2026-02-03 20:56:58
Yesterday I ran across the following mashup by Amy Swearer of a Polish proverb and the Serenity Prayer.
Lord, grant me the serenity to accept when it’s no longer my circus,
the courage to control the monkeys that are still mine,
and the wisdom to know the difference.
The proverb is “Nie mój cyrk, nie moje małpy,” literally “Not my circus, not my monkeys”.
The post Polish serenity first appeared on John D. Cook.2026-02-03 03:11:03
I saw an animation this morning showing how the space above our planet is dangerously crowded with satellites. That motivated me to do a little back-of-the-envelope math.
The vast majority of satellites are in low earth orbit (LEO), which extends from 160 to 2000 km above the earth’s surface. The radius of the earth is about 6400 km, so the volume of the LEO region is
There are about 12,500 satellites in LEO, so the average volume of LEO per satellite is about 100,000,000 km³.
Now this isn’t the last word in collision avoidance—there are lots of complications we’re not going to get into here—but it is the first word: there’s a lot of space in space.
The post Satellites have a lot of room first appeared on John D. Cook.2026-01-31 03:46:37
Demis: “[to get to AGI] maybe there’s one or two big innovations needed”
Sam: “everything based off what we see today is that it will happen.”
Ilya: “But is the belief really that if you just 100x the scale, everything would be transformed? I don’t think that’s true.”
Dario: “If you just kind of like eyeball the rate at which these capabilities are increasing, it does make you think that we’ll get there by 2026 or 2027.”
Jerry: “is [the transformer architecture] the last thing? I’m pretty sure it isn’t.”
For years leading researchers have been speculating one way or the other as to whether better algorithms are needed to get to AGI, artificial general intelligence (however that might be defined).
Around the time of the release of GPT-4, some were saying they felt something more was needed. Since then, we have had several major new advances, like reasoning models and tool use. If we’d said, “we don’t need anything else” three years ago, where would we be now?
For frankness, I like this from John Schulman: “it’s hard to know what we need.” And for strategy, Demis: “you can think of as 50% of our effort is on scaling, 50% of it is on innovation. My betting is you’re going to need both to get to AGI.”
The post AGI, ASI, A*I – Do we have all we need to get there? first appeared on John D. Cook.2026-01-31 01:09:30
Cryptocurrency and privacy don’t fit together as easily as you might expect. Blockchains give you the illusion of privacy via pseudonymization: you don’t put your name on a blockchain, but you do put information on a blockchain that can be used to determine your name. Blockchain analysis can often reveal information that no one intended to share.
This is true even for privacy coins like Monero and Zcash. These coins put less information directly on chain in the clear, but they still have to be used with skill to maintain privacy. And because they can offer more privacy, they are harder to use. For example, an exchange might let you swap between a thousand different currencies, but privacy coins are conspicuously missing from the list of options. Or maybe you can move money into Zcash, but not with privacy, i.e. not into the shielded pool.
The Privacy trends for 2026 report from a16z summarizes the current situation very well.
Thanks to bridging protocols, it’s trivial to move from one chain to another as long as everything is public. But, as soon as you make things private, that is no longer true: Bridging tokens is easy, bridging secrets is hard. There is always a risk when moving in or out of a private zone that people who are watching the chain, mempool, or network traffic could figure out who you are. Crossing the boundary between a private chain and a public one—or even between two private chains—leaks all kinds of metadata like transaction timing and size correlations that makes it easier to track someone.
As is often the case, the weak link is the metadata, not the data per se.
The post Bridging secrets is hard first appeared on John D. Cook.2026-01-25 00:56:33
I saw a post on X recently that said
Bill Gates is closer to you in wealth than he is to Elon Musk. Mind blown.
For round numbers, let’s say Elon Musk’s net worth is 800 billion and Bill Gates’ net worth is 100 billion. So if your net worth is less 450 billion, the statement in the post is true.
The reason the statement above is mind blowing is that in this context you naturally think on a logarithmic scale, even if you don’t know what a logarithm is.
Or to put it another way, we think in terms of orders of magnitude. Musk’s net worth is an order of magnitude greater than Gates’, and Gates’ net worth would be an order of magnitude greater than that of someone worth 10 billion. Musk is a notch above Gates, and Gates is a notch above someone with a net worth around 10 billion, where a “notch” is an order of magnitude.
To put it another way, we think in terms of geometric mean √ab rather than arithmetic mean (a + b)/2 in this context. 100 billion is the geometric mean between 12.5 billion and 800 billion. Geometric mean corresponds to the arithmetic mean on a log scale. And on this scale, Gates is closer to Musk than you are, unless you’re worth more than 12.5 billion.
Here are three more examples of geometric means.
The size of Jupiter is about midway between that of earth and the sun; it’s the geometric mean. On a linear scale Jupiter is much closer to the size of the earth than the sun, but on a logarithmic scale it’s about in the middle. More on that here.
The tritone (augmented fourth) is half an octave. So, for example, an F# is in the middle between a C and the C an octave higher. Its frequency is the geometric mean of the frequencies of the two C’s. More here.
Finally, the humans body is a middle-sized object in the universe. From Kevin Kelly:
Our body size is, weirdly, almost exactly in the middle of the size of the universe. The smallest things we know about are approximately 30 orders of magnitude smaller than we are, and the largest structures in the universe are about 30 orders of magnitude bigger.
The post Fortunes and Geometric Means first appeared on John D. Cook.2026-01-25 00:21:32
There is a way to prove that you know two numbers a and b, and their product c = ab, without revealing a, b, or c. This isn’t very exciting without more context — maybe you know that 7 × 3 = 21 — but it’s a building block of more interesting zero knowledge proofs, such as proving that a cryptocurrency transaction is valid without revealing the amount of the transaction.
The proof mechanism requires an elliptic curve G and a pairing of G with itself. (More on pairings shortly.) It also requires a generator g of the group structure on G.
The prover takes the three secret numbers and multiplies the generator g by each, encrypting the numbers as ag, bg, and cg. When G is a large elliptic curve, say one with on the order of 2256 points, then computing products like ag can be done quickly, but recovering a from g and ag is impractical. In a nutshell, multiplication is easy but division [1] is practically impossible [2].
The verifier receives ag, bg, and cg. How can he verify that ab = c without knowing a, b, or c? Here’s where pairing come in.
I go more into pairings here, but essentially a pairing is a mapping from two groups to a third group
e: G1 × G2 → GT
such that
e(aP, bQ) = e(P, Q)ab.
In our case G1 and G2 are both equal to the group G above, and the target group GT doesn’t matter for our discussion here. Also, P and Q will both be our generator g.
By the defining property of a pairing,
e(ag, bg) = e(g, g)ab
and
e(cg, g) = e(g, g)c.
So if ab = c, then e(g, g)ab and e(g, g)c will be equal.
[1] The literature will usually speak of discrete logarithms rather than division. The group structure on an elliptic curve is Abelian, and so it is usually written as addition. If you write the group operation as multiplication, then you’re taking logs rather than dividing. The multiplicative notation highlights the similarity to working in the multiplicative group modulo a large prime.
[2] The computation is theoretically possible but not possible in practice without spending enormous resources, or inventing a large scale quantum computer. This is the discrete logarithm assumption.
The post Proving you know a product first appeared on John D. Cook.
