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Posted by: rp
« on: March 20, 2022, 09:34:46 pm »

https://www.nature.com/articles/d41586-020-02338-w#:~:text=If%20the%20Universe%20holds%20enough,any%20life%20on%20nearby%20planets.
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Scientists know how the world will end. The Sun will run out of fuel and enter its red-giant phase. Its final burst of glory will expand and engulf the closest planets, leaving Earth a charred, lifeless rock. Our planet has around five billion years left.

With this grim image, theoretical astrophysicist Katie Mack begins her book on the end of the Universe — a much more uncertain prospect. Cosmologists generally look backwards, because all the evidence they can examine with telescopes is far away and concerns things that happened long ago. Using the motions of distant stars and galaxies to predict possible futures involves more speculation.


From Big Bang to cosmic bounce: an astronomical journey through space and time

In Mack’s hands, this speculation makes for a fascinating story. Humans are, she writes, “a species poised between an awareness of our ultimate insignificance and an ability to reach far beyond our mundane lives, into the void, to solve the most fundamental mysteries of the cosmos”. She is a talented communicator of complex physics, and the passion and curiosity about astronomy that have made her a popular speaker and Twitter presence are evident here. (As are some nerdy jokes and a less compelling coda about new physics research tangential to the central theme.)

Mack begins at the beginning, with the Big Bang. What followed was inflation — a period of rapid expansion. Then, structures of dark matter formed and the building blocks of stars, planets, life and galaxies assembled. Currently, dark energy, thought to pervade the Universe, somehow counteracts the forces of gravity to keep driving expansion.

The Universe’s fate depends on whether that expansion will continue, accelerate or reverse.

The Big Crunch
Astrophysicists long considered the most likely denouement to be a reversal of the Big Bang — the Big Crunch. Outside our cosmic neighbourhood, every galaxy is zooming away from us; a clear sign of expansion. If the Universe holds enough matter, including dark matter, the combined gravitational attraction of everything will gradually halt this expansion and precipitate the ultimate collapse. Over time, galaxies, then individual stars, will smash into each other more frequently, killing off any life on nearby planets. In the final moments, as densities and temperatures soar in a contracting inferno, all that remains will extinguish in a single point.
Posted by: Polinc_Socjus
« on: February 17, 2022, 01:56:58 pm »

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The Earth may be destroyed by the Sun becoming a red giant in 5 billion years, but life has existed on Earth for 4 billion years--so even if an asteroid wiped out all multi-cellular lifeforms (extremely unlikely), it is possible for them to re-evolve to the same level of complexity that exists today.

I remember saying something similar on the old forum. They would still have a whole billion years to escape the solar system.
I also mentioned a more effective way to destroy the world on the old forum.

https://youtu.be/ijFm6DxNVyI

But still it's not perfect because as the narrator says, It would only destroy life as we know it, and it wouldn't keep up with the expansion of the universe.
Posted by: Zea_mays
« on: February 17, 2022, 06:09:05 am »

There are bacteria that live miles underground, on the bottom of the ocean, bacteria species which can tolerate extreme acidity, extreme sunlight, extreme heat and cold, etc. I think even an extreme asteroid would not end life.
https://en.wikipedia.org/wiki/Extremophile

The Earth may be destroyed by the Sun becoming a red giant in 5 billion years, but life has existed on Earth for 4 billion years--so even if an asteroid wiped out all multi-cellular lifeforms (extremely unlikely), it is possible for them to re-evolve to the same level of complexity that exists today.

I would also be concerned that the particles ejected into space from the impact could contain bacteria, which would then drift throughout space, possibly leaving the solar system and landing on another planet... (Westerners want to simulate this process to put lifeforms on other plants...)
https://en.wikipedia.org/wiki/Panspermia

Also note that the narrator around 8:45 says such an event actually occurred on Earth around 4 billion years ago, but within only ~1000 years, things went back to "normal", allowing for life to evolve in the first place.


I think launching the Earth into the Sun (in a controlled manner to minimize the number of particles that are launched out) may be one way to safely end Earth's existence. But apparently the physics required to change Earth's orbit to make that happen are not very practical.
Posted by: guest55
« on: February 14, 2022, 01:56:00 pm »

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Because at this point, this is the best I could hope for a solution that is realizable within my lifetime
  :D

Hey, maybe it's time for you to accept the fact that victory is for a couple generations down the line and the best we can do is to just keeping passing as much information forward as possible so they are not easily misdirected or deceived by our enemies?
Posted by: rp
« on: February 14, 2022, 01:52:00 am »

What are your thoughts on something like this happening?:
https://youtu.be/PENT_hnyO-o

Do you think it would be a surefire way to solve all our problems?

Because at this point, this is the best I could hope for a solution that is realizable within my lifetime