This concept troubles me

Unless we're considering Celestia or some other astronomical sim, this really has no relevance to anything. It just came up in a conversation about calendars...

How do people living on planets with no axial tilt know when to celebrate their birthdays?

Determining your planet's and your sun's positions relative to each other and to the rest of the universe is something that comes very late in a society's development, and if there's no moon then they can't even have a birthday every month...

I expect they would use the starsigns.

https://earthsky.org/space/what-is-the-ecliptic/

How do people living on planets with no axial tilt know when to celebrate their birthdays?

This is not related to axial tilt, it's related to the period at which the planet moves around the sun. In our case of our solar system anyway.

You have to remember that in other solar systems the period of a planet may be vastly different than our own. Especially true if there are more than one star (sun). Which sun do you use for the period at which you were born? For example, my body's mass has thus far been around the sun 41 times. In that time I've rebuilt my entire skeleton ten times among other things the body does that most people don't have a clue about.

Now lets take it a step further.

Determining your planet's and your sun's positions relative to each other and to the rest of the universe is something that comes very late in a society's development...

Indeed. We are a very low IQ, immature organism. Other beings probably don't go by the very archaic orbital period to create "years" of time. Their system could be based in the quantum level. Heck, even on Earth we don't have to measure the orbital period to calculate what we determine to be a "year" anymore. We can use something that is pretty damn constant to give use a basis for time. It's called an atomic clock that uses Cesium. This clock is so important it's used for geolocation from GPS satellites. Your phone, tablet, car GPS, planes, ships and submarines all depend on it. My two clocks in my room right now use atomic time. They're constantly calibrated by listening to the radio signal at WWV in Fort Collins, Colorado on the frequency 60 kHz. You can hear the phone (audio) of this transmission on 5000, 10000, 15000, and 20000 kHz on a shortwave radio.

http://websdr.org/

https://shortwaveschedule.com/index.php?now=true

https://play.google.com/store/apps/details?id=com.msi.shortwave&hl=en_US&gl=US

All politics and relation to one's existence is relative to that of physiological time and place...

Through the years:

And the list goes on and on...∞

Unless we're considering Celestia or some other astronomical sim, this really has no relevance to anything. It just came up in a conversation about calendars...

 

How do people living on planets with no axial tilt know when to celebrate their birthdays?

 

Determining your planet's and your sun's positions relative to each other and to the rest of the universe is something that comes very late in a society's development, and if there's no moon then they can't even have a birthday every month...

Why would you expect them, whoever they may be, to celebrate birthdays?

Might be more a case of they day they came out the pipette, for all we know!

Even in this world there are millions who don't celebrate that day because humans don't know they day of their birth, unless it is told to them by people who've known them since birth....

Two things are certain when mankind (I'm sorry, "people") manipulate DNA for all the born via the test tube:

1) The need for "the three sea shells" in that era due to that era's plague of CoV-10 and people's need for rear end sanitation over food and water, etc.

2) Time dilatation, i.e. gravity will have zero effect on the body's muscular system so everyone will be tall, skinny with huge eyes (like a freaking Anime character) because of the "pill" for food and evolution, er, test tube evolution... Refer to

PS:

Worse yet, Bigfoot will STILL be an elusive creature! :D

PPS:

but there's nothing sacred about the anniversary of your birth

Speak for yourself. I think mine should be a global public holiday and religious festival.

This is not related to axial tilt, it's related to the period at which the planet moves around the sun. In our case of our solar system anyway.

That was what got us thinking. We use seasons to mark the annual cycle and they're caused by the Earth's axial tilt. With no tilt there are no seasons and - on Earth at least - it's generally not possible to see stars when the sun is up so a society would have to use parallax or something similar. That requires a degree of precision & accuracy that probably wouldn't be available to early cultures.

We concluded that such societies wouldn't be able to record history by years but would have to use some arbitrary grouping of days. Increased precision in astronomy later in the society's development could cause a change of calendar but we thought that age and birthdays just wouldn't ever be a thing.

