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Old 06-14-2012, 09:47 AM
 
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O.k. so then at first astronomers thought that it was part of our galaxy until Edwin Hubble discovered it as a seperate galaxy as thats just too cool . As for the Egyptians knowing the cosmos well i studied more about how they built the pyramids than what they used them for. Infact i've been studying a bit lately on the Mega Cranes that the ancient greeks were using when constructing the Parthenon as one was eight stories tall and could lift up to 20 ton blocks at a time.

Thanks Glitch and NB as you two are the cosmos guru's
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Old 06-14-2012, 10:03 AM
 
Location: Wasilla, Alaska
17,825 posts, read 20,498,482 times
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Originally Posted by 6 Foot 3 View Post
O.k. so then at first astronomers thought that it was part of our galaxy until Edwin Hubble discovered it as a seperate galaxy as thats just too cool . As for the Egyptians knowing the cosmos well i studied more about how they built the pyramids than what they used them for. Infact i've been studying a bit lately on the Mega Cranes that the ancient greeks were using when constructing the Parthenon as one was eight stories tall and could lift up to 20 ton blocks at a time.

Thanks Glitch and NB as you two are the cosmos guru's
It is truly amazing how much knowledge we lost after the fall of Greece and Rome. The Greeks understanding of geometry was second to none. Thankfully the Arabs were able to preserve some of that knowledge. We could have been almost 800 years more technologically advanced had it not been for the Dark Ages. The Magna Carta could have been written on a word processor. Thomas Aquinas could have written about the moon landing. The mind boggles at the possibilities that were lost.
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Old 06-14-2012, 10:58 AM
 
5,203 posts, read 8,207,066 times
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Quote:
Originally Posted by 6 Foot 3 View Post
O.k. so then at first astronomers thought that it was part of our galaxy until Edwin Hubble discovered it as a seperate galaxy as thats just too cool . As for the Egyptians knowing the cosmos well i studied more about how they built the pyramids than what they used them for. Infact i've been studying a bit lately on the Mega Cranes that the ancient greeks were using when constructing the Parthenon as one was eight stories tall and could lift up to 20 ton blocks at a time.

Thanks Glitch and NB as you two are the cosmos guru's
Sorry about the incorrect link. It should've been to "Observation History".

It was Heber Curtis who in 1917 first presented the idea that M-31 was an external galaxy (beyond our own), regarding it as an "Island Universe". He thought it was located about 500,000 light years away. A debate took place in 1920, and Edwin Hubble pretty well settled the question of distance in 1925, not only putting it outside of the galaxy, but much further out than had been previously thought.

The Greeks thought the Milky Way was some kind of luminous fluid like spilled milk, thus the name Milky Way. I don't know if the Greeks had ever noted the M-31 galaxy, but I think it's safe to say people had at least seen it considering that it's an object that can be seen without a telescope. We know the Egyptians were knowledgeable about celestial objects, so I'd have to guess they too had at least seen it, although I don't know if they had ever recorded anything about it.
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Old 06-14-2012, 12:31 PM
 
13,138 posts, read 37,034,859 times
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Originally Posted by Glitch View Post
It is truly amazing how much knowledge we lost after the fall of Greece and Rome. The Greeks understanding of geometry was second to none. Thankfully the Arabs were able to preserve some of that knowledge. We could have been almost 800 years more technologically advanced had it not been for the Dark Ages. The Magna Carta could have been written on a word processor. Thomas Aquinas could have written about the moon landing. The mind boggles at the possibilities that were lost.
Yeap the Greeks were highly advanced in mathematics e.g. Euclid - Father of Geometry, Hipparchus - Father of Trigometry, Pythagoras - Pythagorean Theorem, Eudoxus - Father of Integral Calculus as i could go on and on . You're exactly correct about muslim Al - Andalus (Spain) being the only light in western Europe during the Dark Ages.

