What-If 0085: "Rocket Golf"

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What-If 0085: "Rocket Golf"

Postby chris857 » Tue Feb 25, 2014 6:35 pm UTC

http://what-if.xkcd.com/85/

Assuming that you have a spaceship in orbit around the Earth, could you propel your ship to speeds exceeding escape velocity by hitting golf balls in the other direction? If so, how many golf balls would be required to reach the Moon?


How am I first poster?? Anyway, this is why no rocket was ever powered by golf ball propulsion.

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Re: What-If 0085: "Rocket Golf"

Postby alessandro95 » Tue Feb 25, 2014 6:49 pm UTC

Randall asking wolframalpha to "please calculate" and thanking it after instead of just giving it the expression makes me feel like an horrible person for being unpolite to wolframalpha, I'll always ask politely too from now on
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Re: What-If 0085: "Rocket Golf"

Postby MyNameHere » Tue Feb 25, 2014 6:53 pm UTC

... a potato cannon fueled by acetylene can launch a potato at 140 m/s (310 mph). If it were capable of launching golf balls at that speed,[8] our ship would have a diameter of only 150 miles!

Not counting the acetylene tank!

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Re: What-If 0085: "Rocket Golf"

Postby gmalivuk » Tue Feb 25, 2014 6:57 pm UTC

When I imagine "rockets" with really low exhaust velocity, for some reason the mental image is always someone just tossing old shoes out the rear airlock. Compared to that, golf balls may as well be ion thrusters.

Also it's woth noting that the LEO-to-Moon figure Randall gave seems to be the figure making use of the Olberth effect to get more bang for the buck. To do that with the low thrust we get from golf balls, we could only use them at perigee, for a few minutes once per orbit.
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Re: What-If 0085: "Rocket Golf"

Postby Barstro » Tue Feb 25, 2014 7:00 pm UTC

It's been a long time since I even had basic physics;

Does the formula boil down to; MA=F=MA; "The force necessary to increase the ship's velocity enough is the same force of N-golf balls times a given ball speed"
or
M(mass of ship)(x)V(velocity of ship(change of velocity?))=Force=M(total mass of balls)(x)V(velocity of each ball from the drive)?


EDIT, never mind. I don't remember how to work change in velocity to Acceleration. It's been a long time.

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Re: What-If 0085: "Rocket Golf"

Postby gmalivuk » Tue Feb 25, 2014 7:03 pm UTC

It's exponential because you have to remember that the first golf ball has to accelerate not only the ship itself, but also all the other golf balls.
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Re: What-If 0085: "Rocket Golf"

Postby Moose Anus » Tue Feb 25, 2014 7:21 pm UTC

MyNameHere wrote:
... a potato cannon fueled by acetylene can launch a potato at 140 m/s (310 mph). If it were capable of launching golf balls at that speed,[8] our ship would have a diameter of only 150 miles!

Not counting the acetylene tank!
Note 8 acknowledges that.
We're not factoring in the weight of the acetylene—but then again, we also weren't factoring in the weight of the hamburgers the golfer would need to eat to keep hitting those drives.
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Re: What-If 0085: "Rocket Golf"

Postby Djehutynakht » Tue Feb 25, 2014 7:43 pm UTC

Raise the water level, eh?....

Gentlemen, I think we've found our counterattack against the Netherlands.

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Re: What-If 0085: "Rocket Golf"

Postby steven807 » Tue Feb 25, 2014 7:47 pm UTC

I'm disappointed that there is no citation on the statistic about the number of Courtneys in the world. Randall's starting to slack off. :)

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Re: What-If 0085: "Rocket Golf"

Postby mcdigman » Tue Feb 25, 2014 8:02 pm UTC

I did a quick relativistic calculation using Randall's numbers to see if it could be done with one golf ball, so we don't have to propel all those extras: apparently, the golf ball only has to be going about 7.7% the speed of light. And we only need 0.068 grams of fuel (antimatter) to get it to that speed.

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Re: What-If 0085: "Rocket Golf"

Postby Klear » Tue Feb 25, 2014 8:29 pm UTC

As I was reading, I clicked the Wolfram|Alpha and read that. Then I noticed that the result can be conveniently measured in light days. Uh oh.

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Re: What-If 0085: "Rocket Golf"

Postby Olaf Klischat » Tue Feb 25, 2014 8:36 pm UTC

Looks like Randall forgot to take the escape velocity of the bag of golf balls into account? That would slow the ball down considerably, or even stop it and pull it back onto the surface, in which case there would be no net acceleration of the "space ship" at all.

