ψ

Zeminem

[BSF 🇬🇧🐀 @BSF42069]

We’ve come a long way

[Latest in space @latestinspace]

🚨 This was the Artemis II crew's view this morning from 41,756 miles (67,200 km) up

No human has seen a crescent Earth in full since 1972

[outside five sigma @jwt0625]

you've joked about a spherical cow, but have you thought about higher multipoles of a cow, thus the tetrahexacontapole cow, and the octacosahectapole cow?

(figure showing 1, 2, 4, 8, 16, 32, 64 and 128-pole cow, and the full cow)

[Aakash Gupta @aakashgupta]

The signal strength hitting Earth from Voyager 1 is less than one trillionth of a watt.

To put that in perspective, your phone’s WiFi signal is roughly 100 billion times stronger, and it drops a connection walking between rooms.

NASA picks up Voyager’s whisper using arrays of 70-meter antennas, then reconstructs coherent data from it at 160 bits per second. That’s slower than a 1990s modem. Downloading a single photograph at that rate would take weeks.

The spacecraft itself runs on 8.8 kg of decaying plutonium-238 that generated 470 watts at launch in 1977. Today it produces roughly 200 watts, losing about 4 watts per year. NASA has been shutting down instruments one by one since the 1980s to keep the math working. They turned off the cosmic ray sensor just this year.

And here’s the part nobody’s talking about: there is exactly one antenna on Earth that can send commands to Voyager. Deep Space Station 43 in Canberra. It went offline for major upgrades from May 2025 through early 2026. During that window, if Voyager had a critical fault, the team would have had to wait months to respond.

A 48-year-old spacecraft built on 1970s computing, running on a plutonium battery that’s lost 60% of its output, transmitting at a power level that barely qualifies as existing, from a distance where light itself takes 23 hours to arrive. And a German observatory just casually picked up its carrier signal on a live stream.

The engineering margin NASA built into this mission was designed for 4 years to Saturn. Everything after that is borrowed time the engineers keep extending by doing math with 200 watts.

[carl feynman @carl_feynman]

When I was about 14, we went to a company that manufactured oxygen sensors. You dip this probe into beer, sewage, or canned food a-stewing, and it tells you how much oxygen is in the slurry. It's got two electrodes, and there's some kind of electrochemical reaction that releases exactly one electron for each oxygen molecule consumed. Measuring the electric current lets you measure the oxygen concentration. However, the electrodes are delicate, and don't work if they're not clean. So they're inside a tiny compartment covered with a membrane of oxygen-porous but everything-else-proof plastic. The oxygen has to diffuse through the plastic before it can be consumed at the electrodes. The current is determined by the rate of diffusion. Gunk on the membrane can slow down diffusion, causing it to read an incorrect low concentration. And when you take the sensor from fresh air and dip it into something, it can take a long time to consume all the oxygen in the compartment and start reading the actual flow.

So my dad suggested the following. Put a third electrode in the compartment, that regenerates one O2 molecule for each one consumed. Now the speed of diffusion doesn't matter because the oxygen isn't getting consumed. You're reading the concentration at the electrodes directly without affecting it. If the concentration around the sensor drops, oxygen can diffuse out of the compartment, instead of waiting for the oxygen to be consumed. And gunk on the membrane will slow down the reading, but it's still perfectly accurate.

We went back next year and saw them manufacturing the three-electrode sensors. IIRC, my father didn't have any good ideas that year.

[Hank Green @hankgreen]

Placing a layer of algorithmic recommendation on speech does not make speech less free, but it does pervert it.

Platforms do not value speech because it is protected, they value the service it provides them.

In most cases, this is fairly straightforward...the service your speech provides for the platform is the capture and retention of attention. Whatever speech is better at capturing and retaining attention is the speech that will be amplified regardless of truth, care, or consequence. In many cases, it is amplified specifically because it does not place any value on truth or consequence.

In an era defined by these platforms, that has resulted in an information economy (and a politics) driven almost entirely by how good something is at capturing and retaining attention. This effect can even do this to our minds, re-forming our thought processes to weight whether a thought would grab attention over whether it is true.

The fact that this is done solely for profit does not change that it is a perversion of your speech. It does not just change how you understand reality, it changes how you engage with that reality. When we know that our speech will be silenced if it does not capture and hold attention, we alter our behavior to say only the most attention-grabbing things.

If the medium is the message, then the message of algorithmic content platforms is not expression or connection or freedom. It is salience above all else.

This is what is happening to us on these platforms. They cannot behave any other way.

[Samplo Corvodina of Streatham @TreborRhurbarb]

Any excuse to post the most tragic segment on the entirety of Wikipedia

[NASA Solar System @NASASolarSystem]

BREAKING: Sugars essential for life have been found in pristine asteroid Bennu samples collected by NASA’s OSIRIS-REx spacecraft. Combined with previous detections of amino acids and nucleobases, we see that life’s ingredients were widespread throughout the solar system: https://t.co/Tb3HpwZG9J

More on the study led by Yoshihiro Furukawa of @TohokuUniPR⤵️

[Surajit @surajit_ghosh2]

Hawaii’s Kilauea volcano just unleashed a massive wing shaped eruption with lava fountains soaring 1,500+ feet high

[Andrew McCarthy @AJamesMcCarthy]

Here's the full photo briefly featured in my recent video post showing @BlackGryph0n against the full solar chromosphere after his jump. Crazy how small he looks despite being nearly 50,000,000x closer!

This ended up being my most popular print (vs the closeup) linked in my bio.

[Andrew McCarthy @AJamesMcCarthy]

Immense planning and technical precision was required for this absolutely preposterous (but real) view: I captured my friend @BlackGryph0n transiting the sun during a skydive.

This might be the first photo of it's kind in existence. See a video of this moment in the reply 👇

[ψ @feynman101]

@Peweiwa69 isto é o início da final saga 💀

[Neymar Jr @neymarjr]

🤍🖤 🇧🇷

[ψ @feynman101]

@_k4yn desenha um

[ψ @feynman101]

houve um ponto na minha vida em que eu conseguia desenhar um pentágono perfeito com um compasso e é triste que essa pessoa já não existe

[ψ @feynman101]

doing the dishes

[Ante D. Luvian @uncle_deluge]

You hear stories about monkeys/apes in the early 20th century that are like "He could operate a railroad switch, was paid in nuts, would know if you were ripping him off. He wore clothes and drank cognac. Someone swore they heard him talking" and then nothing for a hundred years

[ψ @feynman101]

como resolver uma demonstração matemática:

ver o caminho para a solução e fazer todos os passos metodicamente ❌

fazer merda de todas as formas diferentes até chegar à resposta certa sem saber como ✅

[ψ @feynman101]

@_k4yn já disse que foi meu vizinho

[ψ @feynman101]

estou em londres há 2 semanas e já me perguntaram 3 vezes se conheço o diogo dalot wtf