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Stone Skipping the Scientific Way
Quirk writes "National Geographic has a bit on the scientific analysis of stone skipping. Using a machine launching aluminum disks Lyderic Bocquet, a physics professor at the University of Lyon, and his colleagues discovered the 'magic angle' of 20 degrees as that required to maximize skipping. 'Jerdone Coleman McGhee of Wimberley, Texas, holds the current Guinness Book of World Records title for a 1992 toss that yielded an impressive 38 bounces across the Blanco River in central Texas'"
Loogie Hocking.
what they'll be doing at the next foo camp ;)
USE='clever' emerge -u sig
I am horrible at skipping stones, but the best I ever got was on lake oneida up in NY right before it froze over (I think it was like 10 skips; yeah, I suck). I wonder how much the other type of degrees (temperature) effects things . . . physics/chem geek want to wax eloquent?
What we should REALLY be trying to figure out is how to skip more massive stones. That's the next step.
This one time, me and some people were skipping stones *hardcore* style. We got the biggest flat rocks we could lift and tried to spin them. Usually they just glided, but sometimes they would skip fairly high.
Of course, once the government got hold of this technology, they would put it to use bombing Iraq.
Esoteric reference.
I think this is much more about bored scientists.
The more you know, the less you understand.
Why do a scientific analysis of something when you ignore the #1 variable: The Stone.
Can the one who asked for this please step forward, so we can publicly shoot him, and don't let any more money be spent on 'skipping stones'.
If we _do_ plan on wasting money, then at least do a 'Icecream Eating Gets Scientific' : Im first in line to some testing for that !
If so, I can see this being cited sometime down the road by a politician as a bad use of tax funds, a la studying the effects of cow emissions on global warming. Personally, I'd still rather see my tax dollars go to perfecting stone skipping instead of some congressman's son's highway construction company.
I suppose this kind of research fall under 'basic science'?
Steve's Computer Service, Hobbs, NM
...good to see tax payer/student dollars at work
Zillions of years of waves busting up the tough rocks has polished them all smooth and flat. This makes for some of the best skipping stones ever. We're talking about an endless supply here.
Some of the piles I've seen reach 3 to 4 feet in height and run for hundreds of yards down the beach; all made up of beautiful rocks. If you're lucky you can find some other nifty stuff like beach glass or driftwood. And not so nifty stuff, like dead fish and RIAA jackets.
that a human can skip one 38 times, but there is no mention on how many times the machine they built was able to do it. Just watch, this is gonna lead to some wacky robotics competition where teams try to construct different robotic launchers to see which can skip more times or longer distance.
"0101100101? It's just jibberish. *looks in mirror, gasps* 1010011010@!? AHHHHHH!!"
...geeks bringing a stone skipping machine to tweak and experiment with while they go camping with their Wi-Fi gear. Can't we have a normal camping trip? =)
My innocent childhood hobby has been ruined with the introduction of science and actual calculations! Not to mention that I've only ever been able to get like five skips. *runs to hide*
Try actually thinking for yourself. It's quite refreshing.
You centrally located people haven't experienced stone skipping until you have been to the ocean. Easy to get 15-20 skips in a calm inlet. Dense salt water makes it that much easier.
I'm sure at the dead sea you could really make 'em go.
I have witnessed a guy in MINNEHAHA SPRINGS, WVA skip a stone over fifty times. It was on a man made lake with a bank that contained many large peices of slate which were ideal for skipping. When watching him skiped, I noticed that he threw the stones with a slight curve.
I sliced my finger open skipping slate pieces
across the water once. I had a half dozen nice
slices in it because they were so sharp, it didn't
really hurt right away, and I was trying to get a
nice fast spin on them to skip more.
ouch.
It would come in handy to trim the dorsal fins off of all those mean, nasty 'killer' whales savagely tearing cute cuddley seal lion pups to death!
... that some people have entirely too much time on their hands. :)
File under 'M' for 'Manic ranting'
I was disappointed by the lack of pictures in the article, so I went hunting at one of the researchers' sites. Couldn't find the stone skipping machine, but I found a cool movie of a skipping stone. My dad and I used to do this stuff up in Michigan, it's nice to learn the physics behind it!
The article suggests that this is the first time this type of problem has been scientifically studied. As far as I know this kind of problem has been very thoroughly studied for aerospace purposes: a planet's atmosphere is the pond, and a spacecraft is the stone. A google search for 'skip trajectory' shows up lots of serious research.
Warning: not for the faint-hearted!
