Wikipedia:Reference desk/Archives/Science/2017 October 13

= October 13 =

instead of alpha decay or beta decay, why doesn't there also exist decays by a proton and a neutrino, or by a neutron and a neutrino happen?
After all, the spins add up to an integer in the two imaginary cases i've suggested, just as in the case of alpha and beta decay. Is there a reason known why they don't occur? Maybe it is that there aren't many protons or neutrons running around freely inside a heavy nucleus compared to the number of alpha particles?144.35.45.38 (talk) 05:15, 13 October 2017 (UTC)


 * You mean like neutron emission or proton emission? Such things do happen, they are just rare.  Dragons flight (talk) 06:39, 13 October 2017 (UTC)
 * Indeed, if one were to read the article Radioactive decay and specifically the section Radioactive decay both proton emission and neutron emission are listed, as well as included in a nice little diagram along the right sidebar. -- Jayron 32 10:41, 13 October 2017 (UTC)


 * Thanks Draggonflight and Jayron, I didn't notice those articles somehow.144.35.114.38 (talk) 22:57, 17 October 2017 (UTC)
 * It gets even better. Neutrino astronomy is there as well and the 2002 Nobel Prize in Physics was given for the advances in that. --Kharon (talk) 23:47, 14 October 2017 (UTC)


 * Why do you think that a neutrino would be created in such an event? According to the current understanding of particle physics, a single neutrino (or antineutrino) can be created due to an interaction involving a W boson (a W boson can decay to a neutrino and a charged lepton, or a charged lepton can "decay" to a neutrino and a W boson), or a pair of a neutrinos can be created due to an interaction involving a Z boson. Note that particles whose mass-energy exceeds the available energy can occur as intermediates (see virtual particle). In ordinary beta decay, a down quark inside a neutron becomes an up quark and a W- boson, and the W- boson subsequently results in an electron and an antineutrino. In proton emission or neutron emission the whole protons or neutrons are ejected from the nucleus, no neutrino is created.
 * By the way, for every electromagnetic decay of an excited state with an energy of at least twice the mass of the lightest neutrino, there is a competing process of the emission of a virtual Z boson that creates a pair of a neutrino and an antineutrino. These neutrino pair creations are just rare compared to photon emissions (gamma radiation in nuclear physics, but also emission of light from atomic or molecular state transitions), and neutrinos are hard to measure anyway, so this effect probably won't be experimentally accessible any time soon.
 * Icek~enwiki (talk) 20:21, 15 October 2017 (UTC)

What's the highest sulfur fossil fuel ever made?
Processed fuel and fractional distillation products count (i.e. gasoline, diesel) Sagittarian Milky Way (talk) 07:49, 13 October 2017 (UTC)
 * Depends on what you mean by "made"; probably some bituminous coal mined somewhere. Up to 4% 2606:A000:4C0C:E200:9480:46FD:8725:3114 (talk) 08:19, 13 October 2017 (UTC)


 * Otherwise, synthetic fuel, made from lignite using the coal liquefaction process by IG Farben during WW2 is a likely candidate; however, lignite has a relatively low sulfur content (for coal) -- about up to 1%. 2606:A000:4C0C:E200:9480:46FD:8725:3114 (talk) 09:51, 13 October 2017 (UTC)


 * "Typical Sulfur Content in Coal: Anthracite Coal : 0.6 - 0.77 weight %; Bituminous Coal : 0.7 - 4.0 weight %; Lignite Coal : 0.4 weight %". Classification of Coal. Alansplodge (talk) 09:59, 13 October 2017 (UTC)
 * Sulphur in Assam coal  says: "Sulphur in these coals generally occurs in the range of 2.7-7.8%" (p. 87).
 * We may have a winner here. —2606:A000:4C0C:E200:9480:46FD:8725:3114 (talk) 11:12, 13 October 2017 (UTC)


 * Prior to 1993, diesel fuel had relatively high sulfur content, but I can't find anything above 4%; however, there is a "global sulfur cap of 3.50 weight percent". 107.15.152.93 (talk) 10:26, 13 October 2017 (UTC)


 * Bunker C usually has a very high sulfur content. 2601:646:8E01:7E0B:756C:F81D:F1A7:3FB4 (talk) 10:36, 13 October 2017 (UTC)
 * Close, but no cigar -- Bunker C fuel oil has 2.4% sulfur. —2606:A000:4C0C:E200:9480:46FD:8725:3114 (talk) 11:03, 13 October 2017 (UTC)


 * It should be noted that the presence of sulfur is not desirable; it isn't added to fuel or increased intentionally in any way; fuel producers would rather it weren't there at all as it doesn't add to the value of the fuel meaningfully; indeed sulfur oxides produced through combustion can be highly corrosive, and there's literally no good reason for it; so there's no economic reason why a fuel producer would add sulfur to their fuel. It's merely an impurity already present.  -- Jayron 32 10:38, 13 October 2017 (UTC)


 * Density and Sulfer content of selected crude oils --Guy Macon (talk) 16:22, 13 October 2017 (UTC)
 * (None of which exceeds 7.8%; and, crude oil isn't really a fuel). 2606:A000:4C0C:E200:9480:46FD:8725:3114 (talk) 16:49, 13 October 2017 (UTC)
 * So oil tankers don't run on their own supply? Sagittarian Milky Way (talk) 17:24, 13 October 2017 (UTC)


 * Typically, no. The large diesel engines of oil talkers are typically fueled with Bunker fuel. Crude oil is a mixture of long chain and small chain hydrocarbons. The long chain hydrocarbons, have a high boiling point, high flash point, and high viscosity, and are difficult to ignite. The small chain hydrocarbons have a low boiling point, low flash point, and low viscosity, and tend to ignite too soon.


 * The large gas turbines used in many power plants will run off of crude oil just fine. This is usually uneconomical, because you can refine out the gasoline/petrol and sell it for a high price. In certain circumstances, however, such as right at the well head, it may be more convenient to burn crude than to import some other kind of fuel. --Guy Macon (talk) 17:48, 13 October 2017 (UTC)


 * And finally, petroleum coke, which has a sulphur content of between 4% and 7% as well as all kinds of other nasty stuff - see Comparative Properties of Bituminous Coal and Petroleum Coke as Fuels in Cement Kilns. For more on petroleum coke or "petcoke", see also China Is Quietly Burning A Fuel Dirtier Than Coal -- And Buying It From The US. Alansplodge (talk) 11:08, 14 October 2017 (UTC)
 * Personally, I prefer Petroleum Pepsi. 2606:A000:4C0C:E200:7595:47BF:7C36:8BA6 (talk) 17:06, 14 October 2017 (UTC)
 * Better than petroleum heroin. Sagittarian Milky Way (talk) 19:39, 14 October 2017 (UTC)


 * Wouldn't that look like black tar ? StuRat (talk) 23:52, 14 October 2017 (UTC)