What would happen if you tried to hit a baseball pitched at 90% the speed of light?
July 10, 2012 5:32 AM   Subscribe

 
Makes sense. The best was saved for last, however.
posted by wierdo at 5:37 AM on July 10, 2012 [9 favorites]


Agreed. Stay 'til the metaphorical credits. Fun read.
posted by Joey Michaels at 5:40 AM on July 10, 2012 [1 favorite]


Still, the effects described here would pale in comparison to what would happen if someone tried to divide by zero.
posted by surazal at 5:44 AM on July 10, 2012


Awesome.

Also, back when I did physics trollers, I used to base one on this: Air molecules vibrate back and forth at a few hundred miles per hour.

They say heat is caused by molecules moving really quickly. So how come when I stick my hand out the window and the air molecules are move extra fast, my hand feels cold?
posted by DU at 5:44 AM on July 10, 2012


Randall Munroe hit it one out of the ballpark with this entry, didn't he?

Someone had to say it!
posted by the cydonian at 5:47 AM on July 10, 2012 [3 favorites]


Just as I thought.

*Boom*
posted by stormpooper at 5:48 AM on July 10, 2012


I. LOVE. THIS.
posted by EmpressCallipygos at 5:49 AM on July 10, 2012


Greg: at 0.90c, the ball's mass would be a little over twice that of normal (0.87c is when a object is exactly twice normal, IIRC). So, the effects would not be all *that* wacky. Also, the ball's length in the direction of travel would be a little lass than half normal, and time would be travelling at relatively half the speed for the ball (according to an outside observer).

At say 0.9999c, *now* you're talking about some serious relativistic effects, but then you're also going to take out a sizable chunk out of the Earth's surface, too.
posted by surazal at 5:50 AM on July 10, 2012 [1 favorite]


I'm pretty sure he's underestimating the amount of energy in a 5oz object traveling at 0.9c and that the resulting explosion would actually be a line-shaped nuclear detonation starting at the mound and heading out into space, levelling everything for dozens of miles.

But, yeah, the ruling definitely still holds.
posted by seanmpuckett at 5:51 AM on July 10, 2012 [1 favorite]


This is going to be a fun thread.
posted by seanmpuckett at 5:52 AM on July 10, 2012


What kind of bat would you need if you wanted to actually return the ball?
posted by Jehan at 5:54 AM on July 10, 2012


You'd really, really hope it wasn't a beanball?

(Though if it were, you'd never know.)
posted by Gelatin at 5:55 AM on July 10, 2012


I'm going to email Bud Selig and ask for a ruling banning pitches at relativistic speeds for the good of the game.
posted by Renoroc at 5:55 AM on July 10, 2012 [9 favorites]


I'm going to email Bud Selig and ask for a ruling banning pitches at relativistic speeds for the good of the game.

Let's get congress involved, too!
posted by King Bee at 5:56 AM on July 10, 2012 [3 favorites]


"A sa-WING-ana-miss! Strike one," that's what.
 
posted by Herodios at 5:59 AM on July 10, 2012 [3 favorites]


The Home Run Derby was last night, folks.
posted by zamboni at 6:00 AM on July 10, 2012


Energy is energy. Kinetic, heat, chemical, nuclear, whatever. Get enough of it in one place and it can start to move around and shift between types. Stick a whole freaking bunch of it in a baseball stadium and bad stuff happens.
posted by valkyryn at 6:01 AM on July 10, 2012


Haven't read the link yet....

But assuming this in a classical manner -- spherical, uniform density, vacuum, frictionless.

Hmm. Mass of baseball is between 142 and 149g. We'll call it 145g. e=mc2, where e is energy in ergs, m is mass in grams and c is the speed of light in centimeters per second. Speed of light in meters/sec is 299,792,458, so we tack on a couple of zeros to get cm/s. At this scale, we may safely ignore the tiny fraction of a meter/sec the baseball bat is traveling at. We will also ignore that the batter will probably never hit it, never even see it. Let's just say he gets "lucky", and makes contact.

