[MuZI]

About 15 minutes ago my father walked in the door and told my sister to come outside and see something cool, so I go outside and see the most beautiful thing I've ever seen.

Wavy lights and of that sort, I'm most certain it was an aurora but I thought they mostly occured around the northern part of the world?

Anyone want to explain in layman's how they work?

(I already searched google and wiki...)

 

[seanohue]

I think its the same thing as a rainbow, but an aurora is ice particles in the atmosphere as opposed to water droplets.

 

[Asr]

In layman's terms?

Ok so there are 4 states of matter. The fourth is plasma (the other 3 being solid, liquid, vapor) and exists only at extremely high temperature, like on a star.

Solar flares contain plasma. When the flares are "explosive" enough, they get really, really big, and kinda "leap" out great distances, all the way to Earth. When they hit the atmosphere, an aurora results.

 

[Duggeh]

The aurora is now known to be caused by electrons of typical energy of 1-15 keV, i.e. the energy obtained by the electrons passing through a voltage difference of 1000-15,000 volts. The light is produced when they collide with atoms of the upper atmosphere, typically at altitudes of 80-150 km. It tends to be dominated by emissions of atomic oxygen--the greenish line at 557.7 nm and (especially with electrons of lower energy and higher altitude) the dark-red line at 630.0 nm. Both these represent "forbidden" transitions of atomic oxygen from energy levels which (in absence of collisions) persist for a long time, accounting for the slow brightening and fading (0.5-1 sec) of auroral rays. Many other lines can also be observed, especially those of molecular nitrogen, and these vary much faster, revealing the true dynamic nature of the aurora.

Auroras can also be observed in the ultra-violet (UV) light, a very good way of observing it from space (but not from ground--the atmosphere absorbs UV). The "Polar" spacecraft even observed it in X-rays. The image is very rough, but precipitation of high-energy electrons can be identified.



For further information on all aspects of the phenomenon please consult:

http://en.wikipedia.org/wiki/Aurora_%28astronomy%29

 

[DevilDog]

Quote:

Originally Posted by Duggeh The aurora is now known to be caused by electrons of typical energy of 1-15 keV, i.e. the energy obtained by the electrons passing through a voltage difference of 1000-15,000 volts. The light is produced when they collide with atoms of the upper atmosphere, typically at altitudes of 80-150 km. It tends to be dominated by emissions of atomic oxygen--the greenish line at 557.7 nm and (especially with electrons of lower energy and higher altitude) the dark-red line at 630.0 nm. Both these represent "forbidden" transitions of atomic oxygen from energy levels which (in absence of collisions) persist for a long time, accounting for the slow brightening and fading (0.5-1 sec) of auroral rays. Many other lines can also be observed, especially those of molecular nitrogen, and these vary much faster, revealing the true dynamic nature of the aurora. Auroras can also be observed in the ultra-violet (UV) light, a very good way of observing it from space (but not from ground--the atmosphere absorbs UV). The "Polar" spacecraft even observed it in X-rays. The image is very rough, but precipitation of high-energy electrons can be identified. For further information on all aspects of the phenomenon please consult: http://en.wikipedia.org/wiki/Aurora_%28astronomy%29

Got it. Right.

 

[seanohue]

I was way off lol

 

[Jazz1]

I thought Ray Samuels had built another fantastic piece of equipment!

http://www.fas.org/irp/mystery/aurora.htm

 

[mbriant]

Quote:

Ok so there are 4 states of matter.

According the the site linked below, there are 5 states of matter ... and somehow Bose is involved.

http://www.chem4kids.com/files/matter_states.html

http://en.wikipedia.org/wiki/Bose-Einstein_condensate

 

[Asr]

I completely forgot about the Bose-Einstein condensate. I'm ashamed, should've remembered that considering I live near Boulder....

 

[3DCadman]

I thought you were going to say there was a used Oldsmobile in the driveway.

 

[a1rocketpilot]

Not that Bose (Amar Bose), but Satyendra Bose. AFAIK, he doesn't distribute bad audio products for exorbitant costs.