Am I going to get people angry by posting this?

The last time I promise... (for now)
The Venus/Sirius thing
I know this topic is like beating a dead horse... But I made my first you tube vid and I wanted share it with you guy's.

www.youtube.com...





[edit on 6-3-2009 by foremanator]

Why Do Stars Twinkle?
Answer:
On a clear, dark night, our eyes can see about 6,000 or so stars in the sky. They seem to twinkle, or change their brightness, all the time. In fact, most of the stars are shining with a steady light. The movement of air (sometimes called turbulence) in the atmosphere of Earth causes the starlight to get slightly bent as it travels from the distant star through the atmosphere down to us on the ground. This means that some of the light reaches us directly and some gets bent slightly away. To our eyes, this makes the star seem to twinkle.

You will notice that stars closer to the horizon will appear to twinkle more than other stars. This is because there is a lot more atmosphere between you and a star near the horizon than between you and a star higher in the sky.

If you film this above the atmosphere I would say it looks completely different.

Well if you're asking for others opinions I get the feeling you've already made your mind up:

My first video I have ever posted This is supposedly Sirius feb 25 Anyway this Star is acting crazy. Do not listen to the dis info creeps. This is not normal by any stretch of the imagination

The horse is well and truly beaten, so much so it's now a pot of glue.

Originally posted by Chadwickus
Well if you're asking for others opinions I get the feeling you've already made your mind up:

My first video I have ever posted This is supposedly Sirius feb 25 Anyway this Star is acting crazy. Do not listen to the dis info creeps. This is not normal by any stretch of the imagination

The horse is well and truly beaten, so much so it's now a pot of glue.

Oh come on Chadwickus
I thought we were working on your tact.

reply to post by foremanator



Nah no tact today.


All the best with it.

Originally posted by Chadwickus
reply to post by foremanator

 

Nah no tact today.


All the best with it.

Thats aight chadwick
I still love you

Since the OP claims over at YouTube that the star is acting crazy, it is necessary to explain that it is not crazy at all. On the contrary, it behaves quite normal, and it all has to do with turbulence in the atmosphere:

The stars are very far away. In fact, they are so far away that they basically are like point sources as far as we are concerned. That means that the light appears to come from a single point in the sky (unlike the Moon in which light comes from a disk about half a degree across, or a planet in which light appears to come from a very small disk in the sky). As this light passes through Earth’s atmosphere, it is bent a bit whenever it passes through a region of slightly denser air. Different colors of light, in principle, take slightly different paths, since the degree of refraction (bending) that light undergoes is frequency dependent. So, the path of the light through the air from the star to your eye takes a sort of convoluted path schematically shown in the following drawing. Note that this drawing is greatly exaggerated in terms of the effect of the atmosphere.

[atsimg]http://files.abovetopsecret.com/images/member/03bc1cb5f2dc.jpg[/atsimg]

Now, if this were all that was going on, then the star would simply appear slightly out of position in the sky rather than twinkling. If the different colors were bent far enough apart, then the star might appear as a tiny little splotch of colors (like a tiny rainbow) rather than a pinpoint. That would be if the air were completely unmoving. But, that isn’t what happens. The air moves around. Solar heating causes convection. Winds blow. Different parts of the air are compressed and rarefied as the air moves. These different regions refract light differently (which is part of the reason that the light takes a convoluted path through the atmosphere, anyway). But, these regions of thicker and thinner air, more and less humid air, moving air, etc., are always moving around. As the move, the convoluted path changes. In my drawing above, you can think of the different colored lines as being the path of the starlight at different times. The more the air is moving around, the more the path of the light dances around.

astroprofspage.com...