the_Univers...
- mirimir 10y ago> ... researchers have found a variety of other symmetry groups that the existing particles might fit into, with extra features and variables that can make protons decay much more slowly. Well, "extra ... variables that can make ..." is often a sign of EOL desperation for theories. What I got from Kuhn, anyway.
- donretag 10y agoCan someone please explain the role of the tank in the detection of proton decay? Why is water the best solution to use?
- gshubert17 10y agoA neutrino interaction with the electrons or nuclei of water can produce a charged particle that moves faster than the speed of light in water (not to be confused with exceeding the speed of light in a vacuum). This creates a cone of light known as Cherenkov radiation, which is the optical equivalent to a sonic boom. The Cherenkov light is projected as a ring on the wall of the detector and recorded . . . From: https://en.wikipedia.org/wiki/Super-Kamiokande#Description https://en.wikipedia.org/wiki/Super-Kamiokande#Description
- donretag 10y agoExcellent. So the role of the tank is detection and not a means to accelerate proton decay?