I wonder if it's possible to ever find out what our reality is even if we will eventually reach the intellectual and technology necessary because we are part of it and it's probably impossible to have an objective view of the matter.
"There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable." – from The Restaurant at the end of the Universe.
"Any effectively generated theory capable of expressing elementary arithmetic cannot be both consistent and complete. In particular, for any consistent, effectively generated formal theory that proves certain basic arithmetic truths, there is an arithmetical statement that is true, but not provable in the theory" - Gödel (Kleene)
There is this belief propagated among physicists that smaller scales somehow have more to do with reality. I have never been presented with logic or evidence that convinced me that an electron is somehow more "real" than a molecule or a person or the solar system or the observable universe.
I wish the word "reality" would stop being thrown around without justification. "Fundamental" might be a more appropriate term.
Any physical system that can be described by a set of mathematical laws is bound to have some axioms that simply cannot be proven within its context. Godel's incompleteness theorems prove that.
Hence, we will never get to the bottom of the reality of our universe.
For the moment it seems to me that there is no chance to ever know what something REALLY is. There is obviously stuff out there that behaves exactly like mathematical models we made up - there are things called electrons behaving like our model of electrons interacting with things called photons behaving like our models of photons. But what does this tell you about the nature of electrons and photons? Is a electron just a handful of numbers like charge -1 and spin 1/2 behaving according to the laws of physics or is there more to an electron? I can't even imagine how one could bridge the gap between our models of reality and reality but then there is probably so much more to learn about our universe, maybe some day...
There's a very subtle undertone of negativity in this article about physics. Before I get into, William Bardeen is not in the same league as 'Surfer Dude and his E8 Theory of Everything' which throws basic facts about representation theory out the window, coming up with 'todalay boogus' arguments which amazes auntie, mommie and magazine editors but a real physicist would instantly dismiss.
Bardeen is the real deal. His papers are very interesting and feel a bit like reading Sidney Coleman's papers. If you're interested...
Is nature scale invariant? So far the answer is absolutely NO but I strongly advise to wait and see. There are many topics that point to some breakdown in scale or reorganizing what we think of space and distance (dualities in string theory, conformal field theory).
OK, now the important thing I want everyone here to realize. You are living through a GOLDEN AGE of physics. You wouldn't think that based on what all the popular magazines tell you. Here's why...
1. Higgs particle - discovered!
2. Inflation - discovered! Denying this one is like denying the Big Bang itself. The evidence is overwhelming and in fact I would list this as the single greatest scientific discovery of all time. The concurrent discovery of gravity waves, quantum gravity and a real life example of a Hawking process only sweetens the deal.
3. Supersymmetry has basically already been discovered IMHO. They aren't announcing anything at CERN and won't until they have so many sigmas under their belt but trust me, it's coming and truth be told, it isn't really so surprising. SUSY physics has always been rock solid from the beginning. The situation is very similar to that before offical Higgs announcement and before someone went knocking on Andre Linde's front door. Many were extremely confident in the Higgs particle a least a year before the official announcement. The BICEP 2 results were even more glaringly apparent than the Higgs results. Many people were walking around the Earth with 'secret knowledge' that inflation theory was correct even 2 to 3 years before the official announcement.
So you are living through EXTREMELY interesting times but you wouldn't know it with all the big science bashing being thrown around.
I study astrophysics, so I won't be able to say much about SUSY or string theories or conformal field theories. I do agree that we're living in a golden age of physics! But your second and third points, inflation and SUSY-- those are definitely not confirmed. In fact, the primordial gravitational waves from BICEP2 are almost certainly dust contamination signal (e.g., http://arxiv.org/abs/1405.5857). The discovery of supersymmetric particles would also be extremely shocking to me, since my institution is heavily involved in CERN LHC experiments, and I haven't heard any hints of a discovery yet. Perhaps you know something that I don't!
Are there any particular resources that you recommend for a high-level overview of this kind of stuff? I'm an engineer with a solid grasp of classical mechanics and strong math background, but very little exposure to modern physics (basically, anything discovered after 1905) and I would like to be able to read about and appreciate this type of work. Where to start?
Apologies for taking the conversation off on a tangent, but you seem passionate about this.
Do you have any rumors or specific knowledge (even if it's not something you'll share) regarding SUSY? They found missing energy? A new plethora of resonances? Higgsinos or sfermions? Something more exotic?
Thanks for your post and link. I recently watched Particle Fever on Netflix and became extremely fascinated with the field. A lot of the information you posted is touched on in the documentary. It is mostly focused around CERN and the years leading up to the Higgs particle discovery. There are also great interviews with David Kaplan and Nima Arkani-Hamed.
