Alec Chen

loyal customer to: fernando's (champaign, il), nicecream (arlington, va)

[Alec Chen @alecchendev]

A brief explanation of my feed: Experimenting with using Twitter as a sort of public notebook, an incentive to practice organizing/articulating my thoughts, and a record to point people to see the kinds of ideas on my mind. Feel free to pm me about anything!

[Alec Chen @alecchendev]

If you wanted to travel from one place on the ocean floor to another, how would you do it? Would you pave roads and lay rail?

[Alec Chen @alecchendev]

What if you press your car key out of range of your car? Wouldn't they go out of sync? Yes eventually, but the car will look for a window of presses, and will resync automatically. If you press it truly too many times, apparently it'll stop working and you need to take manual action in your car.

[Alec Chen @alecchendev]

Was wondering about identification in car keys. Turns out they are safe from replay attacks. Naively, if you just have a static number ID or signature you send to uniquely identify your key to your car to be unlocked, someone could record that message, and replay it later to unlock your car...which would be bad. They use sequence numbers to solve this. The car and the key increment a part of the signed message in a deterministic way so they can both independently agree without extra coordination on a new message, and so that each unlock requires a new signature, and a previous value cannot be used to unlock your car. I never thought of the cryptography used in such a basic daily tool.

[Alec Chen @alecchendev]

A while ago I remember walking into the bakery nearby my apartment. A man asked "do you guys sell bread?" I thought it was a funny question until, to our surprise, the baker said they didn't. They have to wait a year or two for permitting for a real bread oven. They share power with the Palisades reconstruction, and they're letting them "do their thing." She clarified the real issue is the California grid can't support the electric ovens they mandate. So the world is being deprived of delicious bread because of energy infrastructure issues 😂

[Alec Chen @alecchendev]

i love learning things. and there's a lot i want to learn and haven't yet. i am still struggling to figure out the best way that allows me to follow my curiosity, but be consistent, and continuously increase depth. i still feel the main options for learning today are too extreme on the top-down <-> bottom up spectrum. i read a textbook but i don't stick with it because i lack the meaningful context for the knowledge to stick. i have a conversation with an AI but it's a one-off and lacks sufficient depth. i think my attempts with noobular have been in the right direction, but haven't quite cracked it. let me try and flesh out more details of my ideals:

- nothing can replace writing. i'm not sure if it's necessary to incorporate as a part of some system, or just as a separate habit that enhances learning/thinking.
- spaced repetition seems very key. i find it exciting when i can connect more of my mental models together, and the more i can connect the better things stick. the only way to keep connecting is to actively resurface them into working memory from time to time. i have never tried anki because it feels too mechanical/brute force. but it seems like the core premise is really valuable. just need some way to regularly surface random things i learned or questions I asked over time.
- questions as the entrypoint. the atom of curiosity. a big list of questions i have is probably close to the simplest + most accurate representation of my curiosities. i want a system where my questions are the focal point.
- say all knowledge can be represented in some sort of big graph/tree/network. i basically want to just traverse it freely, but have a coach that keeps me consistent/on track. in platforms like math academy, you traverse a knowledge graph, mastering material before moving onto the next thing, using various effective learning techniques to maximize efficiency. i want to do that but instead of a preset course, an organically growing/interconnecting graph seeded by my curiosity/questions.

[Alec Chen @alecchendev]

TIL apparently nearly 75% of all aluminum ever produced is still in use today due to recycling.

[Alec Chen @alecchendev]

Every day going south on the 405 there's one bridge where there's usually some sort of sign of political activism. Today the sign said, "stop the Epstein cover-up" and there were a bunch of people honking from their cars. There is something empowering about knowing that other random people feel the same and that it's not just you or your part of the Internet.

[Alec Chen @alecchendev]

I recently played a variation of around the world with this guy on the basketball court the other day that he called glory corner.

Instead of just doing 1,2,3,4 4,3,2,1 after the fourth, you can shoot from the corner. If you make it, you shoot from the straight on 3-point line. Depending on if you hit the backboard or swish you can advance straight to the final 2 or 1. Otherwise, you continue to the free throw, then the other corner you have another shot at the 3-point shebang, and if you miss that you proceed like normal.

he kept saying how he should patent it and how he'd make a lot of money if he did so. he kept saying how fun it was to play the other day when it was nice weather, and how the people he played with were so good, and how people were so shocked when he almost made a half court shot, but has never come close to a full court, but that some guys were trying the last time he played. he was disappointed how there wasn't anyone around who really played, and how we couldn't play because he'd just destroy me, and how his friends had made some excuse to not come out and play. but even if we couldn't play 1:1, he at the least could teach me his version of around the world. he won twice and i won once. given the way he talked it didn't really seem like he was the type to let other people win, so i guess i got a little lucky.

the way he shot some very standard balls was so mechanical. i don't watch much basketball, so i haven't seen much of this up close. it was clear he'd played a ton, though he also tossed the ball around for fun as much as someone who didn't play that much, and would throw it in ridiculous ways when he got frustrated and missed. it was fun.

[Alec Chen @alecchendev]

Reloading every hour is ~170 mbps and every day is ~7 mbps (per-martian). Non-trivial. This is mostly a fun thought experiment, and there's some knobs we could turn to maybe make this more practical, but this basic napkin math gives interesting perspective on some martian UX.

[Alec Chen @alecchendev]

I want to watch a youtube video on mars. If I know what video i want to watch (and have some way to identify it), i can simply request the video, and it'll arrive within 3-22min, and I can watch it then. Is that enough?

[Alec Chen @alecchendev]

Say 1 martian has 100 videos * 10 avg min/video, 1080p, 30fps. rough youtube streaming data rates for this are ~10mbps. 10 mbps * 60 sec/min * 10 min/vid / 8 bits/byte / 1000 MB/GB * 100 videos = 75 GB per load. Depending on load frequency this could require heavy bandwidth.

[Alec Chen @alecchendev]

This thread of ideas was inspired by powertown. I found it fascinating that a building could buy energy when prices are low, and transport it through time in order to use cheaper energy during peak hours to save on costs.

[Alec Chen @alecchendev]

Scaling battery storage enables the broader ability to custody energy, a new primitive in the market of energy. There were already ways of trading energy, i.e. oil and gas contracts on a macro scale, and programmatically varying load on bitcoin miners/data centers based on price.

[Alec Chen @alecchendev]

I wonder how much we'll see companies with massive battery deployments, that basically lease custody of energy like financial exchanges today, accompanied by retail + institutional trading -&gt; better price discovery, more liquidity, etc.

[Alec Chen @alecchendev]

How did we do this with vacuum tubes? How do vacuum tubes even work for transforming information? I do not know!

[Alec Chen @alecchendev]

I learned today that the frequency we usually refer to when talking about RF is typically the carrier frequency. When we transmit data over some frequency, we actually introduce multiple waves, often with different frequencies to encode data.

[Alec Chen @alecchendev]

This is actually what AM radio is, and is "relatively simple" (doesn't require fourier transformation) and is how we could have radio long before modern electronics.