Entropy

I had a course in the university about the philosophy of science.
That's where I heard for the first time (about 1957) about entropy. I was very impressed and adopted as my purpose in life to fight against entropy.
 

Entropy is the measure of disorder and of waste.
It ALWAYS increases. That means that the world and the universe are deteriorating and becoming less orderly.
It will bring about the end of the universe.
Of course I can not really reverse this process, but I am aware of situations where I can resist. Examples are recycling materials, and saving water.

The example of entropy that I often use is that of the garden.
If I don't tend to the garden it will be overrun by weeds.
If I want to keep order I have to invest energy (work).
If I want to improve the garden I have to put in more work.
The garden by itself will never become more orderly or even remain orderly by itself.

There 2 laws of thermodynamics (the movement of heat):

The first is well known - that enrgy can neither be created or destroyed. We can only change the type of energy (for example to change the potential energy of water into electicity).
This law was corrected by Einstein in his famous E=MC squared, which united the conservaton of energy with the conservation of mass.
It is not possible to change the energy without waste.

The second law (entropy) is the measure of this waste.
 

It also relates to unuseable energy - heat when there are not 2 sources with different temperatures. In this case we can use the flow of the heat from the source of higher temperature to the source of lower temperature.
 

Example - The water in the sea has relatively low heat. We can not build a system that will pump the sea water and use part of this heat and return the water back to the sea a little cooler.
 

Entropy also denies the possibility of a perpetual motion machine. All motion has waste energy.

My professor said then that entropy was not known to most of the people. He predicted that in 20 years (i.e. 1977) everyone will know about it. He was wrong.

The famous author, C.P. Snow wrote about realistic and humanistic studies in the universities. The administrators were concerned that engineers would calculate the flow of blood in a river without questioning from where this blood comes.
They added to the requirements of realistic students to take courses in the humanities.
Snow thought that this was ridiculous. There isn't an engineer or scientist that doesn't have a painting on the wall, or doesn't listen to music, or doesn't go sometimes to the theatre.
However most of the people don't even know about entropy.

I once attended a series of 4 lectures in Beer Sheva (about 1962) about the philosophy of science. One and a half of these lectures was devoted to entropy.
 

We know about the arrow of time (from the past to the future) from entropy. The past has lower entropy and in the future it is higher.