Freethought & Rationalism Archive

GunnerJ · 03-09-2002, 05:48 AM

Quote:

You've made me out to be some frothing lunatic that believes in magic.

I've snipped out all the martyr-playing and rhetoric about how we like "overwhelming odds" and other such crap. No one ever made you out to be a looney who believes in magic besides yourself. You claim, in essence, that a rock sitting on a table produces heat because "force" is the "same" as "energy." Whne asked where the enrgy comes from, you sidestep with absurd analogies to rocks falling on heads and non sequitir-ious comments about how "gravity keeps planets in orbit." Heat energy does not just spring out of nowhere because of gravity. That is magic.

NOGO · 03-09-2002, 07:59 AM

Corwin
I will revisit the arguement about the rock on the table.

You say that if you put something between the rock and the table it will be crushed.
Example: a peanot.
So you lift the rock and place a peanot on the table and let the rock fall. The rock will crush the peanut.
We all agree. I think? I certainly do.

Now the question is this which energy crushed the peanut?
a) the energy from the earth's gravitational field
b) the energy which you exerted when you lifted the rock off the table.

To answer this question I will propose an analogy.
You have a spring whose natural length is one foot.
If you attach a weight on the spring it will extend to say one and a half feet.
The force of gravity is offset by the spring extending to an appropriate length.
You pull the spring and extend it to two feet and let it go.
What happens?
The spring swings back and oscillates for a while until to comes to rest at one and a half feet.
While it oscillates it consumes energy (kinetic energy) and converts it into heat through friction and possibly, sound. This oscillation can also be used to crush a peanut.
Again, I believe that we can all agree thus far.
Now the question is this. Which energy crushes the peanut in this case?
a) energy from the spring
b) energy which you exerted while extending the spring

In both these cases you can repeat the events and crush as many peanuts as you want.
In both these cases the energy released is the same as the energy that you put in when you lifted the rock or extended the spring.
If you don't lift the rock high enough or if you don't extend the spring far enough then the peanut will not be crushed.

At one and a half feet the system does have some energy which it keeps since it return to this equilibrium.
The energy that crushes the peanut is the energy that you put in while extending the spring or lifting the rock.

To refute this you must show that even if the energy needed to lift the rock or extend the spring is too little to crush the peanut the peanut will be crushed anyway. Then you can theories that some other energy is involved.
Certainly crushing peanut demands quantities of energy which are measurable. No quantity of energy which is too small to measure can crush a peanut.

So conduct an experiment and show that the energy used to lift the rock is too little to crush the peanut yet the peanut is crushed anyway. If you can do this the whole world will be at you feet.

I am still interested in reading some scientific papers (research) that show the gravity exchanges energy.

[ March 09, 2002: Message edited by: NOGO ]</p>

GunnerJ · 03-09-2002, 10:11 AM

Actually, Nogo, I think his point was that if you place a rock on top of something, like, say, and earthworm, the rock will crush it. In this case, the PE from lifting has been negated, or its relevance reduced, by careful placemnt, so only gavitational force is pulling it down.

notto · 03-09-2002, 10:22 AM

Interesting Thread - been awhile since I've seen some of this.

Lets try this example.

I place a floating object in a container of water, seal it, insulate it, measure its temperature.

If what Corwis says is true about pressure creating heat, the temperature of the water should increase (indefinately) if the container is insulated well enough to reduce the heat lost to below the heat created.

Don't think this can happen or else it would be pretty easy to harness this energy from nothing but force and solve all our energy problems.

Am I correct in my example?

tronvillain · 03-09-2002, 11:48 AM

Corwin:

Quote:

Gravity transfers energy. There's nothing magical or supernatrual about this, we simply don't understand exactly HOW it does this yet. The fact that it does, however, is well established. (Or do you have some other magical way for two planetary or stellar bodies to exert enough force on each other for a stable orbit?)

So, the problem comes back to your fundamental misunderstanding of force and energy. The existence of force simply does not imply the transer of energy - it's as simple as that.

