parallax

Can a FEer explain this phemomenon to me?

I don't expect to understand this in terms of wobble, since there is such a wide range of observable parallax (from about 1 parsec to about 200 parsec; i.e. 23 orders of magnitude).  Perhaps the stars swing on long cables suspended from something even more mysterious?

Can a FEer explain this phemomenon to me?

I don't expect to understand this in terms of wobble, since there is such a wide range of observable parallax (from about 1 parsec to about 200 parsec; i.e. 23 orders of magnitude).  Perhaps the stars swing on long cables suspended from something even more mysterious?

Well, I used the search function to see if I could get an answer to this very question.  Sure enough I couldn't find an answer, but I did find the question popping up every once in a while.  So why, not, any Flathead care to take this question on?

Can a FEer explain this phemomenon to me?

Parallax is the pseudonym that Samuel Birley Rowbotham used when he wrote Earth Not a Globe and while on the lecture circuit.

It is also the name of an electronics company. See I can avoid answering questions too.

Can a FEer explain this phemomenon to me?

I don't expect to understand this in terms of wobble, since there is such a wide range of observable parallax (from about 1 parsec to about 200 parsec; i.e. 23 orders of magnitude).  Perhaps the stars swing on long cables suspended from something even more mysterious?

how is 200 parsec different from 1 parsec by 23 orders of magnitude?

Well parallax is measured as an angle, not a length, so it would be arcseconds rather than parsec - one parsec is the distance a star needs to be from earth to create a parallax angle of 1 arcsecond(3 ly or so). It's true that there's a huge range of measurable parallax angles, the closest are close to 1 arcsecond (not much further than a few ly) and the farthest visible stars (not to mention other galaxies that we can observe) being way too far for us to measure their parallax with our tech.
Of course, this is assuming that the earth is a spherical ball of rock orbiting the sun, I'm not sure how you could otherwise account for stellar parallax

yeah, cool story and all, but you still have not addressed my question.

Quote from: turin on May 06, 2006, 09:41:00 PM

Can a FEer explain this phemomenon to me?

I don't expect to understand this in terms of wobble, since there is such a wide range of observable parallax (from about 1 parsec to about 200 parsec; i.e. 23 orders of magnitude).  Perhaps the stars swing on long cables suspended from something even more mysterious?

how is 200 parsec different from 1 parsec by 23 orders of magnitude?

yeah, cool story and all, but you still have not addressed my question.

It's not, probably a mistake by the thread starter. Is it relevant to the question (what explains parallax) in any way?

He says that a wobble cannot explain such a wide range of observations. But, then, the two ranges of values he states contradict each other. So, what's a wide range and what is not? Also, if a distance of 1 parsec corresponds to a stellar parallax equal to 1 arc second, then more distant objects have a parallax smaller than 1 arc second. For example, 200 parsec would correspond to 1/200 th = 0.005 arc seconds. Could the OP or someone else please point us to the measuring equipment capable of measuring angles with this precision?

He says that a wobble cannot explain such a wide range of observations. But, then, the two ranges of values he states contradict each other. So, what's a wide range and what is not? Also, if a distance of 1 parsec corresponds to a stellar parallax equal to 1 arc second, then more distant objects have a parallax smaller than 1 arc second. For example, 200 parsec would correspond to 1/200 th = 0.005 arc seconds. Could the OP or someone else please point us to the measuring equipment capable of measuring angles with this precision?

http://en.wikipedia.org/wiki/Hipparcos

EDIT: Of course, we can only measure the parallax of nearby stars, because as I said earlier, distant stars don't have enough apparent shift to be measured with our technology.

I found this refefernce Nature 427, 326-328 (22 January 2004).

While the precision of technology in the thread may have been somewhat unclear. Parallax has for some centuries been well anough measured to imply that the univer is pretty massive. An most of the stars we see emitted their light a long time ago in a glaxy far far away. I know thats not scientifically rigorous but I wanted to fit in with the tone of the thred and get my little reference in.

He says that a wobble cannot explain such a wide range of observations. But, then, the two ranges of values he states contradict each other. So, what's a wide range and what is not? Also, if a distance of 1 parsec corresponds to a stellar parallax equal to 1 arc second, then more distant objects have a parallax smaller than 1 arc second. For example, 200 parsec would correspond to 1/200 th = 0.005 arc seconds. Could the OP or someone else please point us to the measuring equipment capable of measuring angles with this precision?

Given that you couldn't understand how a star near the horizon would be bent more than a star overhead if bendy light existed, I don't think you are qualified to comment in this thread.

Quote from: parsec on March 03, 2010, 09:46:44 PM

He says that a wobble cannot explain such a wide range of observations. But, then, the two ranges of values he states contradict each other. So, what's a wide range and what is not? Also, if a distance of 1 parsec corresponds to a stellar parallax equal to 1 arc second, then more distant objects have a parallax smaller than 1 arc second. For example, 200 parsec would correspond to 1/200 th = 0.005 arc seconds. Could the OP or someone else please point us to the measuring equipment capable of measuring angles with this precision?

Given that you couldn't understand how a star near the horizon would be bent more than a star overhead if bendy light existed, I don't think you are qualified to comment in this thread.

Cool. Thanks for sharing.