Pint of snake-oil, anyone?

Basic law of physics - you can't get more energy out of a system than you put in. Indeed, you can't even get the same amount out as you put in (the "entropy" principle). So perpetual motion machines can't work - even less can you have a machine which produces energy from nowhere. This hasn't stopped an Irish firm from insisting that they have developed a machine which does just that - they have called it Orbo and it was supposed to have been unveiled in London a few days ago, but (surprise, surprise) due to "technical difficulties" this has now been delayed until further notice. Watch this space? Suggest you don't bother!