Tag: thermodynamics

More on Entropy, but not a fight over it! (yet)

Question from Keisha:

Thanks for “Entropy 101”. It helped me a lot. Are you saying that the sun has an infinite amount of “fuel” ?



Answer by SmartLX:

A lot of fuel, but not an infinite amount.

What the sun has is a vast amount of hydrogen, which burns in constant nuclear fusion and thus fuses together to make helium. It will take about 5 billion years (it’s had 5 billion already) but eventually all the hydrogen will be helium and that specific reaction will no longer occur. The helium will start burning but the reaction will be different and not sustainable, which is why the sun will become a red giant and ultimately shrink to a white dwarf. We’ll all be gone long before then, whether we’ve found a way to escape the solar system or just perished right here.

My point earlier was that as long as the sun burns, it’s an unfathomably huge rate of entropy – “loss of order” – which balances out almost any emergence of order that could possibly happen on Earth. Regardless of the exact mechanics of that process, it’s in no danger of violating the Second Law of Thermodynamics.

The Beginning Ain’t the Be-All and End-All

Question from John:
Universe had a beginning, “proved” by second law of thermodynamics.
Dear Sir, I understand that an argument used by creationists, in favour of a Universe that had a beginning, is that the second law of thermodynamics requires that it will inevitably wind down. In essence, the claim is that the universe can not have been infinite into the past as it would have inevitably already run down. The fact of a purported finite amount of usable energy therefore implies that the universe MUST have had a beginning or else we would not be here now to discuss this. Is there a scientific rebuttal to this claim please?

Answer by SmartLX:
There are two principal possibilities which address the idea of an infinite universe having run down by now, both of which are centered around the concept of renewal.

1. The universe periodically contracts in a Big Crunch before a new Big Bang. This drags together not only all the matter in the universe but all the space and time as well. All the unusable energy lost to the edges of the universe is brought back to the singularity and can be useful once again.
2. The matter and energy in the hypothetical (but currently quite likely-looking) multiverse is infinite. When one universe runs down, countless others are still going and more universes spontaneously start up all the time. No laws of physics are broken by this sudden emergence if the amount of anti-matter that emerges is equal to the amount of matter, because matter and energy are conserved in an equation akin to 0 = 1 + -1.

Creationists often think, as they are told to by people like William Lane Craig, that once they establish that the universe had a beginning the argument is basically sewn up. Even if the above two possibilities are dismissed and you take it as read that the universe began, that it was begun by a god can only ever be an argument from ignorance. Without knowing how it happened, you can’t just assert it was one particular thing without eliminating all other possibilities, even the ones people haven’t thought of yet. The potential for spontaneous emergence from the “quantum foam” suggested by quantum mechanics, for one, ensures for the moment that well-formulated alternatives are out there, and you don’t even have to appeal to the un-thought-of.

Thermodynamics and Anti-Entropic Mechanisms (my most techy title ever)

Question from Simon:
I was debating with a Christian friend about evolution and the genesis of life and I have to admit that he stumped me in regards to thermodynamics. He agrees that you can have a localised reduction in entropy as long as the overall system entropy increases (which is where most of the pro-evolution arguments seem to end) however he argues that to do so, you require some form of mechanism to drive the decrease as spontaneous localised decreases in entropy do not occur either in open or closed systems. Can you offer an explanation which supports or refutes this?

Answer by SmartLX:
Spontaneous localised decreases in entropy (i.e. increases in order) do not require the kind of mechanism you and the creationist are thinking of, only a bit of physical force.
– If you have a jar filled partially with rocks and sand and you shake it randomly for a while, the smaller particles will tend to make their way towards the bottom of the jar while the big ones stay on top, ordering the collection solely through gravity and friction.
– Chemists regularly use a centrifuge to separate heavier elements of a mixture or compound from lighter parts through centripetal/centrifugal force alone.
– Oil and water mixed together will separate vertically to some extent, even if you don’t agitate them. Gravity again, plus surface tension and possibly other parts of fluid dynamics I don’t fully understand.
– A group of small magnets dropped randomly in a bucket will snap together into a structure. Depending on their shape, many of them may join in a very straight line. Iron filings will arrange themselves into beautiful patterns around an electromagnet, and ferrofluid has to be seen to be believed.