This would release the kinetic energy of the ball into the bat. e=145* 29,979,245,800*29,979,245,800, or 1.303x1019 ergs, or 1.303x1012 joules.

1.303x1012J is a big number that doesn't mean much, until you realize that the kinetic energy of an Airbus A380 at cruising speed is two orders of magnitude less than this -- about 2.3x1010J. It's about half a gigawatt hour -- that is, if you captured it and controlled it, it would release 500Mw for an hour. It's about 1/16th of the energy of the Nagasaki bomb.

Basically, you've just thrown a 1-2kt nuke at the batter. The few molecules left of the pitcher will be ejected from the game by the few molecules left of the home base umpire, and the few molecules left of the batter will be allowed to advance to the few molecules left of first base.

This is *not* what the few molecules of the catcher was expecting when he called for the heat.

...now off to read the link.
posted by eriko at 6:05 AM on July 10, 2012 [20 favorites]


With a 5oz ball, the relativistic kinetic energy at the moment of release is going to be ~= 181 MJ if my math is correct. I may be wrong, physics was a long time ago, and I have a bad habit of shifting decimal places.

So it's not the kinetic energy that you have to worry about (I think that's about the same as an M1 Abrams tank heading towards you at top speed) but rather the whole radioactive death issue.
posted by Grimgrin at 6:06 AM on July 10, 2012


The chance of this sort of thing occasionally happening could actually push me into watching baseball. I favour the re-introduction of nitrocellulose balls to pool and snooker for much the same reason.
posted by metaBugs at 6:18 AM on July 10, 2012 [2 favorites]


Okay. So now do it in a vacuum.
posted by Splunge at 6:20 AM on July 10, 2012 [4 favorites]


What would happen if the batter could swing in the same time/energy frame? I mean, basically, what would happen if Superman and Mon-El were having a little back yard practice? (Well, until Braniac's evil ball-lobbing robot appears, of course.)
posted by GenjiandProust at 6:21 AM on July 10, 2012 [1 favorite]


I bet it would help to yell Kamehameha! as you release the pitch.
posted by VTX at 6:22 AM on July 10, 2012


Speaking of large amounts of energy at a baseball game...
posted by drinkcoffee at 6:23 AM on July 10, 2012


Baseball? Pshaw!

I want to know what would happen if Courtney Ambrose bowled a bouncer at 0.9c
posted by Hello, I'm David McGahan at 6:24 AM on July 10, 2012 [1 favorite]


And what would happen if you bet on that game?
posted by blue_beetle at 6:24 AM on July 10, 2012


And what would happen if you bet on that game?

If you are a player? You get barred from reality for the rest of your life.
posted by GenjiandProust at 6:26 AM on July 10, 2012 [3 favorites]


Sorry, Curtly Ambrose.
posted by Hello, I'm David McGahan at 6:27 AM on July 10, 2012


Courtney Walsh is offended now.
posted by howfar at 6:27 AM on July 10, 2012 [1 favorite]


What would happen if the batter could swing in the same time/energy frame?

Vampire baseball!
posted by jeather at 6:28 AM on July 10, 2012 [4 favorites]


But assuming this in a classical manner -- spherical, uniform density, vacuum, frictionless.

