Comments by "Lepi Doptera" (@lepidoptera9337) on "Sabine Hossenfelder" channel.

  1. That's cool and all, but this isn't her work, to begin with. She just reports on other people's efforts.
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  2.  @humeanrgmnt7367  If they were doing that by faith instead of testing, then the rockets would blow up on the pads, kid. :-)
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  3.  @brontehauptmann4217  What is "scientism"? A word you made up to feel better about having failed high school science class? :-)
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  4.  @humeanrgmnt7367  Challenger didn't blow up on the pad, but it is a good example of where faith based reasoning "Nothing ever went wrong too badly, so we have faith that nothing will ever go wrong in the future, either!" gets you. Faith is an accident bound to happen.
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  5.  @brontehauptmann4217  What's the religious dogma in science?
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  6.  @humeanrgmnt7367  You still haven't told me what those beliefs in science are supposed to be. NEXT!
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  7.  @brontehauptmann4217  Next up: flat earths and no sign of climate change. :-)
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  8. It is not a logical game because logic only applies to classical objects, whereas what we are tracking here is energy. Energy does not follow the laws of logic, which happens to be a commutative algebra. Energy in quantum mechanics is subject to the rules of non-commutative algebras (the commutators between linear operators can be non-zero, i.e. non-commutive). What quantum mysticism like this does is to expose the casual viewer to a very naive understanding (or, better, non-understanding) of the theory, which causes unnecessary confusion. That mechanics is somehow non-commutative has already been known since the early 19th century, when the Hamilton formalism was developed. The classical equivalents of these commutators (Lie-brackets) are already showing signs of these internal mathematical structures in the theory.
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  9.  @brontehauptmann4217  Yes, but why would I have faith in a guy who threatens to throw the overwhelming majority of all dead people into a fiery lake for eternity? That's not what nice people do. :-)
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  10.  @Brianboy9494  Approximations are meant to make our lives easier. They have to be "good enough to be useful", which means that only the practitioner in a field can develop a good feeling for the range of applicability of an approximation. You are of course correct that physicists are usually able to smell an approximation from miles away while the layman is, at best, guessing what it is that he is looking at. That's a serious problem in science communications and not just in physics. That is my reason for pointing them out wherever I see somebody misusing them.
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  11. Who is operating all these climate denialist bots? They all sound exactly the same.
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  12. Energy conservation requires (through Noether's theorem) that the universe is time-translation invariant. We can see that the universe is not time-translation invariant, hence there is no globally conserved quantity called energy. We can define it in the small, but all attempts to define the total energy of the universe are doomed to fail.
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  13. You got it. The theory is, indeed, about the flow of energy between systems. "Wave function collapse" is simply a very, very poor choice of words for the irreversible transfer of one quantum of energy from the original, isolated quantum system to the measurement system. Energy never had paths, not even in quantum mechanics. It doesn't have "location", either. The potential energy in a spring is not somehow concentrated in the center of mass of the spring. The kinetic energy of an object is not in the object. It's a function of the relative motion of the object to a rest system. A quantum is, indeed, simply the amount of energy that two systems are exchanging. It's not a particle, it's not an object. It's just work that system A performs on system B.
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  14. I have anti-vaxxers in he family. Trust me, they don't think. That part of the family makes consistently poor choices in all areas of life, not just in terms of healthcare. Marriage, divorce, job choices, financial matters... it's a huge mess.
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  15.  @minanovkiril  Mass is a system property. It's no different from energy. ;-)
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  16. Physics is the art of approximation. If you don't know how to teach approximations properly, then you shouldn't be talking about physics.
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  17. This has nothing to do with publishing. These kinds of problems are always theoretical. The formulas that a theorist can derive about them CAN NOT be solved in practice. They have no predictive power in experimental terms. They are entirely formal in nature. So now you have to ask yourself if you really want to "silence" mankind about completely formal solutions to in practice unsolvable equations. What good does that do, actually? Isn't it more about your ego that feels threatened because a smart person can do something that you can't, no matter how "useless"?
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  18. It's not a matter of technological barriers, at least not in the sense of e.g. LIGO. It's a matter of new theoretical ideas with regards to the question if there could be non-classical effects of gravity that are strong enough to cause a detectable signal. Personally I don't think so. Experiments of this kind are often based on some unusual physical assumptions. An entanglement experiment, for instance, is not sufficient for quantum gravity because classical gravity entangles systems just fine. Entanglement per se is not a quantum effect. A quantum effect detection requires quantized energy exchanges and those are just so far down the rabbit hole that it's not even fun talking about them.