Last edited by Six Foot Three; 06-14-2012 at 01:08 PM.. Reason: Corrections - 6 ft 3
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Old 06-14-2012, 12:33 PM
 
13,138 posts, read 37,034,859 times
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Originally Posted by NightBazaar View Post
Sorry about the incorrect link. It should've been to "Observation History".

It was Heber Curtis who in 1917 first presented the idea that M-31 was an external galaxy (beyond our own), regarding it as an "Island Universe". He thought it was located about 500,000 light years away. A debate took place in 1920, and Edwin Hubble pretty well settled the question of distance in 1925, not only putting it outside of the galaxy, but much further out than had been previously thought.

The Greeks thought the Milky Way was some kind of luminous fluid like spilled milk, thus the name Milky Way. I don't know if the Greeks had ever noted the M-31 galaxy, but I think it's safe to say people had at least seen it considering that it's an object that can be seen without a telescope. We know the Egyptians were knowledgeable about celestial objects, so I'd have to guess they too had at least seen it, although I don't know if they had ever recorded anything about it.
NB

what about Red Shift ... as does or did that have any effect on telling astronomers about distant galaxies?
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Old 06-14-2012, 01:42 PM
 
5,203 posts, read 8,207,066 times
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Originally Posted by 6 Foot 3 View Post
NB

what about Red Shift ... as does or did that have any effect on telling astronomers about distant galaxies?
The Red Shift gives some very important information. It has bearing on determining whether a galaxy is near or far and whether or not the apparent motion of a galaxy is moving toward us or away from is. The closer an object is the less extreme the red shift. That applies to how fast an object is moving. There's a lot more to it than that though. I'm definitely no expert. There's also making a comparison of the object in relation to known objects. An object that is more distant will show the red shift higher than objects that are closer, and the farther that object is, the higher its red shift is going to be. Type II Cepheid stars are used as standard candles because they're more consistent to better help measure and determine distances in the cosmos. Hubble is the guy who first identified Cepheid Variable stars beyond the galaxy from studying photos of M-31.

Some of the most distant galaxies in the universe are so extremely red shifted that it's estimated that they're receding away faster than the speed of light. That's a jaw-dropper!

Cepheid variable - Wikipedia, the free encyclopedia
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Old 06-14-2012, 02:37 PM
 
Location: Wasilla, Alaska
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Originally Posted by 6 Foot 3 View Post
NB

what about Red Shift ... as does or did that have any effect on telling astronomers about distant galaxies?
It did, but not in respect to the Andromedia Galaxy. Since the Andromedia Galaxy is moving toward the Milky Way Galaxy its spectrum will be blue shifted. It was Vesto Slipher, in 1912, who first discovered that "spiral nebula" (actually these were other galaxies, and not nebula) had considerable redshifts.

Red shift is calculated as:

(Observed wavelength - Rest wavelength)/(Rest wavelength) = (v/c)

v = velocity
c = speed of light


Red/Blue shift of a star's spectra is more of a measure of the speed of the star than its distance. However, it has been observed that the more distant the object, the greater its red shift. For example:
  • The Cosmic Background Radiation has a red shift of 1089, corresponding to an age of approximately 379,000 years after the Big Bang.
  • The yet-to-be-observed first light from the oldest Population III stars may have redshifts from 20 < z < 100.
  • The most distant spectroscopically confirmed galaxy is UDFy-38135539, with a red shift of 8.6, which is approximately 600 million years after the Big Bang.
  • The most distant quasar, ULAS J1120+0641, has a red shift of 7.1, which corresponds to approximately 770 million years after the Big Bang.
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Old 06-15-2012, 10:27 AM
 
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Originally Posted by Glitch View Post
  • The most distant spectroscopically confirmed galaxy is UDFy-38135539, with a red shift of 8.6, which is approximately 600 million years after the Big Bang.
Hmm. Looks like everybody and their brother are trying to jockey into position to claim the most distant galaxy prize. SXDF-NB1006-2 was announced this month by Japanese astronomers to be 12.91 light years away (using spectroscopic measurements) with reports that it may be "the most distant galaxy known", although it still needs to be more widely confirmed. A couple of other galaxies have been claimed as well in 2010 and 2011, but according to Richard Ellis at Cal-Tech, the Japanese claim is "more watertight" than the other two.