Any disc golfer or ultimate frisbee player can tell you that changing the shape or weight of your disc can very significantly affect its dynamics. It could be that they've only found the ideal release conditions for the particular disc they were testing with.
i don't get it
Sell em on Ebay
Here is a news article in the science journal which has the original report.
Infuriate left and right
I seem to remember a Scientific American article from years ago that determined, via slow-motion photography, that each time the stone hits, it flips over. Anyone else heard of this?
Tim
http://www.rootstrikers.org/
i don't get it
'Tossing' in UK parlance is the same as jacking off. 'Jizz' is pretty self-explanatory. And Barnes-Wallace was the inventor of the bouncing bomb, which was used during WWII to destroy dams in the Ruhr valley of Germany.
This is what science is all about. Mars? Please. Nanotubes? Come on! Stealth? Get real. Now stone skipping, that's worth at least a Master's dissertation... This has the possibility to advance toy technology YEARS!
"Who are in control, they are not in control of anything - they don't even control themselves!" - Glen Beck
Only in GW Bush's homestate would National Geographic stoop this low. Next they'll be flinging cow pies.
the allies figured this out in ww2. Nazi dam bombing
It never ceases to amaze me the amount of things people can come up with and do for no apparent reason...
For fuck's sake, how is the parent offtopic? Corny, maybe, but not offtopic. Mod it up!
I don't remember the details, but the History channel had a show on about a British aviation (WWII) engineer who was in charge of developing a plane and payload to destroy damns. The plane, flying low, would drop the payload 100's of feet before the damn. Skipping a dozen or more times, bounce off the target, roll back towards the base, due to inertia , and explode.
Very interesting, he had to find the best shape, weight, and attack angle.
How can this be applied to real-world applications? Are they going to redesign jet-skis with this information? Or surfboards or body-boards?
Those are a few things this research could possibly apply to, can anyone give me examples of others?
I ran a benchmark on my quantum computer, now I can't find it anywhere!
The massive spinning bombs that were designed to bounce along the water before sinking and exploding in front of a dam? That technology was developed and used successfully in world war II by the english.
I ran a benchmark on my quantum computer, now I can't find it anywhere!
I'm sure this will be a nomination, if not a winner for the prestigious Ig Nobel awards.
-- Will program for bandwidth
Just think of the applications, like say Skipping Bombs!
yes, but how many degrees of freedom are there in a degree of separation?
A blog about stuff.
I recall watching a documentary about Barnes Wallis, a British scientist who during WWII invented and "perfected" a dam busting bomb. A rather large (multi ton) spinning cylinder full of explosives that would be dropped from a plane at remarkably low altitude over water directly at a dam at high speed, resulting in the bomb's skipping, like a stone, until it would collide with the dam. The bomb would then sink, but it's spinning motion would keep it tight to the dam until it exploded.
Wallis' research involved countless stone skipping tests, that inevitably resulted in the discovery of the perfect angle.
The bombs themselves enjoyed marginal success, succesfully destroying 1 of 3 objectives, if I'm not mistaken.
http://simscience.org/cracks/dambusters.html - Interesting videos and more information.
I mean, the trailing edge is the edge that will hit the water first if you're talking a 20 degree angle, and if the stone skipped, the center of force would have to be behind the stone's center of gravity (otherwise it would sink).
If it skips soon enough, it could be far enough behind the center of gravity to cause the stone to flip. But I doubt it happens all the time, because I can't see getting it to flip the same speed every time. If it doesn't flip by about 180%, the stone would soon hit at a bad angle and sink. The chances of even getting three or four skips in a row would probably be ridiculously small, but I can get at least that many skips fairly consistently.
It's still unfunny at best, and I'm a Brit who knows what tossing is and who Barnes-Wallace was.
Life goes on.
If I only knew about this at camp, I coulda impressed the girls and gotten myself laid. DAMN!
Getting a golf ball to skip...now that takes talent. Yeah, that's it. Talent...
Barnes-Wallace
i wonder how many yanks even know who Barnes Wallis was. Frankly I enjoyed Dam Busters.
try { do() || do_not(); } catch (JediException err) { yoda(err); }
This research has already been done using scientific methodology to develop the infamous Dam Busters bouncing bombs.
The inventor (can't remember his name)used a catapult to determine the angles required to make a cylinder- the bomb - , spinning with back spin on its horizontal axis to skip over the surface of the water in order to hit the dam wall and sink at its base.
Check out the BBC doco. It's also an excellent example of the human cost of warfare.
