We only know about when humans mastered fire or started using metal. But we know the exact date when the first powered flight took place. What are some really early “first ____” we know the date of for sure?
Skimming some material online, it looks like the best mechanism to get day-level dating for very old historical times are going to be celestial events, like eclipses, because we can run motions of those bodies backwards to compute precisely when the event occurred.
I searched for “first recorded eclipse”:
https://www.livescience.com/59686-first-records-solar-eclipses.html
The first recorded notation referencing an eclipse dates to about 5,000 years ago, according to NASA. Spiral petroglyphs carved on three ancient stone monuments in Ireland at Loughcrew in County Meath, depict alignments of the sun, moon and horizon, and likely represent a solar eclipse that occurred Nov. 30, 3340 B.C., NASA reported.
That isn’t a first (well, other than in being the first known recorded eclipse to us), but my bet is that it’ll be some event on the same day or within a specified number of days of an eclipse or similar.
So that probably places an outer bound on when such an event would have been known to have occurred, unless there’s some other form of celestial event recorded way, way back when.
EDIT: Though it sounds like there is some controversy as to whether that is in fact what is being depicted.
https://www.atlasobscura.com/articles/oldest-eclipse-art-loughcrew-ireland
EDIT2: and also according to the article, our accuracy in running those back that far starts to fall off:
Perhaps the biggest hole in Griffin’s theory is the date of the ancient eclipse that coincided, more or less, with the tomb’s construction. Earth’s rate of rotation fluctuates just enough over time to make calculating the path of totality for prehistoric eclipses imprecise. In fact, even programs designed to make those calculations can only do so reliably about as far back as the eighth century B.C. Steele says.
“We can’t just calculate back to 3000 B.C. and say that such-and-such an eclipse was visible in a certain place,” he adds. “The 3340 B.C. eclipse might not have been visible in Ireland at all.”
It sounds like one complexity is that while eclipses can be run accurately (maybe not where they are visible), the problem is that when the day occurred is not, and you want to know the day. Apparently, there are some unknown factors affecting the rate of Earth’s rotation a bit, and the error is enough that it becomes significant across millennia.
Changing predictions
Precisely predicting future eclipses, or plotting the paths of historical eclipses, requires knowing the positions of the sun, moon and Earth. Computers can track the motions of each, but the challenge here is that these motions are not constant. As the moon causes tides in Earth’s oceans, the process also causes the moon to slowly drift away from the Earth and the length of day on Earth to slowly increase.
Essentially, the length of a day on Earth is getting longer by roughly 18 microseconds every year, or one second every 55,000 years. After hundreds or thousands of years, that fraction of a second per day adds up to several hours.
The change in Earth’s day also affects dating historical eclipses — if the difference in the length of day is not corrected for, calculations may be inaccurate by thousands of kilometers. As such, when using eclipses to date historical events a correction must be applied; uncertainties in the correction can make ancient eclipse identifications harder to pin down in the absence of additional information to help narrow down the possibilities.
Measuring changing day-lengths
For those solar eclipses that are well established, they open a window into tracking Earth’s length-of-day across the centuries. By timing eclipses over the last 2,000 years, researchers have mapped out the length of Earth’s day over that same span. The value of 18 microseconds per year is an average, but sometimes the Earth slows down a bit more and sometimes a bit less.
Tides alone can’t explain this pattern — there is something more going on between the moon and the Earth, and the cause is still unknown. This mystery, however, can be explored thanks to solar eclipses.
We can measure a change in length of a day on Earth with instruments now, but we wouldn’t be able to capture that change hundreds or thousands of years back in time without a precise measuring stick and records of eclipses over millennia and across the world. Total solar eclipses allow us to peer into not only our own history, but the history of the Earth itself.
So if you had an event that was recorded happening in conjunction with an eclipse, we could maybe tell you pretty precisely how long ago it was in units of seconds. But we wouldn’t know how many days ago it was, because the day is not a fixed unit of time and we don’t know sufficiently-accurately how the length of a day has changed over that period.
Big Bang, T=0.
Well… Maybe.
Time probably predates the big bang
I kind of wonder if time might be infinite in both directions, just because having a definitive beginning or end would seem to violate the conservation of matter and energy.
Why? Conversation of energy doesn’t include time in any way. I’d love to hear your thoughts!
If we know that time precisely and accurately, then we don’t know any other times more precisely than millions or billions of years ballpark
There is no definite date, but I do love the circa 1750 BCE “oldest customer complaint,” so please forgive me.
Now, when you had come, you spoke saying thus: ‘I will give good ingots to Gimil-Sin’; this you said to me when you had come, but you have not done it. You have offered bad ingots to my messenger, saying ‘If you will take it, take it; if you will not take it, go away.’ Who am I that you are treating me in this manner – treating me with such contempt? and that between gentlemen such as we are.
I have written to you to receive my money, but you have neglected [to return] it. Repeatedly you have made them [messengers] return to me empty-handed through foreign country. Who is there amongst the Dilmun traders who has acted against me in this way? You have treated my messenger with contempt.
And further with regard to the silver that you have taken with you from my house you make this discussion. And on your behalf I gave 18 talents of copper to the palace, and Sumi-abum also gave 18 talents of copper, apart from the fact that we issued the sealed document to the temple of Samas. With regard to that copper, as you have treated me, you have held back my money in a foreign territory, although you are obligated to hand it over to me intact.
You will learn that here in Ur I will not accept from you copper that is not good. In my house, I will choose and take the ingots one by one. Because you have treated me with contempt, I shall exercise against you my right of selecting the copper.
circa 1750 BCE
here in Ur
Wow, I never really thought about how long Ur has stood. The city was already 2000 years old in 1750 BCE
Shout-out to my man Ea-Nasir over at !reallyshittycopper@lemmy.world !
Do you think Ea-Nasir would be ashamed that people over 3 millennia later are learning about how shitty his copper was, or would he be proud that people still speak his name?
That’s a tough one! He clearly didn’t care much about the reputation of his business, and in fact the only reason we know of him at all is that he saved the complaints he got! Most of us will have our names spoken for the last time when our children die; being remembered at all beyond, say, 100 years after your death is a heck of an accomplishment.
He clearly didn’t care much about the reputation of his business, and in fact the only reason we know of him at all is that he saved the complaints he got!
I dunno, we’re just assuming he kept them for the sick pleasure of it. Maybe he was collecting evidence before he lodged a formal complaint with his material supplier?
Or he could have had an excellent product and kept the complaints in the same way people nowadays with excellent products show off the idiot one star reviews.
That’s a possibility!
And people say there’s no niche communities on Lemmy.
It’s low-volume, but one of my favorites.
Low volume and high quality, unlike ea nasir’s copper
Bazinga!
Fuck Ea-Nasir. All my homies hate Ea-Nasir
How can we know there weren’t earlier consumer complaints that didn’t survive tho?
Yeah, that’s just the earliest known written complaint. And since the city was already two thousand years old at the time, the odds of there having been more are very high.
April 16th, 1178 B.C. : the day Odysseus returns in the Odyssey.
https://www.universetoday.com/15253/homers-odyssey-may-chronicle-ancient-eclipse/.
Pretty neat
It’s relatively easy for recent things related to big technological advances (first phone call, first man in space…); but it’s nearly impossible for really old thing, because while you can find out one really old thing existed at one time, it’s always merely the oldest known occurence. An earlier one might’ve not left surviving traces, or it’s traces might’ve not been found yet…
Probably November 30, 3340 B.C - this solar eclipse
When was the first artist signed work? There’s some pottery that has artist emblems in it, but signing art doesn’t seem to be a thing until the Renaissance. Who did it first?
