mc ☕ @mc@qoto.org

Maybe some of the kids are alright.
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RT @TikTokInvestors
She can save us.

https://twitter.com/TikTokInvestors/status/1525191029162315776

http://www.righto.com/2022/04/the-digital-ranging-system-that.html

The basic idea was to send a radio signal to the spacecraft and determine how long it takes to return. Since the signal traveled at the speed of light, the time delay gives the distance. The main problem is that due to the extreme distance to the spacecraft, a radar-like return pulse would be too weak. The ranging system solved this in two ways. First, a complex transponder on the spacecraft sent back an amplified signal. Second, instead of sending a pulse, the system transmitted a long pseudorandom bit sequence. By correlating this sequence over multiple seconds, a weak signal could be extracted from the noise.

In this blog post I explain this surprisingly-complex ranging system. Generating and correlating pseudorandom sequences was difficult with the transistor circuitry of the 1960s. The ranging codes had to be integrated with Apollo’s “Unified S-Band” communication system, which used high-frequency microwave signals. Onboard the spacecraft, a special frequency-multiplying transponder supported Doppler speed measurements. Finally, communicating with the spacecraft required a complex network of ground stations spanning the globe.

And: https://righto.com/apollo/ranging-xor.html

#hardware #random #retro #space

Feels important to pen an #introduction post worthy of a follow or two... 🥴

A lover of #tankespjärn #books #writing #reading #curiosity #singing #gardening #coldbathing #visiblemending and much more... I would not be where & who I am today if I hadn’t learned how to be & do gentle towards myself.

📍 in Malmö, Sweden

Favorite pastime since a year back is my pod of 5x5 meandering agenda-less conversations/season.

For blog posts, pod episodes, books etc, find out more at https://tankespjarn.com/

I have encountered more image descriptions on Mastodon in 24 hours than I have in Twitter in a couple of years. Seriously. I'm not exaggerating.
As a blind person, this means a lot to me. If you read this and you describe your images, thank you so, so, so much on behalf of all of us. If you don't, now you know you'll be helping random Internet strangers make sense of your posts by typing in a few more words than usual.

@deavmi I've always wanted to take a stab at Haskell.

What I've learned so far, for the benefit of other #Elongate refugees:

1) The best way to find people is to browse the #introductions hashtag. It's like walking into a party, talking to people at random, and deciding who you want to know more about.

2) The federated timeline is a firehose of extremely free speech with a very low signal to noise ratio. Your home or local timelines are probably better bets, but if you want to look into the unfiltered heart of the internet, you do you.

Looking for other #Science accounts to follow! Especially #SciComm and #Astronomy!

Some truths about programming:

If it's not documented, it's not useful.

To write fast software, use a slow computer.

Premature optimization is the root of all evil.

Shared mutable state is the root of all evil.

The user is always right.

Software that is designed for someone is more useful than software that is designed for everyone.

Good software can be declared complete in a finite amount of time.

Text is the universal interface.

Software should be able to outlive the author.

I might add more. Feel free to share your own thoughts too.

#software #programming