You've likely seen it but if not you might enjoy it.
Surfer Dude and his E8 Theory of Everything ... 'todalay boogus' arguments which amazes auntie, mommie and magazine editors but a real physicist would instantly dismiss.
I suppose you're referring to Lisi? Neither he nor E8 were even mentioned in the article. You're both OT and unnecessarily unpleasant.
of course. Natural thing when a field is dominated by orthodoxy that closes their eyes to everything that they don't want to see. Like yesterday "entangled photon imaging" where what really happens is that a beam modulated by an image heats/excites crystal (with that heating/excitement thus obviously modulated by the image) which generates another beam (thus that another beam is obviously also modulated by the image) which hits CCD - no miracle of entanglement here, yet Nature published it as such :
https://news.ycombinator.com/item?id=8234221
as "entanglement" and "mutiverse" are very much in fashion this season and get you published.
With Higgs as a "mass" boson it was also non-starter because the theory of it failed to address gravitational and inertial mass equivalence. I mean i don't doubt that CERN found new particle of course, yet nowhere it was shown that it is the boson "generating mass". The article seems to suggest that finally the mainstream physics starts to seriously ponder whether the mass is a result of dynamic interaction - that has been obvious for decades to the "fringe" physicists, who couldn't just dismiss the above mentioned gravitational and inertial mass connection, a pretty fundamental fact that has to be at the center of anything called physics :)
I wouldn't say that the "field is dominated by orthodoxy that closes their eyes to everything that they don't want to see".
I'll admit most physicists I've met are suspicious of wild-eyed theory. But I wouldn't say they're overly orthodox. I think it's more a healthy skepticism of anything which involves humans projecting science-ficiton wish-fulfilment into science.
I'd go further and say that "entanglement" and "multiverse" are not at all en vogue. I think most seasoned physicists realize that these were trendy fields some years ago (for solipsistic reasons - ie, make us feel special).
So I think the return to a fundamental assessment of phenomena is pretty natural thing. Calling out assumptions like scale. What's more, I think the more discerning will also be suspicious of the "post-multiverse" dialectic. It's just the process really.
I'm not sure why you're grouping entanglement in with the multiverse.
One of those is a theoretical idea for reducing the Solomonoff complexity of the universe with no clear experimental implications. The other is an integral component of how we predicted and explain experimentally confirmed phenomena like violations of Bell's inequalities, the Elitzur-Vaidman bomb tester, quantum cryptography, and quantum teleportation.
I don't see why this kills the multi verse theory.
Which is a basic conclusion of a 10 dimensional space-time environment that doesn't include mass anyway.
Well, it's just a hyperbolic headline that tries to call a speculation a theory (the latter meaning an idea with some supporting evidence). It certainly doesn't kill any other current speculation. It's journalism masquerading as science.
It "kills it" because it's only really appealing if the universe we're in appears extremely unlikely, like it's the "just right" goldilocks balance of cosmic variables that we can't explain, that happened to be the stable ones that resulted in life evolving eventually.
If the universe is actually very likely to occur in the state that it's in, then we don't need to use this "vast multiverse where our universe was the one that produced an observer" explanation. It could be a single universe in all of existence, where everything makes sense mathematically and no further posturing is required in that silly unscientific field of cosmic philosophy.
Or if it fails, and it remains that our universe is unexpectedly perfect, then we are forced to resort to statistical explanations within an impossible-to-observe external multiverse. Scientists don't very much like conclusions built on not being able to observe things.
Though to me, the multiverse theory has a sort of fractal appeal to it. It is surely applicable to our planet, after all. Why not our entire universe?
For a heroic attempt to explain this article to laypeople, check out physicsmatt's comments over at Metafilter:
"First, for maximum sense-making, read my previous comments here, here, here, and here. I realize that's a lot, sorry. The Universe is complicated. Then, for what follows, recall that to a particle physicist such as myself, there is no difference between lengths and energies (or indeed, any other dimensional quantity). Length is inverse energy: very energetic phenomenon probe very small lengths ...."
Or don't - it's incredibly badly written, in the sense that it often descends into grammatical gibberish, even without worrying about the physics the gibberish is trying to describe.
When I became interested in modern physics theories of both quantum and universe level, I found the following book [0] by Max Tegmark to have very good explanations regarding origin and nature of the universe, quantum mechanics, and just interesting stories / facts from the life of physicists.
> "Multiverse ennui cannot last forever" says Graham Ross?