Dropping that assumption does not make things better.
posted by valkyryn at 6:29 AM on July 10, 2012


A careful reading of official Major League Baseball Rule 6.08(b) suggests that in this situation, the batter would be considered 'hit by pitch', and would be eligible to advance to first base

Wouldn't it be scored as a ball if "collisions with the air have eaten the ball away almost completely"?
posted by kirkaracha at 6:37 AM on July 10, 2012


This would have happened had the Red Sox and Cubs met in the World Series in 2003. Aaron Boone and Steve Bartman saved a lot of lives.
posted by otters walk among us at 6:37 AM on July 10, 2012 [8 favorites]


He lost me when he said it hit the bat. Even with the batter swinging in anticipation, the ball would arrive far too quickly unless a bunt was on. Poor catcher.
posted by exogenous at 6:41 AM on July 10, 2012


You'd discover the Higgs Boson a second time?
posted by symbioid at 6:42 AM on July 10, 2012


Energy is energy. Kinetic, heat, chemical, nuclear, whatever. Get enough of it in one place and it can start to move around and shift between types. Stick a whole freaking bunch of it in a baseball stadium and bad stuff happens.

ML Baseball protects itself against this threat pretty effectively by being baseball.
posted by srboisvert at 6:51 AM on July 10, 2012 [7 favorites]


What would happen if a ball went through Bill Buckner's legs at 90% of the speed of light?
posted by bondcliff at 6:53 AM on July 10, 2012 [7 favorites]


What would happen if the batter could swing in the same time/energy frame?

I don't think you could. Being Superman wouldn't help. (Well, I guess it might if you can literally make time flow backwards like in the movie.) It isn't a matter of reflexes, it's a matter of the speed of light.

The ball is traveling at .9c. That means that when the light of the ball leaving the pitcher's hand hits you, which is the very earliest possible moment you know he's even thrown it, the ball is .9 * 60'6" away from you, which is about 6'. There is of course no way to tell what kind of ball he's thrown (although maybe every .9c ball is a fast ball).

You now have to bring your bat around and meet it. How far does the tip of the bat travel? It's half the circumference of a circle that has a radius at least as long as the bat and closer to double that if you include your arms. Call it a 2 or 3 foot radius at minimum. That's 6-9' of travel that the bat has to do in the time the ball covers 6'.
posted by DU at 6:55 AM on July 10, 2012 [1 favorite]


I'd bunt.
posted by srboisvert at 7:00 AM on July 10, 2012 [4 favorites]


Metaphorically, this is no different than what happens when someone throws a knuckle ball.
posted by Zerowensboring at 7:01 AM on July 10, 2012 [1 favorite]


That didn't turn out at all the way I expected. I just figured it would be really hard to hit.
posted by TedW at 7:02 AM on July 10, 2012 [1 favorite]


ML Baseball protects itself against this threat pretty effectively by being baseball.

I read this as "Mr. Baseball protects itself..." and immediately thought, "What if you hit Happy Fun Ball at 0.9c?"
posted by ricochet biscuit at 7:03 AM on July 10, 2012


What would happen if a ball went through Bill Buckner's legs at 90% of the speed of light?

On behalf of Red Sox Nation, allow me to say to you: "TTTTTHHHHHHPPPPPPPBBBBFFFFF!!!!"
posted by EmpressCallipygos at 7:05 AM on July 10, 2012


I was in a job interview and I opened a book and started reading. Then I said
to the guy, "Let me ask you a question. If you are in a spaceship that is
traveling at the speed of light, and you turn on the headlights, does anything
happen?" He said, "I don't know." I said, "I don't want your job."

-- Steven Wright
posted by mr.ersatz at 7:06 AM on July 10, 2012 [6 favorites]


Unsuspecting Batter. Disintegrating Pitcher. Developing Fireball.

So Randall Munroe's betting on a Chicago Cubs vs. Oakland As World Series this year?
posted by chavenet at 7:06 AM on July 10, 2012


I read this as "Mr. Baseball protects itself..." and immediately thought, "What if you hit Happy Fun Ball at 0.9c?"

As it is, Happy Fun Ball may suddenly accelerate to dangerous speeds already, so....
posted by EmpressCallipygos at 7:07 AM on July 10, 2012 [1 favorite]


What kind of bat would you need if you wanted to actually return the ball?

