An Layman's Primer on Thermodynamics
To setup the proof for the second proposition, a brief explanation of three foundational precepts to the study of Cosmology is necessary. These precepts are known as Thermodynamics, or the Laws of Energy, Einstein's General Theory of Relativity, which describes gravity, and a model of the Universe predicted by General Relativity known as the "Big Bang."
These scientific laws and theories will provide the proof for the second proposition of the Cosmological Argument.
We can all agree, I hope, that the Universe is filled with energy. Scientists recognize several forms of energy. Some of the more familiar forms are: chemical, nuclear, electrical, and mechanical. Still, regardless of its form, energy is transfered though heat flow, i.e., when heat is transfered from a warmer place to a cooler place.
Why? Because differences in temperature causes heat to flow. The bigger the difference in temperature, the faster heat flows until a uniform temperature is achieved. When temperatures are the same there is no heat flow and, thus, no change in energy.
The study of energy and its characteristics is described by the science and mathematics of Thermodynamics which posits four "laws". Everything scientists know about the operation of the entire Universe, even at the smallest subatomic level, is described by the flow of energy because nothing occurs without an exchange, or transfer, of energy.
Even at the beginning of the Universe, before time began, energy transfers occurred. One might even say the Universe is the result of, and continues to be, the transfer of energy. That's why some scientists consider Thermodynamics to be the ultimate science.
Through experimentation, scientists can mathematically describe 4 laws that govern energy transfer.
The zero law, so named becaused it was discovered after the first law, states there is no heat flow between objects that are the same temperature. We see this in the operation of thermometers. The temperature of a thermometer stops rising when it reaches the temperature of the object under measurement.
Therefore, energy, as heat, flows from a higher temperature to a lower temperature.
The next law, the first law, states that energy can not be created or destroyed; it can only be transfered from one form to another. Thus, in any closed system, (like the Universe!!), the amount of energy is constant.
The second law describes the distribution of energy. When energy (or heat) is transfered, it becomes more dispersed, less organized. An unlit candle, for example, contains potential energy that is organized in one place - the candle. When lit, the energy from the candle is released in the form of heat and moves from a hot place - the candle - to a cooler place - the air. After the candle has been extinguished, the amount of energy once tightly organized in the candle as potential energy, has been dispersed into the air.
No new energy has been created or destroyed in the burning of the candle. Rather, the amount of energy contained in the candle medium has been transfered into another medium, the air.
Scientists describe the tendency of energy to become more disorganized as "entropy." The second law states that entropy always increases in a closed systems (like the Universe!!!) and, because the amount of energy is constant (first law), the exact distribution of energy can be calculated.
Theoretically, it's possible for energy in a closed system to remain the same or even be reversed (energy flowing from cooler to hotter) if the temperature of a system is reduced to absolute zero (–273.15 degreess) where all molecular motion ceases.
However, this is practically impossible to achieve as stated by the third law. If it were possible, for entropy to be reversed, cause and effect would be reversed and we'd experience really strange things, like time flowing backwards; broken objects reassembling themselves and cold objects becoming increasingly hotter.
In summary, the Laws regarding energy are:
1. Energy (heat) flows from hotter place to cooler place.
2. There is a fixed amount of energy in the universe.
3. Energy always moves from a state of organization to state of uniform, but disorganized distribution (entropy).
4. There is no known natural way to reverse entropy.
Because of these laws, it is far more reasonable, in my opinion, to believe that cause and effect has always occurred because some cause must have initiated a transfer of energy to cause the Universe to explode into existence. That's why I maintain that - even at 10 to the minus 43 seconds of the Universe's existence - cause and effect still appy.
Moreover, the law of cause and effect will continue until the Universe no longer exists. According to astrophysicists Fred Adams and Gregory Laughlin, unless some inconceivable event that launched the original Big Bang should recur, the universe will eventually decay, leaving a featureless, infinitely large void.
See the following links for additonal information:
What is Thermodynamics
Answers.com
The Engineering Toolbox
Physics4Kids
The Future of the Universe
posted by Roy Clemmons @ 11:57 PM
7 Comments
7 Comments:
You have presented the standard, layman's take on the laws of thermodynamics reasonably well, although there are a few minor details.