If UDFy-38135539 has been confirmed to be 13.1 billion years away, and SXDF-NB1006-2 is 12.91 billion years away, I don't understand all the recent chatter that SXDF-NB1006-2 may be the most distant galaxy known. It's a long distance to be sure, but the Most Distant Galaxy Known?


UDFy-38135539 - Wikipedia, the free encyclopedia

Oldest Galaxy In The Universe - Business Insider

Astronomers Find Most Distant Galaxy Known | Space.com
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Old 06-15-2012, 10:53 AM
 
Location: Wasilla, Alaska
17,825 posts, read 20,498,482 times
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Originally Posted by NightBazaar View Post
Hmm. Looks like everybody and their brother are trying to jockey into position to claim the most distant galaxy prize. SXDF-NB1006-2 was announced this month by Japanese astronomers to be 12.91 light years away (using spectroscopic measurements) with reports that it may be "the most distant galaxy known", although it still needs to be more widely confirmed. A couple of other galaxies have been claimed as well in 2010 and 2011, but according to Richard Ellis at Cal-Tech, the Japanese claim is "more watertight" than the other two.

If UDFy-38135539 has been confirmed to be 13.1 billion years away, and SXDF-NB1006-2 is 12.91 billion years away, I don't understand all the recent chatter that SXDF-NB1006-2 may be the most distant galaxy known. It's a long distance to be sure, but the Most Distant Galaxy Known?


UDFy-38135539 - Wikipedia, the free encyclopedia

Oldest Galaxy In The Universe - Business Insider

Astronomers Find Most Distant Galaxy Known | Space.com

UDFy-38135539 was discovered in 2009, and spectroscopically confirmed to have a red shift of 8.6 in October 2010.

Most Distant Galaxy Ever Confirmed | Wired Science | Wired.com

UDFj-39546284 was discovered in 2011, and may have a red shift of 10, or about 480 million years after the Big Bang (13.2 billion light years distant) although it has not been spectroscopically confirmed yet.

NASA - Most Distant Galaxy Candidate Ever Seen in Universe
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Old 06-15-2012, 01:29 PM
 
5,203 posts, read 8,207,066 times
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Originally Posted by Glitch View Post
UDFy-38135539 was discovered in 2009, and spectroscopically confirmed to have a red shift of 8.6 in October 2010.

Most Distant Galaxy Ever Confirmed | Wired Science | Wired.com

UDFj-39546284 was discovered in 2011, and may have a red shift of 10, or about 480 million years after the Big Bang (13.2 billion light years distant) although it has not been spectroscopically confirmed yet.

NASA - Most Distant Galaxy Candidate Ever Seen in Universe
I understand that, but neither one of those are the SXDF-NB1006-2 galaxy which was recently reported, are they? See the last two links I posted. As I mentioned for the sake of fairness, the reports say that "spectrocopic measurements" were used by the Japanese for SXDF-NB1006-2 but it still has to be confirmed by other observers.

What I don't understand is that if SXDF-NB1006-2 is determined to be 12.91 billion light years away, how can it be called "the most distant galaxy known" if there are others (at least one confirmed) that are even more distant like UDFy-38135539 which is 13.1 billion years away? The difference may be slight, but there is a difference.

The two above that you mention (datewise) may be that of a galaxy noted by the French (2010), and the another galaxy by a group in California (2011). According to one article dated June 14, 2012, which was yesterday
(Bold highlight added by me for emphasis):
Quote:
Can we be certain that it's really the oldest galaxy?

Not completely. Other astronomers have made similar claims in the past using NASA's Hubble telescope. In 2011, a group from California spotted a galaxy 13.2 billion light years away. The year before that, a French group found a galaxy 13.1 billion light years away.

However, Richard Ellis of the California Institute of Technology told the AP that neither groups have proved their findings with other methods and the Japanese claim was more "watertight."
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