Perpetual Motion Device

[SagaLore]

Originally posted by: smack Down
Isn't the universe a perpetual motion device?

No. Some day the universe will reach "heat death".

 

[SagaLore]

Originally posted by: Inspector Jihad
anti-friction is the answer to perpetual motion. A force that acts like the opposite of friction but pushing an object along. yup anti-friction

Yep.

Unfortunately any work derived from an engine is friction, so it is a pointless exercise. You put an object out in space away from any mass or energy, and spin it, and it's own inertia and centripetal/centrifugal forces will keep it spinning forever, assuming the object itself is perfectly rigid with no decay whatsoever. That motion is perpetual. Doesn't do us a bit of good though - if we try and hook up to this object, you will convert potential energy into kinetic energy until the potential energy runs out.

 

[sdifox]

Originally posted by: smack Down

Originally posted by: sdifox

Originally posted by: smack Down

Originally posted by: sdifox
Not exactly. I would say it is a very large motion device, but not infinite nor perpetual, it's just gonna last a long long time.

Well what is going to stop the universe from expanding? Gravity isn't strong enought to cause the universe to colaspe.

http://antwrp.gsfc.nasa.gov/apod/ap960513.html

Looks like slow down has already happened, and well, like I said, it will take a long long time.

from your link:
Our Universe is expanding. Distant galaxies appear to recede from us at ever-increasing speeds

Read to the end, "Conflicting results indicating a substantially slower expansion rate (smaller Hubble constant) are being reported by astronomer Allan Sandage and collaborators. The value of Hubble's constant was recently the subject of a popular public debate titled "The Scale of the Universe 1996: The Value of Hubble's Constant"."

 

[smack Down]

Originally posted by: sdifox

Originally posted by: smack Down

Originally posted by: sdifox

Originally posted by: smack Down

Originally posted by: sdifox
Not exactly. I would say it is a very large motion device, but not infinite nor perpetual, it's just gonna last a long long time.

Well what is going to stop the universe from expanding? Gravity isn't strong enought to cause the universe to colaspe.

http://antwrp.gsfc.nasa.gov/apod/ap960513.html

Looks like slow down has already happened, and well, like I said, it will take a long long time.

from your link:
Our Universe is expanding. Distant galaxies appear to recede from us at ever-increasing speeds

Read to the end, "Conflicting results indicating a substantially slower expansion rate (smaller Hubble constant) are being reported by astronomer Allan Sandage and collaborators. The value of Hubble's constant was recently the subject of a popular public debate titled "The Scale of the Universe 1996: The Value of Hubble's Constant"."

So the basis for your argument is your own source is full of crap when it clearly states expanding and when it says "substantially slower expansion rate (smaller Hubble constant)" it really means contracting.

Do you even know what the Hubbles constant means?
Recession Velocity = Ho*Distance where Ho is Hubbles constant. Unless by "substantially slower expansion rate (smaller Hubble constant)" they mean Ho is less then zero tell me what value of Distance will give no velocity and therefor stop the universe.

I

 

[smack Down]

Originally posted by: SagaLore

Originally posted by: smack Down
Isn't the universe a perpetual motion device?

No. Some day the universe will reach "heat death".

But the galaxies will still be moving away from each other. Of course they won't be galaxies it will be particles smaller then black holes down to atoms(maybe even sub-atomic particles) that has reached the escape velocity relative to everything else.

 

[Eeezee]

Originally posted by: silverpig
This isn't even a very good perpetual motion machine. You'd have loss in the bearings of the wheel at least. It's basically the same as:

1. Take a wheel, roll it across a flat surface. Perpetual motion.
2. Take a really bouncy ball and drop it on a hard surface. Perpetual motion.

Sure, both situations are examples of perpetual motion, but only if you neglect all forms of friction and heat loss just as you are doing.

Increase the magnitude of the electric field and you've overcome all forms of friction. The electric field generates a constant force. Rolling a wheel on a flat surface or letting a bouncy ball fall on a hard surface just gives it some initial energy. The electric field is constantly increasing the energy of the system. There are a lot of reasons why it can't work, and all of them are interesting =p

 

[SagaLore]

Originally posted by: Eeezee
Increase the magnitude of the electric field and you've overcome all forms of friction. The electric field generates a constant force. Rolling a wheel on a flat surface or letting a bouncy ball fall on a hard surface just gives it some initial energy. The electric field is constantly increasing the energy of the system. There are a lot of reasons why it can't work, and all of them are interesting =p

Where are you getting the energy to generate this field?

