I'm aware that in approximately one billion years time, the increased radiation output of the sun will render any life on Earth impossible. But I'm just curious as to how different the sun might be in the eons leading up to that time, let's say five hundred million years in the future. Would the sun be noticably different to anyone living on the planet by then?
The sun's distant future
- Thread starter EJA
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That, put a solar shield in orbit, or enlarge the Earth's orbit by driving asteroids into grazing encounters to increase its orbital angular momentum -- the inverse of the gravitational boost that the Pioneer and Voyager probes received from the outer planets. Got to be careful with your aiming 'though.
Due to the constant outgassing of the sun, the sun will have less mass in a billion years and this reduced mass will mean earth will orbit further away from the sun as it does now. Maybe it will orbit further out enough to add another billion years of life being able to live on it's surface.
The Sun will leave the Main Sequence and eventually become a White Dwarf.
The Sun will leave the Main Sequence and eventually become a White Dwarf.
I wonder if the Sun will leave the Main Sequence and eventually become a White Dwarf?
Its not out of the realm of the possibility that Earth will actually escape the Sun expansion due to being pushed further out though the odds aren't with us and if we did, instead of being toasted the Earth would freeze...
talk about a lose/lose situation
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Heres a general timeline I believe is correct...
1.1 billion years from now - The Sun becomes 10% brighter than today. Runaway greenhouse effect may evaporate the Earth's oceans. If so, the water in upper atmosphere will photodissociate and the hydrogen will sail off into outer space
3.5 billion years from now - The Sun becomes 40% brighter than today. Conditions on Earth resemble those on Venus today.
5.4 billion years from now - The Sun's core runs out of hydrogen, and it enters its first red giant phase, becoming 1.6 times bigger and 2.2 times brighter than today
6.5 billion years from now - The Sun becomes a full-fledged red giant, 170 times bigger and 2400 times brighter than today.
6.7 billion years from now - The Sun starts fusing helium and shrinks back down to 10 times bigger and 40 times brighter than today.
6.8 billion years from now - The Sun runs out of helium and, too small to start fusing carbon and oxygen, enters a second red phase. It is 180 times bigger and 3000 times brighter than today.
6.9 billion years from now - The Sun begins to pulsate every 100,000 years, ejecting more and more mass in each pulse, and finally throwing off all but the hot inner core, becoming a white dwarf.
Kinds of sucks though not as much as in hundreds of trillions of years when the actual Universe dies by cooling down to absolute zero. Even black holes eventually evaporate, and all other forms of matter eventually disperse into individual elementary particles.
the future sucks
Professor Brian Cox covered this, and 'heat death' in the first episode of 'Wonders of the Universe' last night. An unimaginable amount of time in the future, at which time we'll certainly not be around to have to worry about it. Still a depressing prospect though.
^
Got to watch that later
This thread has me googling all sorts of things...
* Is there anything outside our universe - what is the Universe expanding into.
* Dark Flow - Something just out of our sight is pulling hundreds of galaxies towards one location
oh and did you know there is a super massive Black Hole half the size of a small dwarf galaxy FUCK ME.
Got to watch that later
This thread has me googling all sorts of things...* Is there anything outside our universe - what is the Universe expanding into.
* Dark Flow - Something just out of our sight is pulling hundreds of galaxies towards one location
oh and did you know there is a super massive Black Hole half the size of a small dwarf galaxy
FUCK ME.
Kinds of sucks though not as much as in hundreds of trillions of years when the actual Universe dies by cooling down to absolute zero. Even black holes eventually evaporate, and all other forms of matter eventually disperse into individual elementary particles.
the future sucks
According to Roger Penrose's theory of Cyclic Conformal Cosmology, it then all kicks off again. Our universe succeeds and will be succeeded by a countably infinite number of other universes. So all this might have happened before, and it might happen again, albeit differently given that the number of such universes is not uncountably infinite.
http://en.wikipedia.org/wiki/Conformal_Cyclic_Cosmology
I'm not sure which view is more depressing -- ultimate heat death with no reprieve or eternal return -- no escaping death and taxes, or death and taxes again and again and again...
oh and did you know there is a super massive Black Hole half the size of a small dwarf galaxy
Typically, with heat death, Black Holes will be the last things left in the universe before nothing.
... and black dwarfs, which don't even exist yet as all the white dwarfs are still too hot. Whether black dwarfs decay at all is somewhat moot depending on whether baryonic decay is possible. Assuming that it is, after all the black holes and black dwarfs have decayed to massless particles travelling at the speed of light, time effectively ceases to exist.
Not so much cease as maximise to an equilibrium state. In any case, time doesn't pass for particles that move at light speed.
The arrow of time isn't explained by entropy as Cox appeared to suggest. It's more like one is observed to be correlated with the other. Our perception is formed by memories that depend on entropic processes so we observe a flow in one direction, but no one has demonstrated why that direction appears to be fixed. Some say that Boltzmann, who came up with the famous statistical thermodynamic formula for entropy, S= k.ln(W), committed suicide because he couldn't prove the correlation of increasing entropy with a direction in time (aka Loschmidt's paradox). Others have had a go using cosmological and statistical arguments based on the a priori assumption of low-entropy boundary conditions, but no one has really cracked the problem.
http://en.wikipedia.org/wiki/Loschmidt's_paradox
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Actually, from their perspective, time passes just fine for particles moving at the speed of light. From their perspective, it is we who are frozen in time.
And, of course, from our pespective, time flows just fine for us and the particles travelling at the speed of light are the ones frozen in time.
Contradictory? Yes. That's why the theory is called 'of relativity': it tells you that, in order to have a coherent, non-contradictory image of the universe, you must look at it from only one frame of reference. If you try to look at the universe from two frames of reference at the same time, you will inevitably encounter such paradoxes.
If the universe would be composed only of particles moving at light speed, FAR from being frozen in time, time would flow just fine for such an universe, from his perspective.
And, of course, this is not the only weak point of Cox's speculation about entropy ceasing.
Another one - extraordinary claim require extraordinary proof - and considering just how 'extraordinary' his claim is, Cox didn't even come close to meeting the level of proof necessary. All in all, I find this speculation quite unconvincing.
Fair point about having to choose the correct frame although you might be in danger of falling into the same trap yourself. Can you have a frame of reference other than that of an individual photon in a universe that consists solely of photons? Surely, every other photon would look frozen in time as their relative speed has to be exactly c.
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