Hacker News: nuccy

New comment by nuccy in "Use your Nvidia GPU's VRAM as swap space on Linux"

nuccy — Wed, 03 Jun 2026 07:19:42 +0000

Best case is if gaming and productivity (with high memory use) activities are not concurrent, and productivity applications are stopped before gaming starts, then `swapoff` can easily release swap device without restart.

New comment by nuccy in "White Rabbit – sub-nanosecond synchronization for large distributed systems"

nuccy — Mon, 25 May 2026 07:41:14 +0000

In our lab tests phase lock jitter between WR client and master is about 10ps (picoseconds) over 50km fiber (with temperature change of the fiber, so WR actively compensates elongations), so relative clock of one system can be transmitted with about that accuracy to another.

P.S. There is WR workshop this week with some talks being publicly available on CERN's indico website.

New comment by nuccy in "Ask HN: What are you working on? (May 2026)"

nuccy — Sun, 10 May 2026 22:58:11 +0000

Please comsider adding log-scales to be able to compare related but wastly different in popularity topics. Also would be nice to show one topic versus another to see a correlation.

Thanks.

New comment by nuccy in "62 years in the making: NYC's newest water tunnel nears the finish line"

nuccy — Mon, 29 Dec 2025 00:49:41 +0000

Rivers (e.g. Mississipi) work with much smaller gradient of just 0.01% [1], while with your assumption it would be 0.25%, so 25x.

Maybe instead it needs to pass under the rivers [2: cross-section] surrounding New-York, which may be much deeper, especially when it comes closer to the bay passing Queens and Brooklyn [2: map]

1. https://en.wikipedia.org/wiki/Mississippi_River

2. https://gordonsurbanmorphology.wordpress.com/2014/10/26/wate...

New comment by nuccy in "Clock synchronization is a nightmare"

nuccy — Sun, 28 Dec 2025 20:57:02 +0000

As of now, for testing, the two WR endpoints are sitting on the same desk with 50km fiber in a thermal chamber (simulating temperature changes in the soil), but in future they will be separated indeed.

New comment by nuccy in "Clock synchronization is a nightmare"

nuccy — Sun, 28 Dec 2025 00:04:09 +0000

As a user of WhiteRabbit, I can confirm a sub-10ps sync (two clocks phase lock) over 50km fiber connection for variable temperature of fiber (biggest problem of clock sync over fibers is temperature induced length change of the fiber itself, which needs to be measured and compensated).

New comment by nuccy in "Clock synchronization is a nightmare"

nuccy — Sun, 28 Dec 2025 00:01:25 +0000

Nature (laws of physics) is agains you on this: it is in fact impossible for everyone. What is in sync for some observers can be out of sync for others (depends on where they are, i.e. gravity, and how they relatively move). See general and special relativity principle of simultaneity [1].

1. https://en.wikipedia.org/wiki/Relativity_of_simultaneity

New comment by nuccy in "China reaches energy milestone by "breeding" uranium from thorium"

nuccy — Sun, 23 Nov 2025 00:10:18 +0000

Many reactors are built far away from coasts, they need water in general, but artificial lakes, or rivers are enough.

New comment by nuccy in "AirPods libreated from Apple's ecosystem"

nuccy — Sun, 16 Nov 2025 20:01:04 +0000

Actually even within Apple ecosystem not all devices are made equal. MacBooks lack some features available for AirPods Pro on iPhones, e.g. seal check, translation, everything in the "accessibility" category: button press duration settings, single-airpod noise-cancelling, etc.

Android obviously is out of the game totally for AirPods - no spacial audio, no changes of ANC, no battery level, but at least ANC modes can be changed on AirPods directly, and button press works to answer calls, and pause/play audio, and also volume control works.

I'm three-generation Airpods Pro (around 5 years) user on Android and Macbook (no iPhone at all). In first and second generation there was a "bug" (or intentional feature) that even when connected to Android, and not being connected to my Mac, the latter was showing the charge level on both Airpods, but at some point it was removed.

In first and second generation I had an issue with one AirPod making strange noises, in both cases even Apple Support at the Genius Bar didn't know what to make out of it that I don't use AirPods with iPhone, but only with a Mac (and Android).

New comment by nuccy in "Laptops with Stickers"

nuccy — Wed, 12 Nov 2025 08:49:21 +0000

I would actually consider sticking the opposite "Nuclear power? Yes, please!" (Same for solar, wind, geothermal of course). Is there a sticker for pro-nuclear power movement?

P.S. There's a nice recent video to have a glimpse into nuclear power plant safety in action: https://youtu.be/v0afQ6w3Bjw

New comment by nuccy in "James Webb Space Telescope reveals that most galaxies rotate clockwise"

nuccy — Mon, 31 Mar 2025 22:06:03 +0000

Answering to your and original question above: there are no poles (or axes of rotation) in the Universe. On large scales (think distances to include thousands and millions of galaxies each with billions of stars with even more planets) the Universe is uniform - isotropic and homogeneous [1]. It is expanding with acceleration in all direction in each and every point of its space, so there is no preferred direction thus in average we should have 50% of clockwise and 50% of counter-clockwise galaxies since orientation of those should also be absolutely random in average, unless something when the Universe was being created or evolving affected that balance.

