How do you prove that Earth is older than 10,000 years?

Backreaction ^ | Sabine Hossenfelder

[SeekAndFind]

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?

You can’t.

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.

Last week, I gave a talk at the department of History and Philosophy at the University of Toronto. My talk was followed by a “response” from a graduate student who evidently spent quite some time digging through this blog’s archives to classify my philosophy of science. I didn’t know I have one, but you never stop learning.

I learned that I am sometimes an anti-realist, meaning I don’t believe in the existence of an external reality. But I’d say I am neither a realist nor an anti-realist; I am agnostic about whether or not reality exists or what that even means. I don’t like to say science unveils “truths” about “reality” because this just brings on endless discussions about what is true and what is real. To me, science is about finding useful descriptions of the world, where by “useful” I mean they allow us to make predictions or explain already existing observations. The simpler an explanation, the more useful it is.

That scientific theories greatly simplify the stories we tell about the world is extremely important and embodies what we even mean by doing science. Forget all about Popperism and falsification, just ask what’s the most useful explanation. Saying that the world was created 10,000 years ago with all fossils in place is useless in terms of explaining the fossils. If you, on the other hand, extrapolate the evolution law back in time 4 billion years, you can start with a much simpler initial condition. That’s why it’s a better explanation. You get more out of less.

So there’s your band aid: Saying that the world was created 10,000 years ago with everything in place is unfalsifiable but also useless. It is quantifiably not simple: you need to put a lot of data into the initial condition. A much simpler, and thus scientifically better, explanation, is that planet Earth is ages old and Darwinian evolution did its task.

I’m not telling you this because I’ve suddenly developed an interest in Creationism. I am telling you this because I frequently encounter similar confusions surrounding the creation of the universe. This usually comes up in reaction to me pointing out that there is nothing whatsoever wrong with finetuned initial conditions if you do not have a probability distribution to quantify why the conditions are supposedly unlikely.

People often tell me that a finetuned initial condition doesn’t explain anything and thus isn’t scientific. Or, even weirder, that if you’d accept finetuned initial conditions this would turn science itself ad absurdum.

But this is just wrong. Finetuned initial conditions are equally good or bad explanations than not-finetuned ones. What is decisive isn’t whether the initial condition is finetuned, but whether it’s simple. According to current nomenclature, that is not the same thing. Absent a probability distribution, for example, an initial value of 1.0000000[00] for the curvature density parameter is scientifically equally good as an initial value of 0.0000001[00]… because both are equally simple. Current thinking among cosmologists, in contrast, has it that the latter is much worse than the former.

This confusion about what it means for a scientific theory to be useful sits deep and has caused a lot of cosmologists to cook up stories about the early universe based on highly questionable extrapolations into the past.

Take, for example, inflation, the idea that the early universe underwent a phase of rapid expansion. Inflation conjectures that before a certain moment in our universe’s history there was a different evolution law, assigned to a newly invented scalar field called the “inflaton.” But this conjecture is scientifically problematic because it construes up an evolution law in the past where we have no way of testing it. It’s not so different from saying that if you’d roll back time more than 10,000 years, you wouldn’t find planet Earth but god waving a magic wand or what have you.

A bold conjecture like inflation can only be justified if it leads to an actually simpler story, but on that the jury is out. Inflation was meant to solve several finetuning problems, but this doesn’t bring a simplification, it’s merely a beautification. The price to pay for this prettier theory, though, is that you now have at least one, if not several, new fields and their potentials, and some way to get rid of them again, which is arguably a complication of the story.

I wrote in a recent post that inflation seems justifiable after all because it provides a simple explanation for certain observed correlations in the cosmic microwave background (CMB). Well, that’s what I wrote some weeks ago, but now I am not so sure it is correct, thanks in no small part to a somewhat disturbing conversation I had with Niayesh Afshordi at Perimeter Institute.

The problem is that in cosmology there really aren’t a lot of data. There are but a few numbers. It’s a simple story already without inflation. And so, the current status is that I just don’t know whether or not inflation is a good theory. (But check back next month.)

Let me emphasize that the concordance model (aka ΛCDM) does not suffer from this problem. Indeed, it makes a good example for a scientifically successful theory. Here’s why.

For the concordance model, we seek the combination of dark matter, normal matter, and cosmological constant (as well as a handful other parameters) that best fit current observations. But what do we mean by best fit? We could use any combinations of parameters to get the dynamical law, and then use it to evolve the present day observations back in time. And regardless of what the law, there is always an initial state that will evolve into the present one.

In general, however, the initial state will be a mess, for example because the fluctuations of the cosmic microwave background (radiation) are not related in any obvious way to the structures we observe (matter). Whereas, if you pick the parameters correctly, these two types of structures belong together (higher density of matter corresponding to hotter spots in the cosmic microwave background). This match is a great simplification of the story – it explains something.

