Laws of Thermodynamics

Discussion in 'General Science' started by Wendy, Nov 16, 2008.

  1. Wendy

    Thread Starter Moderator

    Mar 24, 2008
    Courtisy of Wikipedia:

    1st Law - Energy can neither be created nor destroyed. It can only change forms.

    In any process, the total energy of the universe remains the same. It can also be defined as: for a thermodynamic cycle the sum of net heat supplied to the system and the net work done by the system is equal to zero.

    2nd Law - The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.

    In a simple manner, the second law states that "energy systems have a tendency to increase their entropy" rather than decrease it. This can also be viewed as "heat tends to go from hot to cold, and not the other way around. A way of looking at the second law for non-scientists is to look at entropy as a measure of chaos. So, for example, a broken cup has less order and more chaos than an intact one. Likewise, solid crystals, the most organized form of matter, have very low entropy values; and gases, which are highly disorganized, have high entropy values. The entropy of a thermally isolated macroscopic system never decreases. However, a microscopic system may exhibit fluctuations of entropy opposite to that dictated by the Second Law (see Maxwell's demon and Fluctuation Theorem).

    3rd Law - As temperature approaches absolute zero, the entropy of a system approaches a constant minimum.

    In brief, this postulates that entropy is temperature dependent and leads to the formulation of the idea of absolute zero.


    This is a reference for those who won't or don't understand why you can't get something for nothing. Think it will help?

    These are theory only in the same way the threory of electricity is theory. We might discover new wrinkles, but they are a pretty firm foundation for our understanding of the universe.
  2. steveb

    Senior Member

    Jul 3, 2008
    Very nice summary Bill. Personally, I don't think it will help with most of the free energy addicts, but it's worth a try. For myself, I've given up trying to educate them. They seem to be happier believing they live in a world where magic is possible.
  3. studiot

    AAC Fanatic!

    Nov 9, 2007
    First law

    You can't win, you can at best draw

    Second law

    You can't draw, you can only loose

    Third law

    There is a state, known as absolute zero, where you loose your shirt (everything)
    Last edited: Nov 16, 2008
  4. beenthere

    Retired Moderator

    Apr 20, 2004

    1. You can't win.

    2. You must lose.

    3. You will lose.
  5. triggernum5

    Active Member

    May 4, 2008
    And it all translates to the dismal fact that the electrolysis of water won't help improve your gas mileage..:)
  6. Wendy

    Thread Starter Moderator

    Mar 24, 2008
    but it might blow up your carborator. :D
  7. triggernum5

    Active Member

    May 4, 2008
    Another example of unhelpful entropy..:)