What the End of the Universe Will Really Be Like, According to a Theoretical Cosmologist
“Just months before the end, after we’ve lost the outer planets to the great and growing blackness, the Earth drifts away from the Sun, and the Moon from the Earth. We too enter the darkness, alone.”
more…
Tau.Neutrino said:
What the End of the Universe Will Really Be Like, According to a Theoretical Cosmologist“Just months before the end, after we’ve lost the outer planets to the great and growing blackness, the Earth drifts away from the Sun, and the Moon from the Earth. We too enter the darkness, alone.”
more…
So my solar panels will be useless.
Peak Warming Man said:
Tau.Neutrino said:
What the End of the Universe Will Really Be Like, According to a Theoretical Cosmologist“Just months before the end, after we’ve lost the outer planets to the great and growing blackness, the Earth drifts away from the Sun, and the Moon from the Earth. We too enter the darkness, alone.”
more…
So my solar panels will be useless.
afraid so.
Tau.Neutrino said:
What the End of the Universe Will Really Be Like, According to a Theoretical Cosmologist“Just months before the end, after we’ve lost the outer planets to the great and growing blackness, the Earth drifts away from the Sun, and the Moon from the Earth. We too enter the darkness, alone.”
more…
The Moon is already drifting away from the Earth, quite rapidly.
What the end of the universe will really be like sort of depends on lots of things. Here are six possibilities. Listed from most to least dangerous.
1. Universe metastability. The Universe explodes with unimaginable energy at the speed of light, or faster.
2. Quantum tunnelling. Given enough time, anything can happen, literally.
3. Black hole equilibrium. Given enough time, everything falls into black holes, and all black holes evaporate into ordinary matter. So there ends up being and equilibrium between black holes and ordinary matter.
4. Lepton gas. If protons decay to positrons and neutrinos then the positrons annihilate with electrons. Everything tends towards a space filled with neutrinos and photons.
5. Heat death. The expansion of the universe causes everything to cool off towards absolute zero.
6. Nothing much happens. Many atomic elements are unconditionally stable. So planets are unconditionally stable. White dwarfs are unconditionally stable. Neutron stars are unconditionally stable. Some galaxies come closer, colliding with the Milky Way to make it bigger. Other galaxies fade away. Whatever happens, a civilization still has energy available in the form of thermonuclear power and chemical energy.
mollwollfumble said:
Tau.Neutrino said:
What the End of the Universe Will Really Be Like, According to a Theoretical Cosmologist“Just months before the end, after we’ve lost the outer planets to the great and growing blackness, the Earth drifts away from the Sun, and the Moon from the Earth. We too enter the darkness, alone.”
more…
The Moon is already drifting away from the Earth, quite rapidly.
What the end of the universe will really be like sort of depends on lots of things. Here are six possibilities. Listed from most to least dangerous.
1. Universe metastability. The Universe explodes with unimaginable energy at the speed of light, or faster.
2. Quantum tunnelling. Given enough time, anything can happen, literally.
3. Black hole equilibrium. Given enough time, everything falls into black holes, and all black holes evaporate into ordinary matter. So there ends up being and equilibrium between black holes and ordinary matter.
4. Lepton gas. If protons decay to positrons and neutrinos then the positrons annihilate with electrons. Everything tends towards a space filled with neutrinos and photons.
5. Heat death. The expansion of the universe causes everything to cool off towards absolute zero.
6. Nothing much happens. Many atomic elements are unconditionally stable. So planets are unconditionally stable. White dwarfs are unconditionally stable. Neutron stars are unconditionally stable. Some galaxies come closer, colliding with the Milky Way to make it bigger. Other galaxies fade away. Whatever happens, a civilization still has energy available in the form of thermonuclear power and chemical energy.
How can a star be unconditionally stable when it has a finite supply of hydrogen to convert into helium?
