the datetime library developer takes another bottle from the liquor cabinet
this post was submitted on 16 Dec 2025
367 points (99.5% liked)
Today I Learned
26239 readers
237 users here now
What did you learn today? Share it with us!
We learn something new every day. This is a community dedicated to informing each other and helping to spread knowledge.
The rules for posting and commenting, besides the rules defined here for lemmy.world, are as follows:
Rules (interactive)
Rule 1- All posts must begin with TIL. Linking to a source of info is optional, but highly recommended as it helps to spark discussion.
** Posts must be about an actual fact that you have learned, but it doesn't matter if you learned it today. See Rule 6 for all exceptions.**
Rule 2- Your post subject cannot be illegal or NSFW material.
Your post subject cannot be illegal or NSFW material. You will be warned first, banned second.
Rule 3- Do not seek mental, medical and professional help here.
Do not seek mental, medical and professional help here. Breaking this rule will not get you or your post removed, but it will put you at risk, and possibly in danger.
Rule 4- No self promotion or upvote-farming of any kind.
That's it.
Rule 5- No baiting or sealioning or promoting an agenda.
Posts and comments which, instead of being of an innocuous nature, are specifically intended (based on reports and in the opinion of our crack moderation team) to bait users into ideological wars on charged political topics will be removed and the authors warned - or banned - depending on severity.
Rule 6- Regarding non-TIL posts.
Provided it is about the community itself, you may post non-TIL posts using the [META] tag on your post title.
Rule 7- You can't harass or disturb other members.
If you vocally harass or discriminate against any individual member, you will be removed.
Likewise, if you are a member, sympathiser or a resemblant of a movement that is known to largely hate, mock, discriminate against, and/or want to take lives of a group of people, and you were provably vocal about your hate, then you will be banned on sight.
For further explanation, clarification and feedback about this rule, you may follow this link.
Rule 8- All comments should try to stay relevant to their parent content.
Rule 9- Reposts from other platforms are not allowed.
Let everyone have their own content.
Rule 10- Majority of bots aren't allowed to participate here.
Unless included in our Whitelist for Bots, your bot will not be allowed to participate in this community. To have your bot whitelisted, please contact the moderators for a short review.
Partnered Communities
You can view our partnered communities list by following this link. To partner with our community and be included, you are free to message the moderators or comment on a pinned post.
Community Moderation
For inquiry on becoming a moderator of this community, you may comment on the pinned post of the time, or simply shoot a message to the current moderators.
founded 2 years ago
MODERATORS
It kinda depends how you define "a day". The usual standard colloquial definition we use would be a "solar day", i.e. how long it takes for it to go dark and light once each, i.e. noon to noon.
The definition you're using in this post though is a "sidereal day", which if you just say "a day" no one would mean, thus this post is misleading. A sidereal day is how long a planet needs to spin around itself.
A Venus "solar (normal) day" (like we normally use the phrase "day") is 116.75 earth days, while a Venus year is 224.7 earth days. The "sidereal day" that you're talking about here is 243 earth days long. So a day on Venus is actually shorter than a year on Venus, at least if you use our usual definition of "day".
Since Venus itself spins opposite to its orbit around the sun, its own spin together with its orbiting around the sun add up together to make the "solar (normal) day" shorter.
An Earth sidereal day is 23 hours 56 minutes while its solar day is 24 hours long. Here, the sidereal day is shorter than the solar day, because the Earth spins in the same direction as its orbit.
Thanks, I came looking for this clarification.
LLMs love giving the sidereal day as the length for some reason.
I love how much of a rebel non-conformist Venus is. Years longer than its days, rotates the opposite direction than all other planets because fuck you, thats why. And don't you even THINK about getting close and trying to land on her. Just ask the Russians how that went. You can't handle her pressure, temperature nor toxic atmosphere. What a bad bitch. She doesn't need nor ask your permission to do jack shit.
