Impossible Science #4
PART 4: IMPOSSIBLE PERPETUAL MOTION
Impossible Science #1, #2,#3,#4
Perpetual Motion machines are designed to move endlessly without application of outside force.
Inventors have created countless variations of such impossible machines . These so-called "perpetual motion" machines have always failed for one reason or another because they are impossible. The reason such machines never work is because they would produce more energy than they consume. Recent developments in Quantum physics teaches us that “empty space” actually contains vast amounts of untapped energy, which has motivated more recent efforts to obtain energy from nothing. Despite their best efforts modern attempts at perpetual motion machines will fail. Work for nothing or what scientists call a "free lunch" will remain forever impossible. Or will it?
A perpetual motion machine
is a device that can do work forever without any external source of energy. Designs for these machines go back almost 1000 years, but these devices are impossible. Work is defined as a force acting through a distance. Some examples of work being done are when accelerating an object, overcoming friction, or gravity. The most common design for a perpetual motion machine is the unbalanced wheel. Hundreds of such devices have been proposed but actual models do not work. Flemish physicist Simon Stevin discovered the relevant fundamental principle of mechanics: A machine that does not change in some way cannot produce work.
Here are some examples of modern "perpetual motion" machines none of which work without cheating.
source gizmodo
The Idea of energy
was introduced by physicists over the last few centuries, some of the most common types are kinetic and potential.
- Kinetic energy is energy an object possesses due to its motion through space. Faster speeds mean greater kinetic energy.
- Potential energy is energy an object possesses due to its position in space. An object that is placed higher in a gravitational field will have a higher potential energy.
- During the flight of a thrown ball with only gravity acting on it, the total mechanical energy (kinetic plus potential) remains constant.
Heat is another form of energy.
Heat was once believed to be an intangible fluid called caloric. Scientists believed that hotter objects contained more caloric than colder ones. Benjamin Thompson, Count Von Rumford, discovered that heat was created by work when he observed the boring of a brass cannon. Julius Mayer and James Joule showed that heat is a form of energy, calculating how much heat corresponds to how much work. The basic unit of energy is called a joule. Forms of energy other than heat include chemical energy, electrical energy, radiant energy, and others not relevant to this topic.
The First law of thermodynamics
Total energy, including all forms, is always conserved in a closed system. Energy may change in form and move from place to place, but it can never be created or destroyed. Conservation of energy is a fundamental law of nature that we call the first law of thermodynamics. Energy conservation is the underlying reason that perpetual motion machines are impossible. No machine can produce energy from nothing. According to quantum mechanics, even supposedly empty space contains energy, called vacuum energy or zero-point energy, that produces small forces and can be used to perform work via the Casimir Effect. Conservation of energy still holds, however, so that vacuum energy cannot be used to create a perpetual motion machine.
Questions to answer in comments:
The Earth has moved in its orbit around the Sun for several billion years without running down.
Why does this not count as a perpetual motion machine?
If an inventor shows you the blueprints for a perpetual motion machine.
What things would you look for to find the flaw in the design?
photo credit
Impossible Science
#1 - THREE TYPES OF IMPOSSIBLE
#2 - ALMOST IMPOSSIBLE
#3 - ABSOLUTE ZERO IMPOSSIBLE
#4 - IMPOSSIBLE PERPETUAL MOTION
if youve never heard of it, you should look up sterling engines
Just read up more on sterling engines, fascinating use of engineering even if it is not technically a perpetual motion machine because it requires heat input.
yeah, people often call it PM though, and there are often schemes involving using the friction or or magnetic induction of electricity to generate heat to provide the input . That said im actually a dumbass because i was thinking of something completely different when i mentioned stirling engines.
I was thinking of a searle effect generator, which is another kind of fake PM machine that has a big, almost cultish following. Its basically a kind of tesla magnet generator, but with extra stages.
@pjheinz
Just limit yourself to inform (It is much less stressful), as soon as you try to educate someone over Internet, you'll find yourself trying to climb barefooted and with no hands a 50 meter cliff.
The power of youtube videos is strong, almost as powerful as the power of ignorance.
Indeed, the Sterling engines require a temperature "difference" (not precisely heat, you can make it work by cooling a part).
This tells you something, the poor folk did't make it to your part that mentions heat as energy.
Great post, upvoted.
VeryNice Mechanism I ❤️ It
Also supported
I do love the idea, but at the same time agree with the orthodox thinking. For now at least!
Perpetual motion machines could only work in a universe where there was no friction or any radiative loss of energy... Since we do not live in that universe, they will continue to be impossible. :)
Great post @pjheinz.
the most cockamamie one I had pitched to me lately was a car running on "brown's gas" - stoichiometric hydrogen and oxygen from electrolysis - so far so good. But then he wanted to use the alternator to do the electrolysis as you drove, replenishing the gas - so all you added was water.
He couldn't understand that even if your engine was 100% efficient, you'd still have to add energy equal to the work done in moving the car around.
My favorite nearly impossible machine is the fully reversible Carnot heat engine. Although a "perfect" engine is only a theoretical construct and cannot exist in the real world. Carnot's design sets an upper-limit on the efficiency any classical engine can have in the conversion of heat into work.
Carnot's is the best heat engine that could ever be built, but never can.
It defines the line between possible and impossible.