That is naive. There is no way to prove or disprove it; it can be safely regarded as true without ever contradicting any possible observation we can ever make.
I do not think physics will ever settle the questions in such a way that the "multiverse ennui" is not invoked to cover the loose ends; in fact, it will become more and more obvious as the inescapable conclusion.
The deeper we dig into nature, either we keep finding more mathematics, or we encounter some absolute that can no longer be analyzed.
Once we know every physical law, and are certain nothing more is to be discovered, how do we distinguish our universe from a set of mathematical axioms? We have two choices then: to suspect there is some outer universe which implements the rules and axioms of this one. Or else admit that axioms do not require an implementation: they just are, and that's what makes their system exist (which means that any other axioms and rules we can imagine also exist just as much).
Either hypothesis is an unprovable "cop out"; but the latter of the two is more plausible. The first hypothesis still leads to an infinity of universes, and they have to be nested in each other in an infinitely regressing sequence. The second one has no such silly requirement; and it has the anthropic principle which plausibly explains everything that seems arbitrary or special.
To be fair, this only kills one of the multiverse hypotheses. I'm reading Brian Greene's "The Hidden Reality" right now, and he describes about 8 independent (or semi-independent) multiverse hypotheses. From what I understand (and I'm no physicist), this just provides evidence against the anthropic principle, and the multiverse associated with that line of thinking...
Things like this keep me wondering if eventually we will reach a point where we are unable to distinguish theories about our own past due to lacking the energy necessary to experiment with those conditions thanks to entropy.
I once read that "black holes orbiting each other follow the exact same mathematics as electrons orbiting protons", but I was unable to find the direct source. I did find another article comparing black holes to elementary particles:
They would naturally follow the same mathematics, since the formula for gravitational attraction and the formula for electrical attraction are both following the inverse square law.
> Perhaps the fundamental description of the universe does not include the concepts of “mass” and “length,” implying that at its core, nature lacks a sense of scale. This little-explored idea, known as scale symmetry, (...)
Ah, no, that's a completely different sense of scale invariance. In a fractal you still have to measure the sizes of different similar structures, and generally pay attention to length. It seems that this article is discussing a much deeper abandonment of length.
"That shit would be too much," Gupta said. "It'd be like that Dr. Seuss book Horton Hears A Who and shit. I read that when I was, like, six, and it totally weirded me out."
Actually it should feel more like a tall story from your uncle at a family dinner, that's not corroborated and doesn't even imply what he insists it implies.
That is, half of the article is trash and the other doesn't represent the science correctly.
So two things standing next to each other are the same size as one thing alone?
Damn hard to imagine. I would think "size" does not really "exist" but is a man made concept. And by its definition, two things next to each other form a "bigger" thing.
The article is badly written, but it doesn't really mean sizes are illusory (even if it says so at the beginning). It goes on to say that sizes and mass "spontaneously emerge" from lower interactions, which is to say, they become real for us.
But, to address your example: "So two things standing next to each other are the same size as one thing alone? Damn hard to imagine".
That might not hold for size, but a very similar thing does occur (and is proven) for speed.
If you are in a car that goes at 0.8 miles per minute, and you throw a dart that goes at 0.3 miles/minute, its speed is 1.1 miles/minute (the sum).
But if you travel at the 0.8x the speed of light and you throw something forward at 0.3x the speed of light, its speed is not 1.1x the speed of light, but c. That is, trying to add velocity doesn't get you faster than the speed of light.
[+] [-] givan|11 years ago|reply
[+] [-] unfunco|11 years ago|reply
[+] [-] snarfy|11 years ago|reply
[+] [-] protonfish|11 years ago|reply
I wish the word "reality" would stop being thrown around without justification. "Fundamental" might be a more appropriate term.
[+] [-] axilmar|11 years ago|reply
Any physical system that can be described by a set of mathematical laws is bound to have some axioms that simply cannot be proven within its context. Godel's incompleteness theorems prove that.
Hence, we will never get to the bottom of the reality of our universe.
[+] [-] danbruc|11 years ago|reply
[+] [-] noiv|11 years ago|reply
[+] [-] macspoofing|11 years ago|reply
[+] [-] collyw|11 years ago|reply
[+] [-] MisterMashable|11 years ago|reply
Bardeen is the real deal. His papers are very interesting and feel a bit like reading Sidney Coleman's papers. If you're interested...
http://arxiv.org/find/hep-th/1/au:+Bardeen_W/0/1/0/all/0/1
Is nature scale invariant? So far the answer is absolutely NO but I strongly advise to wait and see. There are many topics that point to some breakdown in scale or reorganizing what we think of space and distance (dualities in string theory, conformal field theory).