Yeah she's hot and toxic, but I can change her...
Bro talking about terraforming venus while we're still not done venusforming earth.
I ate Taco Bell last night and let me tell you about hot and toxic.
You can't handle her pressure, temperature nor toxic atmosphere.
But... but my ex's name wasn't Venus.
Hot, toxic, corrosive, and capable of crushing a man. Just how I like them.
Years longer than its days
That sounds oddly familiar
That was like living with my ex-wife.
rotates the opposite direction
By this, you mean its rotation around its own axis?
Venus sure as shit wont rotate around anyone else's axis. Venus dgaf.
😂 joking aside, was referring to its solar orbit 😁
Yeah, most planets have the same rotation direction as orbital direction (counter-clockwise rotation, counter-clockwise orbit) but Venus rotates clockwise.
Then there is ~~Neptune~~ Uranus that just rolls around...
Neptune has learning disabilities and we accept him just the way he is.
Uranus rotates on its side. Instead of rotating with its axis roughly perpendicular to the plane of its orbit (like all the other planets in our Solar System), Uranus rotates on its side (along its orbital path). This tipped rotational axis gives rise to extreme seasons on Uranus.
My son went back to college in his late 20s to get a degree that might lead to a job, so he was in class with a lot of 18 year olds.
He had a astrophysics class, and got in an argument with a girl who insisted that the Sun went around the Earth. He asked her how the length of a year was measured, and she said that long, long ago, some guys just chose an arbitrary number of days to make a year.
How sure are you that she was not the reincarnation of Aristotle?
Cite your source ffs
Wow that is incredible. Isn’t Venus year equal to 200 or so Earth Days?
Pretty sure it also spins the "wrong way" compared to all the other planets, probably a massive impact at some point stopped it spinning and sent it backwards slowly
That's a good observation. I think you're right. It really is insane how much evidence of impacts and other forms of geological trauma is extant on other worlds
Makes you imagine if the galaxies didn't spin so slow (relative to human timescales), we'd be watching rippling shrapnel as shit collides with one another in real time
Space is so cool, fuck
Cosmic billiards
Are there any ramifications of that?
According to Superman (1978), time would move backwards.
It's basic science really.
I think (although I could be wrong), that that film was trying to depict that Superman was flying so fast that he went back in time. And the best visual they could come up with was that the earth was spinning "backwards" in order to depict this.
Could this also have contributed to the massive greenhouse effect it has?
According to Wikipedia, it seems that the current scientific explanation is that the runaway greenhouse effect was caused by the evaporation of oceans (caused by the brightening of the sun). The presence of vapor in the atmosphere led to the runaway greenhouse effect.
https://en.wikipedia.org/wiki/Runaway_greenhouse_effect?useskin=monobook#Venus
I guess whatever hit it could have been made of largely carbon dioxide? No idea if anyone knows where the CO2 came from
Imagine there's a leap year and suddenly the year is three times as long
One is rotation, but the other is revolution.
Rotation: circular motion of a body about its own axis.
Revolution: motion of an object moving around another object.
This one fact always blows my mind.
Hey OP! I'd rather spend a day with you than on Venus!
I think my physics teacher told me this fact but followed it up with "Measuring a planet's rotation around the sun by how fast it rotates around it's center is like trying to measure the speed of a truck based on how many rotations a ballerina can spin inside of it."
That quote haunts me.
Bit silly. In this scenario, you're not measuring the speed of the truck. You're measuring the time it takes to complete a lap. And we are the ballerina rotating, and as we are a miniature plastic ballerina with no outside frame of reference, our own regular rotation is the only consistent measure we have.
How did the ballerina get inside the truck? Is she alright?!
Is she spinning because she's happy? Or is she spinning to drill a hole in the floor and escape?
quality TIL post. we didn’t know this either!
It took me like three readings of the post title to comprehend it wasn't a typo lol
Are we talking sidereal day or solar day? Both?