Think about a spring: stretch it and attach it to two stable points. How much force does it now exert? F = -kx, where k is the spring constant and x is the displacement from the equilibrium position. Oddly enough, this force neither endlessly produces heat nor uses up energy - potential energy of the system remains constant. Unless the spring deteriorates of course, in which case the force would gradually decay.

Quote:

Exactly HOW this happens will most likely be explained in a theory of quantum gravitation. We don't have this yet. So I can't GIVE you an explanation for it yet.

The question is how gravity acts like a spring that exerts a force of approximately -Gm1m2/r^2. We're not asking you to give an explanation of this. You claim that pressure caused by the force of gravity constantly produces heat, which is not predicted by any of the known laws of physics, and this is what we want you to explain.

tronvillain · 03-09-2002, 11:51 AM

Rimstalker:

Quote:

Actually, Nogo, I think his point was that if you place a rock on top of something, like, say, and earthworm, the rock will crush it. In this case, the PE from lifting has been negated, or its relevance reduced, by careful placemnt, so only gavitational force is pulling it down.

There is no way for a rock to crush something it's placed on top of without decreasing its potential energy. The potential energy from lifting is a product of lifting against the force of gravity, like pulling back on a spring.

Bill · 03-09-2002, 12:04 PM

Quote:

Originally posted by notto:
<strong>I place a floating object in a container of water, seal it, insulate it, measure its temperature.

If what Corwis says is true about pressure creating heat, the temperature of the water should increase (indefinately) if the container is insulated well enough to reduce the heat lost to below the heat created.

Don't think this can happen or else it would be pretty easy to harness this energy from nothing but force and solve all our energy problems.

Am I correct in my example?</strong>

People have been speculating for ages on just how to extract useable energy from gravitational potential energy. I've never heard about this particular device, but I (as do you) see no reason at all why we ought to expect it to produce a positive energy flow.

Yes, I think you have a reasonable example of why pressure doesn't produce heat as a byproduct. However, of course, a CHANGE of pressure will certainly produce either cold and/or heat, as appropriate. Anybody with a good air conditioner or "heat pump" can certainly testify to that fact!

== Bill

NOGO · 03-09-2002, 02:37 PM

Note that a change in pressure is like a change in the length of the spring.

What Corwin is saying is that a system under pressure like a spring extended or gravity are capable of generating energy. I agree they are but not the way Corwin has it.

You need to lift the rock and let it fall, extend the string and let it bounce back, and you need to increase the pressure and then release it. All these examples are equivalent and they all give back the exact same energy it took to change their state from the state of equilibrium to the release state.

It would be nice however if Corwin can answer my last post and in particular give us some references for energy transfers through gravity.

The example of the worm is not really a good one. What you have done is picked a very fragile target. I can remedy this situation by picking a very small rock. Lifting a very small rock to say one inch will not crush the worm. However dropping it from ten feet may. To have a valid experiment you need one where all quantities are measurable. Obviously if you pick a worm and a 50 ton rock then the height of displacement of the rock may be impossible to measure. Obscuring the issue this way does not increase our knowledge.

Coragyps · 03-09-2002, 03:19 PM

Would it now be fair to ask Purple Monkey Dishwasher: "Does that answer your question?"

[ March 09, 2002: Message edited by: Coragyps ]</p>

Corwin · 03-09-2002, 04:17 PM

People.... it's saturday. Do ANY of you have lives?

Nogo.... if there's no energy involved... what FUCKING difference does it make how fragile the object is? Hell even snowflakes will last forever if you don't direct energy at them.

