Just What Is A Parsec?????

Discussion in 'Star Wars Saga In-Depth' started by OBI-GYN_Kenobi, Feb 9, 2003.

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  1. OBI-GYN_Kenobi Jedi Master

    Member Since:
    Jun 25, 2002
    star 3
    OK, all these years, I thought a parsec was an amount of time, but after AOTC, I'm not so sure.......

    In ANH, during the cantina scene, Han asks Obi-wan Kenobi if he ever heard of the Millenium Falcan......

    OB1: "No, should I?"
    Han: "It's the ship that made the Kessel run in 15 parsecs."

    OB1 just gives Han a look like "Yeah, right."

    Now "in 15 parsecs" sounds like time to me, like "in 15 hours". Right?

    But in AOTC, Dex tells OB1 that "Kamino is about 12 parsecs south of the Reeshy Maze." That sounds like a distance.

    Also, when R2D2 gives Anakin the message from OB1 to send to "the old folks home on Coruscant", Padme checks out where Geonosis is compared to Tattoine:
    "Look Geonosis is less than a parsec away."
    Again, that sounds like a distance, although this could also be a time, like "New York is less than an hour away."

    So, what's the deal here?

    It seems in each of the 1st 2 cases, a paresec is exclusively a time & then exclusively a distance. In the 3rd case, it could be either...
  2. DARTH_NAFOD Jedi Master

    Member Since:
    Nov 20, 2002
    star 1
    Found this on badastronomy.com

    The name "parsec" is indeed a distance of 3.26 light years. The definition is not arbitrary. It depends on the size of the Earth's orbit!
    First off, we need to know about "parallax". This means the change in the apparent position of an object when your position changes. A great example is easy to show: hold a thumb up in front of your face, about 20 centimeters away. Close your left eye, and move your thumb so that while looking through your right eye it is lined up with some distant object like a tree. Now close your right eye and look at your thumb through your left eye. See how it no longer lines up with the tree? That's because the angle formed by your eye, your thumb and the tree has changed. That angle is called the parallax angle, and it depends on two things: how far apart your eyes are (the baseline), and how far away your thumb is. If your eyes are really far apart, the angle gets bigger. If the thumb is held farther away, the angle gets smaller. When you are in a car and you look at trees nearby, they appear to race past you. Far away trees appear to move slowly. This is because for the nearby trees the parallax angle is large and so it changes rapidly if the car moves a little bit. Trees farther away appear to change less as the car moves along. Their parallax angle is small.

    This parallax method has been used for over a hundred years to find the distances to nearby stars. The Earth has an orbit about 300 million kilometers across. That's a long baseline! Even nearby stars will appear to change position due to parallax when you have such a long baseline.

    Astronomers needed some sort of unit to measure this change in position. What they decided was to make a standard distance unit. A star at this distance would change position by 1 arcsecond due to parallax. This distance is 3.26 light years, and is abbreviated parsec for parallax second (one arcsecond is 1/3600 of a degree; the full Moon is 1800 arsceconds across).

    Stars farther away than one parsec would shift by less than 1 arcsecond, and closer stars by more. The nearest star to the Sun is Proxima Centauri, which is about 4.3 light years away, or 1.3 parsecs away. That means that even the closest star has a parallax less than an arcsecond. Stars out to a distance of about 100 parsecs have had their distance measured this way. To imagine how small a shift that really is, imagine someone standing 200 kilometers away from you and then moving to the left by one centimeter. That is the same shift!

    The short answer is 3.26 light years, and it is a distance.

    How I have heard Han's boast justified is that he picked the shortest route through a cluster of stars or black holes, that most navigated around.
  3. Emos-Edud Jedi Master

    Member Since:
    May 29, 2002
    star 4
    Han's boast could also involve avoiding patrolling Imperial ships, which would make it hard to take shorter, more direct routes.
  4. Ternian Jedi Youngling

    Member Since:
    May 16, 2000
    star 4
    There was suppose to be a joke in that dialogue about parsecs and the way Han uses it.

    Sil could probably explain better.
  5. OBI-GYN_Kenobi Jedi Master

    Member Since:
    Jun 25, 2002
    star 3
    That'll do.

    And I just thought it was a word GL made up, like 'Banta'.....

    Well, I always did hate science. ;)
  6. GrandAdmiralJello Moderator Communitatis Litterarumque

    Manager
    Member Since:
    Nov 28, 2000
    star 10
    TOS had a answer to that in their Ask the Jedi Council area. The response was that Han Solo was a smuggler and didn't know what he was talking about.
  7. D_Lowe Jedi Grand Master

    Member Since:
    Aug 15, 2002
    star 6
  8. Jobo Force Ghost

    Member Since:
    Aug 14, 2000
    star 5
    Well, it's what Lucas claims, anyhow. Methinks he's covering up for his, uh, errors :p
    _jOBO
  9. DarthAttorney Manager Emeritus

    Member Since:
    Nov 8, 2000
    star 6
    All I knew before the above explanation was that it was a measure of time against distance in space. I remember that Asimov uses it occasionally in his Foundation series of novels.

    "Help us Silmarillion!
    You're our only hope!"


    ;)
  10. Darth-Horax Force Ghost

    Member Since:
    Aug 22, 2001
    star 6
    Ok people...I guess I'm the only one who ever paid attention in Physics class.

    A parsec is the distance that light travels in one year.

    Look it up. :)
  11. Emperor_Billy_Bob Chosen One

    Member Since:
    Aug 9, 2000
    star 7
    Actually, that would be a Light Year Darth Horax
  12. Aiwendil Jedi Knight

    Member Since:
    Jun 1, 2002
    star 1
    Ok people...I guess I'm the only one who ever paid attention in Physics class.

