Show newer
R. A. Dehi boosted

I really can’t believe how far #3dprinting has come since I started with my first #reprap. I’m printing this #DarkSaber and the QUALITY coming out of a $700 #Prusa is bananas. And the fact that I BUILT IT MYSELF FROM A KIT is mind blowing. And using #OctoPrint by @foosel and OctoEverywhere to monitor remotely? It’s Star Trek levels of awesome. #Irony

R. A. Dehi boosted

Tonight, Artemis Orion will sail past the moon's orbit and then fall back towards the moon, getting as close as 100 km to the lunar surface. At 07:44 ET tomorrow morning, thrusters will be fired to further accelerate Orion and send it towards the DRO insertion point. 4 days later, the DRI burn will insert Orion into DRO proper.

eyes.nasa.gov/apps/solar-syste

Go #Artemis #Orion

6/n

Show thread
R. A. Dehi boosted

@howard and even the defun sometimes gets saved for later, as I often make things in a scratch buffer or src block in the process of figuring out my actual intention (and thus the function name and parameters). Sometimes I even leave things unnamed. :)

R. A. Dehi boosted

Experimenting with 3D modeling using mathematical functions to define a surface using Python in @Blender. A bit different than my usual go-to modeling tool @FreeCAD, but works really great! #3dprinting

R. A. Dehi boosted

@radehi

Touché.

The last thing I learned was TypeScript and the Playwright framework for automation and testing. I learned it because I found it a sound, useful, and innovative new technology.

In the past 27 years, I have seen lots of fancy whiz-bang technologies come and go. At the launch, during the early adoption phase of the technology it seems like, "THIS is IT! The next BIG THING. It's going to be super popular." Then, it runs into problems. and quietly fizzles out.

Use discernment.

I was looking around to see what open-source alternatives to GPT-3 there are, and I came across something called "GPT-NeoX-20B". Apparently you need a pair of GPUs and 20 gigs of VRAM to run it?

github.com/EleutherAI/gpt-neox

R. A. Dehi boosted

Responses to some frequent comments:

* I'm certainly not suggesting that algorithmic feeds should be imposed on everyone! Choice is great. I recognize that many, perhaps most current Mastodon users like chronological feeds.

* "Reverse chronological" is an algorithm, albeit a simple one. It's currently the only option. Chronological feeds are not normatively neutral. There is, unfortunately, no neutral way to design social media. mastodon.social/@randomwalker/

Show thread
R. A. Dehi boosted

@scottjenson @jeffjarvis Also if you're running your own instance you can afford to deploy staggering amounts of CPU power. Like, you could plausibly run GPT-NeoX-20B on your own dual-GPU rig to try to guess which Fediverse posts you'd be most interested in seeing.

The NSA can do this with Twitter, but you're not allowed to.

R. A. Dehi boosted

I was giving a computing ethics lecture about #FOSS and #antifeatures around 2014. Lots of folks there had never even heard of #FDroid. Maybe it's still not well-known?

F-Droid is a repository and platform for FOSS on Android. Their app can manage your other apps, much like you do with the Google Play Store.

When I need an Android app for something, I always check F-Droid first, just because the apps are trustworthy.

@fdroidorg

I'll reply with a few of my favorite apps on F-Droid... 🧵

R. A. Dehi boosted

Greetings. I'm an armchair student of history (not just tech history), but given that I've been involved in the development of the Internet continuously since the early DOD ARPANET days (so, technically before there *was* an Internet) I'm watching the Twitter->Mastodon migration (and the nightmarish, shameful disintegration of Twitter itself) with considerable interest indeed. There is no historical precedent that I know of, and what's happening is even more remarkable given that it has been precipitated by a single chaotic individual in a matter of weeks.

The high speed with which I see social graphs rebuilding here is fascinating, and we can be sure that there are a bunch of PhD theses and books in the future that will attempt to explain all of this for future generations.

Sometimes when you're living through significant historical events it's not obvious except in retrospect, often many years later. What we're living through now with Twitter is clearly significant history, from technology, business, social, and other standpoints.

And even if Mastodon turns out ultimately to be a steppingstone on the way to other social media models able to scale far upward more easily, it is playing a crucial role now in providing a "lifeboat" for Twitter users who are unable to stomach what is happening to that firm with every passing day.

For all its many faults over the many years, we built the Internet to be resilient. And what we are seeing today is that not only has the technology met that goal from ARPANET onward, but thanks to the Internet's vast numbers of dedicated and caring users, even a monstrous train wreck like Elon's Twitter can't bring it (or us!) down.

