Stellar engine

[Curious layman]

Not likely soon, but...

New research has put forward another idea for what such a radical stellar engine might look like.

Via this beautiful video via Kurgesagt you can learn all about the so-called Caplan Thruster, which would use the Sun's own energy to propel it across the galaxy and beyond. It's named after the scientist who came up with the design, astrophysicist Matthew Caplan from Illinois State University.

 

....The Caplan Thruster would sit close to the Sun, using electromagnetic fields to gather hydrogen and helium from the solar wind to use as fuel. That would power two jets of energy – one using helium, pushed through a fusion reactor to create a jet of radioactive oxygen that would move the Caplan Thruster forward, and one using hydrogen, to maintain distance from the Sun and to push it forward. The Caplan Thruster would essentially act as a kind of tugboat.

 

https://www.sciencealert.com/what-is-a-stellar-engine-and-could-it-help-us-escape-a-supernova/amp?utm_source=quora&utm_medium=referral

https://www.sciencedirect.com/science/article/abs/pii/S0094576519312457

 

Edited January 1, 2020 by Curious layman

[swansont]

!

Moderator Note

Moved. This doesn’t belong in the Lounge

 

[dimreepr]

If we have nuclear fusion why do we need to move the sun?

[MigL]

One of the reasons given in the video was in the case of a nearby supernova event, we would need to get about 50 LY away to survive.
The video estimates that this engine could move the Sun ( and planetary system ) 50 LY in a million years.

Unfortunately, if a star 40 LY away were to go supernova, we would need to know about it a couple of hundred thousand years ahead of time to make good our 'escape' from the death zone.
So it is kind of useless for that reason.

[Janus]

2 hours ago, MigL said:

One of the reasons given in the video was in the case of a nearby supernova event, we would need to get about 50 LY away to survive.
The video estimates that this engine could move the Sun ( and planetary system ) 50 LY in a million years.

Unfortunately, if a star 40 LY away were to go supernova, we would need to know about it a couple of hundred thousand years ahead of time to make good our 'escape' from the death zone.
So it is kind of useless for that reason.

I get about 450,000 yrs to move 10 ly.   That's assuming a constant thrust-acceleration scenario.  You'd start slowly at first and then pick up speed, and after 450,000 yrs you would be moving at 4.5e--5 ly/yr ( ~13.5 km.sec) having traveled a bit over 10 ly.   In the next 550,000 yrs you would accelerate up to .0001 ly/y (~30 km/sec) while covering a bit under 40 ly.

[MigL]

I was just going by numbers mentioned in the video, Janus.

The point I was making was that the lead time you have on a star going supernova is greater for more distant stars.
And those are the ones that pose no danger.

Any star closer than 50 LY gives very little lead time to get 'out of the way'.

[J.C.MacSwell]

How much acceleration can our solar system handle? If it means losing Pluto...I'm out...Pluto's already been humiliated enough

#SavePlutoToo

Edited January 3, 2020 by J.C.MacSwell

[dimreepr]

If we have the tech to move the solar system then we have the tech to move just us, and faster... but youre welcome to stay J.C. 

[J.C.MacSwell]

5 minutes ago, dimreepr said:

If we have the tech to move the solar system then we have the tech to move just us, and faster... but youre welcome to stay J.C. 

It's going to be cold on Pluto...for a while

At least I get my Spartacus moment...

...er...million years

Edited January 3, 2020 by J.C.MacSwell

[dimreepr]

Also, wouldnt a dyson sphere just absorb the energy?

[J.C.MacSwell]

Okay...(my survival instincts/cowardice kicking in)...how about we leave Pluto (et al) to fend for itself, set up to "hover" in the habitable zone behind the Sun, then reset orbit when the worst is over? Wouldn't that be easier?

[dimreepr]

11 minutes ago, J.C.MacSwell said:

Okay...(my survival instincts/cowardice kicking in)...how about we leave Pluto (et al) to fend for itself, set up to "hover" in the habitable zone behind the Sun, then reset orbit when the worst is over? Wouldn't that be easier?

If we could just piss off... Wouldn't that be easier?

[J.C.MacSwell]

1 minute ago, dimreepr said:

If we could just piss off... Wouldn't that be easier?

I think the energy budget would be considerably higher..

("we" does include me right? RIGHT?)

[dimreepr]

1 minute ago, J.C.MacSwell said:

I think the energy budget would be considerably higher..

would it? youd have to work against physics rather than using it.

14 minutes ago, J.C.MacSwell said:

("we" does include me right? RIGHT?)

for now.

[Janus]

14 hours ago, MigL said:

I was just going by numbers mentioned in the video, Janus.

The point I was making was that the lead time you have on a star going supernova is greater for more distant stars.
And those are the ones that pose no danger.

Any star closer than 50 LY gives very little lead time to get 'out of the way'.

So was I. Essentially, if you can go 50 ly in 1 million years under constant acceleration, then it would take ~450,000 yrs to go 10 ly starting from "rest".

Waiting until you get warning of an imminent supernova is likely not an option.  But that doesn't mean we couldn't try and keep our distance from supernova candidates. We know that only stars above a certain mass supernova.   So maybe the strategy would be "Why wait for trouble?  Let's just keep our distance from any stars that could even possibly supernova."

 

5 hours ago, J.C.MacSwell said:

How much acceleration can our solar system handle? If it means losing Pluto...I'm out...Pluto's already been humiliated enough

#SavePlutoToo

Pluto shouldn't be left behind.  If we go by the 50 ly in 1,000,000 year at constant acceleration scenario, then the acceleration needed is 4.27e-10m/s²,  While the centripetal acceleration for Pluto is 3.8e-6 m/s^2, several magnitudes larger.

[J.C.MacSwell]

5 hours ago, Janus said:

 

 

Pluto shouldn't be left behind.  If we go by the 50 ly in 1,000,000 year at constant acceleration scenario, then the acceleration needed is 4.27e-10m/s²,  While the centripetal acceleration for Pluto is 3.8e-6 m/s^2, several magnitudes larger.

Thanks Janus. So presumably just minor adjustments to orbits?