Source: Sun becoming HOTTER each day – ‘Will render Earth uninhabitable’ | Science | News | Express.co.uk As the sun continues to burn through its ingredients, every day it gets slightly warmer and eventually it will make our home uninhabitable. This is because the sun, which already has a surface temperature of 5,505 degrees Celsius and a core which can reach 15 million degrees Celsius, is burning through its ingredients. The sun is already unfathomably large, containing 99.8 percent of the solar system’s mass, but this mass is being used up, causing our host star to expand and give off more heat in a process known as nuclear fusion. Works for me. <GRINS> Bob Wilson
"THE SUN is heating up and that will eventually spell the end for life on Earth, scientists have revealed." [emphasis added] "Thankfully, we still have a few billion years before this happens." "Science podcast Starts with a Bang wrote in an article for Forbes: “When enough time goes by, the sun’s changes will render Earth uninhabitable." Maybe new to some Express and Forbes readers, but the "scientists have revealed" part happened before I was born. ... and I'm now retired!
Sun, El Sol, began its career ~4.6 billion years ago doing hydrogen fusion, at about 70% of current luminosity. It has now fused about half of starter hydrogen, and is diversifying into (more energetic) helium fusion. About 4.8 billion years in future, transition to helium fusion will be complete, and luminosity will be about 1.7 times current amount. Physicists and astronomers 'on the case' seem confident about this overall pattern. In timescales of greater human relevance, the solar constant (~1370 watts per square meter) is thus increasing by about 14 microwatts per square meter per million years. Not found in linked article. Just trying to be helpful On top of that, solar magnetic cycle (easily seen by ~11 year sunspot cycle) causes cyclic variation here on Earth of about 1 watt per square meter. If El Sol decides to string together a few weak solar cycles, that is your impact. Little Ice Age had (lacked) those, along with volcanic dimming and some CO2 drawdown associated with forest expansion. At the same time, atmospheric CO2 is increasing and net trapping about 1.5 more watts per square meter. This is the largest persistent effect on thermal balance of Earth at present. Solar (sunspot) cycle is a jiggle. Solar fusion increase is a trickle. == If things go well for humans, 1.3 million years hence they will witness Gliese 710 (a red-orange star not yet eye visible) pass through the Oort cloud. That would be quite a sight. It may change orbits of some large Oort iceballs such that they come here.
Gliese 710 is about 63 light years away now and closest will be about 1 light year. Presuming the existence of eyeballs, heck yeah it will be visible. I suppose it is still doing old-school hydrogen fusion. Perhaps just as amazing is that Oort Cloud is > 1 light year across.
Perhaps I should not be polluting what appears to be a 'ridicule' thread. But dang, there are a lot of interesting and important things going on. Fourteen microwatts per square meter per million years just does not seem to rank highly among them.
Most solar energy does not arrive at Earth, it being a small distant target. But on 'production' side it works out to 150 milliwatts per day increase. Something like that. Plenty to keep your phone charged. I mean, if you built a Dyson sphere. So there is that.
i also learned this in elementary school. no worries, as bezos tubes will take us far enough away to avoid a severe tan.
Tan@7 is not as capricious as it was (probably) intended to be. During solar cycle, while visible flux varies little (percentage wise), ultraviolet flux varies about 20%. Your sunburn depends on many factors (where, when, SPF40, etc.) including sunspots. Solar melanoma, if one may say. The real good cooking happens when sunspots are many. Presently they are not, and next sunspot maximum might be a low one. Not suggesting irrational exuberance in tanning, but as astronauts may be 'going places' circa 2025, they may do so in relatively benign conditions. Because as UV varies, so do angry solar protons...
The least-spotty forecast for solar cycle 25 you are likely to see is here: Forget global warming - it's Cycle 25 we need to worry about (and if NASA scientists are right the Thames will be freezing over again) | Daily Mail Online It may have been mentioned around here earlier. It is certainly very frothy "forget solar warming" "Thames will freeze over" They (well, David Rose) is not strong on retractions either. Quoting again “In 2009, it [UK Met Office] predicted that at least three of the years 2009 to 2014 would break the previous temperature record set in 1998. So far there is no sign of any of this happening.” According to HADCRUT, 2010 and 2014 'beat' 1998, as did 2015, 2016, 2017 and 2018. So yes, one might conclude that there is sign of any of this happening. == My attempt to tie this to thread is that all those recent record-T years had low sunspot activity. What an interesting world, where both 'oooh sun hot' and 'oooh sun cold' seem intended to distract from heat trapping in earth's atmosphere.
