The Sustainer of the Worlds (رَبِّ الْعَالَمِينَ) https://signsandscience.blogspot.com/2018/03/the-sustainer-of-worlds.html
Origins of Water http://signsandscience.blogspot.com/2014/10/origins-of-water.html > On 27-Sep-2022, at 11:06 PM, John Clark <[email protected]> wrote: > > Our sun is brighter than every star you can see in the night sky with your > naked eye and yet the sun is brighter than 80% of the stars in the universe, > that's because most stars are red dwarfs but I have long thought that life > could not develop on any planet orbiting such a star. Proxima Centauri is a > red dwarf, it has 12.2% the mass of the sun but gives off 588 times less > heat, that's why although its the closest star to us it's far too dim to be > observed with the naked eye. Any planet around a star as dim as Proxima > Centauri would have to be 24 times closer to its sun than the Earth is to > ours to be at the same liquid water loving temperature. A planet that close > would be gravitationally locked so one side continuously faced the sun and > the other side would never see it, so either mega-hurricane force winds would > continuously sweep the planet's surface or one side would be far too hot to > support life and the other side so cold the atmosphere with freeze out. And > that's not even the worst. > > Outside the fusion producing core of our sun is a several hundred thousand > mile thick radiation transfer zone, in this zone there is very little > movement of matter, the temperature decreases only very slowly, and the > primary method of transferring energy is smoothly made through radiation. > Outside the radiation zone is a several hundred thousand mile thick > convection zone where there are lots of plops and bubbles and movement of hot > matter that transfers energy up to the surface in an irregular way. It is > the movement in the convection zone that causes magnetic fields which causes > sunspots and solar flares. In red dwarfs there is no radiation zone, the > convection zone reaches all the way down to the center of the star, so > although red dwarfs are much dimmer than the sun they have solar flares that > are hundreds or thousands of times as intense as the suns, and such evil > dwarfs produce more life destroying X-rays too. Because the planet is so > close to the red dwarf the situation is made even worse. So although the > planet may have the right temperature for liquid water I doubt if it actually > has any because any water in its upper atmosphere would be blasted apart by > the intense solar wind into free hydrogen and oxygen, and unless it was as > massive as Jupiter it would not be able to hold onto its hydrogen. So > regardless of how wet it started out, after a few million years it would be > bone dry. > > And now researchers have proposed yet another reason why life is unlikely to > develop around red dwarfs. We've never found a planet in the habitable zone > around a red dwarf that also had a Jupiter type gas giant planet, and without > that you can't have an asteroid belt, and without astroids an earth wannabe > would have no way to receive water like the earth did during the Late Heavy > Bombardment. > > Life on Exoplanets In the Habitable Zone of M-Dwarfs? > > John K Clark See what's on my new list at Extropolis > lhb > > > > > > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/CAJPayv1pYPmFnRsBMHBMgqO8ej1UXFt1gmdxCykhCPo0z5xq9Q%40mail.gmail.com. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/051FB9CB-C045-4CDF-BFAA-3239DDBF3DEB%40gmail.com.