    A parsec is the distance that light travels in one year.


    Apparently, you didn't pay quite as close attention as you thought. Nor did you read Darth Nafod's excellent explanation above.

    The distance light travels in a year is a light year.

    A parsec is the distance that corresponds to a parallax of one arc second. Parallax is the change in position in the sky of a celestial object as viewed from earth over the course of a year.
  13. Darth-Horax Force Ghost

    Member Since:
    Aug 22, 2001
    star 6
    You're right...I didn't pay attention...I was in a meeting when I wrote that.

    I meant to say it was the distance light travels in 10 years...I havn't been in physics in about 9 years or so, so back off.

    :)

    I'm old, ok?
  14. yodahs-daddy Jedi Grand Master

    Member Since:
    May 20, 2002
    star 5
    1 Parsec=3.26 light years or 19,200,000,000,000 miles says my science in space text book.

    there is an actuall thing as a parsec and thats it. above.

    1 lightyear=5,880,000,000,000 miles

    light year the distance light travels in one year.
  15. VadersLaMent Chosen One

    Member Since:
    Apr 3, 2002
    star 9
    The thing is, Earth's orbit is used for the measurement of the parsec to get 3.26 light years.

    So, what planetary system is used for a standard parsec in a GFFA? I would assume Coruscant. The Earth's distance from the Sun is 93 million miles. According to a nice liitle book similar to Incredibel Cross Sections called "Inside The Worlds Of SW Episode I" Coruscant's orbit varies from 128 million to 155 million.
  16. NmdWy2Cl Jedi Padawan

    Member Since:
    Feb 9, 2002
    K now i will tell u what he meant, and no Han isnt a smuggler who doesnt know what he is talking about. I read several books concerning this cause i wanted to know and here r my findings:

    Parsec is a distance. The Kessel Run as it has become known as is a trading lane the Spice Smugglers use. they smuggle spice that dirty Imp officers steal and sell to criminal cartels to make pocket money. Anyway on the Kessel run there is the Black Hole Maw cluster just outside of the Kessel system. The Maw is on the Kessel Run. The Kessel Run trading lane goes around the Maw, but Solo skimmed the Maw closer than any1 else could, and cut time off the trip this making the Kessel Run in under 15 parsecs. He went the shortest distance (15 parsecs) and thus went the shortest distance from the black hole cluster than any1 ever making the Kessel Run, and in doing so took the shortest amount of time.
  17. D_Lowe Jedi Grand Master

    Member Since:
    Aug 15, 2002
    star 6
    One day they will explain a parsec in more detail. It's like what the official site says about it. They are a measure of distance. So is a mile. We have miles-per-hour. Or kilometers for those who live outside the United States. So now we will have ships traveling at parsecs-per-hour.
  18. Ben Kenobi Force Ghost

    Member Since:
    Mar 27, 2000
    star 5
    This may be a quibble, but isn't it 12 parsecs?
  19. JHC_JEDI Jedi Master

    Member Since:
    Jan 21, 2002
    star 1
    In hyperspace travel, time and distance are very closely related.

    I'm not sure how this forum reacts to EU sources, but in one of the EU books, they gave the story of Han's Kessel run.

    Anyway, the story went that Han was smuggling spice from Kessel, and was ratted out to the imperials by his supplier. In order to outrun the imperials who were trying to board him, he skirted closer to the black hole in the area than anyone had done before, thus cutting both distance and time off his "Kessel Run", and making it in under 12 parsecs.

    Take it for what its worth, being an EU source.
  20. VoijaRisa Force Ghost

    Member Since:
    Oct 12, 2002
    star 5
    1st: Yes, it is 12 parsecs.

    2nd: I believe it was the 3rd book of the Young Han Solo trilogy that explained what Han meant. Which I feel is one of the best book series since it didn't **** up the continuity like many other series.
  21. CUBIE_HOLE Force Ghost

    Member Since:
    Jun 15, 2001
    star 4
    As several others have pointed out, the parsec is a measure of distance, and Han did it in 12 parsecs, which means he made the Kessel Run in a shorter distance, which also implies a quicker time. What's so special about that?
    In the EU, the Kessel Run is close to a black hole(s). If something gets close to a black hole, it gets 'sucked into' the black hole, because of the huge gravitational forces.

    With that in mind, the closer you get to the black hole(s), the faster you ship needs to go, so it can escape the gravitational pull of the black hole(s). Han was bragging that his ship was so fast, it could make the run in 12 parsecs, which implies that most other ships, or maybe no other ships, couldn't get that close to the black hole(s) because they couldn't go fast enough to escape the gravitational pull.

  22. D_Lowe Jedi Grand Master

    Member Since:
    Aug 15, 2002
    star 6
    Very interesting analyses CUBIE_HOLE! :)

    Notice that when Han said that to Obi-Wan, Obi-Wan gave him a funny look like he was full of it.
  23. foxbatkllr Jedi Grand Master

    Member Since:
    Jul 27, 2001
    star 6
    I think Han was just blowing smoke. The look Obi-Wan gives him makes me think that.
  24. Yomin_Carr Force Ghost

    Member Since:
    Jan 12, 2002
    star 4
    I always assumed that either the GFFA word 'parsec' was a term for some sort of distance/time word with higher meanings that is impossible to understand unless you're in some sort of food establishment (or anywhere on Tatooine) and has the unfortunate fate as to have the same pronunciation as the word 'parsec' in English.


    Ummmm... yep. :D
  25. Kwenn Force Ghost

    Member Since:
    Mar 30, 2001
    star 5
    As above, I think it has a different meaning in the GFFA. It's mentioned twice in AotC, as if to say the 'parsec' in ANH wasn't just an error...
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