Search results

  1. N

    US solar power generation for 2014-17

    Solar generation results for US are out for 2017. Year over year: http://www.eia.gov/electricity/annual/html/epa_01_02.html https://www.eia.gov/electricity/annual/pdf/epa.pdf US: Net Generation (Thousand Megawatthours) 2014 Solar: 17691 (that's 0.43%) All sources: 4093606 US: Net Generation...
  2. N

    Medical Do one-piece dental implants exist yet?

    I thought I read about these a few years ago, but for the life of me, I can't find it now. Believe me, I tried. I would appreaciate if someone has links about current status in this area.
  3. N

    I Implications of Nishida's mass/CKM observation

    https://arxiv.org/abs/1708.01110 "Phenomenological formula for CKM matrix and its physical interpretation" This paper was mentioned in "Koide sum rules" thread, but not discussed much. But to me, this looks like a big deal. Here's the "numerology": Square roots of experimental quark masses...
  4. N

    B Planet Nine race, how is it going?

    Pardon this possibly information-free post... Since Mike Brown published his papers on the possibility of ~10 Mearth mass body beyond ~200 AU, and it was discussed a lot, I imagine now there is sort of a quiet race among astronomers in TNO field to find this thing. IIUC, Mike has his own team...
  5. N

    I Core collapse of a supernova: the "void" left by the collapsed core?

    When core collapse occurs, a ~10000km diameter core of the star collapses into neutron star or a black hole. Let's look at NS case here: the resulting neutron star is on the order of 20 km across. And this happens in a few seconds. The upper layers of the star cannot immediately fall onto the...
  6. N

    I "Thermal" neutrino generation?

    Consider the Sun. It radiates energy by generating EM radiation. However, Sun is not transparent to EM, and therefore energy can only escape from the surface using this mechanism. Hot plasma below the surface generates and absorbs gazillions of photons, but they are "trapped" there. But EM is...
  7. N

    I QCD: Asymptotic not-exactly freedom?

    "The strong coupling from a nonperturbative determination of the Λ parameter in three-flavor QCD" https://arxiv.org/pdf/1706.03821.pdf Their calculation gives strong coupling constant g^2/4pi ~= 0.08523 at 1.508 TeV. Small, but not tending to zero. Lattice calculations seem to converge on...
  8. N

    US solar power generation for 2014-16

    Solar generation results for US are out for 2016. Year over year: http://www.eia.gov/electricity/annual/html/epa_01_02.html US: Net Generation (Thousand Megawatthours) 2014 Solar: 17691 (that's 0.43%) All sources: 4093606 https://www.eia.gov/electricity/annual/pdf/epa.pdf: US: Net Generation...
  9. N

    I Magnetic moment of a massless charged Fermion?

    The spin magnetic moment of a charged, spin-1/2 particle is $$g \frac e {2m} \frac \hbar 2$$ where g is the g-factor (2 for any particle in tree-level approximation, 2.00231930436182 for electron), e is charge m is mass ##\frac \hbar 2## is spin But with zero mass this expression does not make...
  10. N

    I Inflation "cooled Universe from 10^27 to 10^22 kelvins" why?

    I've seen numerous descriptions of inflationary phase a-la "The universe was supercooled from about 10^27 down to 10^22 kelvins". However, I do not understand what is the basis for such estimation. We do not even know with any certainty how long the inflationary phase lasted. For one, "eternal...
  11. N

    Comparison of Cs, Sr and Pu fallout from meltdown

    I combined three maps of Chernobyl fallout: Cs-137 map, Sr-90 map and Pu-239 map. Map scales are the same. Lowest contour levels for Cs and Sr are the same (1 Ci/km^2), Pu contour is ten times lower (0.1 Ci/km^2). This visually demonstrates that Cs is about ten times more widespread fallout...
  12. N

    News Illegal wood pellet business in Chernobyl Zone

    Investigative journalists discovered that the wife of deputy head of National Police of Ukraine (his name is Igor Kupranets) is a "successful businesswoman", but this is hardly unusual in our country. What is a little peculiar is that her business is in making wood pellets, and it is located in...
  13. N

    I Are neutrinos definitely ruled out as Dark Matter?