OK, now the important thing I want everyone here to realize. You are living through a GOLDEN AGE of physics. You wouldn't think that based on what all the popular magazines tell you. Here's why...
1. Higgs particle - discovered!
2. Inflation - discovered! Denying this one is like denying the Big Bang itself. The evidence is overwhelming and in fact I would list this as the single greatest scientific discovery of all time. The concurrent discovery of gravity waves, quantum gravity and a real life example of a Hawking process only sweetens the deal.
3. Supersymmetry has basically already been discovered IMHO. They aren't announcing anything at CERN and won't until they have so many sigmas under their belt but trust me, it's coming and truth be told, it isn't really so surprising. SUSY physics has always been rock solid from the beginning. The situation is very similar to that before offical Higgs announcement and before someone went knocking on Andre Linde's front door. Many were extremely confident in the Higgs particle a least a year before the official announcement. The BICEP 2 results were even more glaringly apparent than the Higgs results. Many people were walking around the Earth with 'secret knowledge' that inflation theory was correct even 2 to 3 years before the official announcement.
So you are living through EXTREMELY interesting times but you wouldn't know it with all the big science bashing being thrown around.
[+] [-] jwuphysics|11 years ago|reply
[+] [-] dllthomas|11 years ago|reply
For the record, my father was far more amazed by rambling, not entirely coherent speculative physics ideas than my mother or either of my aunts.
[+] [-] jrussino|11 years ago|reply
Apologies for taking the conversation off on a tangent, but you seem passionate about this.
[+] [-] evanb|11 years ago|reply
[+] [-] AtmaScout|11 years ago|reply
You've likely seen it but if not you might enjoy it.
[+] [-] dandrews|11 years ago|reply
I suppose you're referring to Lisi? Neither he nor E8 were even mentioned in the article. You're both OT and unnecessarily unpleasant.
[+] [-] angersock|11 years ago|reply
I'm just an engineer, so I'm not sure I see the utility in any of that--sorry to sound closed-minded, but am genuinely curious.
[+] [-] trhway|11 years ago|reply
of course. Natural thing when a field is dominated by orthodoxy that closes their eyes to everything that they don't want to see. Like yesterday "entangled photon imaging" where what really happens is that a beam modulated by an image heats/excites crystal (with that heating/excitement thus obviously modulated by the image) which generates another beam (thus that another beam is obviously also modulated by the image) which hits CCD - no miracle of entanglement here, yet Nature published it as such : https://news.ycombinator.com/item?id=8234221
as "entanglement" and "mutiverse" are very much in fashion this season and get you published.
With Higgs as a "mass" boson it was also non-starter because the theory of it failed to address gravitational and inertial mass equivalence. I mean i don't doubt that CERN found new particle of course, yet nowhere it was shown that it is the boson "generating mass". The article seems to suggest that finally the mainstream physics starts to seriously ponder whether the mass is a result of dynamic interaction - that has been obvious for decades to the "fringe" physicists, who couldn't just dismiss the above mentioned gravitational and inertial mass connection, a pretty fundamental fact that has to be at the center of anything called physics :)
[+] [-] l33tbro|11 years ago|reply
I'll admit most physicists I've met are suspicious of wild-eyed theory. But I wouldn't say they're overly orthodox. I think it's more a healthy skepticism of anything which involves humans projecting science-ficiton wish-fulfilment into science.
I'd go further and say that "entanglement" and "multiverse" are not at all en vogue. I think most seasoned physicists realize that these were trendy fields some years ago (for solipsistic reasons - ie, make us feel special).
So I think the return to a fundamental assessment of phenomena is pretty natural thing. Calling out assumptions like scale. What's more, I think the more discerning will also be suspicious of the "post-multiverse" dialectic. It's just the process really.
[+] [-] Strilanc|11 years ago|reply
One of those is a theoretical idea for reducing the Solomonoff complexity of the universe with no clear experimental implications. The other is an integral component of how we predicted and explain experimentally confirmed phenomena like violations of Bell's inequalities, the Elitzur-Vaidman bomb tester, quantum cryptography, and quantum teleportation.
[+] [-] mSparks|11 years ago|reply
[+] [-] lutusp|11 years ago|reply
[+] [-] calinet6|11 years ago|reply
If the universe is actually very likely to occur in the state that it's in, then we don't need to use this "vast multiverse where our universe was the one that produced an observer" explanation. It could be a single universe in all of existence, where everything makes sense mathematically and no further posturing is required in that silly unscientific field of cosmic philosophy.
