there's nothing quite as disappointing as a skimmed stone that doesn't skim but disappears with a mute plop in the middle distance.
this is a handheld machine about the size of a mobile phone which when pointed at the horizon will calculate the angle required to fire off any reasonably sized pebble collected from the beach as long as it is fairly round and smooth. according to scientists who previously experimented with aluminium discs, this is most likely to be a trajectory of 20º to the horizon.
for even greater precision, factored into the calculations would be such details as the height of the user, the speed of the wind and the current local position of the tide and so it comes with all kind of neat gadgets for measuring stuff like the position of the moon and atmospheric pressure etc.
it is recommended that up to 3 pebbles can be fed into the machine between rounds or it gets a bit on the weighty side.
it comes complete with 7 indestructible inflatable balls which resemble swimmers' heads. *these are strung together in a fixed line which is fired out to sea beforehand and attached to the first pebble by something like bluetac or chewing gum.
* the inflatable balls not the swimmers' heads.
the fired stones are guaranteed to prang at least one of them.-- po, Nov 15 2006 Stone skimming machine http://web.archive....lg-2-numpage-2.htmlOk, mostly for really big stones. That explode. [Worldgineer, Nov 15 2006, last modified Jul 21 2012] 65m, chef? http://news.bbc.co....cotland/4280078.stmrecord is determined on distance not bounces. [po, Nov 16 2006] Stone skimming Machine http://news.bbc.co....3359000/3359809.stmNot pictured, though. And it's French. [DrCurry, Nov 16 2006] The magic angle http://poco.phys.to...-skip/nagahiro.html [Shz, Nov 17 2006] Simple formula? http://physicsweb.o...cles/world/19/2/6/1Air time - the real problem, or my problem, anyway. [Shz, Nov 17 2006] Find the faces http://www.bitoffun...inteasers_faces.htm [DesertFox, Nov 17 2006] 617 Squadron, RAF http://www.dambusters.org.uk/ [Dub, Nov 18 2006] MonkeyFilter | Stone-Skipping Robot http://monkeyfilter.com/link.php/17676 [Dub, Jul 20 2012] Excellent ("Look, I've just got it - it's the new 7200rpm Acme Spinner! Guaranteed at least 4 skips with any shaped stone!")-- hippo, Nov 15 2006 Does it calculate wave clearance?-- Shz, Nov 15 2006 +
Where can I get one of these?-- DenholmRicshaw, Nov 15 2006 Probably baked on another planet.-- daseva, Nov 16 2006 Who the hell cant skip a stone?-- Chefboyrbored, Nov 16 2006 The 7ft dia bouncing bombs were conceived by Barnes Wallis who initially used his kid's marbles with a sling-shot and a tin bath. Back spin apparently helped the bouncing (500rpm), and the maximum number of bounces was 20, over a distance of 1300 yds.-- Ling, Nov 16 2006 If the inflatable heads line is fixed to the first stone, won't it sink? Anyway, love the idea (+) but think the inflatable thingies should look like bathtime rubber duckies to celebrate the name of the game (which is "Ducks and Drakes" where I come from).-- squeak, Nov 16 2006 Yay, gonflable skimming.-- skinflaps, Nov 16 2006 + [Chef] I can only skim maybe 1 out of every 3 or 4 times that I try...so I could really use this.-- xandram, Nov 16 2006 //Who the hell cant skip a stone?//
People with bad elbows or movement disorders, mostly.
I've never needed one of these, but anything that makes me seem better than a machine is awesome.-- shapu, Nov 16 2006 Skimming stones is not about precision or trajectories or even, really, skimming stones. It's about spending quality time with your father, or your siblings, or your loved one, or your own children, while doing nothing terribly important on the beach.
No machine can take the place of that, so I have to fishbone this one. (Sorry po!)-- DrCurry, Nov 16 2006 come now, in real life you'd be the first in the queue to buy one of these...
mind you, I do remember several occasions, sat with my dad for hours, chucking pebbles at a tin can :)
...and actually, yes, skimming stones is exactly about a skilful amount of spin and trajectory.-- po, Nov 16 2006 Only if you're in some hypothetical stone skimming contest. And they'd probably outlaw your contraption as being against the rules.-- DrCurry, Nov 17 2006 see link above for hypothetical stone skimming contest. grrrrr!-- po, Nov 17 2006 I've gotten 16 to 18 skips a few times.-- DesertFox, Nov 17 2006 that is enviable, DF-- po, Nov 17 2006 Indeed.-- shapu, Nov 17 2006 Esp. that he can count that fast. Those things don't skip for more than two or three seconds.-- ldischler, Nov 17 2006 He must have a Stone Skim Counter™.-- jtp, Nov 17 2006 Hm, 20º is the optimal angle for minimizing projectile speed while still producing a skip, but a distance or number of skips record would require higher speeds and faster rotation, but less angle. When I throw for distance I frequently keep the stone in the air too long. It curves off to one side thus diminishing skipability. If it touches the water, it stabilizes yet slows. A heavier stone helps, but these contests have limits. I need more rotation or less speed. So complicated, my brain hurts.-- Shz, Nov 17 2006 wrong thread, 21.-- po, Nov 17 2006 I had 3 people watching and counting for me. They didn't all agree, one said 16, one said 17, and the last said 18. Hence the non-definite number. I got similar numbers a few times. Its real hard to get it to skip a lot. You can count the moire patterns afterwards for a rough estimate, too. I can count/see things quickly. You know the optical illusions where you find stuff? The one in the link, I found all 11 faces in scant seconds. Never had seen the picture before either.
I had one rock hit an unexpected swell from a boat perfectly, and it flew very high in the air. It was very suprising.-- DesertFox, Nov 17 2006 perhaps video it...-- po, Nov 17 2006 //there's nothing quite as disappointing as a skimmed stone that doesn't skim but disappears with a mute plop in the middle distance.// sp. Throwing Stones-- Dub, Nov 18 2006 My personal best is three skips. I feel rather small.-- stilgar, Nov 19 2006 yeah but you forget to mention the *size* of your stones.-- po, Nov 19 2006 //I had 3 people watching and counting for me//It's not the times the rock hits the water. What's important is the times it hits your head.-- ldischler, Nov 19 2006 The machine should be extremely light, so it wouldn't trouble me too much to carry it to the shore, when I don't get a good parking spot.-- undata, Nov 19 2006 //Who the hell cant skip a stone// Posted in poor taste and less thought. My mistake.-- Chefboyrbored, Nov 20 2006 You know, [chef], my opinion of you has definitely been ratcheted up a notch. Anyone, who thinks enough about others to apologise when no apology has been demanded, deserves respect for it.-- david_scothern, Nov 20 2006 I beat him to a pulp off-site ;)
but he *does* deserve the notch-- po, Nov 20 2006 Often times upon po's suggestion I am forced to "rethink" my posted thoughts. It is then and only then do I realise the error of my ways. She is like my ethics check in that spell check sort of way.-- Chefboyrbored, Nov 20 2006 random, halfbakery