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Perseid Trail (APOD 14 Aug 2008)
Posted: Thu Aug 14, 2008 4:35 pm
by emc
http://apod.nasa.gov/apod/ap080814.html
Bet we wouldn’t be so enamored with meteors if we didn’t have the atmosphere to protect us.
As I was admiring
today’s APOD, I began to appreciate how the Earth’s atmosphere works like a protective shield against black heel marks… excuse me, I mean meteors
(too many old TV commercials floating around in my synapses). And just think… if it weren’t for the
atmosphere, we would have an unobstructed view of the
heavens… Wait! Except for the breathing thing, LOA (lack of atmosphere) would be good… no more tornadoes, hurricanes, mosquitoes… Uh oh, now I am drifting a bit… Back to the subject, the threat of
meteors and our extra special atmosphere designed to protect and sustain.
But what about those poor unfortunate meteors… happily flying around in space for who knows how long only to vaporize in a brief inferno much to the twisted delight of on-looking Earthlings. Even though meteors are eons older than any one of us, surely we can empathize with the matter changing end to their journey, after all the
Solar System is on a
specific timeline and each of us merely a flash in the midst! Kind of like the single blink of a
firefly, a life begins and… oops! I’m drifting again…
Re: Perseid Trail (APOD 20080814)
Posted: Thu Aug 14, 2008 5:15 pm
by neufer
Bet we wouldn’t be so enamored with meteors if dinosaurs still ruled the earth.
Re: Perseid Trail (APOD 20080814)
Posted: Thu Aug 14, 2008 6:10 pm
by emc
neufer wrote:Bet we wouldn’t be so enamored with meteors if dinosaurs still ruled the earth.
![Image](http://upload.wikimedia.org/wikipedia/en/thumb/7/70/When_dinosaurs_ruled_the_earth.jpg/200px-When_dinosaurs_ruled_the_earth.jpg)
Re: Perseid Trail (APOD 20080814)
Posted: Thu Aug 14, 2008 8:17 pm
by neufer
emc wrote:neufer wrote:Bet we wouldn’t be so enamored with meteors if dinosaurs still ruled the earth.
![Image](http://upload.wikimedia.org/wikipedia/en/thumb/7/70/When_dinosaurs_ruled_the_earth.jpg/200px-When_dinosaurs_ruled_the_earth.jpg)
I've just stopped thinking about meteors altogether!
"neecha" = "stop"
<<Perseus stopped in the Phoenician kingdom Ethiopia, ruled by King Cepheus and Queen Cassiopeia. Cassiopeia, having boasted herself equal in beauty to the sea Nereids, drew down the vengeance of Poseidon, who sent an inundation on the land and a sea-monster, Ceto, which destroyed man and beast. The oracle of Ammon announced that no relief would be found until the king exposed his daughter Andromeda to the monster, and so she was fastened to a rock on the shore. Perseus slew the monster and, setting her free, claimed her in marriage.>>
----------------------------------------------------
<<When Dinosaurs Ruled the Earth is a 1970 movie starring Victoria Vetri. A small tribe is struggling to survive by giving a sacrifice of a blond woman to their gods in return for protection from the giant lizards looking to snack on them. Sanna, one of the sacrificial offerings, finds herself on her own when a freak storm interrupts the ceremony. As she searches for a safe haven she encounters hostility from rival tribes and lots of huge and very hungry dinos. The special effects are considered a benchmark in stop-motion animation believability, so much so that the film is referenced in the movie Jurassic Park.>>
http://www.imdb.com/title/tt0066561/
A 27-word "caveman language" was devised for this movie, supposedly drawing on Phoenician, Latin, and Sanskrit sources. Some of the key words in this language are:
"neecha" is "stop" or "come back";
"zak" is "gone" or "left";
"akita" is "look" or "see";
"neecro" is "bad" or "evil";
"m'kan" is "kill" or "killed";
"mata" is "dead";
"yo kita" is "go".
Posted: Thu Aug 14, 2008 9:07 pm
by apodman
When I asked my Geography teacher who put the lines on the globe, she explained that dinosaurs ruled the Earth.
Posted: Thu Aug 14, 2008 10:00 pm
by neufer
apodman wrote:When I asked my Geography teacher who put the lines on the globe, she explained that dinosaurs ruled the Earth.
How many cylinders were graduated in your high school class?
Posted: Thu Aug 14, 2008 11:14 pm
by emc
I learned about meteors in school once... or was that meat eaters???