There’s a creationist idea that all new order (physical, chemical, linguistic, etc.) requires a mind to create it. You’re up against a more flexible idea that new all order requires a mechanism, whether or not a mind is ultimately behind that, but there’s no more evidence for this idea than for the other. The inorganic forces of this planet (wind, tides, tectonic shift, orbital spin) were what the initial chemicals of life needed in order to come together and form a useful configuration. Once life existed it was capable of exerting its own forces, for good or ill, and evolution took hold through natural selection. We don’t know the details, but there is no discernible problem with the principle, no matter how much creationists would like there to be.

Louis Pasteur on Life

Question from Truk:
Evolution directly contradicts Pasteur’s laws, that state life can only come from life, as well as the laws of thermodynamics. Why does evolution, a flawed theory with more holes in it than a sponge, still stand, when it contradicts proven science?

Answer by SmartLX:
If evolution contradicted proven science, it wouldn’t still stand. That’s the whole point of science: if it’s proven wrong, it changes. The biology departments of the universities of the world don’t have the resources to maintain a massive conspiracy to prop up a bogus theory, but they have the evidence to support a sound one.

Thermodynamics first: you haven’t specified which laws you think evolution contradicts, so I’ll assume you mean the Second Law of Thermodynamics. There are several creationist arguments based on this idea, and I’ve addressed two of them here, here and here. If I haven’t covered your specific objection, comment and tell me what it actually is.

Now for the less run-into-the-ground material. Louis Pasteur only produced one “law”, and even that is only tentatively attributed to him: the Law of Biogenesis, which states that life can only come from other life. Pasteur did make such an observation, whether or not he made it official. The competing hypothesis of the day was spontaneous generation, the idea that life springs from non-life everywhere, all the time. People used to think that a bag of grain would spontaneously generate maggots, for instance. Pasteur examined many apparent examples of this, and in every case discovered that life was somehow getting in from outside and propagating.

Pasteur did not demonstrate, nor could he have, that it’s impossible for life to emerge from non-life in any circumstances. He simply established that it does not happen in everyday life, and that the life all around us is far more connected than people once thought. If genetics had been further along at the time he could have known this for certain, because all known life is genetically related and therefore descended from a single organism, a common ancestor.

This fact has an important implication: all life on earth can be explained by a single ancient event of abiogenesis (literally genesis from non-life). This means it’s to be expected that the circumstances in which abiogenesis can occur are incredibly rare, and might not even exist in the present day. However, given a billion years, half a billion square kilometres of surface area and countless different chemical compounds on this planet, it’s not unreasonable to suppose that the elements of life came together in just the right way, at least once. Living tissue doesn’t contain any element which isn’t also found in non-living material; it is literally made of the things around it.

Abiogenesis isn’t part of the theory of evolution anyway, because that’s only concerned with what life has done since it came about. Even if a god had created the first living thing, evolution could have occurred from then on without the god’s help, producing all the diversity of life from that single organism. This isn’t important to you though, Truk, because you want to establish that at least some part of the process was impossible without divine help, necessitating the existence of the divine. Abiogenesis, while unlikely in any single moment and circumstance, is not so unlikely that it can’t have happened naturally at all, so a god isn’t needed there either. Better keep looking for a spot to force one in.

Thermodynamics (it’s not what you think)

Question from Anon:
Hi,

I’m engaged in a discussion with a Christian friend of mine who has presented this syllogism to me:

“1. Simply put, if there is no external cause of the universe, then the universe is either eternal or self-created.

2. But, it is cosmologically ridiculous and anti-scientific (i.e. against laws of thermodynamics) to propose that the universe is either eternal or self-created.