Well, DU's comment about it being impossible to hit would apply, but very simply, you would need a stick capable of delivering enough force, in one swing, to stop the ball cold, plus accelerate it backwards. Assuming you wanted it going outbound at least as fast as it came inbound, then you'd as much energy, delivered instananeously through your stick, as two small thermonuclear bombs.

So, in other words, you'd need a bat so strong that when you hit a skyscraper, you would vaporize the entire base of it with the sheer awesomeness of your mighty swing.

I suspect materials science may need some time to reach that level of awesome.
posted by Malor at 7:08 AM on July 10, 2012 [4 favorites]


Good thing I didn't turn pro.
posted by randomkeystrike at 7:10 AM on July 10, 2012 [3 favorites]


eriko,

The relativistic mass-energy of a baseball is more like 10^16 J. Fat Man only converted about a gram of mass into energy.
posted by Pre-Taped Call In Show at 7:14 AM on July 10, 2012


Well, I suppose any scenario that has the ball being pitched at that speed the bat could let the bat swing as quickly as well. The batsman can start his swing when he sees the pitcher wind up or something along those lines ? Would we then have to wavefronts colliding or collapsing ?
posted by asra at 7:16 AM on July 10, 2012


Does this apply to softball too?
posted by mazola at 7:18 AM on July 10, 2012 [1 favorite]


I believe that slow-pitch is only allowed to get up to 0.8 c, mazola.
posted by ardgedee at 7:19 AM on July 10, 2012 [6 favorites]


But it's not a matter-antimatter reaction, Pre-Taped -- it's just kinetic energy. It's a LOT of kinetic energy, and as the original link says, there'd probably be some short-lived fusion events at the front of the shockwave that would increase the energy output substantially. But it's not an annihilation event, which would probably evaporate an area best measured in square miles.
posted by Malor at 7:20 AM on July 10, 2012


Broken bat, I'm guessing.
posted by chundo at 7:22 AM on July 10, 2012 [3 favorites]


The batsman can start his swing when he sees the pitcher wind up or something along those lines ?

But what if the pitcher vaporizes the first base runner rather than you?
posted by DU at 7:27 AM on July 10, 2012


I think hitting the thing is actually much more complicated. Let's just assume that, if the pitcher can throw it at that speed, the batter can get the timing down, swing fast enough to meet the ball and with enough force redirect it.

The bat doesn't have to travel as far but it has more mass. I lack the knowledge to do the math but I think that if it had the same amount of energy as the ball on contact the ball would stop dead right?

The problem is that the bat will do a lot of the same things as the ball (disintigrate, generate fusion reactions, etc) but it doesn't travel in a straight line so you could really get that force to rotate around. Since most of the bat's mass is near the business end, the inertia of the heavy end would probably cause it to break at the weak point just above the handle. Again, without being able to do the math, I hypothesize that it would take some incredible advances in material science and engineering to make a bat that doesn't snap in half the moment the batter tries to swing it with that much force let alone holds together long enough to rotate around far enough to meet the ball (or what's left of it).
posted by VTX at 7:31 AM on July 10, 2012


The plane takes off, btw.
posted by Wolof at 7:35 AM on July 10, 2012 [13 favorites]


I think that if it had the same amount of energy as the ball on contact the ball would stop dead right?

Nope. The bat and ball would have to have the same momentum. That's proportional to only mass * velocity, not mass * velocity2.
posted by DU at 7:38 AM on July 10, 2012


Yeah, I want to know when the batter would have to start swinging to hit what's left of the ball. Of course he'd be dead and it would all be meaningless, but I still want to know.
posted by papercake at 7:39 AM on July 10, 2012


What would happen if a ball went through Bill Buckner's legs at 90% of the speed of light?

At 90% of the speed of light, the ball would have reached Dwight Evans in plenty of time to throw Mookie Wilson out at first by 89.999999999999999 feet. On to the 11th we go.
posted by otters walk among us at 7:40 AM on July 10, 2012 [2 favorites]


Nope. The bat and ball would have to have the same momentum. That's proportional to only mass * velocity, not mass * velocity2.

