Too good to be true?

[Spacecadet]

It was an example where an infinitesimal small energy input, arbitrarily close to zero, allows an infinite distance to be travelled for an infinite period passing through an infinite number of points in-between.

Still takes energy... its getting boring now

Yes, in practise it is difficult to attain, I never stated otherwise. You try to minimise losses and that minimum is zero.

not difficult, impossible.. all you can do is minimise

Strictly speaking energy, like speed, is relative so the object could have any amount of kinetic energy. I think you mean it takes energy to accelerate, but again that's not true as you could see if you read that link I gave on the gravity train, or if you drop something.

Energy is not relative. Potential energy can be relative, although thats usually refered to as a potential difference.
Gravity trains and dropping something require potential energy, same as going downhill.

I'm going to stop now, this is pre-GCSE level physics

[TimberWolf]

Energy is not relative. Potential energy can be relative, although thats usually refered to as a potential difference.
Gravity trains and dropping something require potential energy, same as going downhill.

I'm going to stop now, this is pre-GCSE level physics

Kinetic energy is relative. See any physics book or http://en.wikipedia.org/wiki/Kinetic_energy
"Thus kinetic energy is a relative measure and no object can be said to have a unique kinetic energy".

Gravity is a conservative force, meaning total energy is conserved when something falls and returns to the same height, or alternatively when something is raised and dropped. No energy need be expended in moving down and up to the same height, or to another position at the same height.

I'm going to stop now, this is pre-GCSE level physics

Pre-Newton actually. They really did think as you describe until Galileo, i.e. that moving bodies require a force to keep them moving. Now we know it doesn't take energy to get from A to B.

[Spacecadet]

Kinetic energy is relative. See any physics book or http://en.wikipedia.org/wiki/Kinetic_energy
"Thus kinetic energy is a relative measure and no object can be said to have a unique kinetic energy".

my bad, i should have consultated the great wiki first... doesn't excuse your other attempts to state that a perfect "perpetual motion" machine is possible

Gravity is a conservative force, meaning total energy is conserved when something falls and returns to the same height, or alternatively when something is raised and dropped. No energy need be expended in moving down and up to the same height, or to another position at the same height.

In a frictionless environment yes, is a frictionless environment possible? in space yes, on earth no
secondly, to stop what ever you want to move bouncing up and down in gravity you need to exert a force which mean expending energy

Pre-Newton actually. They really did think as you describe until Galileo, i.e. that moving bodies require a force to keep them moving. Now we know it doesn't take energy to get from A to B.

you are an idiot, how many times do i have to say... its getting something moving and then stopping it that takes the energy. Anything can float around for infinity in space once its already been set in motion.

[TimberWolf]

my bad, i should have consultated the great wiki first... doesn't excuse your other attempts to state that a perfect "perpetual motion" machine is possible

Any physics book would tell you the same, also notice the V in 0.5 M V^2. Regarding perpetual motion machines, getting from A to B, where both are at the same potential doesn't require work to be done. Doesn't prevent it either. Perpetual motion machines must do work to qualify for the title.

In a frictionless environment yes, is a frictionless environment possible? in space yes, on earth no[

secondly, to stop what ever you want to move bouncing up and down in gravity you need to exert a force which mean expending energy

Please read the article on the gravity train. Alternatively think of a very slippery roller coaster.

you are an idiot, how many times do i have to say... its getting something moving and then stopping it that takes the energy. Anything can float around for infinity in space once its already been set in motion.

Did you try dropping something?

[Xenophon]

ENOUGH

[Advocate]

ENOUGH

WHS

[DimPrawn]

[Spacecadet]

Did you try dropping something?

arrgghhh thats downhill

to get a stationary object from point A to point B with no difference in height and again be stationary (and remain stationary) will always need some sort of energy transfer.

Stop talking about perfect systems (frictionless travel on a surface is impossible to achieve except under unique conditions which themselves take lots of energy to attain) and systems where although there may be motion is due to natural oscillations in the system - ie anything in a perpetual freefall (ie orbiting bodies, or the gravity train)

Even in the perfect vacuum of space, if there was such a place where there was no gravitational forces, to get an object to move between 2 points of YOUR choosing is going to take energy.

[TimberWolf]

arrgghhh thats downhill

to get a stationary object from point A to point B with no difference in height and again be stationary (and remain stationary) will always need some sort of energy transfer.

Yes, potential and kinetic energy transfer. Total mechanical energy stays the same.

Stop talking about perfect systems (frictionless travel on a surface is impossible to achieve except under unique conditions which themselves take lots of energy to attain) and systems where although there may be motion is due to natural oscillations in the system - ie anything in a perpetual freefall (ie orbiting bodies, or the gravity train)

I'm talking about what's possible in theory, not in practise. As I already said, before you appeared, that in practise there is great deal of inefficiency (I think I said cars is carp). In practise you can only approach what's possible in theory. By using a really slippery road in a tunnel evacuated of air for instance and a light transportation device. This might not be practicable but could in theory have great efficiency.

Even in the perfect vacuum of space, if there was such a place where there was no gravitational forces, to get an object to move between 2 points of YOUR choosing is going to take energy.

Again, I refer you to the Gravity Train first examined by Hook and described to Newton. I don't know what Newton thought about it. Personally I think a slippery flat surface (or even magnetically levitated surface, etc) would be equally as good in practise, but that's not the point.

[Xenophon]

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