TechBrief — تازه‌ترین اخبار فناوری

The ‘Lonely Runner’ Problem Only Appears Simple

Take a group of runners circling a track at unique, constant paces. Answering the question of how many will always end up running alone, no matter their speed, has vexed mathematicians for decades.

Category Theory Illustrated – Orders

Article URL: https://abuseofnotation.github.io/category-theory-illustrated/04_order/

Comments URL: https://news.ycombinator.com/item?id=47813668

Points: 57

# Comments: 11

Amiga Graphics

Article URL: https://amiga.lychesis.net/

Comments URL: https://news.ycombinator.com/item?id=47813566

Points: 51

# Comments: 1

It is incorrect to "normalize" // in HTTP URL paths

Article URL: https://runxiyu.org/comp/doubleslash/

Comments URL: https://news.ycombinator.com/item?id=47813454

Points: 28

# Comments: 15

Once close enough for an acquisition, Stripe and Airwallex are now going after each other

For most of its life, Airwallex and Stripe have mostly operated in different geographies, selling to different buyers. That's changing.

Show HN: I made a calculator that works over disjoint sets of intervals

I've been studying interval arithmetic for the past few weeks and it's a really interesting field because while there is a ton of super interesting research published over the past decades, it has never really gotten the recognition that it deserves, IMO.

One reason for this is that standard interval arithmetic has really poor handling of division by intervals containing zero. If you compute 1 / [-1, 2] in regular interval arithmetic, you get either [-∞, +∞], or you have to say that the operation is undefined. Both solutions are virtually useless. The real answer of course is [-∞, -1] U [0.5, +∞]: i.e. a union of two disjoint intervals.

This is useful because you can confidently exclude a non empty set of the real numbers ([-1, 0.5]) from the set of possible values that you can get by dividing 1 by a number between -1 and 2.

But this definition of interval division yields a value that is not an interval. This is a problem if you want to define a closed arithmetic system, where you can build and evaluate arbitrary expression over interval values.

(This behavior extends to any non continuous function like tan() for example, which is implemented in my project - not without difficulties!)

Well the obvious solution is to define your arithmetic over disjoint unions of intervals. This is the subject of a 2017 paper called "Interval Unions" by by Schichl, H., Domes, F., Montanher, T. and Kofler, K..

This open-source project I made implements interval union arithmetic in TypeScript in the form of a simple interactive calculator, so you can try it out for yourself! The underlying TypeScript library is dependency free and implements interval union arithmetic over IEEE 754 double precision floats (JS native number type) with outward rounding. This guarantees accuracy of interval results in the presence of rounding issue inherent to floating point.

Comments URL: https://news.ycombinator.com/item?id=47812341

Points: 147

# Comments: 25

Casus Belli Engineering

Article URL: https://marcosmagueta.com/blog/casus-belli-engineering/

Comments URL: https://news.ycombinator.com/item?id=47812331

Points: 38

# Comments: 12

Anthropic’s new cybersecurity model could get it back in the government’s good graces

The Trump administration has spent nearly two months fighting with AI company Anthropic. It's dubbed the company a "RADICAL LEFT, WOKE COMPANY" full of "Leftwing nut jobs" and a menace to national security. But some of the ice may reportedly be melting between the two, thanks to Anthropic's buzzy new cybersecurity-focused model: Claude Mythos Preview. […]

Sam Altman’s project World looks to scale its human verification empire. First stop: Tinder.

World, which has raised eyebrows (but also a lot of interest) with its Orb-centered anonymous verification project, is looking to expand its influence via a bevy of new partnerships.

Landmark ancient-genome study shows surprise acceleration of human evolution

Related: Ancient DNA reveals pervasive directional selection across West Eurasia [pdf] - https://news.ycombinator.com/item?id=47791282 (64 comments)

https://x.com/doctorveera/status/2044679999450664967 (https://xcancel.com/doctorveera/status/2044679999450664967)

Comments URL: https://news.ycombinator.com/item?id=47811283

Points: 78

# Comments: 63