But the more you try to turn back time in the early universe, the harder it becomes to obey the scientific credo of storytelling, that you should seek only simpler explanations, not more complicated ones. The problem is the story we presently have is already very simple. This really is my biggest issue with eternal inflation and the multiverse or cyclic cosmologies, bounces, and so on and so forth. They are stories, all right, but they aren’t simplifying anything. They just add clutter, like the programmer that set up our universe so that it looks the way it looks.

On some days I hope something scientific will eventually come out of these stories. But today I am just afraid we have overstepped the limits of science.

[SeekAndFind]

ABOUT THE AUTHOR:

Sabine Hossenfelder, aka Bee
Research Fellow at the Frankfurt Institute for Advanced Studies

I am a physicist. More exactly, I am a theoretical physicist. People often wonder what a theoretical physicist does. You might not believe it, but most of the time I think. Sometimes, I scribble funny looking things with a pencil on a notebook. Processes like this usually involve lots of coffee and walking up and down the corridor.

I am working on physics beyond the standard model, phenomenological quantum gravity, and modifications of general relativity. You find more about my research on my homepage.

[VanDeKoik]

I hope she isnt a flat-earther as well.

[Pearls Before Swine]

I hope she isnt a flat-earther as well.

If she is, her relativity and cosmology research must be quite unusual.

[BuffaloJack]

You can’t rely on Carbon-14 dating anymore. The Japanese scientists recently discovered that lightning is hot enough to convert, via thermonuclear fusion, some normal C12 into C14. Thus, the amount of C14 is increasing all the time, so you can’t just look at how much C12 is left, because we no longer have a fixed starting point.

[Disestablishmentarian]

What she is saying is that cosmology is a lot of theory and assumptions based on few facts.

The main “Facts” are the relative velocity of galaxies from Earth (our vantage point) based upon red shift.

The interpretation of red shift has been STRONGLY CHALLENGED by astrophysicist Halton Arp. It has also led to huge contradictions when general relativity is applied, which in turn have led to the MASSIVE FUDGE FACTORS: Dark Matter & Dark Energy.

These very fudge factors, as improbable as they are, were essentially refuted in the recent experiments at CERN which detected the Higgs boson (solidifying the Standard Theory of Particle Physics, but further FALSIFYING the current cosmology fairy tale).

[Bryanw92]

>>with all fossil records in place

God does not lie.

I don’t design universes so I really don’t care if the Young Earthers are right or the Old Earthers are right. But I cannot accept the idea that God would create a false fossil record to confuse us.

TBH, the ending of the Battlestar Galactica reboot is the best origin story for Earth’s human race. ;-)

[Chuckster]

Publish or perish.

[Da Coyote]

The article is solid. Good stuff.
Yes, I also have one of those blasted PhDs.

[mountainlion]

You can’t prove the theory of evolution. You can’t prove how old the earth is. There are so many theories out there that do not agree you can not even guess with a Bill Clinton type of consensus.

[freedumb2003]

>>TBH, the ending of the Battlestar Galactica reboot is the best origin story for Earth’s human race. ;-)<<

Actually the “B Ark” feels right to me.

And I agree that “God the Trickster” is a very cynical idea.

[SkyDancer]

Dig down and count the rings?

[PLMerite]

"How do you prove that Earth is older than 10,000 years?"

Sorry.

[Alberta's Child]

Fields of study like cosmology, astronomy, and even meteorology here on earth are probably best described as “quasi-science” because it’s impossible to test most theories under controlled conditions that you need for a legitimate scientific method.

[wbarmy]

God would create a false fossil record

God did not create a fossil record, the flood did.There is even some evidence in Mt St Helens that fossils can form rather rapidly.

And there is the blood still in T-Rex to show that it happened not to long ago.

[ex91B10]

>>People often wonder what a theoretical physicist does. You might not believe it, but most of the time I think.<<

Didn't Fermi contemplate splitting an atom while standing at a crosswalk?

That's what I've heard.

Those that can do DO, others...

[humblegunner]

And there is the blood still in T-Rex to show that it happened not to long ago

You have to know that is just plain retarded.

[MasonGal]

Bookmarking this for later. (My husband and I had a conversation about some of this just the other day.)

[Bryanw92]

>>There is even some evidence in Mt St Helens that fossils can form rather rapidly.

I know. I took that class at Liberty University about 5 years ago. The ICR research is pretty interesting, but they still cherry-pick as much on the geological Uniformitarianism vs Catastrophism battle as the Darwinists do on the biological Evolution vs Creation battle. They also throw out ID too easily.

[BenLurkin]

Is this satire?

[Dr. Ursus]

The article or the posts?