Comments on: The Cepheids Aren't Falling http://www.universetoday.com/2008/09/19/the-cepheids-arent-falling/ Space and astronomy news Sun, 8 Nov 2009 08:15:54 -0600 http://wordpress.org/?v=2.8.5 hourly 1 By: Mark http://www.universetoday.com/2008/09/19/the-cepheids-arent-falling/comment-page-1/#comment-33612 Mark Tue, 23 Sep 2008 13:12:13 +0000 http://www.universetoday.com/?p=18378#comment-33612 "The astronomers found that the deviations in the measured velocity of Cepheids were linked to the chemical elements in the atmospheres of the Cepheids considered. " Was the velocity measured through redshift? If so, this seems to be saying that there is an intrinsic component to redshift, right? If there is an intrinsic component then all of redshift based distances could be wrong ... right? "The astronomers found that the deviations in the measured velocity of Cepheids were linked to the chemical elements in the atmospheres of the Cepheids considered. "

Was the velocity measured through redshift? If so, this seems to be saying that there is an intrinsic component to redshift, right? If there is an intrinsic component then all of redshift based distances could be wrong … right?

]]> By: watchful stone guardian http://www.universetoday.com/2008/09/19/the-cepheids-arent-falling/comment-page-1/#comment-33518 watchful stone guardian Mon, 22 Sep 2008 15:12:17 +0000 http://www.universetoday.com/?p=18378#comment-33518 I am not an astronomer so I too have had some troubles understanding this article. If the composition of the cepheid atmospheres are responsible for the "falling" artifact then I have to ask what is the chemistry of these atmospheres and why is distributed among these stars such that this artifact is visible in the first place. I would have thought that the atmospheric composition would be randomly distributed thus giving the illusion that these variable stars would be falling in random directions. Since they do appear to us as if they are falling towards the Sun would an astronomer on one of the other galactic arms of the Milky Way see these cepheids appear to fall towards themselves or towards our Sun? There seems to be some background information missing in your article that would go a long way to explaining the significance of these findings to those of us who are not formally trained in astronomy. I am not an astronomer so I too have had some troubles understanding this article.

If the composition of the cepheid atmospheres are responsible for the "falling" artifact then I have to ask what is the chemistry of these atmospheres and why is distributed among these stars such that this artifact is visible in the first place. I would have thought that the atmospheric composition would be randomly distributed thus giving the illusion that these variable stars would be falling in random directions. Since they do appear to us as if they are falling towards the Sun would an astronomer on one of the other galactic arms of the Milky Way see these cepheids appear to fall towards themselves or towards our Sun?

There seems to be some background information missing in your article that would go a long way to explaining the significance of these findings to those of us who are not formally trained in astronomy.

]]> By: Bravehart http://www.universetoday.com/2008/09/19/the-cepheids-arent-falling/comment-page-1/#comment-33399 Bravehart Sun, 21 Sep 2008 02:55:49 +0000 http://www.universetoday.com/?p=18378#comment-33399 Hi Nancy. I'm confused, the Name cepheids is realy an terminollegy for an objet is it not? We use this (object) as a reference point to estimate a probabel distance? At least that is my understanding of this artical. If I may make an anology, When we measure a distance from point A to point B we have an absolute distance yes? Now we are taken a measurement in the realm of space, we can not take tape measure and walk from Earth to where ever yes/ At least not jet. Since everything is moving, and I mean moving sometimes at light speed but because of the fast distances the objects seams to be relatively standing still! Try taking a measurement from a moving bullet train from the point at the station where you are standing with a tape measure? It will not work right? The astro people say that the distance from earth to the moon is .....miles/ kilometers? We had the oppertunity to go to the moon and we were able to verify that? Here on earth we use telemetry to determine distanses and angles, BUT the objects are standing still. I do understand that you can do a measurement relative to?Just like the days in school when we set out distances playing by simply using our foot as a measuring guide. I do except the distances we the astro community is giving use, BUT they are certainly not absolute, right? These measurement are by observation and imaginary values yes? May I humbly propose That we use a symbol when giving distances and speeds in the astronomical community Such as ^[........]^ ? From your artical I have the impression that Cepheids are used as refference (yard sticks) yes? The distances between Cepheids or the distances them and Earth? Are they (trajectory or point to point? Cepheids used as a yardstick, without having a scaling is really compounding the error and therefore not realistic yes? Pease forgive me if I'm sound synical, it is not my intension. Like I said from the start, I'm confused as to what the artical is saying? The Astro community is an undiciplend at best, one should follow certain standarts or general conformmity, so we all can understand as to what they are saying, right? Respectfully Yours. Hi Nancy.
I'm confused, the Name cepheids is realy
an terminollegy for an objet is it not?
We use this (object) as a reference point to estimate a probabel distance? At least that is my understanding of this artical. If I may make an anology, When we measure a distance from point A to point B we have an absolute distance yes? Now we are taken
a measurement in the realm of space,
we can not take tape measure and walk from Earth to where ever yes/ At least not jet.
Since everything is moving, and I mean moving sometimes at light speed but because of the fast distances the objects
seams to be relatively standing still! Try taking a measurement from a moving bullet train from the point at the station where you are standing with a tape measure? It will not work right? The astro people say that the distance from earth to the moon is …..miles/
kilometers? We had the oppertunity to go to the moon and we were able to verify that?
Here on earth we use telemetry to determine
distanses and angles, BUT the objects are standing still. I do understand that you can do
a measurement relative to?Just like the days in school when we set out distances playing
by simply using our foot as a measuring guide. I do except the distances we the astro community is giving use, BUT they are certainly not absolute, right? These measurement are by observation and imaginary values yes? May I humbly propose
That we use a symbol when giving distances
and speeds in the astronomical community
Such as ^[........]^ ? From your artical I have the impression that Cepheids are used as refference (yard sticks) yes? The distances
between Cepheids or the distances them and Earth? Are they (trajectory or point to point? Cepheids used as a yardstick, without
having a scaling is really compounding the
error and therefore not realistic yes?
Pease forgive me if I'm sound synical, it is not my intension. Like I said from the start, I'm
confused as to what the artical is saying?
The Astro community is an undiciplend at best, one should follow certain standarts
or general conformmity, so we all can understand as to what they are saying, right?

Respectfully Yours.

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