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A machine that can sustain motion forever with no energy input is the greatest dream
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in engineering.
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And while many have tried to invent a perpetual motion device, all have failed.
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Will we ever create such a machine and harness free energy forever?
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Short answer?
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Nope.
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Sorry to be a stick in the mud, but a machine that can keep its parts moving forever violates
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some pretty fundamental laws that govern how we think our universe works, and videos on
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the youtubes where people claim to have invented perpetual motion machines are as fake as my
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girlfriend's laughs at my jokes.
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First let's lay out just what we mean when we say a machine that can keep going forever.
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If you created a perpetual motion machine and set it running it would just keep going,
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longer than any of us would live, longer than our sun would live, as long as the entire
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universe itself would live.
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And getting more energy from an outside source is cheating, it should keep running in total
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isolation.
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You're not allowed to power it with light or ambient heat or by leaving money in your
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will for your grandchildren if they give it a push every now and then.
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That's a pretty daunting challenge, but it hasn't stopped people from trying.
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Over the years they've come up with ideas that seem plausible in a sketch on a patent
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application, but less workable in reality.
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A classic example that comes in many variations is the overbalanced wheel.
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No matter if they use fluids or rolling balls or weights on articulated arms, the concept
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is always the same: as the wheel spins, masses on one side move to a wider radius, providing
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more torque and unbalancing the wheel to keep it spinning forever.
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Except the wheel isn't unbalanced.
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There are more weights on one side of the wheel, balancing out the side with fewer weights
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but more torque.
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All that really accomplishes is the center of gravity gets shifted below the axle, making
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the wheel behave more like a pendulum, swinging back and forth before stopping.
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A simple wheel might work better, and while a well made wheel will spin for a long time,
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it will eventually succumb to the great nemesis of all machines: friction.
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If friction could be totally eliminated it would be possible to make a machine that runs
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forever.
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Just give it that initial bit of energy and so long as it doesn't lose any, it'll
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just keep going.
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But no surface is smooth enough to be frictionless.
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Well maybe with the exception of superfluids, but even those are usually supercooled which
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means you'd need to use energy to maintain those low temperatures.
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Mechanical parts will rub, which will turn some of the mechanical energy into heat and
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cause the machine to slow down.
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But while a machine that, once started, can run forever is theoretically possible at best,
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machines that power themselves and generate free energy from nothing are flat-out breaking
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the law.
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Which law?
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The first law of thermodynamics, which is you do not talk about thermo- wait no I'm
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thinking of something else.
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It's the idea that in a closed system, energy cannot be created or destroyed, only converted
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into other forms of energy.
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This is one of those laws on which we've built our entire understanding of the universe,
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anything that would upend it would rewrite multiple scientific disciplines.
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A machine that can keep itself running forever and could power your toaster to boot would
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be more than 100% efficient.
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In other words, it would get something from nothing, and from everything we've ever
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seen ever, that's just not possible.
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So, sorry but every time a video surfaces of some zany wheel that can supposedly spin
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forever, you can rest assured that it's fake.
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At this point the never-ending stream of phony claims about them is the only thing that's
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perpetual.
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So getting your own perpetual motion machine might be a far away fantasy, but getting a
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When you think the future of phone service, think Visible.
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Don't forget to subscribe so you never miss an episode, and check out this video for more
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on the science of engineering.
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One last thing- Despite their impossibility people still keep dreaming up perpetual motion
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machines, to the point that the U.S. patent office flat out refuses to review new patents
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for them.
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Thanks for watching, I'll see you next time.
