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The Milky Road (APOD 2009 June 13)

Posted: Sat Jun 13, 2009 11:27 am
by neufer
http://apod.nasa.gov/apod/ap090613.html

<<The Greek name for the Milky way (Γαλαξίας Galaxias) is derived from the word for milk (γάλα, gala). One legend explains how the Milky Way was created by Heracles when he was a baby. His father, Zeus, was fond of his son, who was born of the mortal woman Alcmene. He decided to let the infant Heracles suckle on his divine wife Hera's milk when she was asleep, an act which would endow the baby with godlike qualities. When Hera woke up and realized that she was breastfeeding an unknown infant, she pushed him away and the spurting milk became the Milky Way.>>

Gala, n. [F. gala show, pomp, fr. It. gala finery, gala; of German origin. See Gallant.] Pomp, show, or festivity.

Galaxy, n. [F. galaxie, L. galaxias, fr. Gr. (sc. circle), fr. , , milk; akin to L. lac.]

Lactucarium, n. [NL., fr. L. lactuca lettuce.] The inspissated juice of the common lettuce, sometimes used as a substitute for opium.

Inspissate, v. t. [L. inspissatus, p. p. of inspissare to thicken; pref. in- + spissare to thicken, fr. spissus thick.] To thicken or bring to greater consistence, as fluids by evaporation.

Lettuce, n. [OE. letuce, prob. through Old French from some Late Latin derivative of L. lactuca lettuce, which, according to Varro, is fr. lac, lactis, milk, on account of the milky white juice which flows from it when it is cut.] (Bot.) A composite plant of the genus Lactuca (L. sativa), the leaves of which are used as salad. Plants of this genus yield a milky juice, from which lactucarium is obtained.
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http://en.wikipedia.org/wiki/Milky_Way_(mythology) wrote:
Milky Way (mythology)

. Egyptian

In Egyptian mythology, the Milky Way was considered a pool of cow's milk. It was deified as a fertility cow-goddess by the name of Bat (later on syncretized with the goddess Hathor).

. Greek and Roman

A story told by the Roman Hyginus in the Poeticon astronomicon (ultimately based on Greek myth) says that the milk came from the goddess Ops (Greek Rhea), the wife of Saturn (Greek Cronus). Saturn swallowed his children to ensure his position as head of the Pantheon and sky god, and so Ops conceived a plan to save her newborn son Jupiter (Greek Zeus): She wrapped a stone in infant's clothes and gave it to Saturn to swallow. Saturn asked her to nurse the child once more before he swallowed it, and the milk that spurted when she pressed her nipple against the rock eventually became the Milky Way.

Older Greek mythology associates the Milky Way with a herd of dairy cows/cattle, where each cow is a star and whose milk gives the blue glow.[citation needed] As such, it is intimately associated with legends concerning the constellation of Gemini, with which it is in contact. The constellation was named for the twins, Castor and Polydeuces, who sometimes raided cattle. In addition, Gemini (in combination with Canis Major, Orion, Auriga, and the deserted area now called Camelopardalis) may form the origin of the myth of the Cattle of Geryon, one of The Twelve Labours of Heracles.



. Armenian

Ancient Armenian mythology called the Milky Way the "Straw Thief's Way". According to legend, the god Vahagn stole a straw from the Assyrian king Barsham and brought it to Armenia during a cold winter. When he fled across the heavens, he spilled some of the straw along the way.

. Khoisan

The Khoisan people of the Kalahari desert in southern Africa say that long ago there were no stars and the night was pitch black. A girl, who was lonely and wanted to visit other people, threw the embers from a fire into the sky and created the Milky Way.

. Cherokee

A Cherokee folktale tells of a dog who stole some cornmeal and was chased away. He ran away to the north, spilling the cornmeal along the way. The Milky Way is thus called Gili Ulisvsdanvyi "The Way the Dog Ran Away".

