The entropy of systems

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17 years 10 months ago #17855 by tvanflandern
GD: No off-site links please. They can be present as a supporting reference, but not as a primary source. Your messages here need to be complete enough to understand without the links.

Also, you completely missed LB's point. Which is bigger: a 10 meter rod or a 10 cubic meter sphere? You can't compare lengths to volumes because they do not have the same units. For the same reason, you cannot compare accelerations and speeds.

If you want to be taken seriously in physics and astronomy discussions, you do need to learn the basics. -|Tom|-

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17 years 10 months ago #17856 by GD
Replied by GD on topic Reply from
for a particle to reach the speed of light, it has to be accelerated...

Simple physics.

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17 years 10 months ago #19199 by Larry Burford
[Gd] "for a particle to reach the speed of light, it has to be accelerated... Simple physics."

Yes it does, and yes it is.

[GD] "F=ma if E=ma when “a” is small."
[GD] "When “a” approaches the speed of light, then E=m."
[GD] "(Example: at center of galaxies m=E)."

However:
E can never equal m*a, even if a is small
a can never approach the speed of light, or any other speed
m can never equal E.

Do you understand the significance of units when using math to do do physics? Based on your original incorrect equations and statements, and based on your off-the-point responses to our corrections, I think not.

[tvf (to GD)] "If you want to be taken seriously in physics and astronomy discussions, you do need to learn the basics."

The proper use of units is also simple physics. If you make a serious attempt, you should be able to master it in a few days of surfing the physics tutorial websites.

You can ask questions here if you have any trouble. Most people need to ask a few questions.

Regards,
LB

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17 years 10 months ago #17860 by GD
Replied by GD on topic Reply from
How then, would you write an equation which would define the following:

1) A system which evolves or changes with time.

2) The relationship between acceleration of a system and it's entropy.

3) The variation of energy in the atom with time or acceleration.

4) the variation of energy within a mass.

5) <b>How</b> an atom becomes "energy".

6) The relationship between gravity and entropy.

7) why a system accelerates.

Also, isn't there "master" equation which could combine these three equations and include entropy:
E=1/2mv^2, E=mgh, E=mc^2 ?


I would appreciate your comments on this.


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17 years 10 months ago #15074 by Larry Burford
[GD] "How then, would you write an equation ... "

I would start by understanding about units. Google on "deminsional analysis" and you will find what you need. Here is an example of the sort of thing I'm talking about. In some of the equations you posted earlier you tried to equate force and energy. You should be able to see why this doesn't work by comparing the basic units of each quantity.

Code:
Physical Derived Basic Quantity Units Units -------- ---------- ------------ energy joule (J) kg*m^2/sec^2 force newton (N) kg*m/sec^2

LB

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17 years 10 months ago #17862 by Larry Burford
Leaving off an equation's units is a short cut that experienced scientists and engineers and technicians often take. But this is a shortcut that can bite you.

The less familliar and comfortable you are with dimensional analysis, the more likely it is that you will get bitten. But even those with decades of experience sometimes make mistakes. We lost at least one satellite (going to Mars) because two experienced contractors were using different systems of units, and neither one made the required conversions when sharing data or using shared data. Some other losses may have the same cause.

===

A good understanding of units and their correct manipulation is especially important to kooks. You know, the kind of people that hang out on Websites like this one. As we go about the process of trying get Big Science back on the right track we are likely to need to invent a new unit, or to use an existing unit in a novel way.

Before you can hope to do this you must know how to use and manipulate existing units in ordinary ways.

LB

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