This still doesn't seem right to me since bunting works. The bat is stationary but the ball still gets it's momentum redirected. I'm convinced that I'm wrong about how hard the bat needs to get swung to stop and redirect the ball (but really we're talking about an explosion that redirects a different explosion at this point...I think). I suspect I'm using terminology incorrectly and/or trying to apply human speed baseball physics that don't work at those speeds.
posted by VTX at 7:48 AM on July 10, 2012


I hypothesize that it would take some incredible advances in material science and engineering to make a bat that doesn't snap in half the moment the batter tries to swing it with that much force let alone holds together long enough to rotate around far enough to meet the ball (or what's left of it).

Not to mention the performance enhancing substances the batter would need to swing the bat.
posted by never used baby shoes at 7:53 AM on July 10, 2012


What would happen if you tried to hit a baseball pitched at 90% the speed of light?

I'd put my foot in the bucket, swing at the wrong time, miss the ball completely and everybody would roll their eyes. Same as every other speed.
posted by PlusDistance at 7:58 AM on July 10, 2012 [11 favorites]


This is why I stay away from that cage at the amusement center.
posted by yerfatma at 8:17 AM on July 10, 2012


This part seems contradictory: The batter hasn't even seen the pitcher let go of the ball, since the light carrying that information arrives at about the same time the ball does.

The light (image of the ball release) does get there first, so at least there is the image of the ball leaving the pitcher's hand impinging on the batter's retinas.

Maybe the batter can't see it because they are defining seeing as consciously registering the event sensed by the eye, or maybe it can't be seen due to the x-rays, plasma, fireball, or whatever that is preceding the ball, but it's not because of the reason given in the statement.
posted by achrise at 8:20 AM on July 10, 2012


Well, it is just not a single ball when it reaches the batter anyways . As the article states - "Collisions with the air have eaten the ball away almost completely, and it is now a bullet-shaped cloud of expanding plasma (mainly carbon, oxygen, hydrogen, and nitrogen) ramming into the air and triggering more fusion as it goes. The shell of x-rays hits the batter first, and a handful of nanoseconds later the debris cloud hits." . So it wouldn't be about making contact/hitting a baseball anymore. Oh well. Bye bye batter.
posted by asra at 8:22 AM on July 10, 2012


Batter, batter, batter... VAPORIZE! Batter, batter.
posted by Splunge at 8:27 AM on July 10, 2012


DU: They say heat is caused by molecules moving really quickly. So how come when I stick my hand out the window and the air molecules are move extra fast, my hand feels cold?
"Really quickly" in heat terms is more like thousands of miles per hour. The heating effect from a mere 50-70mph wind is negligible.

However, the heat transfer by conduction at those speeds is significant. If the air is cooler than your skin, there is a net heat loss.

Additionally, evaporation is accelerated in the wind, so your sweat glands don't even get a chance to push water to the surface; your skin is dehydrating at the outer layer, cooling you.
posted by IAmBroom at 8:30 AM on July 10, 2012 [2 favorites]


On the bright side, the pitcher probably doesn't get a chance to realize he's torn his rotator cuff given the speed of nerve impulses.
posted by tommasz at 8:30 AM on July 10, 2012 [2 favorites]


Yeah, I want to know when the batter would have to start swinging to hit what's left of the ball.

Well, consider that, in human terms, the ball takes zero time to get from the point of release to the plate. Ignoring all other factors, and assuming a human batter swinging at human speed, he would need to have his bat in exactly the right position at the instant the pitcher released the ball. The swing and the pitch would have to be simultaneous by human standards.

Further, as DU points out, you'd only get about 6 nanoseconds warning... the light takes 60 nanoseconds to show you that the pitch is on the way, but by the time it gets there, the ball has already traveled 90% of the distance. By the time it's even possible to see the ball, it's almost exactly six feet away.