The way humans think about stuff is tied so closely to our evolution and that of our environment that considering stuff from such a different perspective is interesting to say the least. Someone recently pointed out to me that as we have ten fingers (broadly, I know. And I have more than the average number of legs) so in the west we group numbers in tens. But if you count in binary with your fingers, suddenly you can count up to 1024 before having to use your toes...

everyone will be tall, skinny with huge eyes (like a freaking Anime character)

I'll still be chibi.

But not cute.

We concluded that such societies wouldn't be able to record history by years but would have to use some arbitrary grouping of days. Increased precision in astronomy later in the society's development could cause a change of calendar but we thought that age and birthdays just wouldn't ever be a thing.

Curios. Who's "we?"

Here ya go. https://en.wikipedia.org/wiki/Birthday#Early_centuries

The way humans think about stuff is tied so closely to our evolution and that of our environment that considering stuff from such a different perspective is interesting to say the least. Someone recently pointed out to me that as we have ten fingers (broadly, I know. And I have more than the average number of legs) so in the west we group numbers in tens. But if you count in binary with your fingers, suddenly you can count up to 1024 before having to use your toes...

It's really an interesting one. Especially since I count exactly 668 times the word "seven" or "seventh" shows up in the in the King James pure Cambridge edition of the Bible. Also, the number word "forty" appears 158 times. No mention of the number "666" however. But the aforementioned "ten" in written word shows up 1,550 times... Now if we just had the complete canon...

Speak for yourself. I think mine should be a global public holiday and religious festival.

HA! I see your declared day of praise and raise you all my King's horses and men for battle in this day of our Lord two thousand and twenty two! ;)

\

No mention of the number "666" however.

Try Revelation 13:18, where it says "For it is the number of a man; and his number is Six hundred threescore and six" though it obviously isn't in numerical form.

Curios. Who's "we?"

Us:

It just came up in a conversation about calendars...

QUOTE=CRJ_simpilot;2179239]Here ya go. https://en.wikipedia.org/wiki/Birthday#Early_centuries

Origen of Alexandria was a miserable old so and so wasn't he? He and I wouldn't have got along.

All this just resulted in me badly needing a long nap. Wake me when it's over.

Oh oh. Grampa Chuck's snoring again. Too many birthdays...

Origen of Alexandria was a miserable old so and so wasn't he? He and I wouldn't have got along.

I think we (the people of today) wouldn't have gotten along with a lot of people in the past due to physiological differences. And this can be said of our time just going from one city to the next or even a country... It's probably why Norway can have this and that prison system versus that of the U.S. as an example. I mean, I highly doubt the gangs and what not we have in south central LA exist in Norway. Yeah, time as well as place can have stark physiological differences and why you would probably absolutely HATE a lot of people back then. Just as relatively recently as the 1960s or the 1860s... Never mind ancient Rome and what have you. I would love to send a Millennial to 1966...

I think we (the people of today) wouldn't have gotten along with a lot of people in the past due to physiological differences. And this can be said of our time just going from one city to the next or even a country... It's probably why Norway can have this and that prison system versus that of the U.S. as an example. I mean, I highly doubt the gangs and what not we have in south central LA exist in Norway. Yeah, time as well as place can have stark physiological differences and why you would probably absolutely HATE a lot of people back then. Just as relatively recently as the 1960s or the 1860s... Never mind ancient Rome and what have you. I would love to send a Millennial to 1966...

Try Revelation 13:18, where it says "For it is the number of a man; and his number is Six hundred threescore and six" though it obviously isn't in numerical form.

Yep, it's there. And "threescore" is mentioned 93 times. "Fourscore" 36 times. "God" is mentioned 4,788 times. And since this is about time, that word is mentioned 819 times. :D

All this just resulted in me badly needing a long nap. Wake me when it's over.