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  • A machine that can sustain motion forever with no energy input is the greatest dream

  • in engineering.

  • And while many have tried to invent a perpetual motion device, all have failed.

  • Will we ever create such a machine and harness free energy forever?

  • Short answer?

  • Nope.

  • Sorry to be a stick in the mud, but a machine that can keep its parts moving forever violates

  • some pretty fundamental laws that govern how we think our universe works, and videos on

  • the youtubes where people claim to have invented perpetual motion machines are as fake as my

  • girlfriend's laughs at my jokes.

  • First let's lay out just what we mean when we say a machine that can keep going forever.

  • If you created a perpetual motion machine and set it running it would just keep going,

  • longer than any of us would live, longer than our sun would live, as long as the entire

  • universe itself would live.

  • And getting more energy from an outside source is cheating, it should keep running in total

  • isolation.

  • You're not allowed to power it with light or ambient heat or by leaving money in your

  • will for your grandchildren if they give it a push every now and then.

  • That's a pretty daunting challenge, but it hasn't stopped people from trying.

  • Over the years they've come up with ideas that seem plausible in a sketch on a patent

  • application, but less workable in reality.

  • A classic example that comes in many variations is the overbalanced wheel.

  • No matter if they use fluids or rolling balls or weights on articulated arms, the concept

  • is always the same: as the wheel spins, masses on one side move to a wider radius, providing

  • more torque and unbalancing the wheel to keep it spinning forever.

  • Except the wheel isn't unbalanced.

  • There are more weights on one side of the wheel, balancing out the side with fewer weights

  • but more torque.

  • All that really accomplishes is the center of gravity gets shifted below the axle, making

  • the wheel behave more like a pendulum, swinging back and forth before stopping.

  • A simple wheel might work better, and while a well made wheel will spin for a long time,

  • it will eventually succumb to the great nemesis of all machines: friction.

  • If friction could be totally eliminated it would be possible to make a machine that runs

  • forever.

  • Just give it that initial bit of energy and so long as it doesn't lose any, it'll

  • just keep going.

  • But no surface is smooth enough to be frictionless.

  • Well maybe with the exception of superfluids, but even those are usually supercooled which

  • means you'd need to use energy to maintain those low temperatures.

  • Mechanical parts will rub, which will turn some of the mechanical energy into heat and

  • cause the machine to slow down.

  • But while a machine that, once started, can run forever is theoretically possible at best,

  • machines that power themselves and generate free energy from nothing are flat-out breaking

  • the law.

  • Which law?

  • The first law of thermodynamics, which is you do not talk about thermo- wait no I'm

  • thinking of something else.

  • It's the idea that in a closed system, energy cannot be created or destroyed, only converted

  • into other forms of energy.

  • This is one of those laws on which we've built our entire understanding of the universe,

  • anything that would upend it would rewrite multiple scientific disciplines.

  • A machine that can keep itself running forever and could power your toaster to boot would

  • be more than 100% efficient.

  • In other words, it would get something from nothing, and from everything we've ever

  • seen ever, that's just not possible.

  • So, sorry but every time a video surfaces of some zany wheel that can supposedly spin

  • forever, you can rest assured that it's fake.

  • At this point the never-ending stream of phony claims about them is the only thing that's

  • perpetual.

  • So getting your own perpetual motion machine might be a far away fantasy, but getting a

  • brand new cell provider isn't.

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  • When you think the future of phone service, think Visible.

  • Visible is the new way to think about phone service.

  • $40/mo phone service that's actually $40/mo.

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  • When you think the future of phone service, think Visible.

  • Don't forget to subscribe so you never miss an episode, and check out this video for more

  • on the science of engineering.

  • One last thing- Despite their impossibility people still keep dreaming up perpetual motion

  • machines, to the point that the U.S. patent office flat out refuses to review new patents

  • for them.

  • Thanks for watching, I'll see you next time.

A machine that can sustain motion forever with no energy input is the greatest dream

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永久運動マシンが欲しいのに、まだ手に入らない理由 (Why We Want a Perpetual Motion Machine, But Still Can’t Get It)

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    林宜悉 に公開 2021 年 01 月 14 日
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