Posted: Fri Aug 15, 2008 1:04 am
by apodman
neufer wrote:How many cylinders were graduated in your high school class?
Only the
evil cylindrical robot and "King of the Moon" named The Master Cylinder.
In chem lab we had to titrate by eye.
Re: Perseid Trail (APOD 20080814)
Posted: Fri Aug 15, 2008 1:20 pm
by emc
Two dinosaurs gazing up at the night sky enamored with the firework spectacular of a meteor shower.... one looked at the other and uttered, “I have a neecro feeling about this!”
......................................
There were two dinosaurs eating a clown... one looked at the other and uttered, "This taste funny to you?"
......................................
Q. Why are carnivorous dinosaurs sometimes confused with meteors?
A. Because they are meat eat'ors...
(in case someone needed a second helping)
......................................
"More than a meteor may have m'kan dinosaurs"
Posted: Sat Aug 16, 2008 2:51 pm
by ta152h0
Posted: Sun Aug 17, 2008 9:45 pm
by JohnD
I read that Persieds occur every two or three minutes at the storm height. I couldn't say, it has ALWAYS been cloudy over North West England.
So why could a photo from Vancouver only show two in an hour and a half?
John
Posted: Sun Aug 17, 2008 10:27 pm
by neufer
JohnD wrote:I read that Persieds occur every two or three minutes at the storm height. I couldn't say, it has ALWAYS been cloudy over North West England.
So why could a photo from Vancouver only show two in an hour and a half? -
John
1) Only a small fraction of the sky is visible
2) Only a relatively bright meteor would have registered(?)
3) It wasn't storm height(?)
4) <<In early medieval Europe, the Perseids came to be known as the "tears of St. Lawrence.">> ...which is on the other side of Canada.
http://en.wikipedia.org/wiki/Perseids
Posted: Tue Aug 19, 2008 12:49 pm
by bystander
JohnD wrote:... So why could a photo from Vancouver only show two in an hour and a half?
I think it's only one not two.
Posted: Wed Aug 20, 2008 11:13 am
by jimmysnyder
I think Clinton was hounded by the meteor too. But why don't the star trails have gaps in them? And why did the meteor take 4 (or is it 6) seconds to streak across?
The turtle and the hare
Posted: Wed Aug 20, 2008 12:34 pm
by henk21cm
jimmysnyder wrote:But why don't the star trails have gaps in them? And why did the meteor take 4 (or is it 6) seconds to streak across?
http://antwrp.gsfc.nasa.gov/apod/ap080816.html
refering to the gap in the meteor trail and the continuous trails of the stars. This image has been made by some sort of automatic machine. It repeatedly takes an image. Between two images is halts for a short while, maybe a few tenth of a second.
- During 93 minutes the stars leave a trail of about 280 pixels. That is about 0.05 pixel per second. If the time between two images when the camera is off line, is 0.2 seconds, the gap between the consecutive trails of the stars is 0.01 pixel.
- The meteor trail is approximatedly 280 pixels long as well. The duration of a meteor is 1 maybe 2 seconds. As a worst case: 2 seconds, that means 140 pixels per second. If the camera is for 0.2 seconds off line, the gap between two consecutive sections of the trail is 28 pixels.
A gap of 0.01 pixel in length is NOT visible, while a gap of 28 pixels is clearly visible. Compare it with the fable of the turtle and the hare. When the hare runs, and when you close your eyes for 1 second, the hare is gone, when you open them again. When the turtle runs and when you close your eyes for 1 second, when you open them, the turtle is still at the same position.
Posted: Wed Aug 20, 2008 12:37 pm
by bystander
APOD: 2008 Aug 16 wrote:The large gap in the single meteor trail corresponds to the time gap between the consecutive frames.
The stars would not appear to move in the relatively short time between frames.
Posted: Wed Aug 20, 2008 2:53 pm
by emc
My father and I rowed our boat out to the middle of the lake, not to fish this particular night, but to watch the
Perseid meteor shower. We had just settled in, my father aft and me to the front, reclining into a relaxed upward view when there was a hard bump against the side of the boat. We both jerked up, steadying the boat and saw a ten foot
alligator eyeing us from its watery domain. Dad quickly grabbed one of the thick handled oars and gave the alligator a hard
whack to the head. Fortunately this was all that was needed to encourage the alligator to leave and we soon settled back to our
meteor viewing. After a while Dad said, in his deadpan tone, “Good thing we have those meaty oars.”