TIL: Today I Learned

[Truthy]

Jeez, the ancient Egyptians sure were show offs.

Including so many constants in one pyramid is a bit gaudy for my taste. But that's just me

 

[aimeeandbeatles]

I read somewhere that the pyramids were originally very very shiny but it all wore off after a while. That might be wrong though.

 

[Birdjaguar]

I was wondering that too. It seems pretty reasonable to me to think they knew of both and had approximations of both.

After all, they did build the Great Pyramid on a latitude that encodes the speed of light

Yes, and here is the long answer for those who need additional proof.

Why is the speed of light (in tens of million metres per second) the same as the latitude for the Great Pyramid at Giza (in degrees north of the equator)?

https://www.google.se/maps/place/Th...2!3m1!1s0x14584587ac8f291b:0x810c2f3fa2a52424
This question previously had details. They are now in a comment.

34 Answers

Sarah Weaver, selected to be Quora Top Writer 2018
Answered Nov 26, 2016

Originally Answered: Why is the speed of light also the coordinates for the great pyramid at Giza?
Why is the speed of light also the coordinates for the great pyramid at Giza?

Let us look at the basics:

C = 299,792,458 m/s

Coordinates of the Great Pyramid of Giza: 29.9792° N, 31.1342° E

The first problem we encounter is that the speed of light is in meters per second.

Why is this a problem?

Because the meter was defined - in 1795 - as 1/10,000,000th of the distance from the North Pole to the Equator through Paris. The Great Pyramid of Giza was constructed circa 2580–2560 BC, 2,200 years before the first europeans started settling in the area where the city of Paris would eventually be founded.

Even assuming that the builders of the Pyramid were aware of the correct size of the Earth AND the precise location on the north pole and the equator, there is no way of guaranteeing that they would come up with A) the exact positions of the north pole AND the equator calculated by the French (down to the meter), and B) the distance through the location where the city of Paris will be located 2,200 years in the future (they would more likely select a different longitude, probably closer to the Nile).

This means that even if the ancient Egyptians chose to use the meter (similar to the one defined in 1795), their meter would be different from our meter, so the measurement for the speed of light would have a different number.

To this we add that the ancient Egyptians defined time differently than we do in modern times: they DID split days and nights into divisions of twelve hours each, but these were based on the length of the day, which varied through the seasons, AND they did not divide hours into groups of 60 minutes/3,600 seconds.

Realistically, if they were inclined to calculate velocities in something like meters per second, it would be something like cubits per beat, which would certainly result in a number vastly different than that obtained by measuring by m/s.

Do you doubt this? Next time you drive down the highway, look at your speedometer: if you are traveling at 55 mph, you are also traveling at 88.5 kph, and 80.66 feet per second: Same velocity, different means of measuring it.

We have neatly shown why the m/s number is irrelevant: it is the result of a particular unit of distance and a particular unit of time. Now we have to look at a coordinate system: ours is based on 360° (° = degrees) of longitude (180° E ↔ 180° W) and 180° of latitude (90° N ↔ 90° S). Each degree is divided into 60 minutes (′) and each minute is divided into 60 seconds (″).

Got that? It is called a sexagesimal notation system and, surprisingly enough, was known by the ancient Egyptians who built the pyramids at Giza. We know this because the system was invented by the Ancient Sumerians a couple hundred years earlier, and the Egyptians divided days into four groups of six hours each.

Keep in mind that their smallest unit of time was the hour, which varied seasonally.

Still, let us assume, for purpose of this argument, that they did choose to use the same exact measurement system we use today for global coordinates; it is a safe bet that they will not select Greenwich (which would not be settled for at least another 2,500 years) as the Prime Meridian!

Memphis (no, not the one in Tennessee) would be a much better choice, being the location of the seat of power of the pharaohs of the sixth dynasty. Given that Memphis is located at 29°50′41″N, 31°15′3″E, it is easy to see that the Great Pyramid would NOT be assigned the same coordinates if Memphis were at 0°0′0″N.

So let us recap: Without our seconds, meters, sexagesimal coordinate system, and Greenwich as prime meridian, the numbers will be completely different.

I have not even addressed the issues of the inaccuracies present in the numbers presented in the meme, leaving those to someone else to crush.

