First Law of Thermodynamics

Climate of Sophistry

Did you know that there are only two (2) ways to increase a body’s temperature? Indeed, there are only two ways to increase a body’s temperature. One is with work, the other is with heat.

To repeat: There are only two ways to increase a body’s temperature, and the first is with work being done on the body, and the second is with heat being sent to the body. The 1st Law of Thermodynamics captures this. This is all of the 1st Law! All of it. And it is written as

dU = dQ – dW,

where dU is the change in internal energy of a system, dQ is the heat entering the system, and dW the work done by the system.

Next, if we refer to the definition of heat

“Heat is defined as any spontaneous flow of energy from one object to another caused by a…

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2 thoughts on “First Law of Thermodynamics

  1. Come on, Roald, don’t get taken in by that fraud! You’re better than that! Reposting his drivel just allows the alarmists to discount you as someone who doesn’t understand basic scientific principles.

    Joe gets the most basic points of thermodynamics and heat transfer completely wrong, as any basically competent engineer or scientist immediately realizes.

    In this post, Joe states that the equation dU = dQ – dW for a body is a complete statement of the 1st Law. Completely wrong, as a quick check into the opening chapters of any thermo textbook will tell you.

    U, the internal energy of a body, is only one of the forms of total energy E of that body. You must also include the kinetic energy KE, and various forms of potential energy PE (such as gravitational). So to generalize a little more, you could say dE = dU + dKE + dPE = dQ – dW.

    If you throw a ball, you are performing work on the ball, but you are not increasing its internal energy U, but instead its kinetic energy KE and possibly its potential energy PE if you throw it up at all. So his statement is just wrong.

    More seriously for his argument, he claims the “heat only flows from hot to cold” is a 1st Law argument. It is not! It is a (fallacious) 2nd Law argument. If a kilojoule of energy transferred from a cold to a hot body, that would not violate the 1st Law.

    Most importantly, he completely misunderstands the role of the 2nd Law in heat transfer, especially radiative heat transfer. Open any introductory engineering heat transfer text or E&M physics text (nothing to do with climate) and they will start their discussion with the concept of “radiative exchange”, with Body 1 radiating energy toward Body 2 and Body 2 radiating energy toward Body 1. Typically, there is no explicit distinction in the text of which is the hotter and which is the colder body, only that the hotter body will have a greater value for T in the equations, which means that it will radiate more toward the colder body than it receives.

    This understanding goes all the way back to Clausius, “father of the 2nd Law”, who called the transfer of energy from colder to hotter the “ascending transmission of heat” (yes, he had an explicit name for it), and said it just needed to be compensated for with a greater “descending transmission of heat” to be in compliance with the 2nd Law.

    Today, what we call the “heat transfer” between two bodies is the “net” of these two transfers of energy by electromagnetic radiation. This has been well understood for a century and a half, but Joe still does not get it!

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  2. It really doesn’t matter how many roman numbers you put in to your aunt’s garden plants water need equation, the earth’s cold atmosphere can not (NEVER) heat the surface just because dishonest, criminal, rent and grant seeker activists, pretending to be scientists, WANTS IT TO (in order to travel to fancy places to take part in 5 stars hotel vacation paid for by the taxpayers where they have free access to sex slaves and underage boys and girls) ..

    STUDY BLOWS ‘GREENHOUSE THEORY OUT OF THE WATER’ ‘All observed climatic changes have natural causes completely outside of human control’

    “Hence, there are no greenhouse gases in reality – as in, gases that can cause warming,” Nikolov said when asked to explain the paper in layman’s terms ..”

    .. no “greenhouse gases” = No “greenhouse effect” = No “back radiation”!
    Weasel words can not make latent heat from water vapor serve as a rent and grant providing tool for criminals!

    http://www.newscats.org/?p=10386

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