The zeroth law does allow us to reliably compare the temperature of different objects, but the form of the law is somewhat different. The usual form is as follows: If object A is in thermal equilibrium with object C, and object B is in thermal equilibrium with object C, then object A is in thermal equilibrium with object B. (This seems so intuitively obvious, that most people wonder why we bother.)
The first law is indeed simply a statement of the law of conservation of energy.
The second law is a very technical law that is the heart of modern thermodynamics. The statistical nature of the second law bothered many physicists when it was first presented, but experiment and theoretical development has confirmed its essential details many times. There are several different forms of the law that have been proved to be mathematically equivalent. The most common form is:
It is impossible to construct a heat engine that, operating in a cycle, produces no effect other than the absorption of energy from a reservoir and the conversion of that energy into useful work.
In other words, all real heat engines have an exhaust. This is known as the Kelvin-Planck version.
The Clausius version looks completely different but is mathematically equivalent:
Energy never flows spontaneously from an object at a lower temperature to an object at a higher temperature.
A third version uses the thermodynamic state variable entropy. In terms of entropy, all natural processes result in an increase of entropy of the universe.
The third law of thermodynamics is a curious one. It asserts that it is impossible to operate a heat engine in such a way (backwards) so as to produce a reservoir whose temperature is absolute zero. That is, there is no way to pump all of the energy out of a reservoir.
Now, here is the major problem. None of these laws apply to microscopic systems. The second law is a purely statistical law that only applies to large systems with large numbers of particles. The second law only applies to very carefully defined systems whose "microstates" can all be identified. it is just not of much use when applied to the whole universe. Furthermore. local reversals of entropy occur all the time and are perfectly allowed (crystal growth, us).
Violations of the law of conservation of energy also occur all the time at the sub atomic level. Empty space is constantly "bubbling" with massive amounts of energy as pairs of particles pop into existence and then mutually annihilate each other. These "vacuum fluctuations" are what give space itself its character. They are responsible for the values of all of the constants of nature.
Furthermore, the energy of the universe is steadily increasing. As the universe expands, the amount of space increases, so the amount of vacuum energy of space (sometimes called dark energy) also increase. So, in modern physics and cosmology, the law of conservation of energy does not hold for the entire universe. It is still true locally.
And, the laws of thermodynamics only apply to systems in thermal contact with each other in quasi equilibrium states. If systems are moving at high speeds to each other, then relativity makes it more difficult to compare temperatures and impossible to establish thermal equilibrium. The field of relativistic thermodynamics is still developing and there are various theories about how the thermodynamic state variable transform between systems in motion with respect to each other.
You also assert that it "is far more reasonable, in my opinion, to believe that cause and effect has always occurred because some cause must have initiated a transfer of energy to cause the Universe to explode into existence. That's why I maintain that - even at 10 to the minus 43 seconds of the Universe's existence - cause and effect still apply."
I can only repeat what I said in a previous comment. If there is no time, then there can be no cause and effect relationship. Time started at t = 0. There is no before to talk about.
Furthermore, at 10 to the minus 43 seconds, the universe is well within the limits of the Heisenberg Uncertainty principle, where conservation of energy can be violated. This is the realm of quantum mechanics, Grand Unified Theories and quantum gravity. Cause and effect do not apply.
Finally, you say: "According to astrophysicists Fred Adams and Gregory Laughlin, unless some inconceivable event that launched the original Big Bang should recur, the universe will eventually decay, leaving a featureless, infinitely large void."
Not just Adams and Laughlin. The great majority of cosmologists and astrophysicists would agree with this description. According to the Standard Model of fundamental forces, even protons will eventually decay. After about 10 to the 100 power years, all black holes will have evaporated and all "heavy" particles will have decayed, leaving behind a universe filled with a thin "gas" of photons, electrons, positrons, and neutrinos. This universe will continue to expand forever.
Actually, it's my understanding that formation of crystals occurs when enthalpy - the amount of energy in a system capable of doing mechanical work - overcomes entropy. If true, crystal growth isn't an example of reversing entropy but of enthalpy.
