Nice thumbnail sketch of Earth's future by John Baez

In summary, the Sun will become much brighter in the future, and the Earth's atmosphere will dry out. Many solar systems will be destroyed, and the Republican Party will finally admit the existence of global warming, but point out that it's not human-caused.
  • #1
marcus
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http://math.ucr.edu/home/baez/week252.html

includes a concise timeline of the solar system future

===quote Baez===
* In 1.1 billion years the Sun will become 10% brighter than now, and the Earth's atmosphere will dry out.

* In 3 billion years the Andromeda Galaxy will collide with our galaxy. Many solar systems will be destroyed.

* In 3.5 billion years the Sun will become 40% brighter than today. If the Earth is still orbiting the sun, its oceans will evaporate.

* In 5.4 billion years from now the Sun's core will run out of hydrogen. It will enter its first red giant phase, becoming 1.6 times bigger and 2.2 times brighter than today.

* In 6.5 billion years from now the Sun will become a full-fledged red giant, 170 times bigger and 2400 times brighter than today. The Republican Party will finally admit the existence of global warming, but point out that it's not human-caused.

* In 6.7 billion years from now the Sun will start fusing helium and shrink back down to 10 times bigger and 40 times brighter than today.

* In 6.8 billion years from now the Sun will runs out of helium. Being too small to start fusing carbon and oxygen, it'll enter a second red giant phase, growing 180 times bigger and 3000 times brighter than today.

But then, about 6.9 billion years from now, the Sun will start pulsating, ejecting half of its mass in the form of solar wind! It'll become what they call a "planetary nebula". Eventually only its inner core will be left. In "week223" I quoted Bruce Balick's eloquent description:

"The remnant Sun will rise as a dot of intense light, no larger than Venus, more brilliant than 100 present Suns, and an intensely hot blue-white color hotter than any welder's torch. Light from the fiendish blue "pinprick" will braise the Earth and tear apart its surface molecules and atoms. A new but very thin "atmosphere" of free electrons will form as the Earth's surface turns to dust."
...
...
==endquote==
 
Last edited:
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  • #2
How can the atmosphere "dry out" before the oceans evaporate?
 
  • #3
marcus said:
* In 3 billion years the Andromeda Galaxy will collide with our galaxy. Many solar systems will be destroyed.

This part I'm not so sure of. The odds of an Andromedan star coming close enough to ours to tidally disrupt the orbits of the planets are very small as I understand it.
 
  • #4
Wallace said:
This part I'm not so sure of. The odds of an Andromedan star coming close enough to ours to tidally disrupt the orbits of the planets are very small as I understand it.

I have the same impression from what I've read, Wallace. The chance of OUR solar system being disrupted is judged to be slight.

But I guess it is possible that a fair number of solar systems could be disrupted even if it is a small percentage of the total. Hard to figure. Perhaps he should have said "some planetary systems (but not necessarily ours)" instead of "many solar systems" will be destroyed.
 
  • #5
This estimate obviously must come from what we know of the life cycle of a star, so if our solar system came from a nebula from a previously passed star and our sun is 4-5 billion years old, then the star that went supernova and eventually formed our solar system must have been born 15 -16 billion years ago at least correct? Or do some stars have shorter lifespans? That star must have been one of the 1st ever formed in the universe...:uhh:
 
  • #6
BoomBoom said:
Or do some stars have shorter lifespans?
More massive stars have shorter lifespans, sometimes much shorter lifespans.

For a ~10 MSun star the lifespan can be measured in millions rather than billions of years.

Garth
 
  • #7
Garth said:
For a ~10 MSun star the lifespan can be measured in millions rather than billions of years

Wow...that IS short indeed!
 
  • #8
Even knowing that, it is one of the most surprising things in astronomy, how quickly galaxies formed and enough generations of early stars went through their lifecycles to give us our metal rich enviroment.

ps. love the smiley
 
  • #9
marcus said:
* In 6.5 billion years from now the Sun will become a full-fledged red giant, 170 times bigger and 2400 times brighter than today. The Republican Party will finally admit the existence of global warming, but point out that it's not human-caused.

LOL.

"LOL" couldn't be posted because it was "too short".
 
  • #10
‪‪‪‪‪‪‪ Lol
 
  • #11
...that sucks

glad I won't be around
 

1. What is John Baez's thumbnail sketch of Earth's future?

John Baez is a mathematical physicist who has proposed a model for the future of Earth based on his research in cosmology and theoretical physics. His thumbnail sketch suggests that in the distant future, the universe will continue to expand and eventually enter a state of maximum entropy, where all energy is evenly distributed and no usable work can be performed. This means that all life on Earth and in the universe will eventually come to an end.

2. How does John Baez's model differ from other theories about Earth's future?

John Baez's model differs from other theories in that it takes into account both the expansion of the universe and the concept of maximum entropy. Many other theories focus on only one aspect, such as the Big Crunch or the Big Rip, but Baez's model incorporates multiple factors in a comprehensive way.

3. What evidence supports John Baez's model?

While there is no definitive proof for John Baez's model, it is based on well-established principles in cosmology and physics. The expansion of the universe is supported by observations such as redshift in distant galaxies, and the concept of maximum entropy is a fundamental law of thermodynamics.

4. What are the potential implications of John Baez's model for humanity?

John Baez's model suggests that there is a finite timeline for the existence of life on Earth and in the universe. This could have profound implications for humanity's future and the importance of preserving our planet and exploring other worlds. It also raises philosophical questions about the ultimate fate of the universe and the meaning of life.

5. Is there any way to avoid the future described in John Baez's model?

John Baez's model is based on our current understanding of the laws of physics and the behavior of the universe. While it is possible that new discoveries or technologies could change this model, it is unlikely that we can completely avoid the eventual end of life on Earth. However, by understanding and taking action to mitigate potential threats such as climate change, we may be able to prolong the existence of humanity and our planet.

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