HNHacker News
TopNewBestAskShowJobs

mafm

159 karma · joined January 3, 2015

submissionscomments
mafm··on Read the novels and forget everything else
I read the books, and enjoyed them in the early 2000s. I was quite amused to see the article on O'Brian in Yachting World in 2004 when I was halfway through the series. I don't have a link to the yachting world article, but the BBC article seems to be a reasonable summary of what I think I remember reading in yachting world: http://news.bbc.co.uk/2/hi/uk_news/magazine/3570988.stm

I think the yachting world and BBC article were following up on Tom Perkins original story published in latitude38: https://www.latitude38.com/features/O%27Brian.htm

mafm··on DIY AI-powered robot arm
Nikodem Bartnik video on building and training a cheap robot arm. At least to me, this looks significantly more interesting than using AI to generate text.
mafm··on Email was the user interface for the first AI recommendation engines
Thanks - just tried gnovies and got a great recommendation.

I'm surprised that something I'd never heard of appears to work that well.

mafm··on Talent Is Alignment
It's true that talent is almost entirely curiosity/enthusiasm/drive.

But that curiosity/enthusiasm/drive has a large genetic component - like every pretty much every other individual characteristic that humans exhibit.

mafm··on The first release candidate of FreeCAD 1.0 is out
Onshape is wonderful. Free users complained a lot about the changes to the free license years ago when they changed the rules, but I have no issue with it. TBH, I'm grateful they make it available on the terms that they do.

Solvespace is beautiful, but limited.

I spent enough time using FreeCad to get the hang of the user interface, but got enormously frustrated by it more or less randomly crashing and frequently generating bizarre shapes due to numerical issues when trying to do things like complex lofts. I have had no similar problems with OnShape.

I honestly don't know why there was so much noise about 'topological naming' in FreeCad, the stability issues I kept running into were way more frustrating than the clunky UI or counter-intuitiveness.

I did think about digging into FreeCad to fix some of the issues I was having, but once I started playing around with OnShape I totally lost interest. I am a lot more interested in designing parts than in debugging and fixing stability issues in complicated software in my spare time.

I am quite interested in trying out dune3d. It looks like the author has some expertise and interesting ideas about what's wrong with the other free CAD options.

mafm··on Show HN: High school robotics code/CAD/design binder release
Nice work!

Cool that you made this available for other people to benefit from.

mafm··on How to keep lambda calculus simple
This looks nice. Looking forward to going through it and the related earlier stuff carefully at leisure.

I'm sure the author is well aware, but Lennart Augustsson wrote a really nice blog post responding to the original "Simply Easy!" in 2007 that was a lot more fun and simple than the "Simply Easy" paper.

http://augustss.blogspot.com/2007/10/simpler-easier-in-recen...

mafm··on CPM MagnaCut
I'm not bob, but I bought a ruixin pro 8 (~40AUD) and 3 diamond stones (~5AUD a piece) on aliexpress a couple of weeks ago.

Watched a YouTube video and got half a dozen kitchen knives sharp enough to shave arm hair in about an hour. They seem to be holding their edges reasonably well a couple of weeks later.

I'd previously not had much success with Japanese water stones and with the lansky(?) gadget.

It seems like the key part of the process is (a) detecting when you have formed a burr so you know when to change sides/move to the next grit and (b) stropping at the end (get the leather strip with polishing wax).

The Chinese gadget is a bit crude but was honestly surprisingly effective.

I don't think the theory is that complicated but getting good practical results reliably can be a bit tricky. The gadget seems to work quite well for that.

Ps: Just looked at Cliff Stamp's sharpening site. I think that's an order of magnitude sharper than I was going for with my kitchen knives.

mafm··on Nbterm: Jupyter Notebooks in the Terminal
You may already be aware of it, but jupytext solves most of the problems ipynb files cause.
mafm··on Show HN: I made a minimalist spaced repetition tool
Nice.

I would not pay for this but might buy it as an app on my phone.

I would be more likely to buy a subscription of you had a ton of decks on it like memrise does.

mafm··on Turkey reconverts Istanbul's Hagia Sophia museum into a mosque
I hope Turkey does what you're suggesting with lighting.

There's also an ayasofya in trebizond that was converted back to a mosque in 2013. That building is still open for visitors but unfortunately the main dome and its mosaics are now obscured by barriers put up during the conversion.

It would be a trajedy if the same thing happens in Istanbul. Hopefully it's enough of a tourist attraction that it doesn't happen.

Ayasofya is an incredibly impressive and beautiful building. There's nothing else like it in the world (even though it was a major influence on subsequent buildings for a thousand years.) Far more beautiful than European churches.

mafm··on Building AI Trading Systems
The parent comment is the most useful one in the thread so far for anyone who seriously wants to learn about quantitative trading.

Sports betting is essentially the same thing as proprietary trading in financial markets. The paper gives a good summary of a technique that was very successful in its day.

There is very little publicly available material on quantitative techniques that are useful for proprietary trading. Lo and Mackinlay's "non-random walk down wall st" was good, but that's 20 years old.

The mathematical literature on gambling is a lot more accessible. It's also probably easier to consistently make at least small money gambling, because the barriers to entry are lower.

mafm··on Why the US military usually punishes misconduct but police often close ranks
Because being ordered to do something that might get you killed isn't reasonable.
mafm··on Why the US military usually punishes misconduct but police often close ranks
Acoording to ethics class during basic training in the Australian army, the key difference between soldiers and civilians is that military personnel are under a legal obligation to follow all lawful orders. The class highlighted that police are (by definition) civilian because police are only obligated to obey reasonable orders.

