Is the Earth Going to Just (Yikes!) STOP Some Day?

[Chessic_Sense]

Here’s a question with an answer I’ve never been able to find. When the sun does start to expand into a red giant, how long will that take? Let’s start a stopwatch when Mercury gets swallowed. Is it minutes or centuries until the Earth is consumed?

[Czarcasm]

@Asympotically_fat

Yep, on a Tuesday: we don’t know which Tuesday, but we know it will happen on a Tuesday.

Nope.
It’s going to happen on a Friday while we’re all stuck in rush hour traffic.

[outlierrn]

Still can’t get the hang of Thursdays, can you.

[Lemur866]

@Hari_Seldon

The day was once about five hours long and the moon at about 1/10 the distance it is now. It has taken 5 billion years for this to happen. Imagine the tides! Tidal force varies as the cube of the distance, so the force of the lunar tides would have been 1000 times as strong and twice in every five hours! (Some of the tidal forces come from the sun.)

In only a billion years, the increased solar radiation as the sun starts to exit the main sequence will render the earth unsuitable for human life, at least as we know it. So we better start terraforming Mars. Today! This will give us time to build a starship and escape old Sol.

If we have the technology to set up self-sustaining colonies on Mars we won’t need colonies on Mars. We could just live in space. The only thing special about Mars is that it’s a really big hunk of rocks. There are lots of big hunks of rock on the universe. Earth is special because we can breathe the air and drink the water and go outside and eat the plants and animals we find there. Mars has none of those features, and never will.

[LSLGuy]

Not really, IMO.

There are very few resources “in space”. There are lots of resources on Mars. And on other bodies.

Living in a ship freely orbiting the Sun or in /on some sort of interstallar colony ship is vastly more difficult than living on a planet, even an inhospitable one, where you have a functionally infinite supply of raw materials to consume.

[Stately_Greek_Automaton]

@Lemur866

If we have the technology to set up self-sustaining colonies on Mars we won’t need colonies on Mars. We could just live in space. The only thing special about Mars is that it’s a really big hunk of rocks. There are lots of big hunks of rock on the universe. Earth is special because we can breathe the air and drink the water and go outside and eat the plants and animals we find there. Mars has none of those features, and never will.

DARPA disagrees with your assertion that Mars will never have those features.

[eburacum45]

@Chessic_Sense

Here’s a question with an answer I’ve never been able to find. When the sun does start to expand into a red giant, how long will that take? Let’s start a stopwatch when Mercury gets swallowed. Is it minutes or centuries until the Earth is consumed?

Here’s a timeline for the lifespan of the Sun;
http://www.astronomy.ohio-state.edu/~pogge/Lectures/vistas97.html
note that it is about 1.3 billion years between the Sun leaving the Main Sequence and the red giant phase, so it won’t happen overnight.

On the other hand the Sun will get a lot hotter before it leaves the Main Sequence, si the Earth won’t be very comfortable a mere billion years from now.

[Johnny_L.A]

@eburacum45

Earth won’t be very comfortable a mere billion years from now.

Oh, than god! I was thinking millions!

[chorpler]

@DrCube

Yes, the moon slows down earth’s rotation and would, if the sun were immortal, eventually tidally lock the earth and moon together, like a barbell spinning in space, one side always facing the other, permanently.

Actually, this wouldn’t be permanent; interactions between the sun, earth, and moon would cause the moon to then begin moving back toward the earth, until it broke up into a delightful ring system and we got all Saturny.

But that would take a long, long time. Much longer than the lifetime of the sun. But you did postulate the immortality of the sun here…

[dtilque]

@eburacum45

On the other hand the Sun will get a lot hotter before it leaves the Main Sequence, si the Earth won’t be very comfortable a mere billion years from now.

Someone cameup with a way to avoid that

[eburacum45]

Greg Benford suggested an easier way to cool the Earth- a partial sunshade at or near the L1 point. But by the time this sort of planetary engineering is necessary, the human race will no longer exist in its present form, and probably not in any form).

[TriPolar]

@Johnny_L.A

Oh, than god! I was thinking millions!

Even so I’m not waiting until the last minute.