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  19. It's clearly winning. ;-)
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  20. Not in the case of Sabine, though. Sabine is mostly very good at selling nonsense. ;-)
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  21.  @NephilimFree  Yes, that was all bullshit. :-)
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  22. Here, let me give you some attention. You are begging so nicely. ;-)
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  23. It depends. If there are modifications of gravity at short macroscopic ranges, then we might learn something. The Washington group has been using conventional methods in the search for post-Newtonian gravity for decades and that is very important research in my opinion. It might be possible that there is a regime where the new experimental techniques can push these limits further down. Unfortunately, at some scale electrostatic effects will invariable swamp the gravitational interaction, so nature may not let us see what is really going on in that regime.
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  24. Did you just repeat the "I failed high school science class... hence god!" proof for gods? :-)
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  25. I am not telling you what to do, but I reserve the right to laugh about your poor decisions. ;-)
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  26. It is not getting "bigger" because spacetime is falling inwards "at the same rate". Imagine swimming in a river... you have to swim against the flow just to stay still relative to the banks of the river.
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  27.  @skhi7658  IMHO it's the way we teach introductory quantum mechanics. I was completely lost after my own QM 101 class. I understood the math, of course, that's easy enough, but I had no idea what it actually meant. I didn't develop a working intuition until after I got into experimental high energy physics, had to read the CERN detector design documents and began to work on actual detector hardware. After that it became clear very quickly that all we are ever measuring are energy, momentum, angular momentum and charge. It was really that "hands on" experimental work that clarified the concepts for me. The textbooks, however, are usually being written by theorists and are staying close to the original "particle" language from the early days, which, unfortunately, is misleading. So, yeah, we have a century's worth of quantum mechanics textbooks that should be rewritten... same math but emphasizing that we are looking at energy that is distributed in a quantum field.
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  28.  @skhi7658  I agree. Here is the thing, though: I can not compete with Sean Carrol and Michio Kaku... I don't have the hair and the kind of face that people want to see. Neither am I willing to lie to people to make things "more interesting". That means nobody is ever going to listen to my technically correct explanation that are about as interesting as watching paint dry.
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  29. Now that is what I call a wall of bullshit.
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  30. Well, with the caveat that she is lying to you. ;-)
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  31. She is getting seriously wacky now. ;-)
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  32. Of course she is not crazy. She is a calculating troll who needs views. ;-)
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  33. ​ @SteveKelly1  The particle language goes back to Einstein's 1905 paper on the photoelectric effect. In that paper he gives a congenial explanation for the macroscopic photoelectric data in terms of the quantization of the electromagnetic field. But at the same time he commits his actual biggest blunder. After having identified quanta of energy, he immediately concludes in a single sentence that these quanta have to have location properties like Newtonian corpuscles. That conclusion isn't backed up by any observational detail of the photoelectric effect. It doesn't match the well known definition of energy as a system property. It's also completely unnecessary for the remainder of the paper. It's a completely unforced slip of Einstein's mind. Unfortunately other authors after Einstein have picked up this mistake and they kept building on it (to this day). What physicists mean by "a particle" is actually a quantum of energy, momentum, angular momentum and charge. Neither of these properties refers to a "small, localized object". They are all system properties. The theory does not describe particles. It describes changes in the energy of systems. You can find this clearly expressed in Heisenberg's matrix mechanics paper where initial and final energy was used as index into the matrices. That's the correct interpretation except that it's not just energy but the quad of energy/momentum/angular momentum and charges. Why these? Because these are the only locally conserved quantities in nature. Everything else changes, but these quantities get transferred from system to system. We have language for property exchanges. Energy FLOWS. It does NOT take a path. The entire concept of path makes no sense because systems are random subdivisions of nature. They don't even have to be some continuous regions of spacetime. Even in classical mechanics the energy of a spring is not localized, for instance. It's in the entire spring. The kinetic energy of an extended object is not in the center of mass of that object, either. We never had this illusion that energy etc. has to be focused in some tiny region of spacetime. That is purely an invention (and not a good one) of non-relativistic quantum mechanics. In quantum field theory it's even worse. the only well defined states are the plane waves of the (interaction) free theory. Everything else is a jumbled mess without any known physical interpretation. Whatever happens in the interaction volume can only be described with classical quantities if we look at it from infinitely far away. In other words: the closer we look, the blurrier nature gets. It doesn't get more "point-like". So, no, not only do particles not travel along paths, there simply are no particles. There are initial and final system states and they are characterized by changes in energy, momentum, angular momentum and charge. That is a fundamentally different (and 100% correct) way of looking at the world.
