22 December 2007

the Sun moves across the Italian sky on Winter Solstice 2007, the shortest day of the year / also PizzaQ!

You know the drill: Click for larger.

This is the Sun's motion from rise to set on 21 December 2007. The Winter Solstice is the shortest day of the year in the Northern Hemisphere, the day Winter begins. The photo looks out over the Tyrrhenian Sea on the coast of Italy from Santa Severa toward Fiumicino.

PizzaQ (1 slice plain): I count 40 exposures. How long did the Sun take to travel from Sunrise to Sunset above Italy on the Winter Solstice -- and so how much time elapsed between two consecutive exposures?

In the Southern Hemisphere, this is the day Summer begins, and is the longest day of the year.

Amy said...

Oh boy oh boy oh boy! Mike hasn't gotten to this one yet! OK, so I suppose it is my turn to do this, which is probably going to involve brain cells (which I'm in the process of transferring many of mine to the growing of mini-Amy at the present) and me having to do some calculations...

Stand by... :)

Sunday, 23 December, 2007
Amy said...

OK, I've now used my fancy internets (sic) abilities, and discovered that in Santa Severa, Italy, the sun rose at 7:38:36 and set at 16:42:05. I owe my mad abilities to www.earthtools.org (since I'm sure the exact time the sun rises and sets depends on where you are in latitude, and I suppose longitude matters as well if it is local time we're talking about...Santa Severa appears to be a teensy bit north west of Rome, so looking up what time the sun rose/set in Rome isn't as exact!)

Okay, so, mini-AmyMike says...the sun was up for 9 hours, 3 minutes and 29 seconds? So that is...umm...32609 seconds. 40 exposures (I think I counted 40 too...a bit hard to tell with the ones at sunset and all), and if they were taken at equal times...there was one exposure taken every 815.225 seconds? Which converted back to minutes is 13.58 minutes. Does that work?

Since mini-AmyMike has never seen the sun or that picture (only gets a view of where the sun don't shine every day), I'm sure they didn't take into consideration that the first picture looks like it's been taken after the sun came up? Is there some correction that I'm just missing here or I'm too tired to take into account?

How's that work so far for pizza :)

Sunday, 23 December, 2007
Vleeptron Dude said...

Credit your account 1 slice of Pizza!

Listen ... Mike's a Genuine Pizza-Winning Rokkit Scientist yadda yadda, but long before Mike, you just looked at a bunch of colored spheres and knew it was an insulin molecule.

AND I read your dissertation/whatchamacallit ... and easily understood 1/638 of it, it was a real Walk In The Park for moi.

So uhhh you need to Stand In Your Own Radiant Sunshine and Take It Like a Woman: You're an A-Number-One Pizza-Winning Rokkit Scienteusse all by yourself. The spirit of Rosalind Franklin dances around in your mitochondrial DNA.

As soon as I saw this photo I knew this would make a nifty PizzaQ. I also knew (based on my clumsy blundering astronomy skills) that it was going to take me a little time to work out the Precise Answer.

So I am declaring yours The Authoritative Correct Answer.

Fiumicino btw seems to be the place-name for Rome's airport. Longitude is irrelavent for this calculation according to all the geek mathematical astronomy sites I surfed. Likewise I know Long doesn't matter from my correspondence with the astronomy prof goddess of my neighborhood Astronomical Stone Circle, the U-Massachusetts Sunwheel (the world's newest and most sophisticated advanced full-featured Neolithic Stone Circle).

It's all about the Latitude, and Fiumicino, Italy's is 41.48N .

My surfing -- and I'm sure yours as well -- discloses a lot of Grey Area about twilight and pre-dawn and such -- in other words, there's a lot of fuzzy, almost subjective malarky about defining the Instant The Sun Rises and the Instant The Sun Sets. I'm thrilled with your grasp of these issues.

Tell ya what I'll do, since you spat back the answer in lightning speed. I'll see if I can e-mail the photographer Danilo Pivato (he has a website of stunning photos) and get him to tell us what the time between exposures was.

Sunday, 23 December, 2007
Amy said...

Yayyyyy! You know how much I love pizza :)

I really do love the internet though, there's tools out there that give such precise sunrise/sunset at a given location, that I need not do the math any more!

If the person to which photo originated responds, my guess would be that he might have set the elapse time to be something even...maybe 12 or 13 minutes. Or maybe he's an uber-geek and calculated it out himself :)

Yeah, longitude doesn't really matter either, in terms of how long the day is, it's just handy for knowing when you can expect the sun up and down according to local time (e.g., scenic Tonopah, NV, home of the stealth bomber is about the same latitude as San Francisco, but according to local time, the sun rises and sets about 23 minutes "later" in SF than it does in Tonopah) Meh...I'm sure the local newspapers know this :)

Then again, I'm sure I could have looked up what time the sun rises and sun sets for all locations along that latitude. Now I'm thinking too hard :)

It's certainly a fine fine line between when sunrise and sunset is around here anyway. The dawn and twilight thing, like you said. Sun goes behind the mountains here, so I have no idea when it actually disappears behind the horizon!

Muchas gracias once again for pizza! Mini-AmyMike shall appreciate much, and I shall now be fat and happy in spirit :)

Sunday, 23 December, 2007
Vleeptron Dude said...

Okay I e-mailed Sgr. Pivato and asked him to provide the real On-The-Ground skinny about his lovely photo.

I just (shot up my morning coffee and) looked closely at your answer. 13.58 minutes looks so suspiciously like 14 minutes ... maybe the timer he used forces him to specify whole minutes, and his computations like yours indicated 14 minutes between exposures would likely do the trick.

How hungry are you? 'Cause there's another obvious PizzaQ:

What's the mathematical curve of the Sun's voyage over the sea from sunrise to sunset?

At first glance it sure looks like a parabola. It might help if I *really* knew something about astronomy and the movements of the Earth and Sun rather than just bullsh***ing like I always do. 2 slices with extra anchovies.

Sunday, 23 December, 2007
Vleeptron Dude said...

He's obviously very familiar with the local Sun geography so he knew exactly where to aim his camera for the center of the Sun's all-day voyage. So it's no surprise that there's that Big Lens Burst at the Noon exposure. Every other exposure is a perfect little circular Sun, free of lens burst effects.

But I wonder what mathematical conditions caused the symmetrical light bursts 6 exposures earlier and 6 exposures later? 6 exposures is roughly 84 minutes.

Sunday, 23 December, 2007
muebles en murcia said...

The thing you're writing is a big blunder.

Thursday, 13 October, 2011