What the Creation Museum did to me

[Cyberman]

Exactly my point, although chemistry would still like a word with you. However, now you've switched gears; you began this point by stating that "The size of the universe is necessary, it's not an accident or chance"; in other words you didn't mention life. I repeat, nobody apart from creationists insist that it had to be either of those things.

The Earth was formed 4.5 billion years ago, while the universe itself was still too hot to support life.

No it wasn't. I'm sorry, but it wasn't. It's rather like saying the rate at which paint will dry on your front door is determined only by the temperature of Mars. The temperature of the early proto-Universe dropped, primarily if not solely by expansion, at most several million years after its formation. The conditions that allow the formation of life on individual planets is governed by the temperature at and/or below its surface, which is governed chiefly by the temperature of its star(s); though there are obviously atmospheric considerations as well, greenhouse conditions and all that. Once the temperature of the Universe had dropped below that required for atomic structures to form, it became a non-factor.

Its formation occured at exactly the right time to allow life to start, life started and began evolving 3 billion years ago.

... some 'billion' and a half years after the Earth's formation. If the Earth had formed a 'billion' years earlier, or later, the arrival of self-replicating molecules and hence life would still follow the same basic schedule, all else being equal.

If the universe is 13.7 billion years old, this means that for the first 10 billion years, while it couldn't support life, it was expanding - ultimatly to the size it is now. Thus, the size of the universe is a direct side-effect of its ability to support life.

There is no 'ultimate', at least not yet - the Universe is still expanding. Once the Universe could start forming atomic structures, which clumped together in accordance with physical laws, the first stars began to appear. They progressed through their life cycles towards their end, fusing heavier elements in their cores as they try in vain to remain viable, then faced the inevitable as stars of appropriate mass exploded, seeding nearby molecular clouds with these new, heavier elements, forming new stars with the added bonus of rocky and metallic planet-forming material. Once suitable planets had formed and the system stabilised, as long as conditions were appropriate then life could arise, at least potentially. The size of the Universe at this point had nothing to do with it.

Nope; Occam's Razor is a principle of parsimony, that one should not multiply the number of entities more than necessary; or given competing hypotheses, the one more likely to be correct is the one making the fewer assumptions. It's by no means a fundamental law of nature, more a labour-saving guideline for sorting the potentially fruitful wheat from the potentially inconsequential chaff, and it's hardly infallible.

My point is that it isn't infallible, in fact sometimes it's downright detrimental.

Only when it becomes inconvenient. If one is making far too many assumptions, or multiplying non-essential and unproven entities to the point at which you fall faul of the Razor, then it's a sign to stop and re-evaluate your argument. It may be the case that the points you wish to establish are indeed valid and sound, but Occam's razor provides a useful guideline to correct reasoning.

The problem though is that there is an infinite number of theories which you could "simplify" into any current theory. You can create exactly the same predictions as general relativity, for instance, by complicating the theory further, and further, and further. You may be on the correct path, or you may just be creating unnecessary complications where simplicity should reside, it's difficult to know. You could just be finding interesting coincidences.

Which is where Occam's Razor comes in. See, one of the guiding principles that can make a good theory out of a plain old ordinary theory is that of economy. If I was asked for directions to a place and I gave a route that took you every which way but up before your destination (what we in the Black Country refer to as "going all round the Wrekin"), though it gets you where you want to go, it's clearly a less satisfying route than one that takes you straight there. Some detours may be inevitable, but essentially the most direct route is often the best; though not always, if you're driving then fuel economy may be your guiding principle.

Apart from being simple, another benchmark for a good theory is, believe it or not, elegance - a simple, elegant explanation is often preferred to a tortuous, ugly one.

My example on Pi is that you can't derive the number from physics - despite the fact that it is used in physics.

What, like this you mean?

http://www.youtube.com/watch?v=yJ-HwrOpIps?rel=0

Fairly long video, though the only parts pertinent to this thread are those involving Professor Roger Bowley at his draftboard. Incidentally, I can recommend wholeheartedly subbing to the Numberphile channel, as well as their related ones. You won't be sorry.

What if you had something else absolutely essential in physics, that can be derived no other way except through physics - how would you ever know if your theory on it is actually correct, or, if it is simply a good approximation?

There are plenty of mathematical things essential for physics - Tau for instance, or the Golden Ratio, Phi. Even if they could only be derived by physics, they must still be describable mathematically. There's your independent verification. But let's assume that you are correct, that there is something that can't be verified mathematically and independently. It would still have practical use in the real world. Your red herring of Pi, for instance. for all practical purposes we tend to use the number only to the first half dozen decimal places, yet the number snakes off into infinity. That in no way prevents us from creating circles, and other things that derive from the concept, that are good enough for everyday use.

So mischaracterising a reliance and a knowledge of the workings of physics as "blind faith" doesn't prevent you from accepting what astrophysicists have to say, then?

It's blind faith because it shows belief in a certain unproven scientific discipline. Thus it is perfectly logical for people to reject the notion that life can self-start if they don't have my world-view, and they can still derive their position from physics.

You're still ignoring chemistry in all this obsession with physics, and I'm starting to wonder why. However, to reiterate what I said earlier, there is a vast difference between a working knowledge and reliance - faith, if you really must - in physical laws as they have been described and understood, and blind faith which is faith in something without reason. As a wise philosopher once said, "you can tell me you put your faith in God to put you through the day, but when it comes time to cross the road, I know you look both ways."

Why would you even need to do that? What Georges Lemaître and others before, and contemporary with, him did is take the state of the Universe as we see it today, apply the knowledge that the Universe is expanding, then extrapolate backwards to investigate what the early Universe must have been like and how long ago it was like that. The whole of the rest of the science in that area is based on examining varous aspects of that early state experimentally. For instance, by examining the Universe with a microwave detector, Bell lab technicians Penzias and Wilson discovered - completely accidentally - the long-sought-after cosmic microwave background, essentially the glow from the Big Bang now Doppler shifted down into microwave region of the spectrum. This CMB radiation has since been mapped and can be, in fact has been, investigated by anyone with an interest in it.

Bottom line, for now, would be: while it would be extremely difficult to recreate the Big Bang, though not impossible given the technology and a colossal amount of energy (remember the fuss about the LHC from the perennial doomsayers?), we don't need to.

Okay, why don't you forget everything you just wrote there.

Why should I, just because you did?

Think about this. Supposedly, the laws of quantum mechanics give rise to the laws of chemistry which themselves give rise to the laws of biology which give rise to the laws of evolution. Typical reductionism 101. So what if the big bang is an event which gives rise to the laws of quantum mechanics? That would mean there's something more fundamental to nature upon which the laws of quantum mechanics work. Now, clearly, nobody can work backwards from the laws of chemistry to get the laws of quantum mechanics, so nor can they work backwards from the laws of quantum mechanics to arrive at the fundamental law of nature.

Now perhaps you will explain to the class why you arrive at that conclusion, that we can't work backwards as you suggest? It should be easy, if it's so clear. Be careful not to trip over the glaring non-sequitur you've left lying around.