The article feels like LLM output, too. (And they don't actually credit an author in the byline.) Is there another source out there that this was based on? Can we read that instead, and skip the extra layer of interpretation/distortion?
Here's an actual article, which you can find by following the DOI: https://www.science.org/doi/10.1126/science.adp6699 -- unfortunately not open access, so it's not feasible for me to check if anything in the HN link is actually true, or just LLM guesses.
I'm a physics professor who regularly teaches about special relativity in my Modern Physics course. I've made a web app for drawing spacetime diagrams (technically, two-observer Minkowski diagrams), which are one of the best ways I know for building intuition about how relativity works. The link points to an introduction to the diagrams, including a brief explanation of some key relativity concepts based on diagram illustrations. (It's meant to be at least halfway understandable to people who haven't studied physics before, though it'll be clearer the more you already know.)
Read through the linked page if you want the basics, or if you're eager to just jump straight in, follow the links to use the main app and play with that. (It has multiple predefined scenarios that you can load, each with a brief explanation, but you can design your own scenarios as well.)
[Aside: I feel really good about the UI I've got for this so far, but my last significant JavaScript work before this project was back in 2005 or so. I've had to learn a LOT.]
I don't pretend to know what this simulation is doing, but for the record, electromagnetism works just fine in 2D. You might be thinking "but magnetic fields are intimately tied to cross products, which only work in three dimensions." But you can set up the equations of electromagnetism just fine either using differential forms or bivector magnetism (https://arxiv.org/abs/2309.02548), and it works in any dimension you'd like. (The cross product version is really a narrow and sometimes misleading special case.)
Possibly related: there are options to "View B" and "View H" in the scalar dropdown, not in the vector one. That may be closely related to the fact that in two dimensions, the magnetic field has just a single component. Whether you describe is as a 2-form or a bivector, the magnetic field is an antisymmetric rank-2 tensor: an antisymmetric matrix. In 3D, that means 3 independent components, and there's a one-to-one mapping to vectors (more or less). But in 2D, an antisymmetric matrix has just one independent component. (And in 4D, it's got six: this is precisely the relativistic electromagnetic field tensor, that in 3D splits into an electric part and a magnetic part. My paper has more details.)
That's exactly right! In my simulation quantities like E and J are vectors with x and y components. In contrast B can be thought of as a vector (or bivector, technically) pointing in the z direction, but since it it only has one component it's simpler to just lump it in with the other scalars. (Aside: Having the simulation be in 2D brings in some interesting toplogical restrictions on circuits).
Thanks but I was thinking more about how fields drop off in 2D space versus 3D space. Simple electrostatic example: consider a 1D string of identical resistors. Voltage drops linearly as you go along this string. Now consider a 2D grid of resistors: voltage does not change linearly anymore if you move between two points (current will move in a more complicated spread-out pattern). So the dimensionality changes how fields behave.
Ah, I see what you're getting at. My instinct here is that (exactly as you've pointed out) fields like E and B will fall off like 1/r instead of 1/r^2, but that all of the qualitative behavior will be basically the same. So I wouldn't trust this simulation to predict the precise behavior of a real circuit (even one whose shape was basically planar), but I suspect that it will behave more or less right.
Looking at the examples, it seems like you can make 1D and 2D strings/grids of resistors here in much the same way you would in a 3D model; you just can't make a 3D grid (or non-planar circuits). My general experience working with and teaching basic circuits is that it's rare that we consider current flow in a genuinely 3D medium: the vast majority of problem-solving examples approximate wires as simple 1D paths for charge to follow, and more careful treatments that talk about where charges accumulate to guide current flow around corners, etc. still almost always illustrate their points in 2D diagrams/examples.
So my impression is that this simulation is likely to give a pretty solid qualitative sense of how these systems work, despite its 2D framing.
That's true, but it's actually a property of the circuit. Any circuit that fits into a 2d space will work the same if simulated in 3d: voltage will still drop off linearly along a 1d resistor.
This is because it's actually an emergent property already in 2d space.
Consider a resistor shaped like a capital letter Z in 2d space, with ground at one end and 1V the other. (Assume also that the Z has a square aspect ratio). The potential along the bar in the middle will initially be equal, because all points on the bar are equidistant from our voltage sources (AKA charges) . But the potential will drop along the arms of the Z. So charge will move along the arms and accumulate at the corners, until there is also a voltage drop along the bar, and ohms law holds.
I think that the previous poster's point is that historical photographs are not in-scope to be added to this project: for example, this project will never include the first known photo of a living platypus (or a living cat, as noted), because such photos existed before this project began. The project collects photos posted to iNaturalist that meet the specified criteria.
It's a cool collection of modern observations of rare or remote species! But the title could also describe an entirely different research project, focused on historical media rather than modern exploration. That could also be very cool.
> ...historical photographs are not in-scope to be added to this project... because such photos existed before this project began.
That contradicts what the website itself says:
> This project is designed to showcase the first known photographs of living specimens of any species. Note that by 'first known' I'm referring to the first known photographs of a species anywhere, not just the first photographs to be submitted to iNaturalist.