Did you know that magnetism produces its own form of friction called "hysteresis loss"?

 

[sdifox]

Originally posted by: smack Down

Originally posted by: sdifox

Originally posted by: smack Down

Originally posted by: sdifox

Originally posted by: smack Down

Originally posted by: sdifox
Not exactly. I would say it is a very large motion device, but not infinite nor perpetual, it's just gonna last a long long time.

Well what is going to stop the universe from expanding? Gravity isn't strong enought to cause the universe to colaspe.

http://antwrp.gsfc.nasa.gov/apod/ap960513.html

Looks like slow down has already happened, and well, like I said, it will take a long long time.

from your link:
Our Universe is expanding. Distant galaxies appear to recede from us at ever-increasing speeds

Read to the end, "Conflicting results indicating a substantially slower expansion rate (smaller Hubble constant) are being reported by astronomer Allan Sandage and collaborators. The value of Hubble's constant was recently the subject of a popular public debate titled "The Scale of the Universe 1996: The Value of Hubble's Constant"."

So the basis for your argument is your own source is full of crap when it clearly states expanding and when it says "substantially slower expansion rate (smaller Hubble constant)" it really means contracting.

Do you even know what the Hubbles constant means?
Recession Velocity = Ho*Distance where Ho is Hubbles constant. Unless by "substantially slower expansion rate (smaller Hubble constant)" they mean Ho is less then zero tell me what value of Distance will give no velocity and therefor stop the universe.

I

a different link that might explain the other link better

http://astron.berkeley.edu/~mwhite/darkmatter/hubble.html

last paragraph

For more information on one promising way to measure the departures from the linear Hubble law and measure the mass density of the universe, see the Home Pages of the Supernovae Cosmology Project and the High Z Supernova Team. These teams were the first to report evidence, from the type of plot above, that the expansion of the universe today is being dominated not by matter but by dark energy, causing distant supernovae to appear fainter than they would in a purely matter dominated universe. Recent work at very high redshift has begun to detect the transition to a matter dominated universe, during which time the expansion of the universe decelerated.

Where did you read it said the universe is contracting? The first sentence said it APPEARED to expand at an ever increasing rate but observation by different teams are coming up with varying constant, which did not make sense. The second one is more recent I guess.

 

[smack Down]

Where did you read it said the universe is contracting? The first sentence said it APPEARED to expand at an ever increasing rate but observation by different teams are coming up with varying constant, which did not make sense. The second one is more recent I guess.

I'm not the one claim the universe is going to stop expanding. That was your claim when you said the universe isn't a perpetual motion device. If the universe stops expanding then due to gravity it must colapse. So if the universe isn't colasping, as your links point out, by hubble's law the universe must be a perpetual motion device.

 

[imported_Soldier]

Originally posted by: Eeezee
I already know why this doesn't work, but I thought it was interesting regardless.

So take two very large plates, one with a positive charge and one with a negative charge. In other words, an enormous capacitor.

Inbetween the plates, place a wheel of positive charge. The top half of the wheel is exposed to the electric field, the bottom half is always passing through a hollow spherical conductor.

If you understand E&M, then you know that there is no electric field if you are inside a hollow spherical conductor. So in other words, there is an electric field acting on the top half of the wheel to make it spin. The bottom half is inside the hollow conductor, so there's no electric field and thus no opposing torque.

Wrong of course, but an interesting idea, right?

It wouldnt count as perpetual motion anyway because even if you got it working the capacitor would have to be charged with some energy source. Even the best capacitor will bleed down eventualy...

You might have a go at flywheels and energy storage though if wheel spin gets you thinking....

 

[imported_Soldier]

As far as the side thread on cosmic exspansion I thought I read in the August issue of Astronomy that "inflation" theory supports multiple universes influencing each other in unforeseen ways so its basicaly an unknowable thing as far as the universe ever stopping and/or contracting. I also thought that recent data supports the Cosmic Microwave Background as evidence supporting the Big Bang but only when "inflation" is included. So basicaly we live in one universe of an infinetly vast and unknowable multiverse....Someone also stated that eventualy the universe would fill with a haze of atoms or some such. I believe that recent research indicates the universe will basicaly keep expanding to immeasurable size but galaxy clusters will always be around do to mass and gravity influences. On day the sky will be completely black except for neighboring galaxies in the cluster we are a part of...

