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What if Pluto was actually a gateway to the stars?


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Okay, okay, I know what you're thinking,  spaceception, that idea is batcrap crazy, and to you I say, no I'm not, Robert Forward is!

http://spaceflighthistory.blogspot.com/2015/06/pluto-doorway-to-stars-1962.html?m=1

His idea for why Pluto was so wierd, was that it was a gift from an alien race, what was that gift? A giant ring about the size of mercury with 6x the mass of Earth made from neutron star matter. He proposed that it could accelerate a spacecraft to near the speed of light by passing through the ring in around a minute, with the acceleration of 1000 Earth gravities. And it wouldn't turn you into gourmet jelly because the spinning ring would act uniformly on all the atoms in your body, so you'd just get catapulted to another star really quickly.

The problem is, I tried to see exactly how fast you could get, but I don't think I found the right equation (or plugged the right numbers in) because the final speed is way below the speed of light, can anyone else help?

Edited by Spaceception
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It's because you're in free fall that you don't get crushed. The gravity you feel on Earth is actually just the ground resisting your fall.

In the article it says that it's after one minute. 1000 gees is 9800 m/s^2. Multiplying by 60 seconds gives us 588,000 meters per second. Which isn't close to light speed, at 300 million meters per second.

That's from the equation at = v. Initial velocity would have very little influence over the final velocity, so we're ignoring it. There's only a few other equations of motion, but that's the only one I know of which uses velocity, acceleration, and time. The others use things like distance instead of one of those components.

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@Bill Phil that's what I got too, I thought I screwed something up with it, cause that's only 588 km/s, how do you think Robert Forward got close to the speed of light? 

Showerthought, since the gravity field of the object would be many times greater than earth, maybe it would accelerate you a fair way before you enter the ring, the acceleration of it vastly increasing the closer you get before putting you out the other end, and throwing you away, how fast would you get then? Would it be significant? 

Edited by Spaceception
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32 minutes ago, Spaceception said:

@Bill Phil that's what I got too, I thought I screwed something up with it, cause that's only 588 km/s, how do you think Robert Forward got close to the speed of light? 

Showerthought, since the gravity field of the object would be many times greater than earth, maybe it would accelerate you a fair way before you enter the ring, the acceleration of it vastly increasing the closer you get before putting you out the other end, and throwing you away, how fast would you get then? Would it be significant? 

It's possible they misquoted Forward.

Acceleration changes like that require some degree of calculus, considering it's an R^2 term. Or we could cheat that and use the geopotential energy equation after solving for the radius of the sphere of influence. Convert that potential energy into kinetic energy and you get a decent estimate of velocity. That breaks down when you get close to the speed of light, though.

Edited by Bill Phil
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17 minutes ago, Bill Phil said:

It's possible they misquoted Forward.

Acceleration changes like that require some degree of calculus, considering it's an R^2 term. Or we could cheat that and use the geopotential energy equation after solving for the radius of the sphere of influence. Convert that potential energy into kinetic energy and you get a decent estimate of velocity. That breaks down when you get close to the speed of light, though.

How would you calculate it for a torus? Or would just calculating it for a sphere be a good ballpark? 

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1 hour ago, Spaceception said:

How would you calculate it for a torus? Or would just calculating it for a sphere be a good ballpark? 

I don't know. Calculating for a point mass might be sufficient for ballpark estimates, but if we're talking near light speeds then the kinetic energy equation won't be accurate.

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Unfortunately I dont think you can accelerate to escape velocity of ANY object just by falling toward it. Think about it. A gravitstional well is symmetrical so whetever kinetic energy I gain by falling toward it, I must lose on the other side trying to escape.

Toruses just simplify to spheres at large distances and as you get close they actually become less effective because more of the mass is to the side of you instead of in front.

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The problem with such ring is that the gravitational acceleration inside would be zero. It's not going to be that fast.

Also, planetary gravity assists to reach interstellar journeys is possible. In fact, it's better if the planet is close to our central star (the Sun).

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1 hour ago, CastleKSide said:

Unfortunately I dont think you can accelerate to escape velocity of ANY object just by falling toward it. Think about it. A gravitstional well is symmetrical so whetever kinetic energy I gain by falling toward it, I must lose on the other side trying to escape.

Then burn your engines toward the center of the thing as you fall.  You'll leave faster than you approached.  Also, if it's in orbit around the Sun and you slingshot with it, you can steal some of its (considerable, given the mass) kinetic energy and dump it into your spacecraft.

1 hour ago, CastleKSide said:

Toruses just simplify to spheres at large distances and as you get close they actually become less effective because more of the mass is to the side of you instead of in front.

But they do have the advantage of their surfaces not getting in the way as you accelerate towards the center and move through it. :wink:

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7 hours ago, CastleKSide said:

Unfortunately I dont think you can accelerate to escape velocity of ANY object just by falling toward it. Think about it. A gravitstional well is symmetrical so whetever kinetic energy I gain by falling toward it, I must lose on the other side trying to escape.

Toruses just simplify to spheres at large distances and as you get close they actually become less effective because more of the mass is to the side of you instead of in front.

This isn't just a chunk of mass, however. A torus such as this would actually provide a kind of artificial gravity. Not by rotating like a Stanford torus. I can't explain it well, listen to Robert Forward.

http://www.projectrho.com/public_html/rocket/antigravity.php#id--Paragravity--Robert_Forward

Take a look at the frame dragging concept in particular. There's no way for us to actually do it anytime in the near future, but if we last long enough, maybe. 

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34 minutes ago, HebaruSan said:

Apologies for reading only the OP rather than the link, but what does Pluto have to do with a ring of neutronium? Last I checked it was a typical spheroid.

A crackpot theory from before we had images good enough to be sure that yes, Pluto actually was a planet.

Also, while I'm not super-sure on how the frame dragging might influence pure slingshot maneuvers, one could at least exploit the Oberth effect quite magnificently at the bottom of a deep gravity well.

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