---------------------------------------http://apod.nasa.gov/apod/ap090601.html wrote:
Explanation: Will Spirit be able to free itself from soft ground on Mars? The robotic Spirit rover currently rolling across Mars ran into unexpectedly soft ground last month while exploring the red planet. A worry is that the ground is so soft that Spirit won't be able to free itself, will have to stay put and thereafter study what it can from its current position near an unusual martian land feature named Home Plate. Pictured above, the front left wheel appears to be primarily digging itself in when spun, while on the other side, the front right wheel no longer spins and is dragged by the five year old mechanical explorer. NASA continues to study the situation, and engineers and scientists have not yet run out of ideas of how to use Spirit's six wheels. Far across Mars, Spirit's twin Opportunity continues on its two year trek toward Endeavour crater.
My Cousin Vinny (1992)
Vinny Gambini: Ms. Vito, it has been argued by me, the defense, that two sets of guys met up at the Sac-O-Suds, at the same time, driving identical metallic mint green 1964 Buick Skylark convertibles. Now, can you tell us by what you see in this picture, if the defense's case holds water?
[Lisa examines the picture]
Vinny Gambini: Ms. Vito, please answer the question: does the defense's case hold water?
Mona Lisa Vito: No! The defense is wrong!
Vinny Gambini: Are you sure?
Mona Lisa Vito: I'm positive.
Vinny Gambini: How could you be so sure?
Mona Lisa Vito: Because there is no way that these tire marks were made by a '64 Buick Skylark convertible. These marks were made by a 1963 Pontiac Tempest.
D.A. Jim Trotter: Objection, Your Honor! Can we clarify to the court whether the witness is stating opinion or fact?
Judge Chamberlain Haller: This is your opinion?
Mona Lisa Vito: It's a fact!
Vinny Gambini: I find it hard to believe that this kind of information could be ascertained simply by looking at a picture!
Mona Lisa Vito: Would you like me to explain?
Vinny Gambini: I would love to hear this!
Judge Chamberlain Haller: So would I.
Mona Lisa Vito: The car that made these two, equal-length tire marks had positraction. You can't make those marks without positraction, which was not available on the '64 Buick Skylark!
Vinny Gambini: And why not? What is positraction?
Mona Lisa Vito: It's a limited slip differential which distributes power equally to both the right and left tires. The '64 Skylark had a regular differential, which, anyone who's been stuck in the mud in Alabama knows, you step on the gas, one tire spins, the other tire does nothing.
[the jury members nod, with murmurs of "yes," "that's right," etc]
Vinny Gambini: Is that it?
Mona Lisa Vito: No, there's more! You see? When the left tire mark goes up on the curb and the right tire mark stays flat and even? Well, the '64 Skylark had a solid rear axle, so when the left tire would go up on the curb, the right tire would tilt out and ride along its edge. But that didn't happen here. The tire mark stayed flat and even. This car had an independent rear suspension. Now, in the '60's, there were only two other cars made in America that had positraction, and independent rear suspension, and enough power to make these marks. One was the Corvette, which could never be confused with the Buick Skylark. The other had the same body length, height, width, weight, wheel base, and wheel track as the '64 Skylark, and that was the 1963 Pontiac Tempest.
Vinny Gambini: And because both cars were made by GM, were both cars available in metallic mint green paint?
Mona Lisa Vito: They were!
Vinny Gambini: Thank you, Ms. Vito. No more questions. Thank you very, very much.
[kissing her hands]
Vinny Gambini: You've been a lovely, lovely witness.
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