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03-09-2002, 07:59 AM	#152
NOGO Veteran Member Join Date: Dec 2001 Location: Canada Posts: 1,562	Corwin I will revisit the arguement about the rock on the table. You say that if you put something between the rock and the table it will be crushed. Example: a peanot. So you lift the rock and place a peanot on the table and let the rock fall. The rock will crush the peanut. We all agree. I think? I certainly do. Now the question is this which energy crushed the peanut? a) the energy from the earth's gravitational field b) the energy which you exerted when you lifted the rock off the table. To answer this question I will propose an analogy. You have a spring whose natural length is one foot. If you attach a weight on the spring it will extend to say one and a half feet. The force of gravity is offset by the spring extending to an appropriate length. You pull the spring and extend it to two feet and let it go. What happens? The spring swings back and oscillates for a while until to comes to rest at one and a half feet. While it oscillates it consumes energy (kinetic energy) and converts it into heat through friction and possibly, sound. This oscillation can also be used to crush a peanut. Again, I believe that we can all agree thus far. Now the question is this. Which energy crushes the peanut in this case? a) energy from the spring b) energy which you exerted while extending the spring In both these cases you can repeat the events and crush as many peanuts as you want. In both these cases the energy released is the same as the energy that you put in when you lifted the rock or extended the spring. If you don't lift the rock high enough or if you don't extend the spring far enough then the peanut will not be crushed. At one and a half feet the system does have some energy which it keeps since it return to this equilibrium. The energy that crushes the peanut is the energy that you put in while extending the spring or lifting the rock. To refute this you must show that even if the energy needed to lift the rock or extend the spring is too little to crush the peanut the peanut will be crushed anyway. Then you can theories that some other energy is involved. Certainly crushing peanut demands quantities of energy which are measurable. No quantity of energy which is too small to measure can crush a peanut. So conduct an experiment and show that the energy used to lift the rock is too little to crush the peanut yet the peanut is crushed anyway. If you can do this the whole world will be at you feet. I am still interested in reading some scientific papers (research) that show the gravity exchanges energy. [ March 09, 2002: Message edited by: NOGO ]</p>

03-09-2002, 10:11 AM	#153
GunnerJ Banned Join Date: Sep 2001 Location: a place where i can list whatever location i want Posts: 4,871	Actually, Nogo, I think his point was that if you place a rock on top of something, like, say, and earthworm, the rock will crush it. In this case, the PE from lifting has been negated, or its relevance reduced, by careful placemnt, so only gavitational force is pulling it down.

03-09-2002, 10:22 AM	#154
notto Regular Member Join Date: Jul 2001 Location: Minneapolis, MN US Posts: 133	Interesting Thread - been awhile since I've seen some of this. Lets try this example. I place a floating object in a container of water, seal it, insulate it, measure its temperature. If what Corwis says is true about pressure creating heat, the temperature of the water should increase (indefinately) if the container is insulated well enough to reduce the heat lost to below the heat created. Don't think this can happen or else it would be pretty easy to harness this energy from nothing but force and solve all our energy problems. Am I correct in my example?

03-09-2002, 02:37 PM	#158
NOGO Veteran Member Join Date: Dec 2001 Location: Canada Posts: 1,562	Note that a change in pressure is like a change in the length of the spring. What Corwin is saying is that a system under pressure like a spring extended or gravity are capable of generating energy. I agree they are but not the way Corwin has it. You need to lift the rock and let it fall, extend the string and let it bounce back, and you need to increase the pressure and then release it. All these examples are equivalent and they all give back the exact same energy it took to change their state from the state of equilibrium to the release state. It would be nice however if Corwin can answer my last post and in particular give us some references for energy transfers through gravity. The example of the worm is not really a good one. What you have done is picked a very fragile target. I can remedy this situation by picking a very small rock. Lifting a very small rock to say one inch will not crush the worm. However dropping it from ten feet may. To have a valid experiment you need one where all quantities are measurable. Obviously if you pick a worm and a 50 ton rock then the height of displacement of the rock may be impossible to measure. Obscuring the issue this way does not increase our knowledge.

03-09-2002, 03:19 PM	#159
Coragyps Veteran Join Date: Aug 2001 Location: Snyder,Texas,USA Posts: 4,411	Would it now be fair to ask Purple Monkey Dishwasher: "Does that answer your question?" [ March 09, 2002: Message edited by: Coragyps ]</p>

03-09-2002, 04:17 PM	#160
Corwin Veteran Member Join Date: Jan 2002 Posts: 4,369	People.... it's saturday. Do ANY of you have lives? Nogo.... if there's no energy involved... what FUCKING difference does it make how fragile the object is? Hell even snowflakes will last forever if you don't direct energy at them.

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