Hacker News: IndrekR

New comment by IndrekR in "Artemis II is not safe to fly"

IndrekR — Tue, 31 Mar 2026 06:37:19 +0000

2/156 lost for Soyuz in 59 years, 2/135 for Space Shuttle in 30 years. Same rate. People often underestimate how intense STS actually was.

New comment by IndrekR in "Triplet Superconductor"

IndrekR — Fri, 06 Mar 2026 21:00:42 +0000

In QC, keeping cold is not just needed to superconduct, but to reduce thermal noise to level below the energy levels operated at.

Air defence in Kyiv visible on ISS video stream [video]

IndrekR — Thu, 26 Feb 2026 14:13:59 +0000

Article URL: https://www.youtube.com/watch?v=m5VHETDtQ_M

Comments URL: https://news.ycombinator.com/item?id=47166369

Points: 4

# Comments: 0

New comment by IndrekR in "How can I build a simple pulse generator to demonstrate transmission lines"

IndrekR — Thu, 15 Jan 2026 07:24:56 +0000

I am using Leo Bodnar’s fast pulse generator (SMA) in my lectures to teach transmission lines. With sufficient length (I use ~1m) it works quite well to demo with a low cost scope. I originally bought it for TDR with 40GSPS/15GHz scope, which works very well with few orders of magnitude smaller lengths. Old on has upper length limit with 10MHz fixed frequency. There is a new one available with external sync and variable frequency, but I have not bought/tested it.

New comment by IndrekR in "What a year of solar and batteries saved us in 2025"

IndrekR — Tue, 13 Jan 2026 17:27:12 +0000

> Except that after 11 years the equipment will have broken down or be obsolete, at which point you have to start over.

If my calculations are correct, that setup probably lasts at least 30 years. This is not a cell phone battery and panels do not degrade that fast.

New comment by IndrekR in "Start your meetings at 5 minutes past"

IndrekR — Sat, 10 Jan 2026 10:34:41 +0000

A similar concept has been used for university lectures to start 15 minutes after the full hour. This was due to nobody having watches and everything being synced to the church bells ringing at the full hour. Then you had 15 minutes to get to the next lecture (in another building). Starting time was given as ct (cum tempore, with time) or st (sine tempore, without time). Usually only st was marked as everybody assumed the 15 minutes delay.

https://en.wikipedia.org/wiki/Academic_quarter_(class_timing...

New comment by IndrekR in "HPV vaccination reduces oncogenic HPV16/18 prevalence from 16% to <1% in Denmark"

IndrekR — Fri, 02 Jan 2026 13:41:47 +0000

In my EU country Gardasil 9 is the most common HPV vaccine nowadays. This protects against 9 most common strains. I would assume the same is true in other countries. We have gone from HPV 16/18 -> +6/11 -> +31/33/45/52/58 protection with 2/4/9-valent vaccines.

Ref: https://en.wikipedia.org/wiki/HPV_vaccine

New comment by IndrekR in "Tesla’s 4680 battery supply chain collapses as partner writes down deal by 99%"

IndrekR — Tue, 30 Dec 2025 09:18:22 +0000

If the input to the weather forecast is mostly /dev/random, then yes, that is called a lie. There is a very big difference between modelling chaotic systems and providing random noise.

New comment by IndrekR in "US blocks all offshore wind construction, says reason is classified"

IndrekR — Mon, 22 Dec 2025 21:15:36 +0000

Taiwan strait is filled with offshore wind turbines from both sides. This is not an issue for PRC nor Taiwan.

Shahed-107 UAV Components

IndrekR — Thu, 27 Nov 2025 12:29:18 +0000

Article URL: https://war-sanctions.gur.gov.ua/en/page-shahed-107

Comments URL: https://news.ycombinator.com/item?id=46068646

Points: 3

# Comments: 0

New comment by IndrekR in "How a devboard works (and how to make your own)"

IndrekR — Sat, 08 Nov 2025 12:58:22 +0000

Few things for starters:

- you have to look at it in frequency domain as well;

- speed of light is too slow;

- often capacitors are inductors, even more so when mounted on PCB;

- capacitance is not what is written on the component.

I am teaching this to robotics and computer engineering MSc students. Quite nice intro book into the topic that I recommend to my students: https://www.oreilly.com/library/view/principles-of-power/978...

New comment by IndrekR in "The Trinary Dream Endures"

IndrekR — Sun, 19 Oct 2025 20:00:31 +0000

Most common quaternary storage system is probably DNA.

New comment by IndrekR in "What Americans die from vs. what the news reports on"

IndrekR — Tue, 14 Oct 2025 21:59:46 +0000

Funny thing is, that news, by definition, are written about things that are newsworthy. Newsworthy things are not common, but exceptional and rare. Thus one shall not worry too much about the news as those things practically never happen in everyday life.

New comment by IndrekR in "Signal Protocol and Post-Quantum Ratchets"

IndrekR — Thu, 02 Oct 2025 20:55:43 +0000

In signal you can change your username any time.

New comment by IndrekR in "Bank of Thailand freezes 3M accounts, sets daily transfer limits to curb fraud"

IndrekR — Sun, 14 Sep 2025 16:54:53 +0000

The funny thing is, that MM in roman numerals means 2000.

New comment by IndrekR in "Bank of Thailand freezes 3M accounts, sets daily transfer limits to curb fraud"

IndrekR — Sun, 14 Sep 2025 16:54:03 +0000

It is to avoid confusing with "M", mīlle -- Latin for "thousand". Quite common in financial world still.

New comment by IndrekR in "Florida lawmaker floats ban on HOAs amid growing backlash"

IndrekR — Fri, 22 Aug 2025 12:57:43 +0000

HOA = Homeowner association

Took me a while to figure this out.

New comment by IndrekR in "In 2006, Hitachi developed a 0.15mm-sized RFID chip"

IndrekR — Tue, 19 Aug 2025 12:09:10 +0000

Used to develop readers based on similar UHF chips (868 MHz in EU). They were quite expensive compared to printed bar codes those were replacing. Also large. With (folded) antennas we are still talking about 40*10 mm minimum for the label. You can not use them on metal surfaces. Readers nearby will interfere as it works by EM wave backscattering, unlike NFC which is essentially a transformer (with electric field intentionally supressed usually). I think it still is a solution looking for problem. QR codes are cheap and NFC (14 MHz) readers are everywhere.

New comment by IndrekR in "The future of large files in Git is Git"

IndrekR — Sat, 16 Aug 2025 10:23:16 +0000

Letsencrypt was founded 2012, but become available in the wild December 2015. git-lfs mid-2014. So same era in general.

New comment by IndrekR in "QNX: The Incredible 1.44M Demo"

IndrekR — Wed, 13 Aug 2025 11:40:25 +0000

This demo seems to be dated 1999. I recall the context where and when (school) I saw it first and I moved to a different school in autumn 1998. It seems there was an even earlier disk that I am confusing it with:

https://marc.info/?l=freebsd-chat&m=103030933111004