> If you see an observation currently in the project that you know is not the first photograph of that species, and you can show the earlier photograph, please do not hesitate to message me and I'll remove it.
Both statements are in fact correct and non-contradictory. It's confusing, but I believe what they mean in the guidelines is that there are two criteria
- The photos must be on iNaturalist
- The photo must be the first photo of the species ever, not just the first photo on iNaturalist
That is, if a species was ever photographed anywhere before, outside of iNaturalist, that species can't be part of the project, ever.
Is there a place to submit an issue with the data? The final map makes it look like a bunch of properties around the neighborhood were purchased by the University between 2004 and 2005. But I recognize one of them (5125 S. Kenwood, just south of Hyde Park Blvd/51st St.) as my first grad school apartment: I lived there throughout the 1998-99 academic year, and it was definitely a university-owned/managed building at the time.
yes, can send an email to [email protected]! there are a chunk of apartments that were very hard to get exact dates for so a few are approx but would love to improve the accuracy.
It's quite possible that there's a real effect here. But while I've only had time to skim parts of the paper, I don't see any indication of whether the authors have accounted for the different norms in different fields when analyzing their data for potentially fraudulent or deceptive behavior.
Just for example, physics papers produced by large international collaborations (e.g. every single paper from the Large Hadron Collider at CERN) routinely have hundreds of authors (e.g. https://www.nature.com/articles/nature.2015.17567): everyone who has made substantial contributions to the design and operation of the facility is listed, as is everyone on the data analysis teams. (My understanding is that people in those specific fields all recognize that "number of citations" is a mostly meaningless number for those involved, and other metrics for productivity are well-known in those communities and routinely used.) I hear that some genomics papers have broken 1000 authors as well.
I could easily imagine that the high end of observed publication numbers and coauthor counts would be dominated by those giant collaborations, even though there is absolutely no attempt to mislead anyone in the process. Can anyone tell from this article to what degree its conclusions might be influenced by this factor?
Accessibility has always been part of DEI. (Certainly it's been a repeated topic of conversation in my campus's Diversity and Inclusion Advisory Board.) And yes, any effort that involves spending time or money to make sure that every person gets to "have some quality of life" falls under this same umbrella. That is literally what people are referring to when they call things "woke".
There is still a difference between actually doing hard work to help disadvantaged and marginalized folks and thinking that “being annoying about one’s pronouns” or “making lists of coworkers who are not woke enough” (both examples are quotes from self-proclaimed social justice activists) solves any problems.
However, thinking that this crop of politicians would take a nuanced stance on anything at all is idiocy at its purest.
Sure! There are always people out there who obsess over linguistic and behavioral purity, and they tend to be very loud. I'm not certain that I've ever met one of them in person. (I've certainly met people who might say (e.g.) "Here's why I've started including pronouns in my email sig," but I think that's not what you're talking about.)
If the current "anti-woke" movement were just about shutting down those obnoxious purists, I think it would be a lot less controversial. But from what I've seen, the political rhetoric (and the associated policy positions now being implemented) strikes just as hard or harder at the folks actually trying to do the hard work.
I don't know how old you are, or whether you ever really knew the web in the prior era that we're talking about. Forgive me if I'm making flawed guesses about where you're coming from.
Back in the day, if I wanted the answer to some specific question about, say, restaurants in Chicago, I'd search for it on Google. Even if I didn't know enough about the topic to recognize the highest quality sites, it was okay, because the sorts of people who spent time writing websites about the Chicago restaurant scene did know enough, and they mostly linked to the high-quality sites, and that was the basis of how Google formed its rankings. Word of mouth only had to spread among deeply-invested experts (which happens quite naturally), and that was enough to allow search engines to send the broader public to the best resources. So yeah, once upon a time, search engines were pretty darn good at pointing people to high quality sites, and a lot of those quality sites became well-known in exactly that way.
I’m old enough that my first paid project was making modifications to a home grown Gopher server built using XCMDs for HyperCard.
My first post was on Usenet in 1994 using the “nn” newsreader
The web has gotten much larger than when it didn’t exist when I started.
But web rings on GeoCities weren’t exactly places to do “high quality research”. You still had to go to trusted sites you knew about or start at Wikipedia and go to citations.
Before two years ago I would go to Yelp. Now I use the paid version of ChatGPT that searches the internet and returns sources with links
Reading through the report, the trouble turns out to be that "devastating disease for humans" is possibly the least of our problems. Even if we had a perfect stockpile of antibiotics that would protect humans against any possible mirror organism (we'd need a wide variety, right?), all of our crops and livestock would be wiped out. All the forests. All the plankton. It would be really bad.
There were easily visible stairs in my level 1 and level 3, but on level 2 I walked around the whole map twice without finding them. Possibly I was just being oblivious, but I eventually tried moving sideways onto what I thought was a slightly odd looking wall segment (I wish I remembered what exactly made me think it looked odd), and suddenly I was on the next level.
I don't know whether somehow the stairs icon just blended in with the walls unexpectedly well and I managed to not recognize it in that context (which seems possible but hard for me to believe, given how much time I spent walking in circles looking for stairs), or whether something odd was going on with the icon being different or distorted for some reason.
