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Scientists uncover exotic matter in the sun's atmosphere
- SAI_Peregrinus 7y agoThe "exotic matter" is plasma. Since the entire atmosphere of the sun (the corona) is plasma the headline is about as relevant to the study as saying that scientists studying hydrology have found water.
- superkuh 7y agoYeah. It's exciting when you don't find plasma on the sun like in the chromosphere. Between the photosphere and corona there's a shift from thermal energy driving plasma motions to a domain where magnetic energy defines plasma motions. The chromosphere sits smack in the middle of it, a high energy gradient but sometimes there are actual molecules of gas found in the spectral lines. Like, not fully ionized, held together, relatively cool molecules. That's some exotic matter.
- ncmncm 7y agoAt least some people are willing to use the word, now. Until recently you would be ostracized by other astronomers for mentioning it. (Thus, "hot gas".)
- SAI_Peregrinus 7y agoAstronomers consider Nitrogen and Carbon to be metals. Their jargon is very particular to astronomy, and they seem to love using words in ways different from how the rest of the scientific community uses them.
- ncmncm 7y agoWhile that is true (anything not H or He is "metal") they have long had a sort of guild requirement that every phenomenon must be explained with nothing but heat and gravitation; if a magnetic field is invoved it has to be generated by a massive body. Anything that can't is not to be discussed, because plasma dynamics is too hard. The wall is starting to crack, though.
- andrewflnr 7y agoI'm, maybe, unreasonably angry about that headline. I sort of knew phys.org was not a top quality science publication, but holy shit.
- sq_ 7y agoI don't think it's unreasonable at all. When I read "exotic matter", I immediately think of things like negative mass, not comparatively run-of-the-mill solar plasma. Something tells me phys.org cares more about clicks than accuracy...
- ncmncm 7y ago> ... plasma remains a mystery, mainly due to its scarcity in natural conditions on Earth ... I guess a candle flame isn't strictly natural, but a forest fire is. I don't encounter forest fires every day, but I daresay more than one is burning somewhere right now. Tornadoes also tend to plasma, although you won't find a meteorologist who will discuss it. But, yes, we generally try to stay clear of plasma events. They tend, inherently, to unpredictability.
- saagarjha 7y agoIs fire plasma?
- sq_ 7y agoAny of our resident scientists are welcome to correct me if I'm wrong, but I believe that most plasmas require much higher temperatures and pressures than a regular fire like a candle can create. The light we see from flames is mostly just photons emitting from the hot gases and other products of the combustion reaction, as far as I know.
- ncmncm 7y agoYes, light is 100% photons, or your money back. Considering that the overwhelming majority of the plasma in the universe is in interstellar space: no, extreme pressures and temperatures are not necessary. The absolute requirement is an ionization rate of more than 0.01%: more than one ion per 10000 neutral atoms. (Above that, regular gas dynamics don't work, and you need plasma dynamics.) This can be achieved by high-ish temperatures, or ionizing radiation, or various physical processes involving strong and varying electric and magnetic fields. Plasma dynamics are interesting because positive ions are at least 2K more massive than electrons. Any field that pushes the positive cores one way pushes the electrons 2k times faster in the other direction. Which, of couse generates other fields, and likely x-rays, too. Whenever you see some astronomy source claiming that x-rays imply a weirdly high temperature, you can be smug knowing that plasma is happy to emit x-rays at any temperature.