Hacker News: sfeng

New comment by sfeng in "SpaceX files to go public"

sfeng — Thu, 02 Apr 2026 16:05:21 +0000

The only thing I can argue with is the thoughts on Starship. Each ship failing in a new way is exactly what you'd expect to see from a research project fixing one issue at a time and progressing a bit further until the next issue crops up. I would be much more concerned to see _the same_ failure happen over and over with no clear plan to resolve the issue.

New comment by sfeng in "My Home Fibre Network Disintegrated"

sfeng — Sun, 11 Jan 2026 06:44:47 +0000

If it’s underground (meaning not in the sun) the lifespan of PVC is 100+ years. It seems unlikely it will be his problem if it ever cracks.

New comment by sfeng in "Custom telescope mount using harmonic drives and ESP32"

sfeng — Tue, 19 Aug 2025 15:16:17 +0000

One tiny nit on this amazing project / write up. He mentions that the traces have to be extra wide to support 24V. In truth though, the higher voltage means lower current, which means if anything the traces can be less wide. The size of the traces is determined by the current they carry, the voltage determines how much space must be between the traces (but it’s unlikely to be an issue at these voltages).

New comment by sfeng in "What do wealthy people buy, that ordinary people know nothing about? (2015)"

sfeng — Mon, 19 May 2025 06:10:43 +0000

What so many people fail to realize is the true purpose of money is to avoid having to spend time with people you don’t like, or do things you don’t value. So if you have a $400/million per month job, but you have to have meetings all day long, you’re not really rich. Similarly, no offense to billionaires, but the ones I’ve met have been someone manic and misanthropic. If you are using your access to spend your time with them, you are not really rich in my book.

True wealth is being able to spend all your time doing things with and for people you love. It sounds trite, but the truth is many people miss the opportunity to jump off the train and enjoy their life while they can.

New comment by sfeng in "Cloudflare R2 Incident on February 6, 2025"

sfeng — Fri, 07 Feb 2025 11:24:27 +0000

You can tell a company really builds using their own products when an abuse system can take them offline!

New comment by sfeng in "CDC: Unpublished manuscripts mentioning certain topics must be pulled or revised"

sfeng — Sun, 02 Feb 2025 10:19:49 +0000

They actually like male/female enforced gender. Maybe what they’ll do is add gender to English grammar!

New comment by sfeng in "Show HN: I built a(nother) house optimized for LAN parties"

sfeng — Sun, 17 Nov 2024 08:28:26 +0000

If you’re a Cloudflare shareholder, Kenton has increased your net worth quite a bit. He is one of the few people who is so unreasonably capable he can and has changed the direction of a multibillion dollar company single handedly. It sounds hyperbolic, but it’s not in this particular case.

I’m also fairly convinced he didn’t capture one tenth of one percent of the value he created, so I’m not sure how anyone can argue this is ‘unfair’.

New comment by sfeng in "In Mexico’s underwater caves, a glimpse of artifacts, fossils and human remains"

sfeng — Thu, 03 Oct 2024 04:39:24 +0000

If you are a SCUBA diver, but always wished that diving was a bit more technical and rigorous, I highly recommend trying cave diving [1]. You can do a cenote tour in just an afternoon, and if you’re hooked a few weeks of training (spaced over time) will make you into a radically better diver.

1- https://www.underthejungle.com/en/cave-cavern-training/

New comment by sfeng in "Portcullis"

sfeng — Thu, 27 Jun 2024 08:55:28 +0000

They lost me at dropping hot oil. There is no evidence of anyone dropping oil, it would have been expensive and hardly better than boiling water.

New comment by sfeng in "First look at the upcoming Starlink Mini"

sfeng — Mon, 17 Jun 2024 09:39:51 +0000

Where in Scotland? There’s 5G almost everywhere.

New comment by sfeng in "Edinburgh, Scotland makes it illegal to advertise SUVs"

sfeng — Sun, 16 Jun 2024 18:24:37 +0000

Those brick heaters are smart because they use electricity at off-peak times to heat the house for the whole day. What about it strikes you as less efficient than any other direct electric heating?