We recently sailed out to Ft Jefferson in the Dry Tortugas. We read where the soldiers would heat cannonballs to red hot and shoot them at enemy ships. They even made an oven with 4 magazines in it for the job. They used layers of wet and dry padding between the poweder and ball in the cannons. My pics don't say what size balls but they were one of 12, 18, or 32 lbs.
These balls would skip along the saltwater and bury themselves in the ships at waterline level where the seamen couldn't get to them. The balls would then burn through the boats hull, hopefully starting a fire.
See, there were even geeks back then with a lot of time and resources on their hands. This must have taken a lot of practice.
Also visited Fort Pulaski outside of Savannah GA. These 2 forts were designed to be very similiar in so many aspects. But there is no mention here of this kind of ball skipping. Where Ft Jefferson is surrounded by water, though, Ft Pulaski only has it near in a 45degree arc, and that's more than a 1/4 mile away. The ships channel is out of cannonball range these days; maybe it wasn't back then.
Mysterious Rock Movements
January 12, 2003
Lake Superior, Minnesota
Scientists and local authorities are struggling to explain the sudden rise in the level of lake Superior. After long investigation the rise was attributed to a big pile of mostly flat rocks that somehow made their way into a pile a few meters from the shore. There was also a smaller pile of not-so-flat rocks much closer to the shore.
Invstigators attempting to trace the people behind this strange event have only a few puzzling clues to guide them. The whole beach appears to bave been trampled by hundreds of thousands of people. The only clues to their presence is all those strange conical pieces of tin-foil with the base roughly the size of a human head. There were also a number of RIAA jackets nailed to tree stumps and impaled with darts.
Darl McBride, strangely showed up and shoved the following quote down our throats: "I'm not sure who is behind this, but I'm certain we own the intellectual property. We can't tell you quite what the property is or how it was violated, but please send us $699"
A few years ago (1997?) in the UK on a beach on the east coast near Harwich I was skipping stones with friends on a small estuary (river entering the sea) where the pebbles were numerous and the water calm. Amongst the pebbles I found the remainder of a modern standard glass milk bottle. All that remained was the round base of the bottle which I discovered was the perfect skipping "stone". The stone skipped at least 34 times before the skips were too small.
i'd always get like 3 normal skips, then like 10 really quick ones that barely leave the water, if that. do those count?
Well, here is another thing I put on the list of things that machines do better than people.
Every year the folks who put out The Annals of Improbable Research , formerly The Journal of Irreproducible Results, formerly The Worm Runner's Digest hands out ten IgNobel Prizes for scientific achievements "which can not or should not be repeated". It's sort of a Feast of Misrule for science.
If they can give an Ig for the first MRI images showing conclusively how men and women's bits fit together during coitus and a scientific study on the optimal way to dunk a biscuit in coffee, then by G-d this deserves one too!
The man who never alters his opinion is like the stagnant water and breeds Reptiles of the Mind -- William Blake
The inventor of the bouncing bomb, from the movie The Dambusters for those with no sense of hostory, was Dr Barnes Wallis. His idea was based on the stories of ship bouncing cannonballs across the water.
and the werewolves came...
and they ate him...
and they drank his beer...
I'm sorry, but when I've skipped stones, half of the challange is finding the right flat stones. This whole experiment takes the fun out of it and turns it into a joyless exercise.
I'd certainly hope this isn't going to lead to 'skipping stones' at the Olympics, or a standard skipping stone, produced by AMF and Wilson. Can't something just be fun without the jocks getting involved?
A Good Intro to NetBS
It seems to me that they're missing several somethings that are fairly important (other than the physics of the stone): the velocity and spin of the stone (to say nothing of the water surface's dynamics).
:P
That said, my personal record was achieved when I was 12 at a cub/boy scount camp. It was in a little river/creek (maybe 10 feet across, no deeper than 1' in most parts, with lots of smallish smooth disc-shaped stones perfect for skipping). My group was out hiking, and we had a competition. Everyone else was picking more roughly-shaped stones off the shore, and not venturing into the water.
Having grown up watching my uncles skip stones on their lake since I was very young, I probably knew a thing or two about stone skipping that the others didn't, simply by example. At any rate, I took a step or two out into the water, and grabbed the smoothest stone I could find.
This was all after the scout master said the person with the most skips gets a candy bar. IIRC, I was the last to have my turn at winning the candy bar. Everyone started bitching about how I was cheating because I didn't take the rock from the shoreline. (bah!) I got into the water, and got as close as I could to the water, and threw the stone upstream like a frisby.
