I'm not sure what is the message of the author here.
Entropy always increase in closed systems, but we are not talking about a closed system here.
My understanding is that, from the point of view of physics, there is not a reason for not being possible to decrease entropy in the body increasing entropy outside (expending energy).
Also, this is untrue:
"DNA can only be repaired when there is an intact replica to copy".
If you have, for instance, three incorrect copies of a DNA sequence you can compare them in order to get the original sequence. The probability that the copies are damaged at the same point being very small.
This is an argument of christian apologists against evolution as well: "evolution can't be true because it violates the 2nd law of thermodynamics". And this superficially apparent conflict has the same resolution: if energy can be put into a system, it absolutely can have less entropy (or more organization, or more specialization) over time.
> If you have, for instance, three incorrect copies of a DNA sequence you can compare them in order to get the original sequence. The probability that the copies are damaged at the same point being very small.
What are you comparing them to? Sure, we humans can do this in a lab, but in a nucleus, there is only the anti-copy of the other side of the nucleotides. Most eukaryotes just use one of their chromosomes and both are needed for mytosis/myosis. Cells have no way of knowing which copy is the 'correct' one. If there is more than one copy of a DNA strand floating about, cells really do not like this and, in many eukaryotes, will deal with it in a very complicated dance. Prokaryotes/Archea are a wildly different story however.
I think I've read something about a CRISPR experiment failing because cells would correct the changed sequence back to the original...I'll see if I can find it.
> Entropy always increase in closed systems, but we are not talking about a closed system here.
That's the point. If we would fall for the authors interpretation of the second law of thermodynamics humans couldn't exists, as they wouldn't be able to develop in the first place.
Yeah, if we get to the point where humans (or whatever our evolutionary progeny are can't imagine it'd be anything resembling humans today) are still around when that starts happening at 10^28 years which is ~10^17 years from now I'll consider that a job extremely well done as a species/civilization.
Even if you count proton decay as a reasonable mechanism of ageing (which it probably isn't, given that proton decay has never been observed), there is no reason to assume that you can't replace parts with decayed protons with new parts. Humans aren't closed systems.
If protons decay, they don't come back -- the whole reason why the Standard Model lacks proton decay is in how it treats conservation of quark number, since there is no path for a proton's components to a lower-energy state. If that part of the Standard Model is not exactly correct, protons may decay, and the final products will generally be useless for structure-building (e.g. a Georgi-Glashow model proton decays into a pair of gammas and a positron, and it is not energetically favourable for an "anti-decay" back into a proton to occur).
That is, when the protons are gone, so is chemistry, electronics, and so forth.
Of course lots of protons -- likely the vast majority of them -- will end up in stellar collapse remnants anyway, and in the black hole cases you're also not getting the protons back, whether or not they would eventually have decayed.
The rest will be in an extremely tenuous gas and dust far outside the black-hole-dominated remnants of no-longer-star-forming galaxies, and most of that will be neutral hydrogen (and in that case if the proton decays, the residual positive charge will annihilate the electron, so all you have left is light flashing off in several random directions).
"Mining" for new components in the extreme future looks like a losing proposition even without proton decay; with proton decay, you run out of usable material all the sooner.
Entropy always increase in closed systems, but we are not talking about a closed system here.
My understanding is that, from the point of view of physics, there is not a reason for not being possible to decrease entropy in the body increasing entropy outside (expending energy).
Also, this is untrue: "DNA can only be repaired when there is an intact replica to copy".
If you have, for instance, three incorrect copies of a DNA sequence you can compare them in order to get the original sequence. The probability that the copies are damaged at the same point being very small.