So a soldier refusing to carry out a lawful order that would result in near-certain death is guilty of a crime. A cop refusing to carry out the same order is entirely within their rights.

And then there was also a lot of discussion of the difference between lawful and unlawful orders, My Lai, Nazi Germany, etc.

Some Australian police recently refused to deal with people who had covid-19, because they argued it was unreasonably dangerous.

At least in theory, military personnel are held to a much higher ethical standard than civilian police.

mafm··on Hong Kong’s security law is going to devastate its economy
When Hong Kong went back to China in 1997, it was 30% of China's GDP. In 2019, HK was less than 2.5% of Chinese GDP.

HK has grown since 1997, but China has gotten so much richer that HK is now basically economically irrelevant to the mainland.

As far as the mainland is concerned, Hong Kong is now only a political issue.

mafm··on New Zealand eliminates Covid-19
Here's a chart that pretty clearly shows how well the US is doing in comparison to the rest of the world: https://twitter.com/yaneerbaryam/status/1256769252369072134

Live version of essentially the same chart here: https://www.endcoronavirus.org/countries

mafm··on Making Emacs Popular Again
If rms doesn't understand org-mode, that seems to be pretty indicative of what the real problems underlying emacs' lack of popularity are.

I suspect that org-mode is responsible for more people using emacs than any other package by a large margin. Not understanding org mode suggests to me that rms is no longer on the same page as most of the users.

I know there's a lot of other good stuff in emacs, but org-mode seems to be particularly key.

mafm··on Joy (Programming Language)
Can you add a link pointing at some examples?
mafm··on Forth Lisp Python Continuum: A small highly-dynamic self-bootstrapping language
Lisp let's you modify its syntax. You're making the standard argument about why that might be a bad idea. At least for Lisp, historically it worked pretty well. As new ideas came along, a lot of the good ones got incorporated in Lisp as syntax extensions.

Overloading in C++ is kind of similar. Im not sure that worked out so well in practice.

mafm··on Why are Soviet math textbooks so hardcore in comparison to US textbooks? (2017)
That's a really interesting document.
mafm··on Why are Soviet math textbooks so hardcore in comparison to US textbooks? (2017)
I think technical education in the soviet union was a lot stronger than it was in the free world, at least in the 20th century. When I was 16, I was enrolled in the top high-school maths units in the early 1980s in Australia. Maths was about 1/3 of the academic contact hours and the curriculum was pretty standard across all the Australian states.

A family from the Ukraine somehow managed to immigrate to Australia and their 16 year old girl was enrolled on our maths classes. She was years ahead of the rest of the class.

She said she was a very mediocre maths student at home in the Ukraine, said quite a few times that in her opinion we had been taught basically nothing in the Australian system. I don't know how much maths the average soviet citizen learned, but I got the strong impression that soviet students who were actually interested in the subject got a much better mathematical education than they would have in Australia/US/UK.

mafm··on Emacs: The most successful malleable system
Large files seem fine in emacs as long as the lines are not too long. A 100MB file is no problem if there are less than a couple of hundred characters per line. If the average line is 2K characters, emacs will be unusable.
mafm··on Nbdev: Use Notebooks for Literate Programming
Jupytext (https://github.com/mwouts/jupytext) solves most of the problems with managing notebooks in git.
mafm··on The History of WD-40
Birds have fragile high performance lungs.

Using teflon cookware around a pet parrot is a well-known way to kill the pet.

Teflon frying pans are supposed to be safe if you never let them overheat, but in practice they're not safe if you have birds in the house.

PTFE is toxic for humans too, but human lungs are more robust than bird lungs.

mafm··on Brave Browser and the Wayback Machine: Working Together
Brendan Eich was also the guy who created javascript.

(In 10 days, which probably explains a lot of the warts.)

mafm··on Ray Tracing Essentials, Part 1: Basics of Ray Tracing
Peter Shirely's Ray Tracing in One Weekend series (https://raytracing.github.io/) is a great way to learn enough about ray tracing to implement it yourself.
mafm··on Is an Aboriginal tale of an ancient volcano the oldest story ever told?
The "first nations" phrase is used frequently on aboriginal radio in perth (Noongar fm 100.9) At least half the people they talk to are from the eastern states, so I don't think that the phrase is unusual (at least among the sort of people who get interviewed on radio stations).
mafm··on Is an Aboriginal tale of an ancient volcano the oldest story ever told?
Don't have sources at hand, but my impression from news articles over the last decade has been that recent archeological evidence has tended to indicate that aboriginal populations have been in australia for for quite a bit longer than the 50/60K years that was previously believed.

One example: I think there were some campfire remains and associated artifacts in Tasmania that were recently dated and turned out to be a lot older than than expected, like at least 80K years old.

mafm··on Cheap zinc/manganese battery being developed commercially
Yes, the batteries are rechargeable. Apparently good for at least 2,000 or 5,000 cycles.
mafm··on Cheap zinc/manganese battery being developed commercially
It seems like there's some competition in this space after an initial breakthrough in 2016.

https://newatlas.com/rechargeable-zinc-manganese-battery-pnn...

http://enerpoly.com/technology/

Page 1 of 3Next →