(1 foot is about 1 nanosecond at light speed, as Grace Hopper was so fond of pointing out.)
posted by Malor at 8:33 AM on July 10, 2012


OK, so we understand the fastball question. But what if the pitcher throws a curve ball that goes into the 4th dimension?
posted by Obscure Reference at 8:36 AM on July 10, 2012 [1 favorite]


If I were a pitcher, I'd immediately have my jersey number changed to 0.9c
posted by Thorzdad at 8:37 AM on July 10, 2012 [2 favorites]


One thing he neglects is Newton's Third Law; when the pitcher imparts that amount of kinetic energy to the ball it's a lot more than enough to overcome the friction of his planted feet and move his own body mass rather rapidly in the opposite direction. So if he throws it at 0.9C, it will be traveling at 0.9C relative to him but he's now moving backward at a fairly rapid clip and the ball is approaching the batter at somewhat less than 0.9C. I assume the speed difference is proportionate to the difference in mass between pitcher and ball, so it probably doesn't skew the figures all that much.
posted by George_Spiggott at 8:38 AM on July 10, 2012


What would happen if you tried to hit a baseball pitched at 90% the speed of light?

Probably the same thing as if I tried to hit a baseball tossed at 30 mph.


*swish!*
posted by mazola at 8:40 AM on July 10, 2012 [1 favorite]


One thing he neglects is Newton's Third Law...

He sidesteps it completely..."We'll suppose it's a normal pitch, except in the instant the pitcher releases the ball, it magically accelerates to 0.9c."

He utilizes the whiteboard convention of scribbling "Then a miracle occurs".
posted by Thorzdad at 8:42 AM on July 10, 2012 [3 favorites]


This must be the reason that Major League Baseball turned me down, despite my great throwing arm. It's the only possible explanation!
posted by wolfdreams01 at 8:45 AM on July 10, 2012 [1 favorite]


Malor's got a good point: the pitcher's retinas don't know about the pitch until 6 nanoseconds before the ball gets there. (Light travels about a foot in a nanosecond).

And of course nerve impulses within your body can't beat the speed of light, either (actually they're much slower, but since we've clearly got superbeings here, whatever).

Even assuming instant processing for the signal on the retina all the way through to the muscles moving the arm to try to hit the pitch, there's another 3 feet or so the signal must travel-- down to 3 nanoseconds, before the batter's arms can even start to respond, much less the legs (which are much closer to 6 feet, or 6 nanoseconds, away).

I don't think you can swing without the muscles in your legs taking action, so even if you're a particularly short batter, even if you magically process infinitely fast and send nerve impulses at the speed of light-- you've got about a nanosecond.
posted by nat at 8:45 AM on July 10, 2012 [1 favorite]


He lost me when he said it hit the bat.

I think he was referring to the wavefront of the explosion, which hits everything.
posted by device55 at 9:02 AM on July 10, 2012


But what if the pitcher throws a curve ball that goes into the 4th dimension?

Nyarlathotep declares it a foul. And, speaking of foul, releases Azathoth upon the trembling ballpark. This is why you don't want to play tricks with physics in the ballpark. The Great Old Ones are serious about sports.
posted by GenjiandProust at 9:52 AM on July 10, 2012 [1 favorite]


I believe the point is that the hard X-Rays generated by the matter of the ball (and the surrounding air) being heated incredibly hot would vaporize most anything sufficiently nearby and cause a shockwave normally only created by atomic bombs. No nuclear reaction necessary.

Regarding vision, that would be impossible. The instant the ball accelerated to 0.9c, X-Rays traveling 1c would begin traveling towards the batter, likely vaporizing the batter's cornea when the wave front arrived. Moreover, the opaque plasma cloud immediately generated would obscure the visible light from the ball, much the same as the CMB surface blocks our view of the Big Bang.

