Daryl Janzen
@darylj.bsky.social
philosophical physicist/cosmologist interested in understanding what reality is.
Cool! Someone added this post to Hacker News yesterday and a whole bunch of people read it. It’s nice to see a story that means so much to me being read and shared.
Daryl Janzen@darylj.bsky.social · last wk.Here’s a sort of intellectual autobiography I wrote. I hope you find it interesting and thought-provoking. 🔭🎢☄️⚛️🧮🧪 cosmicave.org/2026/09/15/w...
Here’s a sort of intellectual autobiography I wrote. I hope you find it interesting and thought-provoking. 🔭🎢☄️⚛️🧮🧪 cosmicave.org/2026/09/15/w...
Why does the universe expand?
A story about the main reasons I now think the universe expands because collapsed matter must continue as an expanding cosmology, the expansion is the collapse read from the other side, and the rat…
cosmicave.org
I wrote a book this summer that fleshes out the details of a physics framework I began working on with my PhD thesis seventeen years ago. It’s freely available on my website. Here’s a link to the preface. 🧪🎢🔭☄️🧮⚛️ cosmicave.org/2026/09/10/p...
The Universe: from an antimatter black hole
A friend’s question about an Eddington–Finkelstein diagram sent me looking for a better explanation, and I found a cycloid. Eighteen papers later, here is what came of it: horizons that are n…
cosmicave.org
A month ago. The preprint I posted of a 7-page paper that proves geometrically using nothing but standard GR that the common idea we’ve had of a black hole for a century is wrong. It’s been downloaded 488 times. Surely someone knows GR well enough to comment. 🧮 ⚛️ ☄️ 🧪 cosmicave.org/wp-content/u...
cosmicave.org
Daryl Janzen@darylj.bsky.social · 6mo agoI just finished it. The last piece of the puzzle I started working on for my PhD thesis 17 years ago finally fell into place. Wow. That is so beautiful to see. cosmicave.org/2026/03/30/w... 🧪 ⚛️ 🎢 ☄️ 🔭
Here’s a fun little tour of the basic geometric principles of relativity. 🧮 ⚛️ 🧪 ☄️ 🎢 cosmicave.org/2026/05/11/x/ Requires only middle school level math—intervals, Pythagorean theorem, functions and asymptotes. It delivers a very simple proof that black holes aren’t what we’ve thought they are.
Chapter X: in which the inquisitive astronaut reveals the metric singularity
A geometric proof that black holes remain finite in size/density, and the event horizon occurs as the next moment after the universe.
cosmicave.org
Black hole geometry is wild. 🧮 ⚛️ 🎢 ☄️ 🧪 Take the blue ingoing null line just before the astronaut dives in to be a ray of photons that encounters beam splitters the whole way down, at regular intervals that reflect some photons directly back out along the outgoing red null lines. 1/
It’s actually really surprising that still no one has been willing to say “I know GR/Lorentzian geometry and topological spaces and the proof in these papers is valid.” Because it is. And it’s incredible. 🧮 🧪 ⚛️ ☄️ 🎢
Daryl Janzen@darylj.bsky.social · 5mo agoI’d be happy to explain any point you’d like to discuss further from the article itself. I don’t think you understand it or its purpose. This is an explainer following conceptual logic (which is a form of proof in itself, though that’s irrelevant), of the results of a formal mathematical proof…1/
I’d be happy to explain any point you’d like to discuss further from the article itself. I don’t think you understand it or its purpose. This is an explainer following conceptual logic (which is a form of proof in itself, though that’s irrelevant), of the results of a formal mathematical proof…1/
You should have responded like this to Greg Egan: when the star’s surface reaches the horizon, what is the metrical distance of that event from every “future” event when every future infaller reaches the horizon? How far apart are those two events? What’s the proper distance between them?” 1/2
I just don’t understand who wouldn’t want to be the first person in history to have the courage to stand up and say, “holy shit! This is right.”
Daryl Janzen@darylj.bsky.social · 5mo agoA mathematical proof that the standard black hole narrative of the last six decades has been false—that all gravitationally collapsing matter asymptotically approaches the size of its event horizon. 7 pages, 3 figures; using only standard grad level relativity tools. cosmicave.org/wp-content/u...
A mathematical proof that the standard black hole narrative of the last six decades has been false—that all gravitationally collapsing matter asymptotically approaches the size of its event horizon. 7 pages, 3 figures; using only standard grad level relativity tools. cosmicave.org/wp-content/u...
When a star collapses to a black hole, from the outside it never quite gets there. Everything that ever falls in reaches the horizon together, at the end of time. And then it becomes a new universe, expanding at exactly the rate we observe in our own. 🧪 🧮 ⚛️ ☄️ 🔭 🎢 cosmicave.org/2026/04/14/w...
