Comments by "N Marbletoe" (@nmarbletoe8210) on "Stanford" channel.

  1. For me, one of Dr. Susskind's best and most accessible lectures.  Stanford thanks so much for sharing these!
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  2. +Gary McAllister Everyone who likes youtube cats by extension likes string :?>
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  3. congrats to Stanford tech staff for quality video, sound, and for keeping up with the action.  Thx!!
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  4. 'imaginary mass is a bad thing'  57:25 'it's hard to have a string with one end. unless you're a buddhist... a zen buddhist.' 1:16:15 A string with one endpoint is a point?
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  5. PJ Datayan Hawking as Bran Stark
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  6. rodluvan1976 +Bud E thx 4link!  i think i have it now. the higgs field's mexican hat potential can produce both higgs and ziggs.   the ziggs particle is related to rotation of the field value around the rim of the hat.   the higgs particle is related to radial movement of the field up and down the rim. ziggs is not standard name, but there is no one standard name and there are various modes of the field oscillating around the rim, so there technically would be various particles.   sound right? btw, i like the way he uses 'zilch' -- he explained it though, unlike the 'ziggs.' A unit of zilch is easier to imagine than a unit of weak hypercharge. (how could it be weak if it's hypercharged, lol)
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  7. zarchy55 at each point in real space, there could be that circular motion of the fields... the circles aren't in x,y,z, we couldn't see them circling. i imagine it like another dimension touches space at each point, and that other dimension can oscillate. also what malawigw said is true
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  8. Randomnick123 there's no energy lost. for example, an electron in free flight doesn't slow down like mollasses because of the mechanism. it just bops back and forth from right spin to left spin, coasting along. somehow this flipping gives it inertia, which actually makes it hard to slow the electron down or speed it up. the vacuum acts like some weird slip-n-slide that keeps particles moving at a constant velocity...
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  9. carlninja1 i think Jack is asking if Cesar or Matt or Maria gave an explanation that answered your question. if so it's nice to tell them. then we all know it's all taken care of :)
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  10. 50:20 or so... question: can a right handed electron absorb a ziggs, giving it a zilch of +2? or, can a left emit a ziggs, giving it -1 zilch?
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  11. Spacetime IS actually expanding in between any two objects. It's just too way small to measure between atoms in our body, or between earth and moon.
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  12.  @petegaslondon  haha!
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  13. OneBigPappa haha, WOODn't. I think planting trees is the best way to go -- along with efficiency and renewables. It should never be forgotten, and plant FRUIT TREES so we can eat yeah!
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  14. Anil chauhan an alternating magnetic field would make the electrons flip back and forth repeatedly, for as long as you kept the field turned on. each flip you'd get photons. you'd have a photon factory
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  15. Hjembrent Kent this stuff is so cool.  i'll check out lecture 4...
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  16. Dennis Edlund "could you please name that position" -The point the earth and sun move around is called the barycenter.
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  17. axel detlofsson that's true, but it's an idealization. No lab setup is perfect, so in a real world experiment the electrons would occasionally give off a photon. For one thing, one can't align magnets or anything else perfectly. Stray environmental field could interfere even with the best shielded chamber. I was hoping Lenny would say something to that effect, but he didn't. Nevertheless, when he says the probability is 1, he means mathematically.
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  18. that's engineering. this is physics
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  19.  @jaredgore4818  In any case elastic and plastic are just two types of deformation. A grid may be deformed hyperbolically. That's math, which physics may use if it is useful.
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  20.  @jaredgore4818  Searched "hyperbolic deformation" on google scholar. Returned a few hundred results, such as: "Hyperbolic deformation on quantum lattice hamiltonians" (Ueda and Nishino 2008, J Phys Soc Japan)
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  21. Biology is fine, but people who want to make it political who are barking up the wrong tree
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  22. lol because they ran out of letters in the alphabet
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  23.  @schmetterling4477  Moral of the story: don't put Descartes before the horse.
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  24. why can't they produce a pair? they have enough energy...
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  25. It is just the field value. Just two numbers that a point in space can have.
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  26. Lenny doesn't mention that type of vacuum energy detector, but i thought vacuum energy was measured in the lab as casimir force.
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  27. It took me three years, but I estimated how fast the Sun and Alpha Centauri should be expanding according to the Hubble whachamacallit. It's the speed of a running snail, about 3 mm per hour or so. I had the exact number here a year ago, lemme go find it...
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  28. 1. energy of string proportional to length; as you stretch, new 'string' field gets added. 2. what else acts like that? dark energy. 3. is our U inside a higher D string that is being stretched?
