[vodkasim]

Hi, I'm posting this for any stragglers who, like me, are still working their way through the Season 1 cards.

The explanation on the boards here, while eventually correct, is not the complete story... just in case, I've spoilered (what I believe is) a fuller explanation:

Spoiler (Rollover to View):

The card is asking a question purely about the Earth's orbit, which does not have anything to do with any previous historical position, Egyptian or otherwise. But, when discussing the precession of the equinoxes, as this card appears to imply, more information can be found leading to the accepted answer. The first thing that needs to be checked is the wobble of the Earth's axis of rotation, which has previously been noted as a roughly 26,000 year cycle. The second point is that, as well as the axial wobble, the changing shape of the Earth's elliptical orbit around the sun also affects the precession of the equinoxes. This leads to the precession of the equinoxes following a slightly different timetable than the axial wobble as the entire earth orbit itself slowly rotates around the sun. As a generalisation, it has been stated as following a cycle of 23000 years, but is actually between 23,700 and 22,400 years with a minor cycle of 19,000 years.

Information gleaned from various websites e.g.:
http://www.unisa.edu.au/planetarium/Info/eclip.asp
http://www.soes.soton.ac.uk/staff/ejr/DarkMed/ch5.html
and the book:
'Frozen Earth: The Once and Future Story of Ice Ages' by Doug Macdougall

Hope this helps,
Simon

[angadeon]

The picture in the background is of RCW 79, a gas bubble in the southern Milky Way. It sits in the southern constellation Centauri.
The image of our sun is superimposed over it and not part of the original. Also of note, given the position and angle of the earth, the cube is pointed at the north pole.

*more for my own contemplations than anything*

[rokison]

Has anyone noticed that on wikipedia's page on precession, it states

Spoiler (Rollover to View):

It is generally understood that the gravitational pulls of the Sun and the Moon cause the precession of the Earth's orbit which operate on cycles of 23,000 and 19,000 years.

If you want the link it's http://en.wikipedia.org/wiki/Precession#Precession_of_planetary_orbits

Looks like it was as simple as just getting the right value for the time of the precession.

[Rand0m]

Would any wonderfully public-spirited person consider writing a summary of how to solve this card for the 'black summaries' thread? Not a cryptic hint, but a guide to the thought and research needed? Oh - and in no more than two sentences?

This is the only black or silver that we don't have a summary for and I can't write it because I simply didn't understand it...

[thalamus]

GuyIncognito wrote:

Didn't somebody mention that Spoiler (Rollover to View): yeah, a full cycle would take 26000 years, but that we were already 3000 years into the cycle...thus earth would have completed a full cycle in 23000 years?! At least that was good enough an explanation for me...

sounds like a plausible explanation, but i'm still fuzzy on why we started counting that long ago. i guess it may be still be to do with

Spoiler (Rollover to View):

what star that is in the box

[GuyIncognito]

Didn't somebody mention that

Spoiler (Rollover to View):

yeah, a full cycle would take 26000 years, but that we were already 3000 years into the cycle...thus earth would have completed a full cycle in 23000 years?!

At least that was good enough an explanation for me...

[thalamus]

Dragonscales wrote:

Well, yeah I know that... I'm just saying... how does that work?! Ben

well, my theory was that it was to do with

Spoiler (Rollover to View):

precession, and the fact that the stars change position in the night sky over time.

...as mentioned above.

at first i looked at

Spoiler (Rollover to View):

polaris, and found the 26000 yr cycle - wasting an answer with '26' .

<-- level 1 hint

i believe that to answer this question you must

Spoiler (Rollover to View):

correctly identify who the 'i' is that will return to it's first point

<-- level 2 hint

in one of the pages i was researching, i found a reference to

Spoiler (Rollover to View):

thuban - the star that was above the poles when the egyptians built the pyramids.

<-- level 3 hint

Spoiler (Rollover to View):

they used this pole star to align the pyramids, 3000 years ago. seeing as there is a bit of an egypt theme on some of the cards, i thought that '26000 minus 3000' was worth a go, and it was

of course, it might've just been a lucky guess with spurious logic attached...

EDIT: it looks as though it was just a lucky guess + spurious logic...

Spoiler (Rollover to View):

thuban was pole star in 3000BC, NOT 3000 years ago. my calculation should've been 26000 minus 5000. i am an eejit. a lucky one, but an eejit nonetheless.

...and i still don't know why the answer is what it is. bumflaps.

[Dragonscales]

Well, yeah I know that... I'm just saying... how does that work?!

Ben

[aliendial]

Dragonscales, look at Asib's post just above yours.

[Dragonscales]

Ditto to Allattar, I'd also like to know where we get that number from. Can anyone provide a reliable solution?

Ben

[Asib]

ill put you out of your misery

Spoiler (Rollover to View):

the wiki is wrong the equinox proccession is 23000 yrs not 22

[Allattar]

I still want to know where they get that number from...

ahhhhh its going to haunt me now.

[Dragonscales]

fretty wrote:

Hooray, solved it: Spoiler (Rollover to View): There is one number that managed to slip through the woodwork in the twenties.

Precisely. I'll post the solve but only cos I'm nice...

A couple of you were so close... but the answer is

Spoiler (Rollover to View):

23

Ben

[aliendial]

woo! finally! black leitmark! thanks for the hints, guys. top 12 only. I'll take it.

[rainbowtrout]

woohoo!!! my first top ten.

Spoiler (Rollover to View):

and NOW i see the clue above