Hmmm. In practice, that depends in part on what people would consider evidence and whether or not they would be convinced by the evidence offered. Here:
Planet Earth formed around 4.5 billion years ago. The first primitive forms of life appeared about 4 billion years ago. Natural selection did the rest, giving rise to species increasingly better adapted to their environment. Evidence, as they say, is overwhelming.
Or is it? Imagine planet Earth began its existence a mere 10,000 years ago, with all fossil records in place and carbon-14 well into decaying. From there on, however, evolution proceeded as scientists tell us. How’d you prove this story wrong?
I know it hurts. But hang on there, band aid follows below.
You can’t prove this story wrong because of the way our current theories work. These theories need two ingredients: 1) A configuration at any one moment in time, called the “initial condition,” and 2) A hypothesis for how this initial configuration changes with time, called the “evolution law.”
You can reverse the evolution law to figure out from the present configuration what happened back in time. But there’s no way you can tell whether an earlier configuration actually existed or whether they are just convenient stories. In theories of this type – and that includes all theories in physics – you can therefore never rule out that at some earlier time the universe evolved by an entirely different law – maybe because God or The Programmer assembled it – and was then suddenly switched on to reproduce our observations.
I often hear people argue such creation-stories are wrong because they can’t be falsified, but this makes about as much sense as organic salt. No, they aren’t not wrong, but they are useless.More.
Do read the rest. Our physics color commentator Rob Sheldon reflects on some of the issues that arise in dealing with a topic that raises emotions:
She presents the clockwork view of the universe where Events = Initial Conditions + Deterministic Machinery.
Her point is that the deterministic machinery is independent of time, just like the clock machinery doesn’t care if it is 1 o’clock or 6 o’clock, it works exactly the same. So if you move the hands to change the initial conditions, no one can tell if you wound the clock five-minutes ago or five hours ago. So given the initial conditions of “fossils in the earth + starlight headed our direction” 10,000 years ago or “Big Bang” 13.7 billion years old and no one would know.
Okay, we’ve heard this argument before. What is her metaphysical preference for one position over the other?
She says she has none. She claims to even front anti-realism on occasion. She says she’s a pragmatist, whatever works best. Last week she was in favor of inflation, this week not so much. Why?
She likes initial conditions that are “simple”.
Yet last week she railed against “naturalness” because its only claim to superiority was “Simpler than everyone else”, yet when analyzed, it included an arbitrary definition of “simple”. So is Sabine guilty of the same crime?
She doesn’t say, but I think she tries to quantify “simple” as “information content”. So her contention is that there is more information in a “fossils + starlight” initial condition than in a “massive Big Bang explosion” initial condition. John Wheeler, the cosmologist who almost single-handedly revived general relativity, might not agree. Where did all the structure of the galaxies come from, if the Big Bang was such low information state? he would ask.
But even if we grant Sabine the assumption that lower-information boundary conditions are better, there’s another flaw in her argument. Who says that the machinery is time-independent? Consider that clock. Suppose a cuckoo pops out at 3 o’clock. And that drives the dog crazy, so he scratches the door and wets the rug. But then he feels bad and hides out in his bed until 5 o’clock. Wouldn’t a quick look at the dog tell us whether the clock was running for 5 hours or had the hands changed recently?
Ahh, you say, but we could put the house into the same condition as if all those things had happened. Really? And how are you going to prepare the dog’s state of mind?
And that is my point. For Sabine or anyone else to take a deterministic view of nature, they must also take a deterministic view of consciousness, of mind. And if mind is not deterministic, and it has resisted all attempts at reductionism, then initial conditions do matter.
Let me say it another way. If consciousness and mind matter, then they change the information of the system. Then nothing in the universe is a closed box, a reversible system, a deterministic machine. As we say in thermodynamics, there is no such thing as a perfect heat engine, they all increase the entropy of the system (lose information). In the same way there is no such thing as a dead mind—they all increase the information of the system (lose entropy).
So Sabine, your argument that initial conditions have temporal ambiguity is only true in a frictionless world without people, without minds, without design. Which is to say, without you.
We regret that free Internet grad pub beer and pretzels are not yet available but do keep watching this space.
See also: Supersymmetry is dead but its ghost still haunts particle physics (Rob Sheldon)
Why I am not a young Earth creationist (Denyse O’Leary)