Impact of heat on most classical physics problems

In summary, the conversation discusses the topic of heat release in various events and the potential impact it may have on the long term. The person also questions the possibility of a "conservation of system state" law and how the release of heat can trigger unforeseen events. They express their concern about not being able to predict the effects of heat release in daily actions. The other person in the conversation suggests that the second law of thermodynamics explains these concerns and recommends taking courses in Thermodynamics and Heat Transfer to learn more about the topic.
  • #1
DarkFalz
71
0
Hello, i am not an expert in physics (i am a computer scientist) but i have a lot of interest in physics, still there are some questions that i can't seem to answer given my limited amount of knowledge in physics (i had only 1 classical mechanics subject in university, although i try to learn a lot by Reading).

The topic that is troubling me the most pertains to the release of heat in almost every reaction or event in nature. In every single physics class i had, heat release was always ignored, professor simply said stuff like "these two bodies colide, the collision is not perfect because heat gets released, still it is something that we can ignore...", or "the body is sliced in two by the knife, some heat gets release through friction between the knife and the object you are cutting, but in the end the object gets sliced into 2 parts, heat release can be ignored".

Although it may seem intuitive, and i actually accepted the fact that the heat released in most collisions, object falls, and so forth was negligible, i am not starting to question the impact that it may have on the long term. I mean, consider that i am moving myself from one point to another, as in the following figure:

person.png


Heat will inevitably be released throughout my movement, i can't believe that when i move myself from point A to point B my position in space will simply change and that's it, that is not correct since heat will be released, and even when i stop moving and both my particles and the ground particles stabilize and reach 0 momentum, the release heat photons will cause other effects like a raise in temperature or even trigger some bigger event (what if the photons reach a pile of dynamite?). Given such, i concluded that even if i move back to my original position, the system won't be on the initial conditions anymore, since my movement backwards will only cause my body to use more internal energy and produce even more heat, hence i cannot return to the original conditions, something that most professors made seem possible because the problema was handled as a simple linear momentum problem.

Therefore i also wondered, could it be possible that there is also some "conservation of system state" law? Like if the released heat will somehow cause a chain of reactions that will eventually cause the system's original state to be restored through a complex chain of reactions triggered by the released heat? We would then be in the presence of a looping universe. Is that possible? I wonder if it could also be the case that if i dodged a bullet, the bullet would hit something and then cause a chain reaction on the universe that would eventually cause me to suffer the same fate as if i had been hit by the bullet.

I also considered other similar situations, like the collision between two bodies:
bodies_colliding.png


My professors always handled this as a problem of momentum conservation, still that is not enough to fully measure the consequences of the collision due to the heat release, and the same also applies to the falling body problem:
body_falling.png


In this problem things are not as simple as the conservation of mechanical energy, heat is also released and may trigger unforeseen events.

I know i may be getting a bit too much obcessive about this subject, but these doubts seem to have some logical support. It seems weird that whenever i perform any action on my everyday life, like speaking, moving, etc i am releasing heat that may trigger unforeseen events.

Do you physicists ever think about these concerns? How can we cope with a life where we can't predict the effects of our released heat?
 
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  • #2
We can attempt predictions of the consequences by quantifying the heat produced. So for the usual cases where it can be 'safely ignored', you will understand that the triggering of unforeseen consequences (though true) is likely to be insignificant. Simple examples of significant heat produced would include lighting a match, the application of brakes on a car, or drilling a hole in a wall to fix something. You can burn your skin in all the above cases if you are careless. That seems both significant and predictable.
 
  • #3
You've discovered the second law of thermodynamics. In some cases, the loss of heat can be ignored, but in a great many, it cannot and indeed you can never truly return a system to its initial state without an external input of energy, because of it.
 
  • #4
As Russ has indicated, most of the questions you are asking are addressed in a course in Thermodynamics. Also, the dispersion of heat from a source to the environment is covered in a course in Heat Transfer. You seem to be craving the material that these courses include. So, sign up.

Chet
 
  • #5


Dear writer,

Thank you for sharing your thoughts and concerns about the impact of heat on classical physics problems. As a scientist, it is important to question and explore all aspects of a topic, even if it may seem insignificant at first.

You are correct in pointing out that heat is often ignored in classical physics problems, as it is usually considered a negligible factor compared to other forces at play. However, it is important to note that heat is a form of energy and it follows the laws of thermodynamics, which govern the transfer and transformation of energy. So, while it may not be explicitly included in calculations, it is still a part of the overall system and can have consequences in the long term.

The example you provided of your movement from point A to point B is a good illustration of this. While the heat released during this process may seem insignificant, it is still a transfer of energy that can have an impact on the surrounding environment. This is known as the butterfly effect, where small changes in initial conditions can lead to larger, unforeseen consequences. However, it is important to note that the laws of thermodynamics still hold true and the energy released will eventually dissipate and reach equilibrium.

In regards to your question about a "conservation of system state" law, there is no such law in classical physics. However, there are principles such as the conservation of energy and momentum that can help us understand and predict the behavior of a system. As for your concern about dodging a bullet, it is unlikely that the release of heat from the bullet hitting something else would have a direct impact on you, as the heat would dissipate and lose its energy along the way.

In conclusion, while it is important to consider the role of heat in classical physics problems, it is also important to keep in mind that it follows the laws of thermodynamics and will eventually reach equilibrium. As scientists, we must continue to question and explore all aspects of a topic, including the impact of heat, in order to gain a better understanding of the world around us. Thank you for your interest in physics and for raising these thought-provoking questions.
 

Question 1: How does heat affect the behavior of gases?

Heat affects gases by increasing their temperature and causing them to expand. This expansion can lead to changes in pressure, volume, and density. The kinetic energy of gas molecules also increases with heat, causing them to move faster and collide more frequently, leading to a rise in pressure.

Question 2: How does heat impact the motion of particles in a solid?

Heat can cause the particles in a solid to vibrate more vigorously, increasing their kinetic energy and leading to an increase in temperature. This increase in motion can also cause the particles to slide past each other, resulting in the solid expanding. Conversely, a decrease in heat can cause particles to slow down and move closer together, resulting in contraction of the solid.

Question 3: How does heat affect the behavior of liquids?

Heat affects liquids by increasing their temperature and causing them to expand. This expansion can lead to changes in pressure, volume, and density. The kinetic energy of liquid molecules also increases with heat, causing them to move faster and collide more frequently, leading to a rise in pressure. Additionally, heat can also cause phase changes in liquids, such as boiling or evaporation.

Question 4: How does heat impact the behavior of objects in motion?

Heat can impact the motion of objects by causing changes in their speed, direction, and trajectory. This is because heat affects the energy of particles, including those that make up the object. For example, if heat is applied to a moving object, it may increase its kinetic energy and cause it to speed up or change direction. On the other hand, if heat is removed from a moving object, it may slow down or stop.

Question 5: How does heat affect the behavior of electromagnetic radiation?

Heat can affect the behavior of electromagnetic radiation, such as light and infrared radiation. When heat is applied to objects, they emit electromagnetic radiation in the form of heat energy. This is because heat causes the particles in the object to vibrate and emit energy in the form of electromagnetic waves. Additionally, heat can also cause changes in the wavelength and frequency of electromagnetic radiation, altering its behavior and interactions with other objects.

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