. Eastern Asia

Peoples in Eastern Asia believed that the hazy band of stars was the "Silvery River" of Heaven (Chinese: 銀河, Korean: eunha and Japanese: ginga). In one story, the stars Altair and Vega were said to be two lovers who were allowed to meet only once a year on the seventh day of the seventh month, when a flock of magpies and crows formed a bridge over the galactic river. That day is celebrated as Qi Xi, the Seventh Night (Chinese: 七夕; pinyin: qī xī, Korean: chilseok and Japanese: tanabata).


. Finno-Ugric

Among the Finns, Estonians and related peoples, the Milky Way was called "The Pathway of the Birds" (Finnish: Linnunrata, Estonian: Linnutee). The Finns observed that the migratory birds used the galaxy as a guideline to travel south, where they believed Lintukoto (bird home) resided. In Estonian folklore it is believed that the birds are led by a white bird with the head of a maiden who chases birds of prey away. Only later did scientists indeed confirm this observation; the migratory birds use the Milky Way as a guide to travel to warmer, southern lands during the winter. The name in the Indo-European Baltic languages has the same meaning (Lithuanian: Paukščių Takas, Latvian: Putnu Ceļš).
Jacopo Tintoretto's "The Origin of the Milky Way"


. Hindu

In the Hindu collection of stories called Bhagavata purana, all the visible stars and planets moving through space are likened to a dolphin that swims through the water, and the heavens is called śiśumãra cakra, the dolphin disc. The Milky Way forms the abdomen of the dolphin and is called Akasaganga which means "The Ganges River of the Sky".

. Hungarian

In Hungarian mythology, Csaba, the mythical son of Attila the Hun and ancestor of the Hungarians is supposed to ride down the Milky Way when the Székelys (ethnic Hungarians living in Romania) are threatened. Thus the Milky Way is called "The Road of the Warriors" Hungarian: Hadak Útja .

. Māori

To the Māori the Milky Way is the waka (canoe) of Tama-rereti. The front and back of the canoe are Orion and Scorpius, while the Southern Cross and the Pointers are the anchor and rope. According to legend, when Tama-rereti took his canoe out onto a lake, he found himself far from home as night was falling. There were no stars at this time and in the darkness the Taniwha would attack and eat people. So Tama-rereti sailed his canoe along the river that emptied into the heavens (to cause rain) and scattered shiny pebbles from the lakeshore into the sky. The sky god, Ranginui, was pleased by this action and placed the canoe into the sky as well as a reminder of how the stars were made.

The slight bulge of the Milky Way around Scorpius is also sometimes pictured as a whale.

. Australian Aboriginal

The Kaurna Aboriginal People of the Adelaide Plains in South Australia see the band of the Milky Way as a river in the skyworld. They called it Wodliparri (wodli = hut, house, parri = river) and believe that positioned along the river are a number of dwellings. In addition, the dark patches are where a dangerous creature known as a yura lives; the Kaurna call these patches Yurakauwe, which literally means "monster water." Moreover, Aboriginal Groups from the Cape York region of Queensland see the band of light as termites that had been blown into the sky by the ancestral hero Burbuk Boon. Further south the band of stars that comprise the Milky Way are seen as thousands of flying foxes carrying away a dancer known as Purupriggie.

In addition, the Aranda who come from central Australia see the band of the Milky Way as a river or creek in the skyworld. This stellar river separates the two great camps of the Aranda and Luritja People. The stars to the east of this river represent the camps of the Aranda and the stars to the west represent Luritja encampments and some stars closer to the band representing a mixture of both.>>

Re: The Milky Road (APOD 2009 June 13)

Posted: Sat Jun 13, 2009 12:02 pm
by geckzilla
I really don't like the bottom half of the pic. It needs to be a lot less saturated and have some actual atmosphere on the horizon. That and the person's shadow is way, way too sharp... it should be incredibly diffuse given the broad, diffuse glow of the milky way. It's not like there's a moon there. Milky way itself is great though.

Re: The Milky Road (APOD 2009 June 13)

Posted: Sat Jun 13, 2009 2:00 pm
by rudomundo
At what latitude would one stand to see the Milky Way directly vertical like that? Is this some sort of December 21st, 2012 reference?