3. Therefore, the premise that there is no external cause of the universe must be false (i.e. there must be an external cause for the universe’s existence, e.g. God)”

I believe he is applying the law where it can’t be applied, but I’ve never extensively studied science in college so I’m not really sure.

My rebuttal was that the universe was not necessarily a closed system and he responded with this:

“I have to remind you that my academic background has required me to not only understand, but apply, thermodynamics. [He has an engineering degree.] I know what the 2nd Law of Thermodynamics means and it clearly eliminates the concept of an eternal universe. If there is any misunderstanding on my part, it is in what you mean by ‘the law of the universe.’ Further, whether the universe is a closed system or not is irrelevant, since the concept of a closed system is theoretical, i.e. we have never actually observed a closed system.”

Thanks and I hope you can sort this out for me.

Answer by SmartLX:
Well, it’s not the usual creationist argument that evolution breaks the 2nd Law simply by producing order, so at least it’s a change.

He’s got one thing right, the universe is unlikely to be self-created. We don’t know of anything that is, or even what that would mean if it were true. For an entity to be the reason for its own existence would require an exception to the idea that an effect follows its cause. Rather than call this ridiculous, however, I’d just say that time would have had to behave non-linearly near the beginning. It’s strange to consider, but it hasn’t been ruled out as far as I know.

To set up the next option a bit, an eternal universe would need to be one where multiple Big Bangs happen in sequence. We have to work from the scientific fact of the Big Bang to achieve a plausible eternal model, especially after Borde, Guth and Vilenkin successfully ruled out the leading eternal models that didn’t involve singularities.

Your friend’s thermodynamic objection to an eternal universe is that any process that’s already been running forever should have run down by now, because no process is perfectly efficient. There are at least two scenarios in which this is averted (possibilities only, mind you):
– The singularity that immediately precedes each Big Bang reclaims all of the matter and energy in the universe by bringing space itself back to a central point. This includes all of the “lost” energy that radiates from decaying systems and is normally declared unusable, so in the end nothing is truly lost and the universe really is perfectly efficient.
– Extending upon your friend’s response, not even the universe itself is a closed system. It receives energy from an outside source, such as other universes. If there is an infinite number of these as some have hypothesised, they can keep a universe such as ours going indefinitely. (If one takes “universe” to mean everything that exists, in other words the whole multiverse, then the idea is available that it may contain infinite matter and energy, and never have to run down for this reason instead. It’s all a matter of perspective, and to some extent semantics.)

As an afterword on eternal universes, it’s worth asking your friend exactly how he exempts his eternal God from the 2nd Law of Thermodynamics. I hold it to be true that whatever constraints you place on the universe to necessitate a god, you immediately have to break them to allow for the god, usually by way of special pleading.

Moving on to the third option, it’s telling that your friend’s syllogism uses “e.g.” and not “i.e.” to invoke God. God is an example of an external cause, not the only possible one. The alternative suggested by the above is a concurrent or previous universe, which is part of a great many theories out there. I would love to hear your friend’s reasoning that starts from the external cause at the end of the syllogism and arrives at the Christian God, because at a glance it’s far from a logical step. (The following isn’t a scientific argument, but additional universes seem a more plausible thing to posit than a god because at least we know there’s such a thing as a universe. If your 5-acre cabbage patch has been devoured and you find one fat little rabbit in the corner, you don’t suppose that Bigfoot ate the rest; you wonder where all the other rabbits are hiding.)

Finally, there is a fourth option not covered by the syllogism: that the universe simply came into being without being created, that the common straw-man concept of “something from nothing” actually happened. Something like this is put forward in Lawrence Krauss’ new book A Universe from Nothing; specifically, that the precursor to the universe in certain models could be thought of as “nothing”. Even if you don’t accept this as quite the same thing, it at least advances another alternative external cause to compete with God.

Most of the options are essentially still on the table, despite your friend’s attempt at an argument by elimination. Even the option he wants to be left with doesn’t help the case for God very much, if at all.