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Re: What-If 0085: "Rocket Golf"

Postby bs1110101 » Tue Feb 25, 2014 9:25 pm UTC

After doing a bit more math, i figured out that for something with a mass and delta-v roughly on par with the S-IVB, you'd only need to shoot them out at about 1.4 km/s, while hard to do with golf balls, i think that a mass driver powered stage could work quite well.

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Re: What-If 0085: "Rocket Golf"

Postby Evadman » Tue Feb 25, 2014 9:33 pm UTC

Am I the only one annoyed by the caption on the last image? A golf ball floating in the dead sea will still raise the water level of the dead sea by the mass of water the golf ball displaced. It is just less than the volume of the golf ball as would occur in fresh water. Well, assuming that the golf ball was not recovered and sold on the space memento market. "Guaranteed to add 10 yards to your drive since it already traveled at least 200 miles the first and only time it was hit by a driver"

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Re: What-If 0085: "Rocket Golf"

Postby Eternal Density » Tue Feb 25, 2014 10:06 pm UTC

Olaf Klischat wrote:Looks like Randall forgot to take the escape velocity of the bag of golf balls into account? That would slow the ball down considerably, or even stop it and pull it back onto the surface, in which case there would be no net acceleration of the "space ship" at all.

I love that we can use the phrase "escape velocity of the gag of golf balls".
Evadman wrote:A golf ball floating in the dead sea will still raise the water level of the dead sea by the mass of water the golf ball displaced.
Plus it would raise the golf ball level of the dead sea.
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Re: What-If 0085: "Rocket Golf"

Postby ethernet » Tue Feb 25, 2014 10:21 pm UTC

Olaf Klischat wrote:Looks like Randall forgot to take the escape velocity of the bag of golf balls into account? That would slow the ball down considerably, or even stop it and pull it back onto the surface, in which case there would be no net acceleration of the "space ship" at all.


Not exactly sure what you mean.

If you mean that if a golf ball driven out the back of the "ship" ends up falling to Earth, then it doesn't impart a net acceleration on the ship, then that's simply false. The fate of the ball after hit out the back doesn't matter at all to the ship. The golfer imparted some momentum to the ball, and thus the ship gained momentum in the opposite direction. That's all that matters.

Also, there's no way driving the ball out the back using the techniques described in the What-If would make the ball "stop". Assuming we're starting from low earth orbit, the bag of balls is starting out traveling at around 7.8 km/s. You'd have to cancel that velocity for it to "stop", and fall down. In fact, the reason the balls would reenter has less to do with the velocity the golfer is canceling out, and more due to atmospheric drag, so anything in low orbits will tend to reenter over time.

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Re: What-If 0085: "Rocket Golf"

Postby WibblyWobbly » Tue Feb 25, 2014 10:36 pm UTC

Did anyone else, upon reading the end and seeing the picture, want to shout "IT'S IN THE HOLE!"?

Edit: RIP Harold Ramis

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Re: What-If 0085: "Rocket Golf"

Postby Flumble » Tue Feb 25, 2014 11:00 pm UTC

Djehutynakht wrote:Raise the water level, eh?....

Gentlemen, I think we've found our counterattack against the Netherlands.

Then instead of putting salt on every snail, we'll pour it in the seas to get all the balls to float and form a land route.

It's the perfect counter-counterattack-attack.

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Re: What-If 0085: "Rocket Golf"

Postby rmsgrey » Tue Feb 25, 2014 11:06 pm UTC

The n-body problem exhibits chaotic behaviour, so, if you're prepared to wait long enough, have enough data about the current positions, masses and momentums (momenta?) of the bodies in the solar system, can launch a golf ball with inhuman precision, and have sufficient computational resources, then, in principle, you could probably escape the solar system with just a modest drive...

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Re: What-If 0085: "Rocket Golf"

Postby gmalivuk » Wed Feb 26, 2014 12:28 am UTC

ethernet wrote:
Olaf Klischat wrote:Looks like Randall forgot to take the escape velocity of the bag of golf balls into account? That would slow the ball down considerably, or even stop it and pull it back onto the surface, in which case there would be no net acceleration of the "space ship" at all.


Not exactly sure what you mean.

