The Second Law of Thermodynamics is one of the most basic and unbreakable laws of Nature. It is responsible for the "Arrow of Time". It is responsible for the ingenious work of Stephen Hawking on the entropy of black holes. It is responsible for your glass of water spilling, but not unspilling. It explains why eggs break, why gas diffuses...and why Organic Macroevolution is a fatally flawed theory.
The Second Law states, to put it rather crudely, that "disorder increases with time". That would explain why my room is a wreck. However, Wikipedia gives us a better definition: "the total entropy of a isolated (closed) system always increases over time, or remains constant in ideal cases." Even better is Brian Greene's definition, summerized in the technical jargon of physicists: "The total entropy of a closed system, entropy being the logarithm of the hidden quantum information, as expressed in bytes, increases directly as a function of time, unless acted upon by an outside source."
Essentially, a system with low entropy has high order. More specifically, in a system with low entropy, a rearrangement is more likely to be noticed. For example, if I have a perfectly clean bedroom (I don't - we're speaking hypothetically here) and someone ransacks it, I would probably notice. My books aren't in alphebetical order, my markers aren't arranged in their drawer in order of their wave frequency, etc. etc. Or, the ransacker might have just dumped all my books onto my bed, in which case it's obvious my room has been ransacked! The ransacker rearranged some of the contents of my "system" (my room) and those rearrangements were easily detectable because my room had low entropy. Now, if my room is a total wreck, with clothes laying about, books on the floor, cups strewn about, (now here's a more accurate picture!) and someone rearranges these items - put these cups on the nightstand, scoot this book off the bed, etc. etc. Do you think I'll notice??? No, I probably won't, because that's the normal order of my room - wrecked. Thus, my room in this scenario has high entropy.
A British scientist once said. "If your theory breaks the Second Law of Thermodynamics, I can give you no hope." That's how unbreakable this fundamental law is.
Of course, this law can be broken if there is an outside source acting upon the system. However, the Universe is a closed system (the only outside force that can act upon the Universe is God, but since we're discussing atheism, he is negligible). These statements will become important in the next few paragraphs.
Organic Macroevolution, the gradual change from simple one-cell organisms to complex organisms such as humans, horses, and oak trees over the course of hundreds of millions of years, breaks this fundamental law. It requires something governed by random chance - mutations of the DNA in organisms - to give rise to something complex from something simpler. Due to the more in-depth definition explained using the room situation described above, the more complex an organism (or system) is, the less entropy it has, because an arrangement of its parts is more likely to be noticed.
Thus, humans have less entropy than one-celled organisms, yet, humans (order) are claimed to have arisen from mutations to one-celled organisms (disorder) and their mutated desendants. This is in direct defiance of the Second Law! Adding in hundrends of millions of years doesn't help any.
On a final note, I would like to point out that every time a positive mutation (supposedly) occurred in the evolutionary sequence, the Second Law was broken, because something more complex and thus more ordered was created. I was merely using one-celled organisms and humans to demonstrate this on the large scale of the beginning of the evolutionary tree and the top of it.
Thus, in conclusion, the Second Law of Thermodynamics dicates that disorder will come from order, but Organic Macroevolution says that order arose from disorder. Seeing how the Second Law is 1) a law; and, 2) proven over hundreds of years; you cannot simply throw it away for the sake of Evolution.
Therefore, the Second Law and Organic Macroevolution are in something of a game of chicken. Honestly, I think the Second Law will win...
[This argument has been deemed invalid by the author and retracted. It might serve as a good explaination of the Second Law of Thermodynamics, but it fails as an argument against Organic Macroevolution. See the comments section of Part 4 for an explaination of why this is so. For arguments without such flaws, read the rest of the series. ~GandalftheWizard]
Part 2 will be coming soon.