1. https://en.wikipedia.org/wiki/Cosmological_principle

New comment by nuccy in "NASA to launch space observatory that will map 450M galaxies"

nuccy — Wed, 12 Mar 2025 11:46:05 +0000

To add to the list (the order is arbitrary):

5. Advances in the multi-messenger observations, where apart of photons and gravitational waves, astronomers can detects also neutrinos with specialized neutrino detectors, e.g.: IceCube [a], though there are many more of those [b].

6. Advances in very-long-baseline interferometry [c] using a globe-sized array of radio-telescopes, like Event Horizon Telescope [d]

[a] https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory

[b] https://en.wikipedia.org/wiki/Neutrino_detector or here https://en.wikipedia.org/wiki/List_of_neutrino_experiments

[c] https://en.wikipedia.org/wiki/Very-long-baseline_interferome...

[d] https://en.wikipedia.org/wiki/Event_Horizon_Telescope

New comment by nuccy in "Walt Disney's MultiPlane Camera (Filmed Feb. 13, 1957) [video]"

nuccy — Mon, 10 Mar 2025 07:36:15 +0000

Some technologies have been lost, even though they were superior to what is available today. Take, for example, the old “green/blue screen” technique using sodium vapor lamps, used by Walt Disney in film production in the pre-digital era: https://youtu.be/UQuIVsNzqDk (12 minutes long, but totally worth it).

New comment by nuccy in "Athena spacecraft declared dead after toppling over on moon"

nuccy — Sat, 08 Mar 2025 09:21:03 +0000

Another non-obvious problem is that RTGs, as any other thermal machines, need a gradient of temperature to work, i.e. to generate electrical power there should be hot (nuclear material) and cold (radiators) side. On interplanetary spacecraft (Voyager, New horizons) Sun is in a predictable (and stable) direction so RTG's radiators can be put in a permanent shadow of the spacecraft. On the Moon the sun is moving, and there is no atmosphere (unlike on Mars where RTGs are used), so on a small spacecraft RTG will need to be dug deep into the regolith which is absoluteky non-trivial since just landing straight sometimes is a problem.

There are always tradeoffs, it is almost never "why don't they just" case in spacecraft development.

New comment by nuccy in "Athena spacecraft declared dead after toppling over on moon"

nuccy — Sat, 08 Mar 2025 08:24:59 +0000

Generally I agree, but Moon is not a bad place for solar panels if a spacecraft has no contingencies and is able to harvest energy during Moon's day and store it in batteries to be used over the night. The sufficient power can be generated by a solar panel of the size (or even smaller) of the spacecraft itself. The other story is for missions like Juno [1] or Europa Clipper [2] which use solar panels near Jupiter - instead of centering develoment and mass budget around payload most of the spacecraft is an enourmously sized solar array. Juno panels generate 14kW on Earth orbit and only 500W near Jupiter [1].

1. https://www.jpl.nasa.gov/news/nasas-juno-spacecraft-breaks-s...

2. https://www.nasa.gov/missions/europa-clipper/nasas-europa-cl...

New comment by nuccy in "U.S. pauses all military aid to Ukraine"

nuccy — Tue, 04 Mar 2025 01:44:51 +0000

Thus two messages for every other country:

1. Make nukes, never give up on those regardless of what assurances of safety you get

2. If you are bigger and stronger - you are right, do whatever you want, international laws and rules do not matter any more

Lets see where all this will bring the world to in the next 10 years or a generation.

New comment by nuccy in "Sri Lanka scrambles to restore power after monkey causes islandwide outage"

nuccy — Sun, 16 Feb 2025 02:44:25 +0000

The operations are international and are carried out not only by squirrels, weasels (some say martens) are also involved. One of those (unlikely unintentionally) had shutdown the Large Hadron Collider at CERN in 2016:

1. https://www.bbc.com/news/world-europe-36173247

New comment by nuccy in "Turn any bicycle electric"

nuccy — Thu, 23 Jan 2025 22:59:12 +0000

The video is indeed very nice, it shows few things [1] not mentioned on the website:

- the chain is routed through the add-on device, so it should be longer than usual

- the pedals don't rotate when the chain and the wheel do, so there is a custom pedal hub with a ratchet mechanism

1. https://youtube.com/watch?v=SFsnS0Yb1Bs&t=83s

New comment by nuccy in "Celestial Navigation for Drones"

nuccy — Tue, 21 Jan 2025 09:01:27 +0000

You are right: to find a location from a star image you need a true horizon, but unless UAV is pulling some Gs even a basic accelerometer would give you the horizon, accuracy of that estimation will limit the accuracy of your location.

Regarding satellites: so "starting with the slowest moving" requires a series of images, doesn't it? Then how do you know "your approximate location"? From stars? In theory I understand what you say but practically it would be much more complicated and the obtained accuracy would not be better than with the stars, since in either case you also need a horizon to know your location.

New comment by nuccy in "Celestial Navigation for Drones"

nuccy — Tue, 21 Jan 2025 07:41:55 +0000

If you see satellites then likely you see even more stars. Unlike satellites the stars barelly move (actually they do, see "proper motion" [1]) relatively to each other, so a catalogue of stars (two coordinates values and two proper motion values) along with the time of observation is sufficient to be used over decades, unlike NORAD orbit elements requiring regular updates. With stars you need just one image at a known time to find your location, with satellites it is much much more complicated: you need to know where the sun is, you need few images of a satellite or even a video (likely on top of image of stars anyway) to distinguish it from the stars and to solve the trajectory.

1. https://en.m.wikipedia.org/wiki/Proper_motion