-------------------- "You learn something new every day if you're not careful" - Wilf Lunn Posts: 893 | From: Durham City, England | Registered: Aug 2005
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quote:Originally posted by Andrew of Ware, England: Does this mean that if I jump into quicksand it will be like hitting rock, but if I wade through it I will sink?
A thixotropic fluid like clay suspensions and other things (custard?) will react to a sharp impact like it was a hard object. But after the impact, the fluid will immediately return to its previous state.
So, you'll hit it and it'll kick back nice, but if you're still standing on it after a couple milliseconds it'll act like a liquid again and you'll immediately sink.
I've screwed around with gypsum solutions, and from my experience the hardening effect is significantly faster than human reaction time, so I suspect you wouldn't be able to run across the stuff either. You'd need to press your feet against the fluid for a good fraction of a second, much longer than the fluid remains hard.
Maybe someone with amazing reflexes . . .
-------------------- Thinking about New England / missing old Japan Posts: 2603 | From: Virginia | Registered: Mar 2001
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posted
I'm thinking of a dessert. It's colored . . . it has a color. It starts with a letter. Starts with S, I think. Does that remind you of anyone? Any dessert you once had? I feel like something happened to this dessert. It was there and then it was gone. I think the name rhymes with a condiment. Rhymes with . . . ketchup. Yes, does anyone remember a dessert called smetchup? No?
-------------------- Thinking about New England / missing old Japan Posts: 2603 | From: Virginia | Registered: Mar 2001
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Richard W
Ding Dong! Merrily on High Definition TV
posted
I thought you were holding a seance - "Yes, the smetchup has a message for John. John, it knows you ate it John. It was there and now it's gone."
Posts: 8725 | From: Ipswich - the UK's 9th Best Place to Sleep! | Registered: Feb 2000
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quote:Originally posted by Finite Fourier Alchemy: I'm thinking of a dessert. It's colored . . . it has a color. It starts with a letter. Starts with S, I think. Does that remind you of anyone? Any dessert you once had? I feel like something happened to this dessert. It was there and then it was gone. I think the name rhymes with a condiment. Rhymes with . . . ketchup. Yes, does anyone remember a dessert called smetchup? No?
YOMANK!
-------------------- "England and America are two countries divided by a common language." - George Bernard Shaw Posts: 555 | From: Ireland | Registered: Apr 2003
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posted
Was it a-two-hundred... and a-forty dollahs... a-worth a-custard? Aw yeaaaaaaah?
-------------------- Mr. Sagan did not go too fars, If you just took the time to scan its, You'd count billions and billions of stars, And billions and billions of planets. Posts: 332 | From: Kansas City, MO | Registered: Jan 2004
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I just discovered that show. They run it here in the US on G4, a cable station dedicated to gaming and high tech stuff-- pretty cool show. I have yet to try the latest thing I saw which is to make a dough from corn starch. As you kneed it it hardens up but goes runny again (almost immediately) when you stop rolling it around.
-------------------- As God is my witness, I thought turkeys could fly. Posts: 1679 | From: Illinois | Registered: Jul 2004
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posted
I've tried the corn flour & water trick, Pretty cool stuff. Solidifies when you stir it then liquidifies again Read about it in one of New Scientists little booklets that came with one of the mags Posts: 116 | From: Australia | Registered: Aug 2005
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posted
That's pretty awesome. That would make a great museum demonstration, although I know most folks where I work wouldn't try it. On the other hand, it might be easier to sell than the bed of nails...
Corn flour and water is the standard demonstration I've run across. It's called Oobleck in most places; here's a recipe if you'd like to try it at home. I recommend if you're going to add food coloring, go ahead and add it to the water before mixing it all together; otherwise, it's a pain to stir into the mixture for obvious reasons.
-------------------- "But about the reindeer...what kind of a nose shines? How did he get it? Maybe it's not a reindeer after all. It could be something else." Posts: 2216 | From: Winston-Salem, NC | Registered: Nov 2003
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posted
Thanks Angels for the recipe. Not sure if I am brave enough to try it. Can porridge be used instead? Then if the experiment goes wrong at least it will be one scientific experiment that I can eat!
-------------------- Andrew, Ware, England Posts: 1709 | From: Ware, England | Registered: Apr 2003
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quote:Originally posted by Angels From the Realms of Dory: Corn flour and water is the standard demonstration I've run across. It's called Oobleck in most places;
We made it in school right after reading the Dr. Seuss book Bartholomew and the Oobleck. (The same Bartholomew of The 500 Hats of Bartholomew Cubbins). That's where the name came from, I wonder when the two first got connected.
-------------------- Bender: Though you may have to make a metaphorical "deal with the devil". And by "devil", I mean the robot devil, and by "metaphorically" I mean get your coat. ------------ My sad site: A new way to be bored. Posts: 722 | From: Colorado | Registered: Mar 2004
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posted
Andrew, I've never made it with anything but cornstarch myself. You could try it and let me know. Generally the best mix for the cornstarch is 1 part water, 1 part starch, but I don't know if porridge would be the same mix. It thickens in water, right? (Apologies...unabashed American-style breakfast eater here. )
Tantei, yeah, I think most teachers use Bartholomew and the Oobleck lesson plan. I know we've done something different at the museum, where you give kids random junk like straws, cardboard, foam, etc. and challenge them to make a "planetary lander" that will sit on the surface of the Oobleck without sinking. It's amazing what some of those kids come up with.
The Glurch listed on the website I gave is also lots of fun. With the right mix and some time, you can actually make yourself a decent bouncy ball.
-------------------- "But about the reindeer...what kind of a nose shines? How did he get it? Maybe it's not a reindeer after all. It could be something else." Posts: 2216 | From: Winston-Salem, NC | Registered: Nov 2003
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Read about it in one of New Scientists little booklets that came with one of the mags ![[Smile]](smile.gif)