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  29. ***** haha that show was set in albuquerque, and it was pretty accurate
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  30. Heyi Wang they can point to different directions until they flip to match the magnetic field. eventually they'd all flip and be the same. the stronger the field, the sooner they flip.
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  31. i'd give $10 to have him say at 2x, "What's up, Doc?"
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  32. Since the U is expanding and the dark energy density is constant, the total mass/energy content is increasing (unless the U is infinite in size, in which case it's mass/energy is always just infinity)....?
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  33. zarchy55 the field. the Higgs field in this case. it can oscillate at any point in spacetime.
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  34.  @jorriffhdhtrsegg  both. he imagined simple scenarios, postulated simple truths, and then deduced dramatic consequences for theory
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  35. I believe that it he is talking about real values of fields, without complex values. It's not an electric field, just two generic fields, just as an example. The z axis gives the energy of the two fields combined for any combination of their values.
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  36. probably something like pent-up energy
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  37. I thought mathematics can't be derived from logic
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  38.  @xaffimarc  That's what I thought, even though I couldn't hear a thing. "It better not" because if it did we'd probably explode faster than the big bang.
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  39. Randomnick123 right, the vacuum isn't empty. they still call it that, but it can have fields. it does have fields.
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  40. cool story! I did not know they were related.
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  41. if we can count the holes in the Multiverse at least we'll know it's topology
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  42. too many electrolytes
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  43. Jannis Alexakis yes, and if you take a small enough volume it will usually be flat, so they take the limit. thus GR describes local fields, but does not specify the exact large scale shape of the universe...
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  44. The Higgs BOSON doens't give anything mass. The Higgs FIELD gives mass to fermions. This is ordinary mass, like we see around us all the time. There is also mass all around us that is not created by the Higgs field. So it doesn't give EVERYTHING mass, only the fermions.
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  45. 20:00 and on, the term i think is "quark gluon plasma." Lots of research on it now, including a string theory-aided prediction that had some support from experiment. Something to do with the QGP acting as a liquid or gas or something.
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  46. life on earth started 3 or 4 billion years ago.  i think he's saying that the time to evolve intelligence, which is now, 13.8 billion years from the big bang, is coincidentally the same as when the hubble horizon matches the age of the universe.  
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  47. Hjembrent Kent 15:20 is a curious moment in the history of physics lectures.  Like you, I don't see how U expansion relates to evolution.  I think Lenny's saying that someday we'll have to explain 1) why the vacuum energy is what it is, and 2) why the speed of evolution is what it is.  Then we can explain why in our U they are the same order of magnitude... coincidence or some deeper linkage.   Perhaps the answer would come from ability to model the probability distribution of possible universes.  Then we could correlate vacuum energy/ expansion parameter vs speed of evolution for the population of possibilities, and ask if there's a significant relationship. In other words, it's less a metaphysical claim that such a deep link exists, more of saying, "it's an anomaly, and science eventually has to deal with anomalies if we want to expand our knowledge"
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  48. Hjembrent Kent re hubble horizon:  maybe it's the difference between Hubble Horizon and Observable Universe.  the HH is about 15 bly, the OU like 45 bly.   HH:  15 bly  -- light rays emitted now can never get to objects that are now 15 bly away.  . OH:  45 bly  -- light rays emitted by objects 13.5 bya are just getting to us now, from objects that are now 45 bly away (back then, they were closer).   HH:  a future message horizon OH:  a past message horizon (but both are cast in terms of current location of objects) i think i understand it better than i did an hour ago... does it sound right?
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  49. Hjembrent Kent I think I have them straight and that we actually agree on HH vs OU.  The OH is present distance of the furthest object we can see in a telescope, because anything further away today can't have sent light to us, even if it did so at the big bang (really, at the last scattering 380 ky after the bang).  The HH defines the portion of space we can't see by light that is emitted now.   (It's a big thing for me to get my head around, so anything i say is a 'maybe.')     Agree, the HH doesn't change size (as long as the Hubble constant of expansion doesn't change?), but the OU does get bigger over time...  It is curious that both rely on a 'cosmic time' that can define a simultaneous "now" for all things.  I guess the CMB does define a central point in spacetime, the big bang... and it also defines a universal rest frame and clock time.  Pretty amazing, since relativity theoretically got rid of the concept of a universal clock... but then we find one that appears physically, due to cosmology.  
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  50. Eduard Stancu the sun and the earth move around a common center of mass
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