 

[cardgame]

I read somewhere that the pyramids were originally very very shiny but it all wore off after a while. That might be wrong though.

you are right but I can't recall the exact details, I'm bringing up like three different things. the top 10% or so was plated in gold, or brass/copper, or just a polished, smooth limestone. I can't remember

 

[Birdjaguar]

I read somewhere that the pyramids were originally very very shiny but it all wore off after a while. That might be wrong though.

you are right but I can't recall the exact details, I'm bringing up like three different things. the top 10% or so was plated in gold, or brass/copper, or just a polished, smooth limestone. I can't remember

The top layer of stones were smooth white blocks that covered the entire pyramid, And yes, as Card game said, there was some fancy metallic plating at the top. Gold? Copper? Bronze? We don't know.

Or there is this: https://www.ancient-code.com/researchers-discover-what-was-located-on-top-of-the-great-pyramid/

 

[Berzerker]

When you look at the second link and see the 1940s photo showing the 8 sides, that does not look like the great pyramid. The GP has several rows of casing stones at the top. You can see those in the top photo. So what happened o the casing stones? The surrounding buildings look similar to the GP site. Photoshopped? There is a disconnect of some sort. Are there more recent photos replicating the one from 1940s.

The top photo (in color) is of Chephren's pyramid. I dont know why the link showed it, but the GP doesn't have casing stones. They were supposedly lost when Cairo suffered quake damage about 4 centuries ago and people grabbed them to rebuild, so there's a bunch of Tura limestone around Cairo.

https://www.sciencenewsforstudents.org/article/scientists-detect-mystery-void-great-pyramid-giza

After all, they did build the Great Pyramid on a latitude that encodes the speed of light

The 30th latitude...well, very close... 29.9792°. I read somewhere the land just north of it that would be on the 30th was unsuitable. Nearby Cairo is 30.0444. I'd be curious to see if there are any structures just north of the GP to mark the 30th.

According to Mesopotamian religion the sky was divided up into 3 regions (the paths of Ea, Anu and Enlil) of 60 degrees with one between 30N & 30S and the other two reaching to the poles.

Its possible the GP was placed just south of the 30th to mark the path of Ea (probably the Egyptian god Ptah, Greek Poseidon). I haven't checked this for accuracy but some researchers claim the GP is the approximate center of all the landmasses.

edit: I'm wrong on that part about the paths of Ea, Anu and Enlil - Anu would have been between the 30s

 

[Hrothbern]

Nice posts on Pyramids
Still much to learn there about what really happened... but speculative theories are nice as well... we are such creative apes

On the builders of those pyramids
Architects were AFAIK not priests... they were their own class and had very, very high status...

and my deep respect to these masters who achieved so much.
Just imagine that we would take a current CEO with engineering background to lead such projects... no Newtonian physics and the engineering calculation knowledge for strength calculations, no Excel to list up people, supplies, money... no Powerpoint to keep your Pharao updated... no middle management with Harvard-MIT MBA grades... etc

 

[Manfred Belheim]

Now all we need is for someone to say that's pure coincidence, just like the ratio of the height and perimeter "just happening" to come out to 2*pi most be just coincidence since the ancient Egyptians were unfamiliar with the concept.

Or, is it possible that the historians who said they were unfamiliar with the concept might have been wrong? Nahhhh, of course not.

There is of course the argument that if you use some sort of rolling thing to measure out your distances, then you'll get factors of 2*pi flying around entirely naturally without knowing a thing about it.

Yes, and here is the long answer for those who need additional proof.

The bit about the Greenwich meridian was a bit meaningless, seeing as the longitude isn't relevant at all here. Plus he seems to have got that bit completely wrong as he's talking about Memphis being at 0 degrees North in the next sentence, as if Greenwich is at 0 degrees North in the current system...

 

[Arakhor]

Given that Memphis is some 30 degrees East, his point still stands, even if he was barking up the wrong tree.

 

[Manfred Belheim]

Can't see how since the whole thing seems to be about the latitude of the pyramids, not the longitude. Changing the prime meridian has no effect on the former. Unless I missed how the longitude comes into it (I did only skim it to be fair).

 

[aimeeandbeatles]

TIL that compressed air can blow crumbs out of a keyboard surprisingly well.