If you mean that if a golf ball driven out the back of the "ship" ends up falling to Earth
No, he means falling back to the bag of golf balls, hence the reference to the escape velocity of the bag of golf balls.
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Re: What-If 0085: "Rocket Golf"

Postby keithl » Wed Feb 26, 2014 1:11 am UTC

I love it when questions are phrased with enough semantic wiggle room to fly an Upgoer 5 through.

The question states only "hitting golf balls", it doesn't specify how or with what or even how many times for the same ball. The brute force answer is to hit some golf balls with the vaporized casing of an exploding nuclear weapon, but where's the fun (or the survivability) in that?

The quickest cheat is that the question only specifies "in orbit around the earth". It does not specify the orbit, which can be many times the radius of the moon's orbit and still remain in "stable" earth orbit for a long, long time. For some arbitrary definition of "in orbit", there is a maximum radius that meets that definition, beyond which an object will get perturbed into trajectories that will stray arbitrarily far from the earth. Give me a definition, and I can escape it with one golf ball hit.

This isn't pure pedantry; read Dr. Edward Belbruno's chaotic-orbital-mechanics book "Capture Dynamics and Chaotic Motions in Celestial Mechanics" and the popularization "Fly Me to the Moon". This guy has an ego as big as the solar system, but his crazy tricks got the Japanese Hiten probe to the moon with a failed thrust stage, using only attitude control thrusters, an "impossible" stunt with classical Hohmann trajectories.

The most fun to think about is the "how many times" gambit. You are in orbit, in microgravity. With ridiculously accurate aim you can hit the same ball over and over again, as it returns one Earth orbit later. Golf balls collide fairly elastically, so you can transfer energy from ball to ball. Until the collisions become violent enough to tear balls apart, the delta V between balls can become significant. A series of balls hitting balls hitting balls can continue until some of those balls are leaving your crazy-complex constellation at faster-than-escape velocity. That escape velocity is the effective exhaust velocity that goes into the Tsiolkovsky equation, not the velocity of a single isolated hit.

Complicating the whole mess (which would already require 20 decimal place accurate hits, superprecise radar, and gigantic banks of computers) is tides from the sun and moon and even Jupiter and the rest of the planets, relativistic frame drag, and all the other tiny effects that show up at 20 decimal places. But that, as my late friend Bob Forward would say, "is a mere engineering detail".

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Re: What-If 0085: "Rocket Golf"

Postby gene123 » Wed Feb 26, 2014 4:38 am UTC

Can someone combine this with http://what-if.xkcd.com/18/ and tell me how many AK-47 bullets would be needed to propel the same spacecraft to the Moon?

A simplistic calculation (substituting 1632mph for AK muzzle velocity and 8kg/liter estimated bullet density) yields 4.7m diameter for the bullet bag - but this doesn't take into account the weight of the spent cartridges. I'm a bit perplexed how to calculate them correctly, because, on one side, the empty shells don't go with the bullets, but on the other side, once the bullet is fired, the empty shell can be discarded from the spaceship and thus no longer be part of its mass (however, shells not yet fired DO need to remain on the ship, making this even more complex to calculate).

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Re: What-If 0085: "Rocket Golf"

Postby gmalivuk » Wed Feb 26, 2014 4:54 am UTC

Instead of treating the bullets as having their true speed, just use the velocity of the center of mass of the moving bullet and stationary cartridge. That works out to the correct amount of momentum transferred from the ship to (the two components of) its "exhaust".
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Re: What-If 0085: "Rocket Golf"

Postby Klear » Wed Feb 26, 2014 8:41 am UTC

Evadman wrote:Well, assuming that the golf ball was not recovered and sold on the space memento market. "Guaranteed to add 10 yards to your drive since it already traveled at least 200 miles the first and only time it was hit by a driver"


Since every place on Earth is going to be littered with such golf balls, selling them isn't going to be very profitable.

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Re: What-If 0085: "Rocket Golf"

Postby snowyowl » Wed Feb 26, 2014 10:50 am UTC

I'd like to check Randall's math on that last one - I think most of the golf balls would end up in orbits of one sort or the other, and not actually on Earth. Are they still likely to score so many holes-in-one?

Well, taking the numbers from his golf-ball-potato-cannon-rocket-equation, there's enough golf balls that if you dropped them on the ground instead of packing them into a sphere, they could cover the Earth to a depth of 15m (although I suspect the ones that landed on mountains and stuff would bounce downhill, so it's even deeper in places). Certainly that's enough - regulation golf balls are less than 5 cm across, so you've effectively hit every point on the planet 300 times. So my question is: Do more than about 1% of the golf balls actually make it to Earth?

