carpdiem (u/carpdiem)

carpdiem commented on Project Hyperion: Interstellar ship design competition projecthyperion.org... · Posted by u/codeulike

namanyayg · 18 days ago

It was indeed incredible. Battled out in a pan Asia round, won it, and got invited to the ISSDC at the Kennedy Space Center in Florida. Felt so fortunate learning from engineers at Boeing and NASA. Incredible experience for a 15yo kid from India.

Coincidentally, it has been exactly 10 years since and my photos app resurfaced some of the memories. Good times.

carpdiem · 17 days ago

Another ISSDC alum here, but from a little more than a decade earlier. It really was a unique experience. I remember the finals at Kennedy Space Center fully exercised the extent of your mental and physical stamina both. It also delivered lots of surprisingly applicable lessons for startup life around coordinating technical teams in high-stress, high-stakes environments.

carpdiem commented on Interstellar Flight: Perspectives and Patience centauri-dreams.org/2025/... · Posted by u/JPLeRouzic

JumpCrisscross · 2 months ago

> Developing propulsion technology to reach 0.1c velocity will move the needle on interstellar propulsion from impossible to just barely feasible

More than barely. "A 40-year one-way interstellar flyby mission to the nearest stars will require a relativistic spacecraft speed in excess of 6000 AU/yr (i.e., > 0.1c)" [1].

That means, practically speaking, nuclear-fusion, antimatter-annihilation and directed-energy propulsion. All of which are TRL ≤ 2.

My bet would be on fusion propulsion. It's inherently easier than fusion power since you don't need to bother converting the energy to electricity. That said, solar sails [2] and directed-energy anti-drone weapons [3] are seeing quiet progress.

[1] https://ntrs.nasa.gov/api/citations/20200000759/downloads/20...

[2] https://www.nasa.gov/mission/acs3/

[3] https://en.wikipedia.org/wiki/Silent_Hunter_(laser_weapon)

carpdiem · 2 months ago

1 AU is about 8.3 light minutes. So 6k AU is about 50k light minutes. with ~525k minutes in a year, that means that 6k AU/yr is almost exactly 0.1c.

carpdiem commented on The future of solar doesn't track the sun terraformindustries.wordp... · Posted by u/surprisetalk

carpdiem · 4 months ago

I used to work on solar power plants and solar tracking technology back in the late 2000s. Even back then, I remember frequently discussing that "eventually panels will be cheap enough that we'll just wallpaper the world...". It's really nice to see that coming true.

carpdiem commented on Go and my realization about what I'll call the 'Promises' pattern utcc.utoronto.ca/~cks/spa... · Posted by u/ingve

carpdiem · a year ago

Lordy, I clicked on this, fully expecting a discussion of a shape-pattern in the board game of Go, and somehow didn't have a thought in my mind for the real, completely different, meaning.

This reminds me of "trompe l'oeil foods"... dishes that appear to be one thing, but are another entirely. Or maybe optical illusions more generally.

carpdiem commented on AppleWatchAmmeter github.com/jp3141/AppleWa... · Posted by u/rcarmo

ramses0 · a year ago

Similarly: supposedly superglue a magnet to your fingernail.

carpdiem · a year ago

I tried this once. There was no convincing effect for being able to "detect by feel" AC currents, but you could definitely notice magnetic materials.

Maybe the most fun, though, was just playing around and "picking up" paperclips and tiny screws by flicking my finger at them.

carpdiem commented on Ask HN: What are some "toy" projects you used to learn neural networks hands-on? · Posted by u/profsummergig

carpdiem · a year ago

https://www.mnist.org

I wanted to actually build first-hand intuition on all of the choices around hyperparameter choices, activation functions, network architectures, etc. So I've been rigorously exploring them by training and testing models off of the mnist dataset.

Coming up soon: vision transformers, depth-of-architecture on CNNs, batch size investigations, and more.

Let me know if any of you have any suggestions of things to investigate next!

carpdiem commented on Miyazaki Might Be Right: Cases of a Town, a City, a Province, & a Country population.fyi/p/miyazaki... · Posted by u/RetiredRichard

carpdiem · a year ago

I'm all for innovative ideas in supporting families and children, but the examples from the article hardly count as "successfully reversing fertility declines".

- Nagi, Japan. TFR: 2.95 (replacement rate is ~2.1). Astonishing. This is the only true success in the article.

- Nagareyama, Japan. TFR: 1.5. At this rate, the population will drop by ~25% every generation.

- South Tyrol, Italy. TFR: 1.64. Marginally better than Nagareyama. Noticeably better than the rest of Italy (TFR: 1.2), but still a population in strong decline.

- Czechia. TFR: 1.6 (https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?location...). Better than the European median, but not exceptional. Roughly on a par with Lithuania (1.63), Belgium (1.59), and the UK (1.57). Noticeably behind France (1.79). None of these countries at such TFRs are even capable of maintaining their population at a stable level, and should all be regarded as undergoing some level of population collapse.

carpdiem commented on I organized a 20-acre game of Capture the Flag ntnbr.com/61/... · Posted by u/ntnbr

tern · a year ago

There's an intensive wilderness school in Washington, and their capstone activity is IIRC a 2 week long game of capture the flag in an even larger area of dense woods

It's a great way to test stalking, camouflage, and survival skills. A lot of the game is played in pitch darkness, where moving silently becomes critical. Rather than a fast-paced running game, capturing the flag often means inching into enemy territory over the course of days, and moving back to your side just as slowly without being detected.

carpdiem · a year ago

That sounds crazy, and amazing. As I've now got a kid of my own who might eventually be interested, could you point out _which_ intensive wilderness school in Washington that is? I did some googling, but wasn't able to find it.

carpdiem commented on Instinctive Sleeping and Resting Postures (2000) ncbi.nlm.nih.gov/pmc/arti... · Posted by u/alecst

carpdiem · a year ago

It would be interesting to know how the comfort or suitability of these postures is affected by physiology.

For example, even the suitability to obtain a deep squat may be affected by things like hip joint geometry: https://www.otpbooks.com/stuart-mcgill-hip-anatomy/

carpdiem commented on The Life and Death of the Bulbdial Clock ironicsans.beehiiv.com/p/... · Posted by u/arantius

floating-io · a year ago

The buried detail that Evil Mad Scientist was acquired by Bantam Tools deserves an article on its own IMO. I find it sad that such a nifty small (and seemingly very personal) business would get gobbled up (though I would be happy if they proved me wrong about the typical fate of acquired companies!).

carpdiem · a year ago

I'm reasonably good friends with Windell & Lenore, and I think "gobbled up" is not the right way to look at it.

It's my understanding that they've known the folks at Bantam for some time now, and that given how hard it can be to run a physical product company (especially one that does some in-house manufacturing for your own products!) in the bay area, that they're looking forward to having such niceties as 'pto'.

They're really excellent people, and made a huge difference to me when I first moved to the bay area, so while it's sad to see them leave, I understand it, and hope this leads to a better situation all around for them.