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Science!

Umbran

Mod Squad
Staff member
I have to disagree with that.

Dude. Celestial deferent and epicycle spheres, an another sphere with the stars upon it. Ptolemy's estimates for distance to the various planets were generally off by an order of magnitude and more. It was wrong.

The Antikythera mechanism is an ancient mechanical computer that calculates the positions of the solar system.

Yes, but a doctor can give you willow bark tea to relieve pain, while still working with a model that says your humors are out of balance, and not washing their hands before surgery.

The Antikythera mechanism could only predict the positions of the major planets for which they had long periods of observation, and extrapolate that into the future. They could not predict the motions of celestial objects not originally in their catalogue - like, say comets. It was not, in fact, a general model of motion.

Impressive? Sure. An accurate model? No.
 

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Nikosandros

Golden Procrastinator
Dude. Celestial deferent and epicycle spheres, an another sphere with the stars upon it. Ptolemy's estimates for distance to the various planets were generally off by an order of magnitude and more. It was wrong.
Ptolemy's system purpose was to calculate the motion of the planets as seen from Earth. As such it worked much better than Copernicus system (as Copernicus himself acknowledged). As you note, the huge problem with Ptolemy's system is that it is non-universal. All the calculations work only in the specified case and would need to be re-done from scratch in a different star system or for previously unobserved celestial bodies.

As an aside, the deferents and epicicles are a way to approximate periodic motions by summing uniform circular motions... the same idea behind a Fourier expansion.
 

shawnhcorey

Explorer
The reason the Copernicus system didn't work was because Copernicus had the planets moving in circular orbits at constant speed. It was not until Kepler changed the orbits to ellipses and varied the speed of the planets did the heliocentric system work.
 

Nikosandros

Golden Procrastinator
The reason the Copernicus system didn't work was because Copernicus had the planets moving in circular orbits at constant speed. It was not until Kepler changed the orbits to ellipses and varied the speed of the planets did the heliocentric system work.
Yes, naturally. But Copernicus' system is the beginning of a universal system, one that can give rise to a theory of motion.
 

freyar

Extradimensional Explorer
Wow, I'm kind of sorry I added anything to the thread. How did we get on the Ptolemaic vs Copernican models? That's not really analogous to the muon g-2 measurement.

As others have noted, the shift between Ptolemaic and Copernican/Keplerian/Newtonian systems is not really geocentrism vs heliocentrism. It's that heliocentrism makes use of the more natural language, which in turn aids theoretical understanding, which actually allows you to make predictions (that's why the Newtonian part is so important!). They're two different frameworks. Ptolemy described planetary motions by fiat. Newton actually gave you a set of laws that explain planetary motion.

The current situation with the muon is very different. If the Standard Model prediction and experimental measurement are in fact different*, the resolution doesn't require any sort of change in framework. It just needs a new type of fundamental particle or maybe a few. And there are plenty of other reasons to believe that we need more anyway. It's worth noting that the measurement and prediction are quite close:
experiment: 2.00233184122
vs prediction: 2.00233183620

*See my first post: there are reasons to think the Standard Model might actually predict the experimental results correctly anyway, if we know how to do the math correctly.
 

shawnhcorey

Explorer
Every time someone says the Standard Model is incomplete, I wonder if future generations will think us naïve for using it. After all, that's what we think of the geocentric model.
 

freyar

Extradimensional Explorer
Every time someone says the Standard Model is incomplete, I wonder if future generations will think us naïve for using it. After all, that's what we think of the geocentric model.
If future generations are smart enough to think the Standard Model is "naive," they will know enough about science to know that the Standard Model has a very wide range of validity. They won't think it naive any more than we think it naive to use Newtonian mechanics rather than special relativity to describe the path of a thrown ball, for example.

The Ptolemaic model is very different because it was descriptive only and not explanatory.
 


aco175

Legend
I realized 3 things from this thread;

1: Man, I'm stupid compared to some of you
2: Am I the only one that needed to Google what a muon is?
3: Did I help pay for the 100 million to figure this out? I guess money better spent than some of the other things my government does.
 

Dannyalcatraz

Schmoderator
Staff member
I can say that if you live in any “1st world” country, some of your tax dollars went to subatomic particle research, dierectly or indirectly.

i can also admit that I have heard of muons before I posted this, but didn’t know precisely what they were. I did know, however, that they were not the smallest particles involved in cows’ sound making.
 

freyar

Extradimensional Explorer
I'd say relatively little of your taxes went to this if you're in the US. I'm not sure of the international participation on this experiment, but I'd expect there's some contribution from other countries as well. Most big experiments like this have international participation and at least some international funding. Of course, there are other big experiments drawing other taxes from a variety of nations. But it's pretty small compared to other things, and particle physics, besides being very cool on its own, has plenty of ancillary benefits (like the web).

If you haven't seen anything about how the big magnet in this experiment moved from Long Island to the Chicago suburbs, it was something else. Here's some on it: Fermilab | Muon g-2 | The Big Move | Photo Gallery
 

Umbran

Mod Squad
Staff member
I'd say relatively little of your taxes went to this if you're in the US.

Yeah. As a point of scale: The entire Fermilab budget for 2019 was $547 million dollars. Which sounds like a lot. But, US income tax revenue for 2019 was about $3.5 trillion dollars.

So, for every $10K you paid in income taxes, about one and a half cents went to Fermilab...
 

Henry

Autoexreginated
it’s muons in rotation
they act a little wobble-y
could be polarization
Explains the whole darn thing, you see
mmm, explained the quirk with science
EXPLAINED THE QUIRK, WITH SCIENCE!
and failed the click-bait test, you see...
 


freyar

Extradimensional Explorer
Don't forget the US isn't the only country running these experiments. It is just the first to publish results. Confirmation from other labs is an important part of science.
If you noticed the rest of my post, I did mention that there is international participation in this experiment (looks like participating institutions from at least 6 countries, which is actually a little low compared to the really big experiments) and that there are other big (in some cases much bigger) international experiments.

There aren't actually any other muon g-2 experiments running yet, though there will be one starting in 2024 in Japan if it stays on schedule. To be honest, I think most of the people involved in these experiments want to improve on, not just confirm results. At least that's how my experimental colleagues talk about it.
 


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