Question Anyone know where I can purchase a Marble Run (perpetual motion toy)?
I really like the Ultimate Techno Balls 920, but none of the UK stores that I have found will ship to the US ... I am looking for something geared more toward adults ... My husband loves stuff like this and I am looking for a birthday present for him ....I have checked Ebay and haven't found anything like this so far... Any help would be greatly appreciated ...

Best Answer Here is a link to a place you can get them. eBay has lots of them too! http://www.target.com/gp/search/602-0664349-8423063?ie=UTF8&LID=2996786&ref=tgt%5Fadv%5Fxsmt0409&afid=msnsearch&field-keywords=marble%20run&LNM=marble%5Frun

Question Perpetual Motion Wave Desk Toy?
Where can I purchase a perpetual motion wave desk toy similar to the one on the HBO series In Treatment?

Best Answer here's one, but at time of writing this they are out of stock. I have no idea why HBO don't sell one in their merchandise shop!! http://www.starmagic.com/store.cgi?1384332+1B2D011

Question Lets say someone makes a Perpetual Motion machine?
Somehow someone came up with a Perpetual Motion Machine. After building it ended up being size of a coffee table and only outputs few watts more than it takes it. Would something that could never(at any scale) make effect power to be cost effective really change anything? Or would it just be another cool toy?

Best Answer Your "thought experiment" does not have to be perpetual motion. Suppose the same idea but it extracted almost all the energy from a mass. Remember E=MC². So if you put in 1kGm of scrap mass and it could produce a few watts for years what uses would it have? First space travel, cost is of (almost) no object there. A few watts will operate most space probes and many satellites. Military uses also. Again high cost can be acceptable. To produce use for you home would be more difficult. Cost matters here. kWHrs of electricity costs the consumer only pennies. You unit might have to run it for years to break even. Would you pay $1000 (or you local equivelent) if it took 5 years or more to break even? How about 10 years? What if it was $5000 and 5 years?