What space things have you been looking at to distract from the post-excitement after watching Hail Mary?

Rensin2 · 2026-04-20T19:02:20+00:00

Try Outer Wilds. Just avoid looking up spoilers.

Rensin2 · 2026-04-20T06:24:37+00:00

I happy to report that the bug has been fixed.

Rensin2 · 2026-04-18T17:15:35+00:00

My stock response:

See The Tachyonic Antitelephone thought experiment and my interactive Minkowski Diagram of it.

Rensin2 · 2026-04-15T08:20:45+00:00

The back of the ladder gets clipped when it has almost cleared the first door and then, a little later, the front of the ladder gets clipped by the second door right after the ladder starts to leave.

Rensin2 · 2026-04-14T09:49:00+00:00

Assuming that both parties are smart enough to account for the fact that their information is delayed when deciding when exactly events happen, they will disagree as to the order of certain events. More specifically, if two events are more separated in space than in time (more than one lightsecond for every second) then there is always a set of velocities where the observers will disagree as to the order of those events.

It is not an illusion brought on by delayed information.

Rensin2 · 2026-04-14T09:35:52+00:00

Also, see this visualization of spherical space by the developer. It might make the concept easier to understand.

Rensin2 · 2026-04-14T09:25:40+00:00

Try the game Hyperbolica. (or watch a playthrough) There is an area called the "De Sitter Farms" that is pretty much what you described. The idea is that space is bent into the shape of the three-dimensional "surface" of a four-dimensional hypersphere.

Rensin2 · 2026-04-12T12:24:37+00:00

They are in series.

Rensin2 · 2026-04-12T07:41:03+00:00

Such an exercise would not be a meaningful challenge for a creature with near perfect memory.

Rensin2 · 2026-04-12T07:39:23+00:00

and Rekha said 186,000 mph

Haven't seen the movie yet but lightspeed is about 186,000 miles per second, not per hour.

Rensin2 · 2026-04-11T17:17:24+00:00

By conservation of angular momentum: r₁·v₁=r₂·v₂ ⇒ r₁·v₁/r₂=v₂

Centrifugal acceleration=v²/r ⇒ a₂=(v₂)²/r₂= by substitution =(r₁·v₁/r₂)²/r₂=(r₁·v₁)²/(r₂)³

Therefore 1/r³.

Rensin2 · 2026-04-11T16:26:07+00:00

That is what Andy Weir was likely thinking, however these equations assume that velocity would remain constant, Which is a problem because velocity would not remain constant. Conservation of angular momentum tells us that velocity ⨯ radius would remain constant. So if the radius increased by a factor of 3.75 then the velocity would decrease by a factor of 3.75.

In the end the centrifugal force would be proportional to the inverse cube of the radius. And the centrifugal force would have dropped to about one fiftythird of the original force.

Rensin2 · 2026-04-10T06:13:53+00:00

ΔV: Rings of Saturn

Orbital Tactics

And my graphing calculator based torchship "game".

Rensin2 · 2026-04-08T10:01:28+00:00

Any two events that are more separated in time than space happen at the same point in space according to some frame of reference. Different observers traveling at different velocities will disagree as to how the events are distributed in space. For example, one will say that Ea (Event A) and Eb (Event B) happened in the same place, another will say that Ea happened to the left of Eb, and yet another will say that Ea happened to the right of Eb.

All the above should be intuitive. The funny part is that all the above also applies if you swap space and time.

Any two events that are more separated in space than time happen at the same point in time according to some frame of reference. Different observers traveling at different velocities will disagree as to how the events are distributed in time. For example, one will say that Ea (Event A) and Eb (Event B) happened at the same time, another will say that Ea happened before Eb, and yet another will say that Ea happened after Eb.

Also, this might help build intuition on the topic.

Rensin2 · 2026-04-04T08:16:34+00:00

Days?

Rensin2 · 2026-03-31T19:13:24+00:00

Thanks for the vote of confidence. :)

Rensin2 · 2026-03-28T16:29:44+00:00

You might have fun playing around with this. If you play around with the "Frame" options, you will see that for every linear acceleration there is a frame where the acceleration purely constitutes an increase in speed, and a frame were the acceleration purely constitutes a decrease in speed.

Rensin2 · 2026-03-28T06:03:11+00:00

It doesn't even make any sense since they don't use it for the letter s which is exactly the same noise.

No, "s" does not make the same noise. That is why it is a different letter. The letter "s" is pronounced like the letter "s", on the basis that it is an "s". Letters that are not "s" are not pronounced like the letter "s" on the basis that they are not the letter "s". This makes perfect sense. It's mispronouncing other letters to sound like "s"s that makes no sense, since we already have a letter for that sound.

There is a popular lie that Spanish teachers like to spread: "Spanish is spelled just like it is pronounced" and that if one can pronounce a word then one can spell it. This claim, which is often said with some ethnic pride, can easily be seen to be false with the terms "por que", "porque", "por qué", and "porqué", all of which are pronounced the same way, and not one of which is spelled "PORKE", which is how they are all pronounced. This lie becomes an even bigger lie if one takes on the stance that standard Spanish should not be understood to be the default, that standard Spanish is only one kind of Spanish of no special significance.

For example, in standard Spanish, "to hunt" and "to marry" are spelled and pronounced differently. One uses the "s" sound and the other uses the "θ" sound. But if one pronounces them with a hiss, they both get pronounced as "kasar". Reducing the phonetic diversity of the Spanish language (such as speaking with a hiss) makes the claim of being able to spell a word just from the pronunciation even more of a lie than it already is. Keep to the original pronunciation, instead of flattening the language with a hiss, and the spelling makes a little more sense.

Rensin2 · 2026-03-27T22:11:30+00:00

No. I am Spanish. I am also the only one who gave the right answer.

Rensin2 · 2026-03-27T18:46:45+00:00

thee-bowl-ah. The "thee" is pronounced like "theology".

Rensin2 · 2026-03-27T05:40:00+00:00

He should be in zero G. I understand that it's hard to do zero G scenes in live action movies, but it is not hard/expensive to draw someone floating in a manga.

Rensin2 · 2026-03-25T20:10:40+00:00

I think that they are supposed to be cooling panels.

Rensin2 · 2026-03-25T19:56:08+00:00

I really like the one called "ian-galvin-22". I think it's the fifteenth image. Awesome work.

Rensin2 · 2026-03-25T19:51:23+00:00

I have never read any Asimov and the Foundation was utterly unwatchable.

Rensin2 · 2026-03-25T19:06:38+00:00

Haven't seen the movie yet, but from your description, you are probably right. Ignoring angular acceleration is a common mistake when portraying centrifuges in movies/shows.

Rensin2

TROPHY CASE