Gauge_Irrahphe

11 ms·

61.
by Gauge_Irrahphe 5y ago
>You can't get a positron/neutrino pair directly, you get a w+ boson which will decay into a positron/neutrino pair, but that w+ boson, like the z0 boson in the other case, is prohibitively heavy so this reaction doesn&#x2
62.
by Gauge_Irrahphe 5y ago
OK, so you'd get nickel-63(+positron and neutrino) which then decays into copper-63.
63.
by Gauge_Irrahphe 5y ago
You can see the emission spectra near the "surface",you cannot see what's inside. Still, plenty of lead heavy stars have been detected. >exactly who are they trying to keep these details a secret from? Pretty much everyone
64.
by Gauge_Irrahphe 5y ago
>total binding energy literally goes down as you get to larger nuclides. No, it goes up. Iron-56: 492.26 MeV Uranium-238: 1801.7 MeV
65.
by Gauge_Irrahphe 5y ago
>Producing neutrinos to carry off spin would violate conservation of lepton number. You need to create a lepton pair, Yes you need a neutrino/antineutrino pair. I don't see what is being violated. >This is not what we see. S
66.
by Gauge_Irrahphe 5y ago
That just doesn't happen. We know that elements are stable. It doesn't normally happen that e.g. gold spontaneously explodes into iron, you'd need the extreme conditions inside a supernova to make that happen.
67.
by Gauge_Irrahphe 5y ago
Also note that this closely corresponds to what we see: A star would be expected to burn by fusing hydrogen into heavier nuclei, which shed helium as alpha particles once they get too heavy, eventually ending up with mostly lead and helium.
68.
by Gauge_Irrahphe 5y ago
That doesn't make any sense, the difference between nickel-62 and copper-63 is one extra proton. It's also bullshit, since the differences in spin get equalized by neutrinos.
69.
by Gauge_Irrahphe 5y ago
OK, Which weighs more? A nickel-62 nucleus and a proton, or a copper-63 nucleus?
70.
by Gauge_Irrahphe 5y ago
Iron. That doesn't contradict that fusing more hydrogen with iron is energeticaly favorable, as the binding energy of hydrogen is zero. So you still get energy from fusing it into iron.
71.
by Gauge_Irrahphe 5y ago
>If you fused into something bigger, it would still be more efficient to split that atom and fuse it's nucleons into more Iron. Of course, but that doesn't easily happen, as the nucleons are already bound together into heavier
72.
by Gauge_Irrahphe 5y ago
>If binding energy increased all the way up you wouldn't be able to have nuclear fission. You would, because the smaller nuclides have higher total binding energy than the large nuclides. That doesn't contradict every step inbe
73.
by Gauge_Irrahphe 5y ago
>the average mass per nucleon in the resulting nucleus must be smaller than the average mass per nucleon in the reactants. That doesn't equal to the binding energy per nucleon though, as you add a nucleon.
74.
by Gauge_Irrahphe 5y ago
You are confusing nucleon (neutron or proton) with nuclide or nucleus. You still get extra energy from fusing a nucleon with nickel-62
75.
by Gauge_Irrahphe 5y ago
Only that this is false, or more precisely intentionally misleading. The total binding energy increases all the way up. See carefully the description: It's binding energy per nucleon . It's the amount of energy you get by fusing
76.
by Gauge_Irrahphe 5y ago
Because heavier elements have higher binding energies than iron.
77.
by Gauge_Irrahphe 6y ago
Is this the reason why the obviously wrong calculation that fusion ends with iron is hammered into everyone?
78.
by Gauge_Irrahphe 6y ago
>But the input to the visual system is still an image on your retina, which obeys the same laws as camera optics. The thing that makes the difference is that the resolution of the retina drops as you move off the center. Which I suppose