Stone skipping

[arcticpenguin]

The physics of stone skipping (http://dpm.univ-lyon1.fr/~lbocquet/)

[Soapy Sam]

How did I miss this? All these years, I didn't know I was an instinctive mathematician.

It is a fact of hydrogeology that flat stones and flat water are never found in the same place, except in a small fishing port in NE Iceland, where once on a day of days, I achieved 23 skips and the stone then hit a moored boat. Two men surveying a building site on the harbour wall turned a laser tellurometer on the boat and said it was 88metres away.

I have never again come close to repeating this feat and conclude it was a freak combination of angle, pitch, stone shape, wind and water conditions. I once got two skips out of a half brick, but wrenched my shoulder so badly I had to eat southpaw for a week.

This should have been an Olympic sport years ago.

[DrMatt]

Originally posted by Soapy Sam
flat water

Wait... if I find flat stones and water, is the water likely to be Selzer?

[Soapy Sam]

In Iceland- yeah, there's a fair chance. Or boiling.:)

[espritch]

I saw a show on PBS a few days ago about an effort by the RAF to blow up damns in Germany in WWII. To hit the damns, they created bombs that were big metal cylinders. The cylinders set rotating at a high rate of speed. They were droped by a bomber flying in over the water at an altitude of 60 feet and would hit the water and skip off it into the damn.

[Hypocolius]

Originally posted by espritch
I saw a show on PBS a few days ago about an effort by the RAF to blow up damns in Germany in WWII. .

An effort? Have you never heard of the Dambusters? [Hum's tunelessly] Dah dah da da der der der da dah....[Humming ends]

[Soapy Sam]

617 squadron. The Dambusters, led by one Guy Gibson.

Note, Esprich, that's "dam" with no "*" on the end.

A dam with an "*" is a curse, especially if it leaks. Don't want a certain Air Force Officer raining censorious comment upon you.

:D

[espritch]

Note, Esprich, that's "dam" with no "*" on the end.

A dam with an "*" is a curse, especially if it leaks. Don't want a certain Air Force Officer raining censorious comment upon you.


You are correct, sir. Dang! :D

[gmol]

There is nothing cooler than seeing a stone skip...
I remember I could never do it as a child, and one day I was up in Cape Cod and decided to give it a go...

I think I got one that was 3 or 4 in a row....northing compared to 23...

[Hypocolius]

Originally posted by Soapy Sam
617 squadron. The Dambusters, led by one Guy Gibson.



That should be Guy Gibson VC.

http://www.chapter-one.com/vc/award.asp?vc=448

[tim]

Originally posted by Hypocolius


That should be Guy Gibson VC.

http://www.chapter-one.com/vc/award.asp?vc=448

Who, in those politally incorrect days, had a black Labrador dog called "******". The dog was killed a couple of days before the raid, but they didn't tell the aircrews in case they took it as an omen. IT didn't help, because a large percentage of them were killed anyway.

[Soapy Sam]

You saw the movie, I can tell.

Absolutely, it should be Guy Gibson V.C., but at the last second , I could not remember if it was VC or DFC, so I left it blank.

[schplurg]

Ok, this may a be a bit out there, but...

In the movie "Pink Floyd The Wall", there are a few scenes where Bob Geldoff is spaced out in front of a TV, and the movie he's watching has a dog named ****** in it. If my memory serves, the dog is apparently run over by a jeep..."It's ******, sir. he's dead."

Is this the movie you are talking about? I watched The Wall dozens of times (obviously) when I was younger and always wondered what movie those scenes were from, and if it was even a real movie. What is the title of the flick? Definitely British.

This is perhaps my fifth post on this board, and I chose this question to ask? Perhaps a mysterious power drew me to this "rock-skipping, dam damning, dog named ******, Pink Floyd" thread. Perhaps it is my destiny to watch this movie?

Thanks :)

[Hypocolius]

Originally posted by schplurg
Ok, this may a be a bit out there, but...

In the movie "Pink Floyd The Wall", there are a few scenes where Bob Geldoff is spaced out in front of a TV, and the movie he's watching has a dog named ****** in it. If my memory serves, the dog is apparently run over by a jeep..."It's ******, sir. he's dead."

Is this the movie you are talking about? I watched The Wall dozens of times (obviously) when I was younger and always wondered what movie those scenes were from, and if it was even a real movie. What is the title of the flick? Definitely British.



Thanks :)

Whenever Pink watches TV during the film, the movie showing is "The Dambusters" from http://www.new.co.za/~currin/thewall.html

Yes, this is the movie.

[chapka]

According to my ex-Brit gf, this is one of those things every British person knows and no American has ever heard of. She claims that every British schoolchild learns that the bouncing bomb was THE turning point of WWII, whereas I can tell you that American schools don't even mention it.

Also, the film is apparently one of those, like The Wicker Man and (to a lesser extent) The Italian Job, which just never made it to our side of the pond, at least in the same way.

Good to see we still have a few differences despite the "special relationship".

On a related note: the film recently released in the U.S. as "Formula 51" was originally called "The 51st State" in Britain. It was retitled because, while Brits think that they are the 51st state, Americans would have assumed it was a film about Canada...

Let the flames begin!

[schplurg]

Excellent! The Dambusters". Now I'm gonna have to find that movie somewhere, I've never heard of it.

The Wicker Man, heard that in a song before too...Iron Maiden. A lot of their songs are based on movies though. Geez I have some catching up to do.

I'm gonna go skip some rocks and think about it (to get back on topic)

Thanks all!

[tim]

On a related note: the film recently released in the U.S. as "Formula 51" was originally called "The 51st State" in Britain. It was retitled because, while Brits think that they are the 51st state, Americans would have assumed it was a film about Canada...

Let the flames begin!

We Brits think of ourselves as a lot of things - not all of them good - but being Americans isn't one of them! We view you lot as a faintly amusing, quaint sort of people who on the past have generally been late for wars, but are trying to make up for it now.
Of course you're always welwome as visitors here, especially if you bring lots of tourist dollars!

[Soapy Sam]

The raid on the Mohne and Eder (and other) dams was real enough. Much revisionist history has been written about whether it was a "success"or not. (Define your terms). No question about the technique though. The bouncing bomb was designed by Vicker's lead aero engineer (later knighted) Barnes Neville Wallis, who can be found in Google.
A lot of interesting design went into both the bombs and the converted Lancasters which dropped them. It was one of the first experiments with extreme low level precision bombing which has remained something of an RAF speciality. The big problem was that the approach had to be straight, level and low- about 60 feet above the surface of the water. This made the aircraft a sitting target for AA fire from the dams, leading to the high casualty rate.

ps-I was once told that the movie (Richard Todd) was shown in the U.S. and that "******'s"name was changed by dubbing. Is this an urban myth?