Wikipedia defines "perpetual motion" as a condition in which an object continues to move indefinitely without being driven by an external source of energy. It then goes on to explain how this would violate the laws of thermodynamics. But these laws are for scientists. Let us look at how to create a perpetual motion machine using the techniques of political spin doctors.
There are two key elements of the definition - motion and energy. Motion is distance moved over a set period of time. Scientists assume that both are constant. But then they tell us that the Universe is expanding, which means things are stretching. There doesn't seem be an estimate of the rate of stretch but it is small enough that we don't notice it from day to day. If things are stretching as they say then it means the metre is gradually getting longer. Therefore it is quite okay to shorten it a little each year. A 3% reduction per year sounds about right. In fact this is only 0.08 mm per day so it won't be noticed by most of us. This puts it in the same ballpark as the expansion of the Universe (not noticeable). Those who need more precise measurements are clever enough deal with the metre shortening by 3% per year.
By changing human laws to redefine the metre in this way, we can turn a 97% efficient machine into perpetual motion.
97% might be a little difficult to achieve and people might complain if we try more drastic reductions of the metre so let's look at the energy side. By way of example let us assume our machine uses electricity. Now scientists like to measure electricity in fancy units like kilowatt hours but what it boils down to is the dollars you pay for that electricity. We could look at the effects of monetary inflation (by coincidence, also around 3%) and see if we can extract some more efficiency from that. But then we might run into some tax deductibility problems.
How about if we define "energy" as electricity that we have to pay for within, say, four years? That solves the problem because we can get a loan. Better still make it a loan where no repayments are required for 50 years. Our grandchildren will have worked out how to pay off the loan by then.
With a shortening metre and a long-term loan for electricity we can easily construct a machine that meets our improved definition of perpetual motion. And so we can solve the world's energy problems with just a little help from the spin doctors.
What if the shrinking metre was real? Length changes at relativistic speeds so why shouldn't it also change over time? Maybe the expansion of the Universe is an illusion and actually everything within it is shrinking so that things further away (and therefore in the more distance past) look like they are moving away from us at higher and higher speeds. After all, the Red Shift is due to the changing wavelength of light and wavelength depends on speed of "recession" which, in turn depends distance and time. A shrinking metre would give the same appearance as a higher speed.
The Big Bang becomes the Big Wither!
See also Carl Sagan's Baloney Detection Kit