# Does life violate the 2nd law of thermodynamics?

russ_watters
Mentor
So it's the same energy no matter what the amplitude? ;)
Don't be intentionally coy. It makes me want to help you less.
I thought entropy is a measure of disorder, not a measure of energy.
Entropy has two related definitions - as an engineer, the one most relevant to me (and I think most useful in this thread) is the thermodynamic definition:
"Entropy is a thermodynamic property that is a measure of the energy not available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines."
http://en.wikipedia.org/wiki/Entropy

It would have been a good idea to do some basic research on the subject yourself before asking the question.
Never seen one? Let's stick to 2D then, like water waves in a pond. They can be ordered, or they can be noisy. As can e/m waves. I want to know how their entropy is defined as an equation in terms of the wave forms. It can't be just energy.
I'm not sure that question has any meaning, but if if it does, I can't answer it.
What does this have to do with intelligent life violating the 2nd law: it's an attempt to define entropy for e/m waves, as they leave the sun and fill the universe. "Entropy = number of photons" seems inappropriate for radio waves.
No one said "entropy = number of photons". Do you understand that the energy of a photon is frequency dependent? Do you understand that any complex conflaguration of waves is simply a mixture of individual photons of different discrete frequencies? There is no fundamental difference for a more or less complex radio signal and no real impact on entropy.

No one said "entropy = number of photons"
Phyzhuy did:
The entropy of radiation is approximately equal to the number of photons in the radiation

There is no fundamental difference for a more or less complex radio signal and no real impact on entropy.
Entropy is used in other sciences too, namely computer science where I am coming from, and random data is said to have more entropy than orderly data. One wonders how this bridges with your engineering entropy.

Let's try a thought experiment:

A radio signal is phase-modulated to carry information like this: 1010101010101010. Another is modulated to carry this: 1101011011110111. Both can warm up a receiver equally. So the useful energy they carry is the same.

But if they go to outer space and never hit anything, is the entropy they carry to the cosmos the same?

When we sent Voyager to outside the solar system carrying a plate of human drawings, would the entropy content of the universe be the same as if we sent a blank plate instead?