Re: The Milky Road (APOD 2009 June 13)

Posted: Sat Jun 13, 2009 2:09 pm
by apodman
rudomundo wrote:Is this some sort of December 21st, 2012 reference?
Maybe not, but this is:

http://asterisk.apod.com/vie ... =8&t=15300

Re: The Milky Road (APOD 2009 June 13)

Posted: Sat Jun 13, 2009 3:13 pm
by petsie
Dear members of this forum,
I did not want to start a new topic about the same image but have got another question.
I am an absolute amteur (I am even unable to find enough "a"s on my keyboard ;-) ), but I am interested in the nature of the very bright and seemingly red spots in the image of our galaxy (in the middle and above). Are they just very bright stars or what kind of objects are these? Shouldn't they appear blue, if their origin are hot stars?
Thank you in advance,
Peter

Re: The Milky Road (APOD 2009 June 13)

Posted: Sat Jun 13, 2009 3:26 pm
by bystander
petsie wrote:I am interested in the nature of the very bright and seemingly red spots in the image of our galaxy (in the middle and above). Are they just very bright stars or what kind of objects are these? Shouldn't they appear blue, if their origin are hot stars?
They are probably H-II emission nebula. And not all bright stars are blue, Betelguese and Antares are examples.

Welcome to the Asterisk*

Re: The Milky Road (APOD 2009 June 13)

Posted: Sat Jun 13, 2009 11:13 pm
by apodman
petsie wrote:I am interested in the nature of the very bright and seemingly red spots in the image of our galaxy (in the middle and above).
Image

http://en.wikipedia.org/wiki/Eagle_Nebula
http://en.wikipedia.org/wiki/Omega_Nebula
http://en.wikipedia.org/wiki/Trifid_Nebula
http://en.wikipedia.org/wiki/Lagoon_Nebula

More objects labeled:

http://www.backyard-astro.com/deepsky/2 ... 6/ITT.html

Re: The Milky Road (APOD 2009 June 13)

Posted: Sun Jun 14, 2009 1:26 am
by neufer
apodman wrote:
petsie wrote:I am interested in the nature of the very bright and seemingly red spots in the image of our galaxy (in the middle and above).
Image
The Day of the Triffids (1962) wrote:
[first lines] Narrator: In nature's scheme of things, there are certain plants which are carnivorous, or eating plants.
This is a newcomer: Triffidus Celestus, brought to earth on the meteorite during the Day of the Triffids.

Narrator: All reports confirm that the world is witnessing an unprecedented shower of meteorites. There is no record of a display such as this in recorded history. At observatories astronomers are noting this fantastic phenomenon, and are carefully calculating the effect on our solar system.

Tom Goodwin: [to Karen] Keep behind me. There's no sense in getting killed by a plant.

[last lines] Narrator: A simple method had been found to destroy the Triffids. Sea water, from which life on Earth had sprung, became the means of preserving life on Earth. Mankind survived and once again have reason to give thanks.
--------------------------------------
Creature from the Black [b]Lagoon[/b] (1954) wrote:
Lucas: I can tell you something about this place. The boys around here call it "The Black Lagoon"; a paradise.
Only they say nobody has ever come back to prove it.

David Reed: We didn't come here to fight monsters, we're not equipped for it.
--------------------------------------
http://antwrp.gsfc.nasa.gov/apod/ap090519.html
http://antwrp.gsfc.nasa.gov/apod/ap081019.html
http://antwrp.gsfc.nasa.gov/apod/ap080715.html
http://antwrp.gsfc.nasa.gov/apod/ap071102.html
http://antwrp.gsfc.nasa.gov/apod/ap070804.html
http://antwrp.gsfc.nasa.gov/apod/ap070716.html
http://antwrp.gsfc.nasa.gov/apod/ap060825.html
http://antwrp.gsfc.nasa.gov/apod/ap010415.html
http://antwrp.gsfc.nasa.gov/apod/ap990925.html

Re: The Milky Road (APOD 2009 June 13)