 

[Takhisis]

TIL in January 2020 India abolished the two reserved seats in the Indian Parliament for the Anglo-Indian community.
On one hand, I'm surprised they lasted so long. On the other hand, I'm sort of sad to see them go.
https://en.wikipedia.org/wiki/Anglo-Indian_reserved_seats_in_the_Lok_Sabha

According to that article they were to be phased out by the 1960s… well, anyway they were nominated by the government so it would appear not to be that much of a loss, unless I'm missing something, which I probably am.

TIL that compressed air can blow crumbs out of a keyboard surprisingly well.

Sewing needles can work a treat when trying to get stuff out from between keys.

 

[Birdjaguar]

Turning it upside down and tapping a corner on the desktop works too.

 

[MaryKB]

TIL how to create a YouTube channel and upload a video

 

[Takhisis]

Turning it upside down and tapping a corner on the desktop works too.

Better just to tap it slightly with a knuckle. I should know, I have been using this keyboard for 11 years and counting.

 

[Birdjaguar]

Better just to tap it slightly with a knuckle. I should know, I have been using this keyboard for 11 years and counting.

Yes that will work too;

 

[Manfred Belheim]

Only 11 years? I'm using one that I've had 18 or 19 years. I even spent far too long fixing it last year (after stupidly breaking it), rather than get a new one. PS2 connector ftw.

 

[Valka D'Ur]

10 years ago. One of my very first experiences in that town (I had moved there days before) was when a black lady walked into a Quiznos with her white boyfriend/husband and their kid...and were promptly shouted out of the restaurant.

Experiences like this are why I react so reflexively and angrily whenever I see posts that suggests the rural areas (especially in the Midwest) are paragons of civil society or whatever compared to more urban areas in the US.

Okay, I won't pretend that outrageously bigoted crap doesn't happen in Canada. There are a depressing number of news articles that relate incidents where customers have been abusive. What tends to really rile people up is when the staff gets abusive... such as black men being asked to prepay before ordering their meals (nobody else was told to do that, and when they refused, they were told to leave; someone on staff called the cops on them), or a white customer being verbally abused for buying a meal for a homeless native man.

I think there was a recent incident somewhere where a black man was arrested for having the gall to visit a bank to withdraw some money.

Is this in addition to the incident where a native man and his 12-year-old granddaughter were detained and handcuffed by the RCMP in front of a bank in Vancouver because they tried to open a savings account for the girl? The excuses made by the bank staff were mind-croggling (who apparently couldn't wrap their tiny minds around the fact that Indian status cards are valid ID and it's actually not illegal for natives to have more than a few dollars at a time). Furthermore, when they called the cops, they described the grandfather and his granddaughter as "south Asian" (honestly, they don't look anything alike).

The grandfather is taking this to the Human Rights Commission and will sue. There's absolutely no excuse for what happened to them.

TIL that the 4th Dr Who had a 12 foot scarf because the knitter, Begonia Pope, used all the wool she was given rather than just picking 1 or 2 colours as intended.

I read that one of the scarves (there were at least two, if not three) was 17 feet long. Since Tom Baker is so tall, it didn't look weird on him. He did say in an interview that there were times when the long scarves were hard to deal with in some action scenes, or in close quarters. If you look closely in some scenes, you can see that he occasionally steps on it, and I'm not sure if the tripping in one scene was a blooper that they just kept in because it added a little comedic foil (the villains in that story were Really Serious and had no sense of humor).

Afaik, civs like the Babylonians and Egypt knew that in practice tied stuff exist (eg the pythagorean theorem) but had no use (and apparently nor concept) of a geometrical proof (no closed system supported by axioms, and no method of arriving to a proof from axioms; both are historically attributed to Thales, who also was the first to calculate the height of the Great Pyramid, by using another of his theorems).
So it isn't out of the question that they'd try to incorporate pi in the building. But one has to keep in mind that the golden ratio is heavily used in aesthetic in the first place, cause it just looks good.

Going by ancient-era historians, it should also be noted that in such cultures only special, small groups had access to math or other orders. In the case of Egypt, it would be the priest class.

Wouldn't the engineers need to know math?

 

[H4run]

TIL

Dang if I spot something like this in the ocean I will freak out instead of being amaze loool

 

[Takhisis]

Only 11 years? I'm using one that I've had 18 or 19 years. I even spent far too long fixing it last year (after stupidly breaking it), rather than get a new one. PS2 connector ftw.

Well, I bought it in late 2008. I cannot have gotten more than the 11 years and a bit that I have now unless somebody gave me a time machine.