I suspect the answer is no. Most of the golf balls will be fired from a low altitude, which might seem like a good thing - they have a bigger target to hit and are closer to the atmosphere. But the orbital velocity of the golf ball spaceship will be about 7km/s, and the golf balls are only being fired at 140m/s relative to the rocket, so they're practically in the same orbit as before. I expect the rocket would eventually catch up with its own exhaust and get pelted with golf balls.

No, the balls that would make it back to Earth would be the ones fired when (the tangential component of) your velocity is 140m/s or lower, because they're practically stationary relative to Earth and would drop straight towards it under gravity. But I don't think there's any point in the planned trajectory when the rocket is moving that slowly, and if there is, it's unlikely to be firing any golf balls at that point (as gmalivuk says, Randall's probably hoping to use the Oberth effect, so the rocket will only be thrusting when it's moving at its fastest). So all the golf balls would remain in orbit, and far from hitting a hole-in-one at every golf course in the world, Randall would manage the equally-impressive feat of firing a hundred quintillion golf balls and failing to even hit the ground.

Edit:
I expect the rocket would eventually catch up with its own exhaust and get pelted with golf balls.


This might actually be a serious problem. There's enough golf balls to cover the Earth, remember - picture a solid ring of balls, ten kilometers thick, and you're trying to fly through it. Any balls that you caught, you'd be able to fire again, so it doesn't affect the rocket equation too badly unless balls bounce off your rocket and fly off at reduced speed (so paint the golf ball bag with superglue). But you won't be able to change orbits at all if every ball you've ever launched eventually comes to rest against your hull.
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Re: What-If 0085: "Rocket Golf"

Postby Olaf Klischat » Wed Feb 26, 2014 11:58 am UTC

gmalivuk wrote:
ethernet wrote:
Olaf Klischat wrote:Looks like Randall forgot to take the escape velocity of the bag of golf balls into account? That would slow the ball down considerably, or even stop it and pull it back onto the surface, in which case there would be no net acceleration of the "space ship" at all.


Not exactly sure what you mean.

If you mean that if a golf ball driven out the back of the "ship" ends up falling to Earth
No, he means falling back to the bag of golf balls, hence the reference to the escape velocity of the bag of golf balls.


Exactly. My wording was a bit ambiguous maybe, but yes that's what I mean. The bag of golf balls would be so huge that its own gravity could not be neglected.

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Re: What-If 0085: "Rocket Golf"

Postby Barstro » Wed Feb 26, 2014 1:58 pm UTC

Thanks for pointing out my error in logic before. Can I get another quick lesson?

Why would hitting a single golf ball from a ship in orbit not be enough to get it to the moon (eventually)?
If it's at a perfect orbit and I am able, despite how little the change is, to decrease the mass of the ship by one unit of golf-ball (which I think is irrelevant), and increase the velocity by just a bit, then isn't the ship now going too fast for its orbit and it escapes until it hits the moon?

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Re: What-If 0085: "Rocket Golf"

Postby snowyowl » Wed Feb 26, 2014 3:20 pm UTC

Barstro wrote:Thanks for pointing out my error in logic before. Can I get another quick lesson?

Why would hitting a single golf ball from a ship in orbit not be enough to get it to the moon (eventually)?
If it's at a perfect orbit and I am able, despite how little the change is, to decrease the mass of the ship by one unit of golf-ball (which I think is irrelevant), and increase the velocity by just a bit, then isn't the ship now going too fast for its orbit and it escapes until it hits the moon?

Hitting a single golf ball just shunts you into a slightly different orbit. Escape velocity is not that easy to achieve.
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Re: What-If 0085: "Rocket Golf"

Postby rmsgrey » Wed Feb 26, 2014 3:39 pm UTC

Barstro wrote:Thanks for pointing out my error in logic before. Can I get another quick lesson?

Why would hitting a single golf ball from a ship in orbit not be enough to get it to the moon (eventually)?
If it's at a perfect orbit and I am able, despite how little the change is, to decrease the mass of the ship by one unit of golf-ball (which I think is irrelevant), and increase the velocity by just a bit, then isn't the ship now going too fast for its orbit and it escapes until it hits the moon?