Posted: Sun Jun 14, 2009 1:50 am
by orin stepanek
petsie wrote:Dear members of this forum,
I did not want to start a new topic about the same image but have got another question.
I am an absolute amteur (I am even unable to find enough "a"s on my keyboard ;-) ), but I am interested in the nature of the very bright and seemingly red spots in the image of our galaxy (in the middle and above). Are they just very bright stars or what kind of objects are these? Shouldn't they appear blue, if their origin are hot stars?
Thank you in advance,
Peter
some stars are blue; some are red; most are yellow.
http://www.schoolsobservatory.org.uk/as ... cold.shtml
http://www.astronomycafe.net/qadir/q2958.html
http://www.enchantedlearning.com/subjec ... ypes.shtml
I think it's cool that we live by a yellow star. 8)

Orin

Re: The Milky Road (APOD 2009 June 13)

Posted: Sun Jun 14, 2009 4:30 am
by Chris Peterson
orin stepanek wrote:I think it's cool that we live by a yellow star.
In this case, "yellow" refers to the peak wavelength of the 5500K blackbody output of the Sun. In reality, our star is white; its output essentially defines that color for human vision.

Re: The Milky Road (APOD 2009 June 13)

Posted: Sun Jun 14, 2009 12:37 pm
by orin stepanek
Chris Peterson wrote:
orin stepanek wrote:I think it's cool that we live by a yellow star.
In this case, "yellow" refers to the peak wavelength of the 5500K blackbody output of the Sun. In reality, our star is white; its output essentially defines that color for human vision.
I'll stand corrected! I guess I placed the white and yellow in the same category. :? I think the truly white get pretty close to being blue.

Orin

Re: The Milky Road (APOD 2009 June 13)

Posted: Sun Jun 14, 2009 1:03 pm
by JohnD
I wasn't going to bother, but as this thread has alreday dealt with etymology.......

"Congeries", in the text about the original APOD. Unless the structure of a galaxy can be seen, that is precisely correct - "Disorderly collection, heap." (OED) - bu the word is so archaic! What Latin word did Galileo use in "Sidereus Nuncius" to describe what he saw through his telescope? What would be a better modern translation?

John

Re: The Milky Road (APOD 2009 June 13)

Posted: Sun Jun 14, 2009 1:03 pm
by neufer
orin stepanek wrote:
Chris Peterson wrote:
orin stepanek wrote:I think it's cool that we live by a yellow star.
In this case, "yellow" refers to the peak wavelength of the 5500K blackbody output of the Sun. In reality, our star is white; its output essentially defines that color for human vision.
I'll stand corrected! I guess I placed the white and yellow in the same category. :?
'at'll teach ya to call our Sol yella!

Plants only "see" red light.

If earth plants had evolved to become Triffids or "the Thing"
would they have call red light "yellow" :?:

Re: The Milky Road (APOD 2009 June 13)

Posted: Sun Jun 14, 2009 1:25 pm
by apodman
orin stepanek wrote:the truly white get pretty close to being blue
Sounds like a lyric for albino blues man Johnny Winter.

Image

Re: The Milky Road (APOD 2009 June 13)

Posted: Mon Jun 15, 2009 2:39 am
by orin stepanek
I guess I'm not completely alone.

http://www.saguaroastro.org/content/Tinted-Stars.htm

At least someone else thinks old Sol' is tinted yellow. I won't argue the point as it is hot enough to keep old Terra nice and cozy. 8) In the summer anyway! 8)

Orin

Re: The Milky Road (APOD 2009 June 13)

Posted: Mon Jun 15, 2009 2:48 am
by Chris Peterson
orin stepanek wrote:At least someone else thinks old Sol' is tinted yellow. I won't argue the point as it is hot enough to keep old Terra nice and cozy.
When viewed high in the sky, the Sun does indeed take a slightly yellow tint. Not because it is intrinsically yellow, however. The Sun looks yellow because the atmosphere scatters away some of its blue content, shifting the apparent color of the source itself. The effect is even more obvious when the Sun is low on the horizon, and enough of the shorter wavelength energy is scattered and absorbed to turn the Sun red.