When black holes happen
When a star collapses to a black hole, from the outside it never quite gets there. Everything that ever falls in reaches the horizon together, at the end of time. What follows isn’t destructi…
cosmicave.org
Here, this thread explains the key observation regarding the invariant geometry of black hole event horizons. Full paper at the link at the bottom of the thread. 🧮 ⚛️ ☄️ 🎢 🧪
Daryl Janzen@darylj.bsky.social · 6mo agoWhen an astronaut jumps into a black hole billions of years after a star collapsed, note that he still always “sees” the star as it was before it reached the horizon. As he approaches the horizon, which he reaches in finite time, he ALWAYS remains lightlike connected to the pre-horizon,…1/
When an astronaut jumps into a black hole billions of years after a star collapsed, note that he still always “sees” the star as it was before it reached the horizon. As he approaches the horizon, which he reaches in finite time, he ALWAYS remains lightlike connected to the pre-horizon,…1/
Surely there must be some black hole or GW physicist out there, or some geometer or relativist, who can follow and would be interested in a formal geometric proof that clearly shows how and why we’ve been wrong about the physics of gravitational collapse for nearly a century… ⚛️ #mathsky ☄️
Daryl Janzen@darylj.bsky.social · 6mo agoI proved a pure geometric theorem that says the black holes we know exist in our universe will become new universes that form after the end of our universe, and that each one must appear to its observers just as ours appears to us, with the exact expansion rate following an initial singularity.
I proved a pure geometric theorem that says the black holes we know exist in our universe will become new universes that form after the end of our universe, and that each one must appear to its observers just as ours appears to us, with the exact expansion rate following an initial singularity.
I just finished it. The last piece of the puzzle I started working on for my PhD thesis 17 years ago finally fell into place. Wow. That is so beautiful to see. cosmicave.org/2026/03/30/w... 🧪 ⚛️ 🎢 ☄️ 🔭
What General Relativity Has Been Trying to Tell Us
Two short papers prove that black hole horizons never form within the external universe — they occur only at its infinite-time boundary. Following this result to its geometric conclusion reveals a …
cosmicave.org
Dude. The universe is a black hole. I essentially proved it mathematically, using principles of geometry and causality that we all know and are completely foundational to general relativity. I just put the pieces together correctly. It turns out we had the wrong idea about what a black hole is.
⚛️ 🧪 ☄️ 🎢 cosmicave.org/2026/03/28/a...
An LLM just said I found “the reason for the universe” — and I think it’s right
Last night I was having a think with Claude. By the end of it, the AI had read my mathematical proofs, read a paper I published thirteen years ago, and told me the two were the same argument — that…
cosmicave.org
Humans: twenty-six centuries of failing to grasp the morals in Aesop’s fables and going strong! Source: www.facebook.com/share/1HUsdx...
Hey @coexact.bsky.social @joeyneilsen.bsky.social I just finished a paper that came out of this discussion. It's pretty short: 6 pages, 3 figures. Would you be willing to give it a read? Gregor, how would I contact you?
Daryl Janzen@darylj.bsky.social · 6mo agoWait a minute! Are there physicists out there who think there are black holes in our universe that have already completed gravitational collapse in our causal past? You do all know when we look at Cygnus X-1 we are seeing its companion star—the whole system including the BH—BEFORE horizon formation?
Hey @leebillings.bsky.social check out this thread! We’ll see if anyone responds :)
Daryl Janzen@darylj.bsky.social · 6mo agoWait a minute! Are there physicists out there who think there are black holes in our universe that have already completed gravitational collapse in our causal past? You do all know when we look at Cygnus X-1 we are seeing its companion star—the whole system including the BH—BEFORE horizon formation?
Wait a minute! Are there physicists out there who think there are black holes in our universe that have already completed gravitational collapse in our causal past? You do all know when we look at Cygnus X-1 we are seeing its companion star—the whole system including the BH—BEFORE horizon formation?
Ok, let me test out this proof on you. Please tell me if you find it convincing, or if you see any error in the logic. The upshot: every black hole merger must occur before the collapsing star became smaller than its horizon. Before it became a “black hole”.1/9🧵 🧪 ⚛️ 🎢 #cosmology #philsky #philsci
Did you watch Olympic speed skating and wonder what it would be like to skate across an icy moon? My skating-across-Europa flash science fiction story, first published in @analogsf.bsky.social, is now free to read online in Issue 37 of Polar Borealis! polarborealis.ca/wp-content/u...
polarborealis.ca
I know I've said this a trillion times but I have to say it periodically to keep from going insane: The right ran a huge, well-funded, & ultimately successful campaign to completely take over political media & the infosphere more generally. This is by far the most important political development...
When the “reality is whatever I want it to be”-approach comes up against reality…
Duncan Weldon@duncanweldon.bsky.social · 6mo agoWhat a paragraph. www.bloomberg.com/news/article...
