File under "unexpectedly interesting and cool". I'd never seen such good visualizations of magnetic fields before, or of the magnetization process.

  I had downloaded the final Aldus TIFF specifications document, hoping to find the author’s name. However, the name is seemingly written in white text on white paper - making it invisible. What?

Is there an explanation for this that I missed? Was it an Easter Egg left by the author?

Just as a side note, there are two versions of tiff6.pdf (titled “TIFF, Revision 6.0, Final — June 3, 1992”) on the ’net: one[1] that mentions Aldus on the title page and one[2] that mentions Adobe. Only the Aldus one has the invisitext. (Curiously, the metadata says it’s newer.)

[1] SHA256: dbcdf729182937ecff415dfd06806894bf03bfd741291aa3ad7ba45335673def, modify date 2002-05-10, created by Acrobat Distiller 4.05 for Windows, e.g. https://www.itu.int/itudoc/itu-t/com16/tiff-fx/docs/tiff6.pd...

[2] SHA256: 8cb1e1a2226e423ba8b88f57366a30ef1b7ad6109443ebdda072b952739a8d76, modify date 1995-09-14, created by Acrobat Distiller 2.1 for Power Macintosh, e.g. https://download.osgeo.org/libtiff/doc/TIFF6.pdf

I've found a number of hidden items in PDFs masked in the same way. The one that comes to mind immediately are Dell product code names hiding in official spec PDFs. (The PowerConnect 6200-series switches are "Kinnick", for example.) I always assumed it was a lazy redaction method and people weren't necessarily aware the text wasn't actually redacted.

Depends on what format you view it in. For the printed version of the spec, it's sufficient ;)

I believe this is likely true and will become evident in time to most, but not all, carbon based systems.

Immich is supposed to solve this nowadays: https://github.com/immich-app/immich

Immich is the closest thing I've found to Picasa. However, I would just point out you can still download and use Picasa 3.9 on Windows.

TLDR: a user of ChatGPT and weed became convinced they had chanced upon earth shattering discoveries while interacting with the chatbot over weeks/months.

"There are only two industries that refer to their customers as users: illegal drugs and software." - Edward Tufte

About the person: https://en.wikipedia.org/wiki/Vera_Rubin

The observatory: https://en.wikipedia.org/wiki/Vera_C._Rubin_Observatory

I'm no expert, but it seems like the bottom of the pyramid has what looks like natural rock formation, seems like that wouldn't be possible if it was man made ?

New to the internet?

New to people on the internet gaining pointless cred for wasting time and typing up pointless critiques on pointless articles?

No cred gained here :) I was just surprised by the low quality of the article and there were no other comments by the time I got here so I thought I'd write this short critique to warn others, but I think it came across as a shallow dismissal so it didn't add much.

Hello fellow hobby factorizer :)

I wanted to share this small gem of a paper in case it helps you like it's helped me:

"Simple divisibility rules for the 1st 1000 prime numbers": https://arxiv.org/pdf/math/0001012

Meh, most of those aren’t all that helpful. Multiplying the last digit by -17 and adding that to the rest of the number to do a divisibility test for 19? I’d be more inclined to do the right-side reduction which isn’t appreciably different and, if you’re good at keeping some side numbers in working memory can give you the actual quotient if it is divisible which these rules won’t give you.

This is by Hans Moravec, of https://en.wikipedia.org/wiki/Moravec%27s_paradox fame; a student of John McCarthy.