# A watertight seal that can also be penetrated by something non-water **URL:** \ **Category:** Factual Questions\ **Created:** [April 27, 2015, 5:42pm UTC](https://boards.straightdope.com/t/a-watertight-seal-that-can-also-be-penetrated-by-something-non-water/718658 "2015-04-27T17:42:05Z")\ **Posts on this page:** 4\ **Page:** 2
**Author:** ![BubbaDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bubbadog/32/333_2.png) [@BubbaDog](https://boards.straightdope.com/u/BubbaDog)\ **Post date:** [April 28, 2015, 1:20pm UTC](https://boards.straightdope.com/t/a-watertight-seal-that-can-also-be-penetrated-by-something-non-water/718658/21 "2015-04-28T13:20:11Z")
> [@Musicat](#): > > It occurs to me – just spitballing here – that if you supplied a link to that device, we could talk about it much more intelligently. > > Just sayin’. [Looks like this maybe?](http://physics.stackexchange.com/questions/556/what-is-the-fallacy-in-this-infinite-motion-machine) ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [April 28, 2015, 1:24pm UTC](https://boards.straightdope.com/t/a-watertight-seal-that-can-also-be-penetrated-by-something-non-water/718658/22 "2015-04-28T13:24:51Z")
> [@Peter\_Morris](#): > > I think he wants a valve that will allow the string of balls to enter, while keeping the liquid inside. I can see a combination of very flexible membrane with small enough balls that the valve would close on the string, but open for the balls, and not leak much. But even a perfect seal would not be adequate for this to work. Each ball (on the way up) has to push against both the water column and the valve. > [@BubbaDog](#): > > [Looks like this maybe?](http://physics.stackexchange.com/questions/556/what-is-the-fallacy-in-this-infinite-motion-machine) That illustration has one more problem than the first. The water in the tank will push against the balls emerging in the downward direction, causing even more energy loss. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [April 28, 2015, 2:30pm UTC](https://boards.straightdope.com/t/a-watertight-seal-that-can-also-be-penetrated-by-something-non-water/718658/23 "2015-04-28T14:30:33Z")
> [@Mangetout](#): > > It will stop, because in extracting the power to run the light bulb, the generator will exert forces upon the wheel tending to slow it. > > A current generated by a moving magnetic field generates its own magnetic field that opposes the change that caused it. Lenz’s Law - the Sod’s Law of Physics. You win one interweb. The point of this experiment is to demonstrate that friction is not the main impediment to creating an infinite energy device. The universe is. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [April 28, 2015, 4:08pm UTC](https://boards.straightdope.com/t/a-watertight-seal-that-can-also-be-penetrated-by-something-non-water/718658/24 "2015-04-28T16:08:35Z")
> [@friedo](#): > > You win one interweb. The point of this experiment is to demonstrate that friction is not the main impediment to creating an infinite energy device. The universe is. Right. **SpyOne’s** error is ignoring the “machine” part of perpetual motion machine. If all you want is perpetual motion and you are able to truly eliminate all friction, then yes, his bicycle wheel can achieve perpetual motion. But when you turn it into a machine by connecting it to a load, it’s the universe that kills it, not friction. [Previous page](https://boards.straightdope.com/t/a-watertight-seal-that-can-also-be-penetrated-by-something-non-water/718658.md?page=1)