IndrekR (u/IndrekR) - Readit News

IndrekR commented on How can I build a simple pulse generator to demonstrate transmission lines electronics.stackexchange... · Posted by u/alphabetter

Aurornis · a month ago

This is a great post about the basics of what happens in transmission lines.

If you need really fast rise times, there are cheap pulse generators that are a couple orders of magnitude faster: https://leobodnar.com/shop/index.php?main_page=product_info&... At this level everything has to be optimized including physical geometry.

IndrekR · a month ago

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.

IndrekR commented on What a year of solar and batteries saved us in 2025 scotthelme.co.uk/what-a-y... · Posted by u/MattSayar

drnick1 · a month ago

> Having our full costs returned in ~11 years is definitely something we're happy with

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

> we've also had protection against several power outages in our area along the way, which is a very nice bonus.

This seems to be the real benefit of the setup.

IndrekR · a month ago

> 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.

IndrekR commented on Start your meetings at 5 minutes past philipotoole.com/start-yo... · Posted by u/otoolep

IndrekR · a month ago

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...

IndrekR commented on HPV vaccination reduces oncogenic HPV16/18 prevalence from 16% to <1% in Denmark eurosurveillance.org/cont... · Posted by u/stared

perlgeek · a month ago

Sounds like in countries like Denmark, they are already on their way to becoming the most prevalent.

Hope we'll develop vaccines against those too.

IndrekR · a month ago

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

IndrekR commented on Tesla’s 4680 battery supply chain collapses as partner writes down deal by 99% electrek.co/2025/12/29/te... · Posted by u/coloneltcb

hdgvhicv · a month ago

When the weather forecast said it would rain on Friday and it didn’t was that also called a lie?

IndrekR · a month ago

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.

IndrekR commented on US blocks all offshore wind construction, says reason is classified arstechnica.com/science/2... · Posted by u/rbanffy

tony_cannistra · 2 months ago

I looked into this a little because I was curious. I guess the ostensible "national security" rationale (which clearly is not the only reason!) for this is that turbines severely degrade the utility of radar surveillance along the coastlines.

This is particularly relevant for low-altitude incursions and drones.

Now, other large governments (UK) have resolved this in several ways, including the deployment of additional radars on and within the turbine farms themselves.

So clearly this is politically motivated, and they're using what seems to be a real but solveable concern as a scapegoat.

IndrekR · 2 months ago

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

IndrekR commented on How a devboard works (and how to make your own) kaipereira.com/journal/bu... · Posted by u/kaipereira

_def · 3 months ago

What do people often get wrong about decoupling capacitors?

IndrekR · 3 months ago

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...

IndrekR commented on The Trinary Dream Endures robinsloan.com/lab/trinar... · Posted by u/FromTheArchives

Nevermark · 4 months ago

Ternary is indeed an enticing, yet ultimately flawed dream.

Quaternary allows for:

  True, “Yes”

  False, “No”

  Undetermined, “Maybe”, “Either”, True or False

And:

  Contradiction, “Invalid”, “Both”, True and False

For logical arithmetic, I.e. reducing tree expressions, True and False are enough.

But in algebraic logic, where more general constraint topologies are possible, the other two values are required.

What is the logical value of the isolated expression “(x)”? I.e. “x” unconstrained?

Or the value of the expression “(x = not x)”?

None of 4-valued logic’s values are optional or spurious for logical algebra.

—-

Many people don’t know this, but all modern computers are quaternary, with 4 quaternit bytes. We don’t just let anyone in on that. Too much power, too much footgun jeopardy, for the unwashed masses and Python “programmers”.

The tricky thicket of web standards can’t be upgraded without introducing mayhem. But Apple’s internal-only docs reveal macOS and Swift have been fully quaternary compliant on their ARM since the M1.

On other systems you can replicate this functionality, at your own risk and effort, by accessing each quaternit with their two bit legacy isomorphic abstraction. Until Rust ships safe direct support.

—-

It will revolutionize computing, from the foundations up, when widely supported.

Russell’s paradox in math is resolved. Given a set S = “The set of all sets that don’t contain themselves”, the truth value of “Is S in S” in quaternary logic, reduces to Contradiction, which indeed it is. I.e. True and False. Making S a well formed, consistent entity, and achieving full set and logical completeness with total closure. So consistency is returned to Set theory and Russell’s quest for a unification of mathematics with just sets and logic becomes possible again. He would have been ecstatic. Gödel be damned! [0]

Turing’s Incompleteness Theorem demonstrates that 2-valued bit machines are inherently inconsistent or incomplete.

Given a machine M, applied to the statement S = “M will say this statement is False”, or “M(S) = False”, it has to fail.

If M(S) returns True, we can see that S is actually False. If M(S) returns False, we can see that actually S is True.

But for a quaternary Machine M4 evaluating S4 = “M4(S4) = False”, M4(S4) returns Contradiction. True and False. Which indeed we can see S4 is. If it is either True or False, we know it is the other as well.

Due to the equivalence of Undecidability and the Turing Halting Problem, resolving one resolves the other. And so quaternary machines are profoundly more powerful and well characterized than binary machines. Far better suited for the hardest and deepest problems in computing.

It’s easy to see why the developers of Rust and Haskell are so adamant about getting this right.

[0] https://tinyurl.com/godelbedamned

IndrekR · 4 months ago

Most common quaternary storage system is probably DNA.

IndrekR commented on What Americans die from vs. what the news reports on ourworldindata.org/does-t... · Posted by u/alphabetatango

IndrekR · 4 months ago

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.