If you were in space, the Sun would look convincingly white, however.

Re: The Milky Road (APOD 2009 June 13)

Posted: Mon Jun 15, 2009 11:28 am
by neufer
Chris Peterson wrote:
orin stepanek wrote:At least someone else thinks old Sol' is tinted yellow. I won't argue the point as it is hot enough to keep old Terra nice and cozy.
When viewed high in the sky, the Sun does indeed take a slightly yellow tint. Not because it is intrinsically yellow, however. The Sun looks yellow because the atmosphere scatters away some of its blue content, shifting the apparent color of the source itself.
Image
Chris Peterson wrote:The effect is even more obvious when the Sun is low on the horizon, and enough of the shorter wavelength energy is scattered and absorbed to turn the Sun red. If you were in space, the Sun would look convincingly white, however.
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Rather than looking at the Sun directly :shock: can't we just look at sunlit white objects outside (e.g., most clouds) and recognize them as being white.

Re: The Milky Road (APOD 2009 June 13)

Posted: Mon Jun 15, 2009 1:21 pm
by Chris Peterson
neufer wrote:Rather than looking at the Sun directly :shock: can't we just look at sunlit white objects outside (e.g., most clouds) and recognize them as being white.
Yes, we can do just that. And some variations. Snow works well: snow under the open, clear sky is white. Snow in the shade is blue, because it receives no direct sunlight but does receive the scattered blue sky light. Patches of sunlight shining through trees onto heavily shaded snow are yellow, because they receive more direct sun and less sky scatter. All of these effects can require a little practice to see, since our brains are quite effective at adjusting our own white point under different conditions. The effects are very obvious in photos.

Another thing to note about the Sun: when it is high in the sky it's far too bright to be able to see color. We don't see color unless the brightness in attenuated, and under natural conditions, that is caused by things that also scatter or absorb shorter wavelengths- dust, fog, a large air mass.

Re: The Milky Road (APOD 2009 June 13)

Posted: Mon Jun 15, 2009 2:52 pm
by orin stepanek
http://www.madsci.org/posts/archives/19 ... .As.r.html

http://zebu.uoregon.edu/~soper/Light/yellow.html

http://www.setileague.org/askdr/suncolor.htm

I still think It is yellow! We see it as white because it is so bright and it still carries all the colors of the spectrum!

Orin

Re: The Milky Road (APOD 2009 June 13)

Posted: Mon Jun 15, 2009 3:05 pm
by Chris Peterson
orin stepanek wrote:I still think It is yellow! We see it as white because it is so bright and it still carries all the colors of the spectrum!
Well, "color" isn't a physical term, it is determined by biology and perception. And the spectral shape of the Sun is what defines "white". If the Sun were actually yellow, why are clouds and snow white?

Another thing to think about if you look at a star just a little hotter than the Sun, its blackbody spectrum will peak in the green- say, around 500 nm. But there are no green stars at all.

Re: The Milky Road (APOD 2009 June 13)

Posted: Mon Jun 15, 2009 5:04 pm
by neufer
Chris Peterson wrote:
neufer wrote:Rather than looking at the Sun directly :shock: can't we just look at sunlit white objects outside (e.g., most clouds) and recognize them as being white.
Yes, we can do just that. And some variations. Snow works well: snow under the open, clear sky is white. Snow in the shade is blue, because it receives no direct sunlight but does receive the scattered blue sky light. Patches of sunlight shining through trees onto heavily shaded snow are yellow, because they receive more direct sun and less sky scatter.
So heavily shaded yellow snow is OK to eat then? :wink:
Chris Peterson wrote: All of these effects can require a little practice to see, since our brains are quite effective at adjusting our own white point under different conditions. The effects are very obvious in photos. Another thing to note about the Sun: when it is high in the sky it's far too bright to be able to see color. We don't see color unless the brightness in attenuated, and under natural conditions, that is caused by things that also scatter or absorb shorter wavelengths- dust, fog, a large air mass.