The end result: 23 skips, at least half an hour of people trying to come close to half as many skips, and a candy bar for me back at camp. And a dozen pissed off cub scouts for 4 more days.
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
- the angle I drop just about anything I don't want to end up under the couch.
I'm laughing at clouds.
some people on /. seem to think doctoral candidates should be releasing Nobel winning work to get their degree...
for best results the dwarf should be stoned. (not a very sensitive comment, sorry)
so next time we play Worms I can show my 1337 skipping skills to my buddies. We used to have a competition for the most skipping worm using baseball bats.
This actually has a useful application. In WWII there were several dams in Germany used to give power to Germany's war industries. Britain decided they needed to destroy them...problem was that they were heavily guarded, protected by nets...basically, it would be impossible to destroy them with any convential weapon of the time. Their solution: A bouncing bomb. A special apparatus in the plane spun a cylindrical bomb(technically a mine) which was launhed from the plane at a specific distance and height(60 ft!) from the dam. It skipped across the water like a stone, past the dam's defenses, and rolled down the edge of the dam, detonating at a pre-determined depth underwater. Plenty more here: http://www.dambusters.org.uk/wallis.htm
once you go slack, you never go back
I skip the Stones whenever they're in town.
I'm not paying $150 a ticket to see a zombie like Keith Richards.
Personally, I was hoping to see diagrams, calculations of inertia, stone-against-water friction formulas, chaos theories, stuff like that. I mean, 20 degrees...? Is that all there is to it?!??!!
All interpreted languages are abstractions over Lisp
that's it.. the P
every day http://en.wikipedia.org/wiki/Special:Random
Getting a golf ball to skip...now that takes talent. Yeah, that's it. Talent...
... where it promptly nailed the only tree in sight and bounced back into the middle of the lake.
There's a little 9-hole course near Boulder CO (Haystack Mtn Golf) with a lake on one fairway. Actually, the lake is the fairway. It's an easy 9-iron shot from teebox, over lake, onto green.
Once, I topped the tee shot horribly, but imparted enough topspin that the ball skipped three times on the water and hopped out the other side
I'll have to take one of those machines with me the next time I go camping by the lake - maybe I can link it to my WiFi enabled laptop and remotely skip stones from the comfort of my tent...
While researching the 'dambuster' bombs, they actually did quite the same thing, built a machine to sling discs to find the 'magic angle'.
So this isn't the first time it's been done.
Skipping stones ain't gonna pay the bills.
My parents complain about skipping Stones.. I just told them to buy a new CD, but nooooo.
This statement is false.
About as many who give a shit about england.
yeah, thats a big 0 right there.
and no one is going to believe it,(and I can't prove it) but I once managed 42 (answer to everything if you read douglas adams) on the River Mersey, mind you this was in the '70's and the river was more polluted then
That's the Kelvin limit angle. The angle the wake waves make from a boat.
Two objectives were destroyed, one damaged.
And that's dam good odds for a military operation.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
eh, let him have his fun... it doesnt cost you anything if he does, and it doesnt gain you anything if he doesn't. unless you like to see people suffer. or don't like to see other people happy.
Heard about a sucker bet one pro golfer used to make - that he could drive a ball for a mile or more, provided he could choose the course, time, and season for the shot.
The course he selected was in or near Chicago, having a tee on a cliff overlooking Lake Michigan. The season chosen was mid winter - on a day and time when the ice would be solid but still flat and the wind strong and from the west. (It's not called "The Windy City" for nothing.)
He'd tee off backward, shooting the ball out onto the lake ice, where, driven by the wind, it would bounce away for miles and then keep rolling for as far as it could be observed.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
I have skipped many rocks at beaches of lakes, ponds, and oceans and found out that one of the best places to skip rocks is on the ocean because you get both more distance and more skips because htere are more waves and the waves are what help you when skipping rock
MonkeysKickAss
Scientific Progress goes 'Boink'!
Wikileaks, no DNS
the author was ridiculed on a french radio show by the name of "les grosses tetes". Since he was dealing with pros, he could not escape from the jokes ; a right-wing paper (Le Figaro) also nailed him for wasting taxpayers' money. Not many people realize that it's quite rare to find a scientist who actually publishes new research from time to time, and not standard crap ("we have worked on nanowhatever and not found anything worth mentioning but still publish it in order to get a pay rise")
to increase his publication record.
Google passes Turing test : see my journal
You're either a kraut, in which case you lost, a yank, in which case what fucking kept you (again), or a frog, in which case you're a cheese eating surrender monkey.
Yeah. Because beaches are, like *so* covered in those. A fucking ton, they are.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."