Daryl Janzen

The astrophysical nature of black holes—and the human nature of physicists What if black holes aren’t really what we think they are? And what if the bigger problem isn’t the physics at all, but how modern science decides which ideas are allowed to be discussed in public?…

I think we got gravitational collapse wrong. Penrose’s singularity theorem doesn’t apply to physics. No information loss.

I doubt black holes can be saved from this paper’s central theorem. If so, it’s not trivial: the paper has been in review 2.5 months. cosmicave.org/2026/01/18/t...

🧪⚛️🔭#philsky

Evaluation has always been challenging. This does make it a lot harder, but I don’t think impossible.

I’m teaching a large 100-level intro to stars class rn with assignments and exams 100% take home/no restrictions on AI use.

Burnout/health scare/crisis, a couple years ago in my early forties.

What’s others’ experience with this? There seem to be fewer people on BlueSky just going around calling others stupid. But does engagement on either platform ever go beyond shallow agreement, nitpicking, or mockery?

I tried to engage you a couple days ago, you stopped responding. Have tried on X as well, and nothing there.

Generally, on either platform I find physicists either respond to obviously stupid takes they can easily dunk on, or where there’s an echo chamber.

I’d welcome real discussion/dialogue.

The 4th dimension that describes 3D objects’ existence is time. To describe a 4D thing as existing requires the same. The fact that spacetime has a time dimension doesn’t change that. An existing 4D manifold doesn’t contain the dimension that describes its own existence, any more than the cup does.

Try this: think of a 3D cup sitting on a table. Now think of every instant of that cup’s existence, as it sits on that table. All those instants can be gathered together to form a 4D worldtube. That worldtube is a 4D model representing all-at-once every instant that occurs in the 3D cup’s existence.

Space-time doesn’t exist — but it’s a useful concept for understanding our reality Space-time isn’t an actual object or event, it’s a conceptual framework for understanding reality.

Hey! You might find this article I wrote interesting. I’d be curious what you think. theconversation.com/space-time-d...

Does space-time really exist?

Imagine mapping every passing moment of its supposed existence to a representative model (3+2)-D space-time. This 5D map contains the entire history of 4D space-time’s existence, just as 4D space-time contains the history of 3D space’s existence.

🧪 ⚛️ 🔭

That is an interpretive choice, not something settled by the empirical evidence for black holes, nor something required by the mathematical structure of GR itself.

I’m not disputing that black holes exist. The question is whether the globally defined event horizon, which is only fixed relative to the entire future of spacetime, should be treated as a physically real boundary in the present, rather than as a retrospective feature of the formalism.

That’s the formal reason the definition is teleological. My question was whether treating that teleology as a feature of reality (rather than of the formalism/interpretation) is actually valid. But enjoy your icebreaker.

Don’t teleological or seemingly paradoxical consequences like this signal to you that the relativity of it all is worth thinking through more carefully? Isn’t it a signal we ought to examine the interpretive framework more carefully rather than just marvelling at the weirdness?

Top-right “leleton” and bottom-left “skuge”?

In fact, the the first quote is about rhetoric, and the examples I listed _are_ very common assertions.

In any case, if you read the actual essays I've linked there, you would see very clearly that I am not focused at all on eternalism or an idea that everyone believes it. Not by a long shot.

Oh I think I see the misunderstanding. Yes, I called eternalism the standard interpretation of relativity, in that it is the historically dominant, canonically taught metaphysical gloss on the formalism (Einstein/Minkowski/Weyl-style reading).
I never meant to claim that's what most people believe.

I never claim the block universe is universally accepted, nor that there’s no debate. I explicitly discuss presentism, growing block, and eternalism, and argue relativity admits an interpretive fork.

I went back through every essay I linked. Your reply attacks a position I didn’t take. That’s a straw man. It’s dishonest. If you want to disagree, engage what I actually argued.

Sorry, but is that a claim I’ve made somewhere? In any case it’s certainly not engagement with essays I’ve written on the subject. I think it’s an odd (straw man) thing to object to if you read the essays.

Is it ethical and intellectually responsible when academics ignore or suppress challenges to their preferred frameworks? When experts declare that time does not really pass and that reality is a static four-dimensional block, they are not merely offering opinions — they are shaping how millions understand the world. …

cosmicave.org/2026/02/16/i...

@chanda.blacksky.app here’s an essay I’ve been sitting on for a couple of months. I initially hoped @theconversation.com would publish it as a follow-up to the linked essays, but I didn’t hear back. I thought it was worth posting now to share with you as an example of my point. 🧪 ⚛️ 🔭 #philsky

This is an example of what concerns me. It’s something I’ve written a lot about. But my views aren’t popular and no one who holds the views promoted in this book will engage. Ever. They simply ignore, then go on promoting a picture I see as wrong and pretending it’s the only option. It’s dishonest.

I feel like, in physics anyway, everyone is allergic to real, deep, critical challenge, and narratives are growing either stale or wildly speculative and nonsensical—and that’s a greater contributor to the science literacy crisis.
And that’s not criticism of you! (I still haven’t read your book.)

I posted it here in case anyone’s willing to have a look at it: cosmicave.org/2026/01/18/t...

I have a very simple and straightforward paper that’s been under review for 2 months at a leading GR/quantum gravity journal. It dos nothing exotic, but proves something about black holes I think no one wants. I’d love feedback, but no one seems to want to offer an opinion.

Well that’s an apt and disconcerting comparison!

Reply all with “ai;dr”

I saw that yesterday and think it should become widely used.

Thanks. I’ve been rather an outsider, never really let into this world. It’s interesting to glimpse behind the curtain.

I agree that conflicts of interest and bias can be messy and difficult to avoid. Even so, it’s good to recognise the problem exists and to want a better way.

Thanks for sharing your experiences and reflections. It matters.

Sometimes it’s difficult not hating the world.

Also: this is an important thread, and you should read the whole thing.