Thank you all! -L

R. A. Dehi boosted

Turns out you can skip the distance estimate (hard calculations) by considering axis-aligned bounding boxes with a long case analysis of possible box positions (e.g. if all corners are in the cardioid, check if the box crosses the axis and if the right edge of the box is the to the right of the cusp).

There are some irrational coordinates, but nicely you can just square both sides to get a dyadic rational that can be compared exactly.

And you can apply perturbation theory to the implicit cardioid test, provided you have enough precision in the low precision type (24 bits (float) is not enough, 53 (double) seemed ok in one brief shader test, I'm using 64). This increases the cost of the test, so it's good to be able to skip these for the whole view via AABB checks.

If using fixed point (instead of floating point) for high precision reference, you need 4x the fraction bits for intermediate calculations to avoid underflow / truncation error.

Symptoms of the problems were false positives (leading to bad images with too much interior) near the cusp, and some false negatives near the cusp too (correct image but takes longer than necessary).

Show thread
R. A. Dehi boosted

excellent mastodon features you'll quickly wonder how you lived without: temporary mutes

on the web interface, hit the three-dots menu on a post, then "mute <whoever>" and you can select a TIME PERIOD to mute them for!

friend posting about a tv show you haven't seen? mute 'em for an hour

someone clogging your local feed with current events you don't care for? mute 'em for a week

lucky won't stop talking? mute 'em indefinitely

it just works

R. A. Dehi boosted

Is at once hopeful and terrifying. A company that doubles in three months usually loses its culture. Hopefully won't happen here.

Mastodon Users  
7,083,862 accounts +9,540 in the last hour +204,289 in the last day +520,320 in the last week
R. A. Dehi boosted

Hello new #API developers who've come here from Twitter.
I've written some guides to help you get started with the #MastdonAPI

Includes how to build #bots, grab conversations, and use search effectively.

Read them at: shkspr.mobi/blog/tag/mastodon/

Show thread
R. A. Dehi boosted

#Underline text in different lightweight markup languages:

Emacs #OrgMode :orgmode:, Muse:
_this_

#DokuWiki:
__this__

#Textile, #Jira
+this+

There is no Markdown syntax for underlined text, but #pandoc's #Markdown reader treats the content of spans with class "underline" or "ul" as #underlined:

[important]{.underline}
[nota bene]{.ul}

"[Lossless Convexification of Nonconvex Control Bound and Pointing Constraints of the Soft Landing Optimal Control Problem](larsblackmore.com/iee_tcst13.p)", paper by Behçet Açıkmese, John M. Carson III, and Lars Blackmore, the guy who got the rockets to land on their tails like CGI special effects.

Abstract: "*Planetary soft landing is one of the benchmark problems of optimal control theory and is gaining renewed interest due to the increased focus on the exploration of planets in the solar system, such as Mars. The soft landing problem with all relevant constraints can be posed as a finite-horizon optimal control problem with state and control constraints. The real-time generation of fuel-optimal paths to a prescribed location on a planet’s surface is a challenging problem due to the constraints on the fuel, the control inputs, and the states. The main difficulty in solving this constrained problem is the existence of nonconvex constraints on the control input, which are due to a nonzero lower bound on the control input magnitude and a nonconvex constraint on its direction. This paper introduces a convexification of the control constraints that is proven to be lossless; i.e., an optimal solution of the soft landing problem can be obtained via solution of the proposed convex relaxation of the problem. The lossless convexification enables the use of interior point methods of convex optimization to obtain optimal solutions of the original nonconvex optimal control problem.*"

R. A. Dehi boosted

I've been using #AnnotatedEquations in my recent papers. I think it really adds to the readability and understanding of the math.

Here are some examples. It uses #tikz in #latex.

Let me know if you like it. Happy for any feedback.

R. A. Dehi boosted

One of my pals told me my Twitter comments were as viscous as AOC and Nancy Pelosi. I though everyone’s were like that! I just got used to it. As much as you can. It’s nothing short of astounding to me that I can just post and engage on here and people respond in a way that seems normal and real. The Twitter comments world is distorted and dangerous. I don’t see how twitter can be fixed. We’re better off here. ❤️

Birdsite 

nitter.net/TechEmails/status/1 has the purported conversation between Dorsey and Musk from March about how Twitter should become "an open source protocol, funded by a foundation of sorts that doesn't own the protocol, only advances it". Purportedly the thread was made evidence in the Twitter v. Musk lawsuit.

If that's the plan, firing most of Twitter's employees does seem like a good first step.

Show older
Qoto Mastodon

QOTO: Question Others to Teach Ourselves
An inclusive, Academic Freedom, instance
All cultures welcome.
Hate speech and harassment strictly forbidden.