I know the Sun will grow bigger and brighter but how long before our eyes no longer cope with its brightness?

Question

Just curious because I had this conversation in my local pub earlier.

Answer 1

First up - the sun will not become a black hole at the end of its life. It simple does not have the mass. Only stars of around 7 or more solar masses do this. These stars are a lot hotter, and burn for much shorter periods of time (millions as opposes to billions like our sun). Black holes are formed (most of the time) by the process of supernova.

Our sun is a very normal G2 type star - one of the most comman stars in the galaxy. It is a very stable star - its output varies by only 1/10 of 1 percent - lucky for us! As the sun approaches its autumn years (in about another 3.5 billion years), the hydrogen fuel in its core will become used up. The sun then starts burning the hydrogen in its outher layers. This causes the sun to heat up, but also cuases it to swell up slightly. From Earth (if we are still around to watch) we would see a brightening of around 10-15%.

When it has used this fuel up, the sun will contract again, sqeezing its core and igniting helium fusion. This causes more heat, and again the sun swells - this time much more. But as it is bigger, the surface cools, and becomes more red. The process (too long to describe here - do a search for 'stellar evolution' for the full picture) eventually causes the sun to swell up massivly. Some models predict it will swell to beyond the orbit of Venus. From earth, the sun would then take up 1/3 of the sky, and all life here would long be over. Slowly - the sun cools and loses more and more mass - blowing off its outer layers like gigantic smoke rings (look up 'planetary nebula' for more info). All that will be left at the end of the suns long long life will be a very small, very dense star called a white dwarf - perhaps no bigger than the earth, but with thousands of times the mass. The planets will be left orbiting this relic until such time as they are purturbed by a passing star or gas cloud.

The white dwarf will also fade slowly - in perhaps 10-15 billion years all that will be left is a dead cinder, and the planets, lifeless - floating in darkness . . . . . . .

Answer 2

This kind of instability is estimated to occur in about 4-5 billion years (not millions). Currently, the Sun is about hals way through its life. Compare this with about 1 billion years, the estimated age of pluricellular life, or with about 500 million years, the age of the oldest species still existing, or with about 160 million years, the duration of the dinosaur era. My guess is that humans will not be around when the expected changes in Sun luminosity will occur. Humans will have left Earth, evolved into something else, or destroyed themselves. After all humanoids have been around for only a few hundred thousand years (with precursors about 2 million years)

Answer 3

You totally missed the point of the entire discussion...

if the Sun grows any bigger, the efective heating of the Earth will increase by several orders of magnitude. That heating of Earth will dry up all water supplies and fry everything on the surface of the Earth. As that starts to happen all life as we know it now will cease to exist. So it has nothing to do with how long you can stand to look at it. What is going to happen is dehydration and starvation/burning to a crisp of everything.

Answer 4

Lexico, you mentioned {i'm assuming an perfect subject the place there is the political will to feed all and sundry. while power fees bypass extreme sufficient to make the transport and distribution too extreme priced, quite some the nutrition alleviation artwork would be affected as there will be extra pressing enterprise to take care at domicile; the Gov't feeding its very own human beings.} that's a Communism form of agriculture, and that spells actual disaster. Texas R has the final answer, different than that 80% 0f our corn and soybeans are no longer used to feed livestock. approximately 17% is for livestock feed and 3% for surely nutrition. very nearly a hundred% of the soybeans used as livestock feed is a byproduct after the oil is bumped off for nutrition. a huge share of corn fed to livestock is likewise byproduct besides, from corn oil, extreme fructose corn syrup and Distiller's dried grain. the U. S. has the super volume export to fall returned on previously we've a actual nutrition scarcity, yet employing that exported grain would be super issues for different worldwide places.

Answer 5

aite listen up dude all the answers below are ****
heres real deal cause this my interest is math, quantum physics which involves black holes so i need to know this....
it will not grow brighter but grow bigger and more red
it will become a read giant...
it takes not millions but over billion year
and many billion years from now like 10 maybe it will collapse and become a blackhole....
it happens to all the stars...

Answer 6

lol i guess nobody does their homework before they post.

they link will describe the natural evolution and death of a star and of course from death comes life even in space.

not sure how much you like adagio for strings song not the dance version but someone on youtube put a video to that song with a space theme and it shows the death of what a star looks like into its red dwarf form. I like it becaseu of the song. I linked the video to that as well i hope that link works great song. watch it at night on full screen with the lights out :)

Answer 7

It wont get bigger or brighter. Scientists say it will take millions of years, but eventually the sun will die out.

Answer 8

First it will become a little dimmer, then it will brighten as you say, however this will happen in a few million years from now, long after you are no longer able to see from other natural conditions.

Answer 9

it will become smaller and brighter, not bigger, and it will happen slowly enough that evolution will not allow that to happen