New comment by sfeng in "Flying planes in Microsoft Flight Simulator with a JavaScript autopilot (2023)"

sfeng — Mon, 06 May 2024 08:31:23 +0000

What’s your definition of finicky? JavaScript is something like 3-10x faster than Lua for most benchmarks (1). If you’re referring to the event loop, it shouldn’t be all that relevant for singleminded code like this that is only processing a single event every half second. If you’re referring to mathematical oddities, it is also not relevant as JavaScripts love of floats is well suited here.

1- https://programming-language-benchmarks.vercel.app/amp/lua-v...

New comment by sfeng in "The unstallable plane that stalled"

sfeng — Sun, 28 Apr 2024 16:38:54 +0000

Canard aircraft, for example, stall the canard first, resulting in the nose dropping, preventing the main wing from ever stalling.

New comment by sfeng in "Compressing chess moves for fun and profit"

sfeng — Fri, 15 Mar 2024 16:57:07 +0000

I would love to see this benchmarked against just running LZW compression on a list of the moves. I think the repeated nature of the moves means the entropy is actually rather low. It should be possible to come up with a compression dictionary which can save a lot more space than just a tight packing like this.

New comment by sfeng in "Tyler Perry Puts $800M Studio Expansion on Hold After Seeing OpenAI's Sora"

sfeng — Fri, 23 Feb 2024 15:03:46 +0000

Sure but an $800M investment is supposed to pay off over 10-20 years. It seems like the industry will change in more like 1-2.

New comment by sfeng in "Nicotine (2016)"

sfeng — Sat, 11 Nov 2023 15:35:57 +0000

It would probably be useful to actually read before you comment. He meticulously cites the sources of his claims with actual studies.

New comment by sfeng in "AWS IPv4 Estate Now Worth $4.5B"

sfeng — Mon, 18 Sep 2023 06:59:47 +0000

I personally would have added one additional byte, but when it is written I would have added two bits to each of the original bytes. That has the advantage of making each segment 0-1023. I would have reserved the 1000-1024 values, such that IP addresses look the same visually: 476.188.049.772, but the available number is increased by a factor of more than 200. Maybe it’s not too late to release IPv5…

New comment by sfeng in "Threat Actors Abuse Cloudflare Tunnel for Persistent Access, Data Theft"

sfeng — Sun, 06 Aug 2023 19:09:54 +0000

I’m sorry, but once an attacker can run arbitrary commands on your machines, it seems like your personal security battle has been lost. Cloudflare Tunnel isn’t doing anything that an attacker couldn’t do with a huge list of other tools, including a script that just loads some remote HTTP address for evil things to do next.

New comment by sfeng in "Freedom Clock"

sfeng — Sat, 25 Mar 2023 15:15:48 +0000

To play devil's advocate, the American format aligns with how (American's at least) speak the date "March 24th, 2022".

New comment by sfeng in "129-year-old vessel still tethered to lifeboat found on floor of Lake Huron"

sfeng — Sat, 11 Mar 2023 10:42:36 +0000

In diving we think in terms of partial pressures. At sea-level, 21% of air is oxygen, and .21 is also your partial pressure of O2. In order to breath at depth, though, we need to be supplied with a higher and higher pressure of gas to fight the pressure of the surrounding environment opposing our lung expansion. At 10 meters, the pressure doubles sea-level, and you are breathing gas at twice atmospheric pressure (meaning there are twice as many O2 and Nitrogen molecules in every liter of gas).

Consequently, the partial pressure of oxygen you are breathing is doubled, to .42. This continues, until you reach a partial pressure which is incompatible with life. That danger-zone is generally considered to be between 1.4 and 1.6, so air cannot be safely breathed below about 60 meters (1.6/.21 - 1 = about 6 atmospheres). Similarly, pure O2 cannot be breathed safely below about 6 meters (1.6/1 - 1 = about .6 atmospheres).

Your description of nitrogen narcosis is correct. To dive deeper than your nitrogen narcosis limits you start replacing some of the nitrogen with helium in the gas you breathe. This works up to the limits of even the most technical recreational diving, after which you will get symptoms of something called HPNS which could mean replacing the helium itself with hydrogen.

Both helium and nitrogen will get stored in your inert tissues and will bubble out catastrophically if you ascend too quickly. With either inert gas you must carefully plan your ascent to avoid the bends.