So you'd pretty much see the ball released and then nothing at all, but if your eyes could survive the x-rays, you'd see the plasma generated by the x-rays, but never the ball itself or its remnants.
posted by wierdo at 9:53 AM on July 10, 2012


I would die almost instantly.

::Reads article::

Yep.
posted by moonbiter at 10:01 AM on July 10, 2012 [1 favorite]


nat, just for the record, nerve impulses travel considerably slower than the speed of light, topping out at about 100 m/s. It is, in effect, ions travelling, not electrons (to oversimplify more than my knowledge allows).
posted by ambrosen at 10:42 AM on July 10, 2012


Hmm. Mass of baseball is between 142 and 149g. We'll call it 145g. e=mc2 ...

E=mc^2 says something about the equivalence of rest-mass and energy, which not the same thing as relativistic kinetic energy. or, to put it differently, E=mc^2 gives you, in relativistic terms, the energy of an object at rest relative to a given reference frame.
posted by oxidizer at 10:43 AM on July 10, 2012 [1 favorite]


Hey Mythbusters, we have an idea for your next season...
posted by backseatpilot at 10:57 AM on July 10, 2012 [2 favorites]


I would die almost instantly.

::Reads article::

Yep.



Well, yeah.

Here's some more philosophica phun with physics, Man of Steel, Woman of Kleenex, on the difficulties inherent in Superman and Lois Lane attempting to consumate their relationship; a problem first discussed in detail in 1971 by Larry Niven, re-examined through the years with diminishing results, and previously discussed in this forum several years ago.
 
posted by Herodios at 11:04 AM on July 10, 2012


If it's a cold day, that would really sting.
posted by mrgrimm at 11:06 AM on July 10, 2012 [1 favorite]


And then the crowd does the Particle!

_o_   _o_   <o>   <o>   \o/   \o/   \o/   \o/   \o/   \o/   \o/   \o/   \o/   \o/   <o>   <o>   _o_   _o_
posted by tzikeh at 11:39 AM on July 10, 2012 [4 favorites]


Gotta getta bigga bat.
posted by mule98J at 11:54 AM on July 10, 2012


...swallowing the backstop, both teams, the stands, and the surrounding neighborhood—all in the first microsecond.

Coincidence - last week I wrote this in my "news" file:

"God Answers Player's Prayer, Incinerates Opposing Team"
posted by mmrtnt at 11:56 AM on July 10, 2012


> But it's not a matter-antimatter reaction...

"Hey battter, anti-batter, batter!"

posted by mmrtnt at 12:09 PM on July 10, 2012


For those who watched the home run derby last night, I present the current frontrunner for American League Cy Young award.
posted by exogenous at 12:20 PM on July 10, 2012


If the ball hits the bat first (or even if molecules of the ball hit molecules of the bat, say) it can't be a HBP, right? If a player hits a ball into himself, I believe it's a foul ball. Most of the blast is not going to land inside the baselines, either.
posted by Earthtopus at 12:37 PM on July 10, 2012 [1 favorite]


this is why chuck norris never played major league ball
posted by pyramid termite at 12:54 PM on July 10, 2012


I know just enough physics to be able to understand half of what you're all saying, and not nearly enough to participate meaningfully. But I do want to say that this is one of the threads that makes me sit back and realise just how much I love this place.
posted by talitha_kumi at 12:56 PM on July 10, 2012




I do not typically enjoy baseball OR understand physics (what can I say, I'm an artist?) and I found this to be fascinating. Fist bumps.
posted by thekilgore at 1:38 PM on July 10, 2012


Calculations unfortunately ignore Newton's old old law "for every action there's an equal and opposite reaction". A careful analysis of what happens to the pitcher dP/dt may move the nuclear effects far away from the stadium before the ball leaves her hand.
posted by Twang at 1:43 PM on July 10, 2012 [1 favorite]


The calculations don't ignore it; the set up of the question ignores it.
posted by Mitheral at 2:34 PM on July 10, 2012 [1 favorite]


One thing he doesn't seem to do is provide any estimate of the amount of energy released. As others have pointed out, it's not an annihilation event; as the leading surface of the ball reacts with the air and ablates, it would slow down. It's going to slow down to the point where there's no longer the temperature/energy levels required for fusion long before the ball's mass is completely reacted.

