Remember that zany Irish company Steorn, who claimed to have built a working perpetual motion machine that could produce clean, free energy out of a few magnets and some plastic discs? Well, they're back again. Undeterred by the fact that their own hand-picked jury of scientific judges unanimously agreed that the technology didn't work, Steorn has put its Orbo perpetual motion machine out for public display, and set up web feeds through which you can watch the thing in motion. But the demonstration has failed to impress critics, and for good reasons.

Perpetual motion, over-unity, whatever you want to call it, Steorn's Orbo is the latest in a long line of wondrous devices that claim to produce energy out of nothing, in direct violation of one of the best-understood and best-proven laws of physics, the second law of thermodynamics.

So many inventors have claimed they've built such devices over the years that the Royal Academy of Sciences in Paris got sick of wasting time evaluating them and has refused even to read proposals dealing with perpetual motion machines for more than 230 years.

And yet, in the enlightened noughties, Irishman Sean McCarthy has still managed to convince enough marks to manage to keep a company running for more than six years based on the promise of limitless free energy.

The Orbo device claims to use time variance in magnetic fields to keep a disc circling in a little stand, and Steorn says that once it's going, it can continue indefinitely without drawing energy from its surroundings or degrading its components - in fact, if you add up the work done by the Orbo "motor" and the heat put out by its magnetic coils, it's said to generate as much as three times the energy of the initial input.

To demonstrate this (after one previous public demo failed), Steorn has put the Orbo on display in Dublin's Waterways center. Rather than using the all-magnetic version of the device, the company has chosen to use one that's connected to a D-cell battery. The sort of D-cell battery that could probably power a similar low-friction electromagnetic device for days at a time with no magic free energy required.

The machine is operating under no visible load - it's just charging its own battery, if you believe McCarthy - and there's no devices attached to prove that it's making any sort of output at all. The Orbo has even stopped spinning on a few occasions, according to folks who have been watching the technology demonstration through one of three live webcasts at the Steorn website.

An electromagnetic motor that spins for hours at a time - riveting, and not the most convincing thing in the world. If it's a hoax, as most people suggest, you have to wonder why people bother with this sort of thing - is it the attention? Is there some sort of significant financial gain to be made from stringing gullible private investors along with a series of developments and tests that all fail for reasons entirely separate from the fact that the device contravenes the laws of physics?

Then again, we'd all love to believe that there's a magic solution for the looming energy crisis that will save the world using the power of unicorn farts and rainbows, so who are we to tell Steorn's investors that there's no Santa, this close to Christmas?

The demonstration is open to the public between 10am and 7pm from December 15-23 this year, and January 5-31 2010 at the Waterways center in Dublin. Pop in and see the future, folks.