For circular orbits, the orbital speed decreases as the radius increases, so, yes, if you speed the ship up, it will then be moving too fast for its current orbit and any circular orbit with a greater radius. However, as the ship moves away from Earth, it'll slow down until it's moving too slowly for a circular orbit (and in the wrong direction) and slow still more until it's moving in the right direction for a circular orbit, but too slowly for an orbit at that distance. From there, it'll fall back, speeding up until it's moving too fast for a circular orbit, and, eventually, moving in the right direction but too fast - under Newtonian mechanics and ignoring the existence of everything other than the ship and the Earth, it'll be exactly where it started.

In general, under Newtonian mechanics, as one of only two bodies in the universe, you have three options for a free-fall trajectory - a closed ellipse, an ellipse that intersects the other body, or a hyperbola that escapes (there's a limiting case of a parabola that only just fails to return). Accelerating at periapsis (the lowest point of your orbit) means your orbit becomes more eccentric (less circular) and raises your apoapsis (highest point), and, if you do it enough, eventually you reach escape velocity and your apoapsis reaches infinity. If you don't escape to infinity or collide, then you will always return to the same point.

A standard Hohmann transfer orbit moves you from one circular orbit to another by accelerating in the lower orbit to turn it into an ellipse tangent to both circles, and accelerating again when you reach the higher orbit to turn the ellipse back into a circle.


It may be easier to think of things in terms of orbital energy rather than speeds, directions and distances - an object in low earth orbit has higher kinetic energy but significantly lower gravitational potential energy than the same object in geostationary orbit, which, in turn, is lower than the energy of an orbit at the distance of the Moon. Hitting the golf ball increases the energy of the orbit, but not by very much, so your orbit is still trapped fairly close to Earth...

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Re: What-If 0085: "Rocket Golf"

Postby Flumble » Wed Feb 26, 2014 4:10 pm UTC

Barstro wrote:Why would hitting a single golf ball from a ship in orbit not be enough to get it to the moon (eventually)?

Because there's not just one orbit. Every orbit* corresponds to a specific total energy, so when you shoot one golf ball in the right direction, you'll increase your (kinetic and therefore total) energy a bit and you'll end up in a slightly different orbit.
Image
Only if you shoot the ball fast enough to get a velocity that nullifies or overtakes the μ/r term, you'll lose your orbit.

...like the two ninjas above me have already said. Damn you ninjas, I had to learn astronomy before I could answer this!


*thinking about it: even shooting rockets straight upwards (from the north or south pole) will get them an orbit, but there's a planet in its way to complete that orbit.

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Re: What-If 0085: "Rocket Golf"

Postby gmalivuk » Wed Feb 26, 2014 5:36 pm UTC

rmsgrey wrote:However, as the ship moves away from Earth, it'll slow down until it's moving too slowly for a circular orbit (and in the wrong direction) and slow still more until it's moving in the right direction for a circular orbit, but too slowly for an orbit at that distance. From there, it'll fall back, speeding up until it's moving too fast for a circular orbit, and, eventually, moving in the right direction but too fast - under Newtonian mechanics and ignoring the existence of everything other than the ship and the Earth, it'll be exactly where it started.
Note here that "wrong direction" just means moving at an angle relative to a circular orbit, instead of directly along the circle. (I initially read this as claiming it would somehow be going backwards, which obviously is never the case, and perhaps others would misread it the same way.)
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Re: What-If 0085: "Rocket Golf"

Postby jpvlsmv » Thu Feb 27, 2014 3:20 pm UTC

As an above-par+ golfer myself, I found this What-If to be highly enjoyable.

But wouldn't it be easier to just stand on the surface (or event horizon) of the planetary-scale bag of golf balls and rotate it until you get to the moon? A spherical, solid space elevator kinda?

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Re: What-If 0085: "Rocket Golf"

Postby solidvoid » Thu Feb 27, 2014 6:14 pm UTC

Can someone please explain the alt-text for the Wolfram Alpha equation screen-cap?
Spoiler:
"I didn't end up getting banned this time."


Thanks!

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Re: What-If 0085: "Rocket Golf"

Postby rmsgrey » Fri Feb 28, 2014 1:03 am UTC

solidvoid wrote:Can someone please explain the alt-text for the Wolfram Alpha equation screen-cap?
Spoiler:
"I didn't end up getting banned this time."


Thanks!