You can't simply say E=m(c^2) where m is the mass of the ball. Only a small part of the ball is going to end up being transformed from mass to energy via nuclear interactions, and I suspect* it's negligible compared to the kinetic energy of the ball that we're magically introducing when we say that the ball is traveling at 0.9c.

Instead, it's going to be something like Ek=(1/2)m(v^2), where m=142g and v=0.9c; Wolfram tells me this works out to about 5.4×10^15 J, or slightly less than 1.3 megatons of TNT.

That's actually sort of a low estimate because of the additional nuclear stuff that would be going on, however I'm not sure what sort of distance the energy would be spread out over. The part that I can't quite work out, and it seems very difficult to do a priori, is how quickly the ball would decelerate. You'd almost certainly get some sort of oblong destruction zone that would run basically along the mound/home-plate axis, but I'm not sure how far it would extend.

* For no particularly good reason, the more that I think about it. It's entirely possible that the energy obtained by these nuclear interactions could be quite significant, and I'm not sure that trusting one's intuition is a good idea when dealing with near-relativistic velocities, or probably anything to do with nuclear interactions in general.
† Meaning, of course, that we should do an experiment. Anyone want to write up a quick grant proposal?
posted by Kadin2048 at 3:44 PM on July 10, 2012


The pitcher's arm would tear off during the wind up long before such a velocity could be reached.
posted by humanfont at 5:17 PM on July 10, 2012


Mod note: Comment deleted. We don't talk about injuring other MeFites with baseball bats. Use the contact form if you have questions about this. Thank you.
posted by jessamyn (staff) at 5:55 PM on July 10, 2012


Just be grateful it isn't a cricket ball. Those things hurt.
posted by schwa at 10:07 PM on July 10, 2012


We're gonna need a bigger bat.
posted by deborah at 2:33 AM on July 11, 2012 [1 favorite]


Kadin, you're low by a factor of about 3 on the energy, because you forgot the relativistic correction. The energy of a particle moving at speed v is

E = gamma mc^2, where gamma = 1/sqrt(1-v^2/c^2)

For speeds very much less than c, the speed of light, we can perform a Taylor expansion and get

E = mc^2 + 1/2 mv^2 + ....

where the ... are terms depending on v^4, v^6, etc. So, for low velocities, the familiar formula is right (and the mc^2 term can be thought of as "rest energy"), but for v near c, you're too low. For one thing, energy approaches infinity when v approaches infinity.

For v = 0.9 c, gamma = 2.3, so the "kinetic energy" is (gamma-1)mc^2, or 1.3 times the rest mass of the particle. That's about 4 megatons of TNT for a 142 g baseball.
posted by physicsmatt at 5:57 AM on July 11, 2012


I'm skeptical of significant quantity of fusion reactions. I'll point to the Rutherford experiment for the reason why here. Even at higher energies electromagnetic interactions between nuclei are much, much, more common than nuclear fusion. Heavy-nucleus cosmic rays and accelerated ion beams tend to zip right through matter until they're slowed by electromagnetic interactions with other nuclei.

My bet is that ball and atmosphere would quickly convert to a hot and dense plasma, and most of the collision energy would be released in the form of accelerated beta particles and ions.
posted by CBrachyrhynchos at 6:45 AM on July 11, 2012


I'm not sure it really matters, CBrach. The kinetic energy will operate as advertised, even if no fusion reactions happen at all.

Sadly, I don't think we can actually experiment with this. That would be an amazingly cool thing to watch. Via remote viewing, of course. :-)
posted by Malor at 12:27 PM on July 11, 2012


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