And, let me state that I appreciate our dialog, and I hope they continue, but I think your arguing from a weak position. Many of the theories you present - like Dark Matter and ZPE - are highly speculative.
Vaccum fluctuation, or zero point energy, (ZPE), to use one example, is the conversion of pre-existing energy into material form. Scientists speculate but don't have the final answer on this phenomenon.
Dark mater is completely hypothetical unless I've missed a recent announcement.
And, here's the thing. The ZPE universe actually provides an additional argument for the existence of God!
1. If the universe has zero total energy, then, the universe came from and amounts to nothing.
2. The universe was and continues to be exnihilated (created from nothing).
3. But, since the universe is everything physical and material, it must have been caused to begin by something beyond or outside itself.
4. Therefore, the universe must have been exnihilated by an exnihilator.
And, you might be confusing causality with predictability. The Heisenberg Uncertainty principle doesn't indicate that conservation of energy can be violated...it only describes the inability to predict the position and momentum of subatomic particle at any given time.
Just because something is unpredictable doesn't mean it's uncaused.
Even if the first Thermodynamic law is violated, it is only for an extremely short time - Plank time - about 1.855 × 10 to the 43 Planck times. Thus, in the quantum world, the thermodynamic laws can only broken for very small intervals of time that have no effect on the macro world (our world).
Isn't it a bit assumptive to extend the micro world to the macro world? Nowhere do we experience true and lasting violations of the energy laws or the law of cause and effect in the macro world.
Moreover, there's good reason to think that no violation actually occurs in the micro world. In the end, eveything "adds up." The following web site explains why.
http://luttrellica.blogspot.com/2005/10/heisenbergs-uncertainty-principle.html
Finally, while ONE model of the Universe is that it will expand forever (there is at least on other model where the Universe collapses), it will be an inert, energy dead Universe.
I guess my point, here, is that much (not all) of your objections are based on speculative theories that, even if they do become true, actually do no damage to my first propostion.
Thanks for your comments and please continue doing so. Hopefully, others will become interested and do the same.
Okay, I am going to make a couple of quick points
Dark matter certainly exists. We can detect it by its gravity. It may not be exotic.
Dark energy or something like it must exist to explain acceleration.
Vacuum fluctuations determine the structure of our space.
These are not pure speculation.
I agree that this dialog is fun, but it is not getting us anywhere, Roy. I already know all of the "proofs," you already know all of the counterarguments. Unless some other discussants start to participate, I will probably leave it at this. Feel free to continue to post more arguments for.
Tbanks for all your comments, however, keep reading, because the evidence builds.
And, keep in mind I'm not trying to prove absolutely that God exists, only that it is reasonable, even more reasonable, to believe in his existence than not.
Elliot quotes:
"Violations of the law of conservation of energy also occur all the time at the sub atomic level. Empty space is constantly "bubbling" with massive amounts of energy as pairs of particles pop into existence and then mutually annihilate each other."
I believe the second law can only be accurately applied when all participating systems are included in the net energy calculations. Violations may appear to occur all the time but that is probably because the observer is unaware of another component interacting with the system, or interacting in an unknown way.
Einstein said that whenever he was stuck he would go back to thermodynamics and it would set him straight. I don't think we are going to find a hole in thermodynamics even for miniscule matter/energy interactions let alone galactic ones.
I would like to push the topic beyond known science however to include though as a concept on par with matter and energy. A possible counter to the second law might be consciousness on a sufficient scale. Humans already affect the localization and distribution of energy. Extrapolated to a galactic scale, might it be possible that intellegence is a balance for entropy? If so the opposite end of the bang might be foretold: the ultimate contraction of all matter and energy in the universe precipitated by an accumulation of sufficient consciousness. Thus the bang might indeed be a repeating event!
I would like to know more of your ideas on consciousness affecting entropy.
Certainly, I would agree that God, or the Ultimate Consciousness, maintains the integrity of the Cosmological constants and the structure of the spacetime continuum.
However, it seems to me the only way the Universe would contract on itself would be if the Ultimate Consciousness stops thinking about it.
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