 

[sdifox]

Originally posted by: smack Down

Where did you read it said the universe is contracting? The first sentence said it APPEARED to expand at an ever increasing rate but observation by different teams are coming up with varying constant, which did not make sense. The second one is more recent I guess.

I'm not the one claim the universe is going to stop expanding. That was your claim when you said the universe isn't a perpetual motion device. If the universe stops expanding then due to gravity it must colapse. So if the universe isn't colasping, as your links point out, by hubble's law the universe must be a perpetual motion device.

Recent work at very high redshift has begun to detect the transition to a matter dominated universe, during which time the expansion of the universe decelerated.

that is the key to my argument. Remember, our timescale is minuscule compare to the universe, so if they are projecting slow downs, what would stop the deceleration?
Newtonian laws still apply no?

 

[SickBeast]

Originally posted by: Eeezee
I already know why this doesn't work, but I thought it was interesting regardless.

So take two very large plates, one with a positive charge and one with a negative charge. In other words, an enormous capacitor.

Inbetween the plates, place a wheel of positive charge. The top half of the wheel is exposed to the electric field, the bottom half is always passing through a hollow spherical conductor.

If you understand E&M, then you know that there is no electric field if you are inside a hollow spherical conductor. So in other words, there is an electric field acting on the top half of the wheel to make it spin. The bottom half is inside the hollow conductor, so there's no electric field and thus no opposing torque.

Wrong of course, but an interesting idea, right?

Energy cannot be created nor destroyed, and in our atmosphere there will always be things like air causing friction slowing the thing down. Not possible IMO.

 

[PowerEngineer]

Originally posted by: Eeezee
The electric field generates a constant force. Rolling a wheel on a flat surface or letting a bouncy ball fall on a hard surface just gives it some initial energy. The electric field is constantly increasing the energy of the system. There are a lot of reasons why it can't work, and all of them are interesting =p

An electric field produces a constant force, but force alone is not equivalent to energy. Force applied over distance produces work (or power) and work over time is energy. This basic misunderstanding of physics leads to many perpetual motion and "free energy" generators based on electric and/or magnetic fields.

 

[Monkey muppet]

Originally posted by: SagaLore

Originally posted by: Inspector Jihad
anti-friction is the answer to perpetual motion. A force that acts like the opposite of friction but pushing an object along. yup anti-friction

Yep.

Unfortunately any work derived from an engine is friction, so it is a pointless exercise. You put an object out in space away from any mass or energy, and spin it, and it's own inertia and centripetal/centrifugal forces will keep it spinning forever, assuming the object itself is perfectly rigid with no decay whatsoever. That motion is perpetual. Doesn't do us a bit of good though - if we try and hook up to this object, you will convert potential energy into kinetic energy until the potential energy runs out.

You might be on to something - could the centrifugal force of the object in a vacuum be used to power something??

 

[SagaLore]

Originally posted by: Monkey muppet

Originally posted by: SagaLore

Originally posted by: Inspector Jihad
anti-friction is the answer to perpetual motion. A force that acts like the opposite of friction but pushing an object along. yup anti-friction

Yep.

Unfortunately any work derived from an engine is friction, so it is a pointless exercise. You put an object out in space away from any mass or energy, and spin it, and it's own inertia and centripetal/centrifugal forces will keep it spinning forever, assuming the object itself is perfectly rigid with no decay whatsoever. That motion is perpetual. Doesn't do us a bit of good though - if we try and hook up to this object, you will convert potential energy into kinetic energy until the potential energy runs out.

You might be on to something - could the centrifugal force of the object in a vacuum be used to power something??

You will only get out as much energy as it took to spin it up in the first place. Basic premise of the flywheel.

 

[soccerballtux]

Well gravity doesn't ever go away, can't we do something with it?

 

[Fizznizzlenuck]

what you described in not a perpetual device... the conductor requires energy input and therefor E(in) != 0 so it doesnt even come close to even being an atempt at perpetual motion. Was a nice idea though. The closest thing to perpetual motion would probably involve a magnetic coil cooled via liquid hydrogen to about 4 degrees kelvin to eliminate almost all resistance and therefor you can capture a never ending current in the wire without having an input source. Can't really come up with the rest of the machine, but that would be my guess as to what might be involved at coming up with a more efficient one. Eh I'm no expert, all I know is what I have learned like 2 years ago in physics 1 and 2, most of which has been forgotten.

 

[SagaLore]

Originally posted by: soccerballtux
Well gravity doesn't ever go away, can't we do something with it?

We can only take out as much energy from a "falling" object as it took to raise it in the first place.