The Rev Dodgson said:
mollwollfumble said:
Tau.Neutrino said:
What the End of the Universe Will Really Be Like, According to a Theoretical Cosmologist“Just months before the end, after we’ve lost the outer planets to the great and growing blackness, the Earth drifts away from the Sun, and the Moon from the Earth. We too enter the darkness, alone.”
more…
The Moon is already drifting away from the Earth, quite rapidly.
What the end of the universe will really be like sort of depends on lots of things. Here are six possibilities. Listed from most to least dangerous.
1. Universe metastability. The Universe explodes with unimaginable energy at the speed of light, or faster.
2. Quantum tunnelling. Given enough time, anything can happen, literally.
3. Black hole equilibrium. Given enough time, everything falls into black holes, and all black holes evaporate into ordinary matter. So there ends up being and equilibrium between black holes and ordinary matter.
4. Lepton gas. If protons decay to positrons and neutrinos then the positrons annihilate with electrons. Everything tends towards a space filled with neutrinos and photons.
5. Heat death. The expansion of the universe causes everything to cool off towards absolute zero.
6. Nothing much happens. Many atomic elements are unconditionally stable. So planets are unconditionally stable. White dwarfs are unconditionally stable. Neutron stars are unconditionally stable. Some galaxies come closer, colliding with the Milky Way to make it bigger. Other galaxies fade away. Whatever happens, a civilization still has energy available in the form of thermonuclear power and chemical energy.
How can a star be unconditionally stable when it has a finite supply of hydrogen to convert into helium?
I said “white dwarf” and “neutron star”. Neither of them burn hydrogen.
mollwollfumble said:
The Rev Dodgson said:
mollwollfumble said:The Moon is already drifting away from the Earth, quite rapidly.
What the end of the universe will really be like sort of depends on lots of things. Here are six possibilities. Listed from most to least dangerous.
1. Universe metastability. The Universe explodes with unimaginable energy at the speed of light, or faster.
2. Quantum tunnelling. Given enough time, anything can happen, literally.
3. Black hole equilibrium. Given enough time, everything falls into black holes, and all black holes evaporate into ordinary matter. So there ends up being and equilibrium between black holes and ordinary matter.
4. Lepton gas. If protons decay to positrons and neutrinos then the positrons annihilate with electrons. Everything tends towards a space filled with neutrinos and photons.
5. Heat death. The expansion of the universe causes everything to cool off towards absolute zero.
6. Nothing much happens. Many atomic elements are unconditionally stable. So planets are unconditionally stable. White dwarfs are unconditionally stable. Neutron stars are unconditionally stable. Some galaxies come closer, colliding with the Milky Way to make it bigger. Other galaxies fade away. Whatever happens, a civilization still has energy available in the form of thermonuclear power and chemical energy.
How can a star be unconditionally stable when it has a finite supply of hydrogen to convert into helium?
I said “white dwarf” and “neutron star”. Neither of them burn hydrogen.
OK, so they no longer generate energy through fusion, but they do emit stored energy.
So when they have cooled so much that they no longer emit energy, are they still “stars”?
The Rev Dodgson said:
mollwollfumble said:
The Rev Dodgson said:How can a star be unconditionally stable when it has a finite supply of hydrogen to convert into helium?
I said “white dwarf” and “neutron star”. Neither of them burn hydrogen.
OK, so they no longer generate energy through fusion, but they do emit stored energy.
So when they have cooled so much that they no longer emit energy, are they still “stars”?
By our present definition of “star”, yes. A star is any compact bady that has passed through a stage of hydrogen burning. It doesn’t matter if they have a temperature near absolute zero.
When they have so cooled, they still contain usable energy. Both contain gravity for releasing gravitational potential energy from infalling matter. White dwarfs still contain chemical elements that could be used for nuclear power purposes.
Add enough external energy to a “dead” white dwarf, which is easy enough, and you get a Type 1a supernova. Which is a lot of energy to feed a civilization in the depths of the far future after the whole universe has cooled.