If you have read the blog post it's a difference between the chemical symbol Ge and Gr, which as I understand is what you would refer to as a "semantic error".
How would the reader know the writer intended Ge instead of Ga? More importantly: why should the burden of figuring that out fall on the reader instead of the writer? Especially when considering that every publication normally has a lot more readers than writers.
In this case, chemistry of Ga and Ge are a bit different, and the Cr compound that was misstated is part of a family of materials that rely heavily on the coordinating chemistry of Ge and its mates in the same period. So it makes more sense. If indeed it were Ga, that would be an interesting compound that probably wouldn't look anything like the material families being discussed by these authors.
I think the reader and the writer share the burden of accurate communication. The reader should ideally come prepared and the writer should provide as best they can. A prepared reader makes quick work of this typo.
Thanks for replying, I understand your original reasoning now in a way that I didn't when I last responded. I was only considering how it would appears to people who don't recognize Gr isn't an element, I agree that it's a syntactic mistake to those who know chemical symbols well.
Versions numbers for LLMs don't mean anything consistent. They don't even publicly announce at this point which models are built from new base models and which aren't. I'm pretty sure Claude 3.5 was a new set of base models since Claude 3.
What do mean by "it's a 1.0" and "3rd iteration"? I'm having trouble parsing those in context.
If Claude 3.5 was a base model*, 3.7 is a third iteration** of that model.
GPT-4.5 is a 1.0, or, the first iteration of that model.
* My thought process when writing: "When evaluating this, I should assume the least charitable position for GPT-4.5 having headroom. I should assume Claude 3.5 was a completely new model scale, and it was the same scale as GPT-4.5." (this is rather unlikely, can explain why I think that if you're interested)
** 3.5 is an iteration, 3.6 is an iteration, 3.7 is an iteration.
Not really. Dirac's trick works entirely at a depth of two logs, using sqrt like unary to increment the number. It requires O(n) symbols to represent the number n, i.e. O(2^n) symbols to represent n bits of precision. This thing has arbitrary nesting depth of logs (or exps), and can represent a number to n bits of precision in O(n) symbols.
Sure, but that was because that was an arbitrary restriction on the problem dirac solved.
Still seems a fairly simple variation once you remove the arbitrary restriction. To the point:
I don't believe for a second that anyone familiar with his solution, asked to make it more bit efficient, would not have come up with this. Nor do I believe they would call it anything other than a variation.
That doesn't make it less cool but I don't think it's like amazingly novel.
I think it's better phrased as "find the best rule", with a tacit understanding that people mostly agree on what makes a rule decent vs. terrible (maybe not on what makes one great) and a tacit promise that the sequence presented has at least one decent rule and does not have multiple.
A rule being "good" is largely about simplicity, which is also essentially the trick that deep learning uses to escape no-free-lunch theorems.
There are two kinds of naturalness principle in physics, sometimes called "technical naturalness" and "Dirac naturalness" respectively.
Dirac naturalness is as you describe: skepticism towards extremely large numbers, end of story. It has the flaw you (and every other person who's ever heard it) point out.
Technical (or t'Hooft) naturalness is different, and specific to quantum field theory.
To cut a long story short, the "effective", observable parameters of the Standard Model, such as the mass of the electron, are really the sums of enormous numbers of contributions from different processes happening in quantum superposition. (Keywords: Feynman diagram, renormalization, effective field theory.) The underlying, "bare" parameters each end up affecting many different observables. You can think of this as a big machine with N knobs and N dials, but where each dial is sensitive to each knob in a complicated way.
Technical naturalness states: the sum of the contributions to e.g. the Higgs boson mass should not be many orders of magnitude smaller than each individual contribution, without good reason.
The Higgs mass that we observe is not technically natural. As far as we can tell, thousands of different effects due to unrelated processes are all cancelling out to dozens of decimal places, for no reason anyone can discern. There's a dial at 0.000000.., and turning any knob by a tiny bit would put it at 3 or -2 or something.
There are still critiques to be made here. Maybe the "underlying" parameters aren't really the only fundamental ones, and somehow the effective ones are also fundamental? Maybe there's some reason things cancel out, which we just haven't done the right math to discover? Maybe there's new physics beyond the SM (as we know there eventually has to be)?
But overall it's a situation that, imo, demands an explanation beyond "eh, sometimes numbers are big". If you want to say that physical calculations "explain" anything -- if, for example, you think electromagnetism and thermodynamics can "explain" the approximate light output of a 100W bulb -- then you should care about this.
She's saying that a different model -- one of the three disagreeing methods for distance ladder measurements -- must be wrong, because they disagree with each other. But if one or more of those models are wrong, then there's not much evidence that the LambdaCDM model is wrong.
Conversely, the hypothesis that LambdaCDM is wrong does nothing to explain why the distance ladder methods disagree.
She clearly isn't saying that any model is infallible, she's just saying that clear flaws with one set of models throw into question some specific accusations that a different model is wrong.
You actually need to pay attention to the details; the physicists certainly are. Glib contrarianism isn't very useful here.
It's the magnetic field that has the arbitrary sign convention. You can't determine the direction of a magnetic field from observations without using the right hand rule.
You don't have to know the sign, you could tell which way the electrons are going.
We tell the aliens: you take all sorts of organics with liquid inside (on earth we typically use a lemon, but other organics will do), and put a stake of element 29 in one side and a stake of element 30 in the other. You then connect them with a length of element 29. Keep trying different organics until you find one that works. They might not have lemons, but there is a good chance that something will eventually work.
You'd need to predefine what the atomic numbers mean and some other things, but we're already assuming some level of communication already being established so this aspect is not far-fetched.
Now arrange the apparatus such that the element 29 side is near you, and the element 30 side is far from you. Additionally, ensure that the wire is up (further from the locally dominant gravitational mass). Now place an election between the "lemon" and the wire. See which way the election moved? That was right (or left, I don't remember).
Edit: if you make the electron move, it will move towards or away from the wire, depending whether it's moving in the same or opposite direction as the electrons in the wire.
Set up whatever apparatus you like, you can always set up its mirror image, and then the electrons are going in the opposite direction. So which is right and which is left?
Remember you haven't yet established with the alien what you mean by right and left, so you won't be able to instruct it to set up your apparatus rather than its mirror image, and of course you can't appeal to the right-hand rule.
This problem has no solution because electromagnetism is right-left symmetric. You would need to use the weak decay (and assume that your alien is made of matter rather than antimatter)
I addressed that. We know which way the electrons flow from the anode to the cathode. I specifically chose this example because of the right-hand rule.
That definition doesn't work well because you can have changes in entropy even if no energy is transferred, e.g. by exchanging some other conserved quantity.
The side note is wrong in letter and spirit; turning potential energy into heat is one way for something to be irreversible, but neither of those statements is true.
For example, consider an iron ball being thrown sideways. It hits a pile of sand and stops. The iron ball is not affected structurally, but its kinetic energy is transferred (almost entirely) to heat energy. If the ball is thrown slightly upwards, potential energy increases but the process is still irreversible.
Also, the changes of potential energy in corresponding parts of two Carnot cycles are directionally the same, even if one is ideal (reversible) and one is not (irreversible).
It's not an exact dupe, but the main part of the content is too similar. You can send an email to dang so he can take a look and give an official opinion hn@ycombinator.com