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  34. You can think that and then nature will slap you with the standard model of particle physics.
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  35.  @hughmoore786  You sound just like the guy who knows how to get around the third law of thermodynamics. So when is your 0K freezer hitting the market?
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  36.  @hughmoore786  Can you argue with any kind of logic?
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  37. That's the definition of the authors. A more rational person would have called this "Quantum mechanical cardboard insertion tester" because all it does is to determine if a piece of cardboard has been inserted into one of the paths of the interferometer. In technical terms the authors are comparing two different experiments with each other. In one experiment the light path is open, in the other one it is blocked. Technically that is neither classical physics nor quantum mechanics. Imagine you did this in classical mechanics e.g. by looking at the motion of a block on an inclined plane... and you calculate the problem once with an inclined plane and once without. Without the inclined plane the block simply drops down straight. Would you find that particularly interesting or strange? If not, then why is this scenario any different? We are simply comparing apples and oranges here. I think the authors were mostly confused by their own attempt to look smart.
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  38. The problem with quantum fluctuations as the source of the cosmological constant is a misunderstanding of quantum fluctuations. They don't exist in the way they are being portrayed in the press. You can look up into the night sky and you can see objects that are millions of light years away (the Andromeda galaxy) with your own eyes and over 40 billion light years with instruments (the CMB). That light was not disturbed by quantum fluctuations, at all. If the universe was "grainy" or "foggy" the way the usual mental model suggests, then this light would have never made it undisturbed and we would probably not even be able to see as far as our own toes. In quantum field theory higher order terms cause changes in energy levels of bound states because these bound states select a distance (size) scale themselves, hence the integrals over contributions at higher energy are cut-off at that scale and they don't average out to zero. These, however, are not simple random terms and they all go to zero at the scale of the universe. At most you can get something like a 1/R_cosmological dependence, which would be important during inflation but can either be neglected today or would, at most, lead to an asymptotically free universe. If an actual cosmological constant exists, then it is not caused by effects that are consequences of the background geometry. It exists as part of the layer of physics that causes the background geometry, to begin with.
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  39. In actual science history Copenhagen went out the window before Bohm even wrote his paper. There is no need for it in relativistic quantum field theory. Even the term "Copenhagen interpretation" seems to have been coined long after it had become more or less obsolete for fundamental physics. The reason why we still teach non-relativistic quantum mechanics to students is because the relativistic theory is mathematically extremely demanding and it is not well suited for the analysis of bound states, which occur far more frequently in the non-relativistic regime (unless one is interested in the structure of proton, neutron and pions). So it's kind of a weird ghost that just doesn't want to die, even though its time has been up since the 1930s.
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  40. Yes, try any of that in the physics community and you get slaughtered. :-)
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  41. ​ @morphixnm  The modern measurements for that were made with radar reflection on Venus. Shapiro did those at Arecibo in the late 1960s, early 1970s. The physically relevant measurement there is the excess time delay, which is a much more precise measurement than the angular deflection can ever be. Phys Rev. Letters Vol. 26, NUM 18 has one of the papers. The max. delay was approx. 180us during the superior conjunction with error bars of approx. 20us per data point. 20us, that's a distance uncertainty of 6km or so, probably dominated by plasma interactions and a bit of topography.
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  42.  @minanovkiril  Yep, that's another one of those childish false dichotomy fallacies. ;-)
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  43.  @minanovkiril  There are no particles in nature. There are lots and lots of people who don't understand physics, though. ;-)
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  44. No. :-)
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  45. The universe is 100% local. It is also 100% real. :-)
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  46. Why are you telling us that you didn't go to an institution of higher learning? Is that supposed to make us like you better? ;-)
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  47. Nah, Jordan Peterson is to Canada as crack cocaine is to the US. ;-)
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  48. Bell wasn't wrong wrong. He made a non-relativistic derivation about a phenomenon that follows trivially from relativity. If you read his actual paper, you will find a few sentences at the end where he makes exactly that remark. He already knew that his paper was useless because there was a much, much tighter bound on these correlations, which happens to be exactly what standard quantum mechanics predicts. The universe is either relativistic and then Bell is unnecessary or it's not relativistic. The latter does, of course, have catastrophic consequences for everything else in physics.
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  49. Bwaahahaha... two thumbs up. That really brought it down to the point. ;-)
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  50. No, that's not what we are talking about. The Higgs is a well defined physical mechanism in the standard model. Vacuum self-energy is a mathematical artifact that tells us that something about our representation of quantum fields is wrong.
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