BleepingComputer.com: Watch This Ad

Hi DSTM, I hear ya and certainly am not trying to dispute you're knowledge. I have 0 engineering experience. I don't believe the tires rolling up hill part. To me I would think the two rubber surfaces on that angle would stick. I was just pointing out that as I was trying to find info on that my brother passed me the snopes link. As I can't figure the trickery in the beer can and I don't see lightning go up as they say it does ... sometimes I'm just amazed. I appreciate your knowledgeable input.

boopme, on Dec 18 2006, 04:52 AM, said:

You are dead right about the tyres sticking on contact.Well done,I can see you are a thinker.Boopme.
Picture 2 tyres travelling in the same direction.when the two tyre surfaces touch, the surfaces are travelling in opposite rotation,at point of contact.The contact point of the rear tyre and the front tyre will act as a brake for a split second on contact.Stick like you said.Rubber against rubber.Easier to draw 2 circles touching and draw arrows next to point of contact,and you will see they are moving in opposite directions,although the wheels are still travelling in the same direction.
I will give the makers of that ad the benefit of the doubt that they didn't use computer trickery.They just used trickery,without a computer IMHO.
If asked,I would be happy to give you my take on how I think this, what looks like being "contary to the law of physics" was pulled off.

DSTM.

Now I don't have any engineering experience. I even spent all my physics courses programming games on my calculator. But I just couldn't stop thinking about the wheels (I'm obsessive like that), and think I may have figured it out. Could somebody say if and how I've gotten everything wrong.

We got two tires, Tire A and Tire B, where tire A is rolling forward and tire B is standing still. The fron of tire A is then moving downwards and when it hits tire B at point C it will start to push the back of tire B downwards as well, thanks to the stickiness of the rubber. The stickiness of tire B at point D will help keep tire B stationary. Now since rubber is elastic tire A will compress the part of tire B between point C and point D until it runs out of momentum. The portion of tire B between point c and point D will then expand, pushing against point D and thus giving tire B the moment needed to roll forward.

The tires are simple, they have a weight inside them balanced at the top. Look at how they behave as they move forward, they start slow, then as the weight inside them gets farther from its center of gravity (out toward the two or three o-clock position) they speed up. After starting the next tire rolling they continue to move uphill until the weight is on the bottom (you can see this clearly with the middle tire on the ramp).

As for the cogs, we don't know how fast or how far the first cog traveled (how much momentum it had to impart) before hitting the second cog and the board it was on was definitely tilted to boot.

Nothing in that video looked impossible to do, it is all about balance and transmitted force.

On a different note years ago on public television someone did an art film that did many of the things that were done in this video and many more. I wish I could remember the name of it but it was done in the mid seventies and lasted about 15 to 20 minutes or more. If anyone else remembers this film I would appreciate it if you post the name of it here.

Ronbo, on Dec 18 2006, 01:13 PM, said:

Ronbo,Well done. You are dead right IMO..I have just this minute logged on and you have saved me the time to explain everything in detail.With out an internal weight,to give the energy needed,the tyres would virtually go no where.because uphill and made of rubber the rear tyre is braking the front one and like Mr Alpha said compressing the front one,to a minor degree.
What the rear tyre is trying to do because of the grip is trying to climb the front tyre momentarily,taking away a lot of the energy needed to propel the second tyre forward at the desired speed.

Ever watched open wheeler racing cars, when the rear cars tyre contacts the rear tyre of the car in front.The rear cars front tyre compresses the car in front's rear tyre, and immediately climbs up the tyre and becomes airborne.I know this example is extreme,only giving an example.

So without internal weight at a given point inside the tyre,nothing much is going far at all.Around 2 o'clock seems about right to me.Strap weights to the sides of a tyre,set the weight at around 2 o'clock,let go and watch it accelerate so fast,all by itself.Only for a short distance of course.

I find all this so interesting, because you never stop learning.

This post has been edited by DSTM: 18 December 2006 - 03:38 AM