    Ordinary Standard Model neutrinos _are_ dark matter particles, in a sense that they have mass, and they only weakly interact with everything else. IIRC they are not considered to be a satisfactory candidate because nearly all neutrinos in the Universe are relativistic, whereas we know that...
  14. N

    I Charges in SU(2) gauge QFT

    In QCD, quark is in fundamental representation of SU(3) and thus it has to have 3 charges (what we came to call "colors"). Gauge bosons are in adjoint representation and there are 8 of them. The choice how to assign color charges to them is not unique, one popular choice is based on Gell-Mann...
  15. N

    I Imagining a Higgsless Universe

    I would like to imagine how would physics look in a Universe governed by Standard model, sans Higgs. IOW: how would the unbroken SU(2)*U(1) be different from our usual broken one? Matt Strassler has a similar article here...
  16. N

    I News on V774104?

    https://en.wikipedia.org/wiki/V774104 "The discovery was announced at the November 2015". "No astrometry has been submitted to the Minor Planet Center, so there are no publicly known orbital elements". Hmm. This is an interesting object, one of the most distant, possibly only the third-ever...
  17. N

    Nitrous oxide energy storage

    Hi, I took part in discussions on various forums on viability of large-scale solar power as a primary energy source (on Earth), and on in-situ resource utilization (ISRU) for space missions. One idea discussed for Mars base was to produce CO and LOX from Mars CO2 atmosphere, obviating the need...
  18. N

    Insights A Brief on the Expansion of the Universe - Comments

    nikkkom submitted a new PF Insights post A Brief on the Expansion of the Universe Continue reading the Original PF Insights Post.
  19. N

    Hawking radiation from not-a-black-hole?

    Since Schwarzschild solution describes exterior not only of black holes, but of any spherically symmetric non-rotating objects, then any such object should emit Hawking radiation, no? Then how exactly is that working? Let's set up a thought experiment. Say, we construct a spherically symmetric...
  20. N

    Need guidance on epoxy resins

    Hi guys, I recently got my hands dirty renovating my house. Learned a lot. I want to fix a floor in one room, want to try epoxy resin for this. Surprisingly, googling was less than satisfactory. Yes, I got it, many epoxy resins are wonderful and there are gazillions of them. That's not...
  21. N

    We *already built* the light water breeder?

    In another thread http://en.wikipedia.org/wiki/Shippingport_Atomic_Power_Station was mentioned. I went to the link, thinking "okay, I remember this one, the first commercial reactor exclusively for electricity generation, not weapon needs. Mostly only historical interesting..." I was reading...
  22. N

    VVER fuel

    I was surprised to learn recently that VVER fuel assemblies are in some respects more advanced than typical Western PWR fuel: namely, fuel rods are arranged in a hexagonal pattern in the fuel bundle: https://www.google.cz/search?q=vver fuel&tbm=isch This is the most dense and uniform packing...
  23. N

    Is a lone quark possible?

    I get the idea of confinement, and how it is impossible to separate a lone quark from a baryon: it needs more energy than creation of two more quarks, so the latter happens first, and you end up with having created a (color-neutral) meson. However, I don't see what prevents free quarks from...
  24. N

    Molten metal fast reactor?

    I was reading lately about fast reactors, breeders, and desirable high-temp reactors; and it seemed most new reactor concepts being studied today are more difficult than existing reactors in at least one way. Supercritical water reactors need to battle with ever more hot and high pressure...
  25. N

    Do gravitational waves penetrate black holes?

    According to General Relativity, do gravitational waves penetrate black holes? My gut feeling says "no, if gravitational wave goes under event horizon, it won't re-emerge", but I'm not an expert...
  26. N

    Chernobyl B. Medvedev Chernobyl Notebook

    G. Medvedev "Chernobyl Notebook" This is the best book about Chernobyl, in my opinion. I read and reread it many times back then in 1990s when it was first published. It gives both a good technical description about the disaster timeline and causes per se, and also it provides an eyewitness...
Top