Or if it fails, and it remains that our universe is unexpectedly perfect, then we are forced to resort to statistical explanations within an impossible-to-observe external multiverse. Scientists don't very much like conclusions built on not being able to observe things.
Though to me, the multiverse theory has a sort of fractal appeal to it. It is surely applicable to our planet, after all. Why not our entire universe?
[+] [-] JackC|11 years ago|reply
"First, for maximum sense-making, read my previous comments here, here, here, and here. I realize that's a lot, sorry. The Universe is complicated. Then, for what follows, recall that to a particle physicist such as myself, there is no difference between lengths and energies (or indeed, any other dimensional quantity). Length is inverse energy: very energetic phenomenon probe very small lengths ...."
https://www.metafilter.com/142211/Multiverse-No-More-a-New-T...
[+] [-] antimagic|11 years ago|reply
[+] [-] playing_colours|11 years ago|reply
[0] http://www.amazon.com/Our-Mathematical-Universe-Ultimate-Rea...
[+] [-] pablisco|11 years ago|reply
[+] [-] kazinator|11 years ago|reply
That is naive. There is no way to prove or disprove it; it can be safely regarded as true without ever contradicting any possible observation we can ever make.
I do not think physics will ever settle the questions in such a way that the "multiverse ennui" is not invoked to cover the loose ends; in fact, it will become more and more obvious as the inescapable conclusion.
The deeper we dig into nature, either we keep finding more mathematics, or we encounter some absolute that can no longer be analyzed.
Once we know every physical law, and are certain nothing more is to be discovered, how do we distinguish our universe from a set of mathematical axioms? We have two choices then: to suspect there is some outer universe which implements the rules and axioms of this one. Or else admit that axioms do not require an implementation: they just are, and that's what makes their system exist (which means that any other axioms and rules we can imagine also exist just as much).
Either hypothesis is an unprovable "cop out"; but the latter of the two is more plausible. The first hypothesis still leads to an infinity of universes, and they have to be nested in each other in an infinitely regressing sequence. The second one has no such silly requirement; and it has the anthropic principle which plausibly explains everything that seems arbitrary or special.
[+] [-] dlevine|11 years ago|reply
[+] [-] 3rd3|11 years ago|reply
http://www.wired.com/2014/08/multiverse#comment-1560643455
Edit: Never mind, http://rationalwiki.org/wiki/Mensur_Omerbashich
[+] [-] Natsu|11 years ago|reply
[+] [-] vecter|11 years ago|reply
[+] [-] ccvannorman|11 years ago|reply
http://www.technologyreview.com/view/413483/could-all-partic...
[+] [-] Bognar|11 years ago|reply
http://en.wikipedia.org/wiki/Inverse-square_law
[+] [-] hcarvalhoalves|11 years ago|reply
Isn't the word for that fractal?
[+] [-] andrewflnr|11 years ago|reply
[+] [-] kazinator|11 years ago|reply
http://www.theonion.com/articles/worlds-top-scientists-ponde...
[+] [-] kimdouglasmason|11 years ago|reply
"That shit would be too much," Gupta said. "It'd be like that Dr. Seuss book Horton Hears A Who and shit. I read that when I was, like, six, and it totally weirded me out."
Nailed it.
[+] [-] teh_klev|11 years ago|reply
http://www.simonsfoundation.org/quanta/20140818-at-multivers...
[+] [-] bellerocky|11 years ago|reply
[+] [-] raldi|11 years ago|reply
[+] [-] dang|11 years ago|reply
[+] [-] notastartup|11 years ago|reply
[+] [-] coldtea|11 years ago|reply
That is, half of the article is trash and the other doesn't represent the science correctly.
[+] [-] walterbell|11 years ago|reply
[+] [-] itry|11 years ago|reply
So two things standing next to each other are the same size as one thing alone?
Damn hard to imagine. I would think "size" does not really "exist" but is a man made concept. And by its definition, two things next to each other form a "bigger" thing.
[+] [-] coldtea|11 years ago|reply
But, to address your example: "So two things standing next to each other are the same size as one thing alone? Damn hard to imagine".
That might not hold for size, but a very similar thing does occur (and is proven) for speed.
If you are in a car that goes at 0.8 miles per minute, and you throw a dart that goes at 0.3 miles/minute, its speed is 1.1 miles/minute (the sum).
But if you travel at the 0.8x the speed of light and you throw something forward at 0.3x the speed of light, its speed is not 1.1x the speed of light, but c. That is, trying to add velocity doesn't get you faster than the speed of light.
http://curious.astro.cornell.edu/question.php?number=145