On a previous What-If, Randall got (temporarily) banned from Wolfram Alpha after trying to use them to calculate something.

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Re: What-If 0085: "Rocket Golf"

Postby phlip » Fri Feb 28, 2014 1:04 am UTC

solidvoid wrote:Can someone please explain the alt-text for the Wolfram Alpha equation screen-cap?
Spoiler:
"I didn't end up getting banned this time."


Thanks!

It's a callback to Falling With Helium.

Code: Select all

enum ಠ_ಠ {°□°╰=1, °Д°╰, ಠ益ಠ╰};
void ┻━┻︵​╰(ಠ_ಠ ⚠) {exit((int)⚠);}
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Re: What-If 0085: "Rocket Golf"

Postby speising » Fri Feb 28, 2014 1:09 am UTC

rmsgrey wrote:
solidvoid wrote:Can someone please explain the alt-text for the Wolfram Alpha equation screen-cap?
Spoiler:
"I didn't end up getting banned this time."


Thanks!


On a previous What-If, Randall got (temporarily) banned from Wolfram Alpha after trying to use them to calculate something.

Which is why he was careful to be polite, this time.

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Re: What-If 0085: "Rocket Golf"

Postby CityZen » Fri Feb 28, 2014 3:01 am UTC

I also was hoping that Randall would go to the limiting case of a single golf ball and figure out its speed.
But then it occurred to me that at some acceleration, what comes out is no longer recognizable as a golf ball.
Well, I suppose that, in a vacuum, a golf ball could attain any speed, given enough distance to accelerate over.
Assuming you could accelerate the ball electrostatically (ie, like a rail gun), how long a barrel would you need
to achieve the above speed and not disintegrate the ball?

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Re: What-If 0085: "Rocket Golf"

Postby SCSimmons » Fri Feb 28, 2014 1:06 pm UTC

The Courtneys of the potato cannon research prove to be more interesting than expected on further research. When I saw that their last names were both Courtney, I questioned whether this was really a coincidence, and I'm pretty sure it's not. Michael Courtney has published papers, besides this one where he collaborated with E.D.S. Courtney, with Amy Courtney and Elya R. Courtney. Michael and Amy are listed as the principal researchers for BTG Research, a ballistics engineering company.

So, it sounds like there's a family of physicists out there who have managed to turn screwing around with potato guns collectively into a career. I've found my new personal heroes. Breakfast conversations must be fascinating, if sometimes frustrating. "What, hash browns again?" "What else am I supposed to do with the spent ammo?"

As an aside, Amy earned a B.S. in engineering mechanics from Michigan State one year before I got my physics B.S. from there. It's a big school, but it seems really unlikely we never had a class together; neither her name nor her face ring any bells for me, but her name probably wasn't Courtney back then--I expect she's a Courtney by marriage. Lucky girl.

flying_kiwi
Posts: 2
Joined: Sat Mar 01, 2014 6:24 pm UTC

Re: What-If 0085: "Rocket Golf"

Postby flying_kiwi » Sat Mar 01, 2014 6:40 pm UTC

Olaf Klischat is correct -- for almost all configurations discussed, the escape velocity of the ship is greater than the launch velocity of the ball, so it will simply fall back to the surface of the ship after launch, and (assuming collisions are at least partially inelastic and it eventually comes to rest) the net change in momentum of the ship will be zero.

In the final configuration, plugging in the density of the average golf ball I get the launch velocity a little larger than the escape velocity, so the ship WILL move. However, the final velocity is still a good deal less than the launch velocity, which reduces the effectiveness of the rocket, forcing the designer to make it larger -- likely to the point you wouldn't be able to launch to escape velocity, and the rocket would fail to change its momentum.

A mass driver or similar "launcher" is needed to make this work. (I once set a homework problem about using a railgun to change the orbit of an asteroid, and realised about a day or so after I handed out the problem set that I had forgotten to take this into account. None of the students checked for this, but for the numbers I used in the problem it would not have been an issue.)

bdew
Posts: 6
Joined: Sun Jul 13, 2008 1:17 pm UTC

Re: What-If 0085: "Rocket Golf"

Postby bdew » Mon Mar 03, 2014 8:59 am UTC

What if it was Yoda hitting those gold balls, accelerating them to 0.99c?

Also how would the the balls floating on the surface of the dead sea affect it's reflectivity and water evaporation? Can we resurrect the dead sea with golf balls?


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