W14: The Second Law of Thermodynamics

The Heat Death of the Universe seems to be a logical consequence of the Second Law of Thermodynamics. What do you think about this theory?

Greetings class,

For this week's discussion, we look into the heat death of the universe.

According to Schlitter (2018), the second law of thermodynamics states that any isolated system's entropy always increases. The heat death of the universe is a theory on the final fate of the universe, which suggests that the universe would evolve to a state of no thermodynamic free energy and therefore be unable to sustain the process that increases entropy (Pimbblet, 2015).The 'heat-death' of the universe is when the universe has reached a state of maximum entropy. This happens when all available energy (such as from a hot source) has moved to places of less energy (such as a colder source). Once this has happened, no more work can be extracted from the universe. Since heat ceases to flow, no more work can be acquired from heat transfer. This same kind of equilibrium state will also happen with all other forms of energy (mechanical, electrical, etc.). Since no more work can be extracted from the universe at that point, it is effectively dead, especially for the purposes of humankind.

This concept is quite different from what is commonly referred to as 'cold death.' 'Cold death' is when the universe continues to expand forever. The heat death of the universe will only occur if the universe will last for an infinite amount of time (i.e. there will be no big crunch). It will occur because according to the second law of thermodynamics, the amount of entropy in a system must always increase. The amount of entropy in a system is a measure of how disordered the system is - the higher the entropy, the more disordered it is.

It is sometimes easier to imagine if you think of an experiment on earth. A chemical reaction will only occur if it results in an increase of entropy. Let us imagine burning petrol, we start off with a liquid that contains atoms arranged in long chains - fairly ordered. When we burn it, we create a lot of heat, as well as water vapor and carbon dioxide. Both of these are small gaseous molecules, so the amount of disorder of the atoms in their molecules has increased, and the temperature of the surroundings has also increased.

Now lets think what this means for the universe. Any reaction that takes place will either result in the products becoming less ordered, or heat being given off. This means at some time far in the future, when all the possible reactions have taken place, all that will be left is heat (electromagnetic radiation) and fundamental particles. No reactions will be possible, because the universe will have reached its maximum entropy. The only reactions that can take place will result in a decrease of entropy, which is not possible, so in effect the universe will have died.

-Rolph

I need to reply this classmate with my personal opinion !!!!!