Hacker News: sehansen

New comment by sehansen in "RISC-V: They Should Have Known Better"

sehansen — Tue, 18 Aug 2026 11:57:39 +0000

No, ARM means "Acorn RISC Machine" and was developed by Acorn Computers, a British computer manufacturer, because the 8-bit MOS 6502 they had based their previous designs on was obsolete, available 16-bit processors "a bit crap"[0] and available 32-bit designs too expensive. So the ARM ISA was developed by a computer manufacturer for use in their own chips in their own products, quite far from an "academic exercise".

0: https://www.youtube.com/watch?v=Hf67JYkUCHQ at 7:35

New comment by sehansen in "NP-overrated"

sehansen — Fri, 14 Aug 2026 11:09:48 +0000

It't not a matter of generations. There are plenty of old mathematicians who are very interested in applications and plenty of young mathematicians who are only interested in generalized abstract nonsense. It's more of a difference in personality that will always be there.

New comment by sehansen in "Norway became a global salmon behemoth. Now it's facing the consequences"

sehansen — Mon, 03 Aug 2026 10:45:46 +0000

Fish and rice isn't synonymous with sushi. Grilled fish, tempura-fried fish and soups with pieces of fish are all popular in Japanese cuisine.

New comment by sehansen in "Chinese chipmaker shares surge 470%"

sehansen — Tue, 28 Jul 2026 11:59:33 +0000

I can't speak for the others, but ST has six fabs in Europe and only one in asia. ST's smallest process node is 18 nm and made in their fab in Crolles, France. In any case trying to compete at the cutting edge of process technology seems to be too expensive to be worth it.

New comment by sehansen in "Helium escaping from atmosphere of nearby rocky exoplanet in a habitable zone"

sehansen — Fri, 17 Jul 2026 10:49:02 +0000

If "closest star" is Proxima Centauri, we're talking 4.5 light-years. Getting there in 1000 years means an average speed of 0.45% of the speed of light. At that speed less than 0.01 cm of titanium is enough shielding to keep the radiation out according to figure 1c) in my source below. Which makes sense because because this is ~10% of the speed of "normal" alpha radiation which is stopped by just your skin.

"Radiation Hazard of Relativistic Interstellar Flight" by Oleg Semyonov: https://arxiv.org/abs/physics/0610030 via Project Rho: https://projectrho.com/public_html/rocket/slowerlight3.php

New comment by sehansen in "Why American ambulance rides are so expensive"

sehansen — Fri, 10 Jul 2026 10:28:51 +0000

Unfortunately that inside source is often coached by the PR department and are just there to say things they can't get away with saying publicly or don't want to have their exact words on record. I.e. just as much a misrepresentation as the official press releases. Or sometimes even more of a misrepresentation since nobody can actually be held accountable for their words.

New comment by sehansen in "Every new car sold in the European Union must include a driver monitoring camera"

sehansen — Wed, 08 Jul 2026 11:51:36 +0000

No they didn't. They had a hiccup in 2020 when the transition to electric cars really started accelerating but after they got their own electric cars into mass production they've reclaimed the top spot at 13.9% of the Chinese market. That's just ahead of Geely at 13.8%, Toyota at 7.8% and BYD at 7.1%.

It was hard to find reputable numbers for all of Q1, so my source is only for january and february: https://www.reuters.com/business/autos-transportation/volksw...

New comment by sehansen in "GAO: DOE Is Prematurely Excluding Less Expensive Options for Nuclear Cleanup"

sehansen — Wed, 08 Jul 2026 11:11:41 +0000

In a nuclear energy context "closed cycle" just means that the uranium and plutonium is separated out from the spent fuel for future reuse. The loop is only closed in the sense that some of the spent fuel material that leaves the reactor will enter it again in the future. It doesn't imply that new inputs won't be added to the loop.

https://en.wikipedia.org/wiki/Nuclear_fuel_cycle_in_France#C...

New comment by sehansen in "Organic Maps"

sehansen — Mon, 06 Jul 2026 12:25:05 +0000

A lot of normal people I know used to love maps.me but have become dissatisfied with the ads and other unwelcome commercial elements. They would definitely chose coMaps over Organic Maps just to lessen the risk of that happening again.

