# The Naked Scientists Forum

### Author Topic: What happens if an object stops orbiting the sun?  (Read 644 times)

#### thedoc

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##### What happens if an object stops orbiting the sun?
« on: 26/11/2015 17:50:02 »
What would happen if an object (like a space ship) was to stop its orbit around the sun. would time slow down with that object (the same way time sped up for the characters in that great film Interstellar). Or even more so, if that object was to stop its orbit around the galaxy so to speak. And so on and so on. At what point is an object considered motionless? Could it be that the finite origin of the big bang has no time?

I am an avid listener and loved to listen to your show for hours whilst I maintained golf courses. Unfortunately now I am a teacher and don't have nearly enough time to keep up with your shows.
Although I never stop to ponder the questions of life.
What do you think?
« Last Edit: 26/11/2015 17:50:02 by _system »

#### evan_au

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##### Re: What happens if an object stops orbiting the sun?
« Reply #1 on: 27/11/2015 08:31:19 »
Quote from: Dean
At what point is an object considered motionless?
If you are floating in a spaceship beside the object, you can consider that object to be motionless.

One of the fundamental basics of the theory of relativity is that what is motionless to one person will be moving quite quickly compared to someone else in a different spaceship, heading in a different direction.

So the basic answer is that there is no such  thing as "absolutely motionless". The best you can do is to nominate "an inertial frame of reference" (eg you floating in a spaceship), and say that the object is motionless in that frame of reference.

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if an object (like a space ship) was to stop its orbit around the sun
This is a very hypothetical situation, with several hypothetical meanings (some of them impossible, as far as we know). Each meaning will have a different outcome.

Do you mean the spaceship stops orbiting the Sun, because:
• the spaceship turns on a rocket for a few seconds or minutes: It will change to a different orbit, but it will still be in orbit around the Sun
• the spaceship turns on a powerful rocket for a really long time: The spaceship will spiral out of the Solar system, and eventually go into orbit around our galaxy.
• the spaceship turns on a powerful rocket for an incredibly long time: The spaceship will spiral out of the Galaxy, and eventually go into orbit around our galactic cluster.
• The spaceship suddenly stops its orbital velocity around the Sun: It will plummet into the Sun, and be burnt up.
• the Sun suddenly ceases to exist? In this case, the spaceship will continue in a straight line into interstellar space (which is different from the space in "Interstellar").

People in a different frame of reference than this spaceship will notice some oddities, such as periodic events will occur at a different rate. But the experience is mutual, so the people in the spaceship will think that the other observers clocks are going at a different rate.

This is the essence of relativity - everything is relative.

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Could it be that the finite origin of the big bang has no time?
The Cosmic Microwave Background Radiation is thought to be the afterglow of the Big Bang.

It comes equally from all directions (to a very high degree of accuracy).
This means we are sitting within the explosion of the Big Bang - some people express this concept as "The Big Bang exploded everywhere".
...and we still experience time!

#### rebeccaspears

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##### Re: What happens if an object stops orbiting the sun?
« Reply #2 on: 28/11/2015 03:44:46 »
Assuming our gravitational bind to the Sun were somehow lost, we would hypothetically be carried off by our momentum at 63° to the ecliptic plane of the Milky Way. If we were lucky, we'd be carried into the Milky Way. It wouldn't save us, but long after we perish our rock might eventually regain some of what it would lose by encountering any of the ~150 million inner star systems. A million-billion-to-one chance we'd smash into a young earth-like body and become its moon the way a large planetoid became our moon. Then that civilization would speculate about all sorts of ridiculous things and my ghost would be immensely amused.

Aside from motion, without the sun's energy we would rely on our quickly dissipating interior energy. No plants would grow. Animals would die. Republicans would deny it happened and blame Democrats and gays. Soon enough, our mantle would cool, we'd lose our magnetosphere, we'd lose our atmosphere, and we'd lose our stock portfolio. Somehow we'd still owe taxes. We'd die long before the sun drags the Oort cloud past our path, which is a shame. I'd've liked to've seen evidence of it.

The sun would continue on its course around the galactic center, completely ignorant that it had lost some little rock. Pluto would give us his rocky-icy middle finger and say "Look who's not a planet now!"

#### The Naked Scientists Forum

##### Re: What happens if an object stops orbiting the sun?
« Reply #2 on: 28/11/2015 03:44:46 »