New comment by sehansen in "Long Island's decommissioned nuclear power plant"

sehansen — Mon, 06 Jul 2026 10:27:19 +0000

Yeah, with how much focus there is on the capital costs of nuclear power plants it's easy to forget they also have moderate operating costs. With the developments we're seeing, you're right that the LCOE of solar and wind is or will soon be lower than the operating costs of nuclear. That leaves the only remaining upsides of nuclear being production stability and energy diversity, and grid batteries are making the first less and less important every year. Not to mention that the capacity factor will be pushed down from the demand side worsening the costs even more since not all operating costs are proportional to the amount of energy generated.

New comment by sehansen in "OpenPrinter"

sehansen — Mon, 06 Jul 2026 09:13:02 +0000

Quite a lot of open source hardware is licensed under the BY-SA Creative Commons license which is an actual open source license. E.g. the Arduinos and things like the Milkymist One which can actually run linux.

New comment by sehansen in "Long Island's decommissioned nuclear power plant"

sehansen — Wed, 01 Jul 2026 07:52:15 +0000

An already built nuclear plant is cheaper than building new solar and wind, which is what this article is about. It had already started operational tests at 5% capacity when it was shut down.

And nuclear power doesn't inherently emit CO2 (or equivalents), which is what is meant by zero-carbon in this context.

New comment by sehansen in "Antares achieves criticality of Mark-0 reactor"

sehansen — Tue, 30 Jun 2026 11:52:35 +0000

If your location already has a well-run nuclear energy sector (Finland, Sweden, South Korea): invest in nuclear energy.

If you don't: stick to renewables.

And it also depends on what you mean by "we". As a Dane, I don't think us Danish taxpayers should invest in nuclear energy, but I'm perfectly happy that private Danish investors invest in Seaborg/Saltfoss and Copenhagen Atomics.

New comment by sehansen in "Show HN: Zanagrams"

sehansen — Mon, 29 Jun 2026 13:06:01 +0000

Cool game. Too bad you didn't include "oranges" on #4

New comment by sehansen in "Historical memory prices 1960-2026"

sehansen — Mon, 29 Jun 2026 11:50:56 +0000

DRAM hit a barrier at 10 nm a few years ago[0], so 16 nm is actually even closer to state-of-the-art. E.g. Micron newest node (1-γ) is their sixth at 10 nm [1] and their first EUV-based node.

The problem is that DRAM is fundamentally based on storing charge in a capacitor and how much charge a capacitor can store is a result of the geometry of the capacitor. So either someone will have to figure out a way to make the same size capacitor take up less space on the RAM chip (this is what broke the previous 20 nm barrier) or someone will have to invent a practical way of making RAM with less than 1 capacitor per bit.

0: https://semiengineering.com/dram-scaling-challenges-grow/

1: https://www.techpowerup.com/333111/micron-announces-shipment...

New comment by sehansen in "Historical memory prices 1960-2026"

sehansen — Mon, 29 Jun 2026 10:48:21 +0000

Hmm, so memory is actually still cheap compared to historical highs. At least cheap relative to other computer components.

New comment by sehansen in "Swiss parliament lifts ban on new nuclear power plants"

sehansen — Tue, 23 Jun 2026 14:49:59 +0000

France does have parallel gas infrastructure though. It's, funnily enough, at around 10% of their electricity supply.

New comment by sehansen in "Swiss parliament lifts ban on new nuclear power plants"

sehansen — Tue, 23 Jun 2026 14:42:19 +0000

I don't see that?

France: 4.12 tons CO2 per capita Denmark: 4.34 tons CO2 per capita

and the electricity price for industrial costumers is also close to identical:

France: 0.153 EUR/kWh (0.130 EUR/kWh without taxes) Denmark 0.122 EUR/kWh (0.121 EUR/kWh without taxes)

CO2 data from EUs EDGAR: https://edgar.jrc.ec.europa.eu/report_2025?vis=co2pop#emissi...

Price data from: https://ec.europa.eu/eurostat/statistics-explained/index.php...

New comment by sehansen in "Swiss parliament lifts ban on new nuclear power plants"

sehansen — Tue, 23 Jun 2026 13:23:12 +0000

The four APRs built in Abu Dhabi cost $32 billion in total and the two they've contracted to build in Czechia is projected to cost $18 billion in total.

New comment by sehansen in "Swiss parliament lifts ban on new nuclear power plants"

sehansen — Tue, 23 Jun 2026 13:18:23 +0000

Just a small nitpick: Renault isn't Stellantis and have been quite competitive (if a bit timid) in the EV space. First with the Zoe and now with the Renault 5.