The Northern Lights Explained (VIDEO)

The northern lights are spectacular for more than just their beauty.

They're also one of the most mysterious phenomena on Earth. Or at least, were at one point.

The video below gives a stunning look at just how these seemingly mystical waves come to be. Did you know that the northern lights are actually created after the sun ejects energy from its core?

Even if you're not a fan of awesome light, this video will get you at least one step closer to becoming an astrophysicist -- sort of.

Special thanks to the Department of Physics at the University of Oslo.

WATCH:

The Aurora Borealis from Per Byhring on Vimeo.

Comments

[fds]

05:19 PM on 08/19/2011

I love science and the universe.

[rjhuntington]

05:56 AM on 07/07/2011

Magnetic field "lines" are not a literal physical phenomenon. Magnet fields are fields; the lines are merely a way of imagining the field's presence and is not a literal representation of anything. Magnetic fields do not "stretch" or "break". Magnetic fields are produced by electric currents.

The solar "wind" is a plasma of ions, i.e., charged, particles. Charge in motion is electric current by definition. The aurora glows due to the current density of the plasma, the greater the current density the brighter the glow. The auroras are thus electrical phenomena.

The currents that feed the auroras are called Birkeland Currents, in honor of the man Kristian Birkeland, who discovered and described them about a hundred years ago. He was rewarded for his effort in making this amazing discovery by derision and ridicule. His work in only now coming to be accepted by mainstream science.

[palindrom]

06:42 PM on 07/07/2011

"Magnetic fields do not "stretch" or "break"." -- Actually, they do, in the presence of resistivity. This is tricky to treat analytically, but it's been known for a long time. The phenomenon is called "reconnection".

" Charge in motion is electric current by definition­. ". Not quite. To have a current, you need a net flow of charge. If equal amounts of positive and negative charge are moving along side-by-side, there's no current.

[SiriusMrE]

10:24 PM on 07/07/2011

Wow. You've been teaching astronomy for thirty years, you say? I am amazed (and a little sad) that you actually buy into (and teach?!) this concept...

Well, maybe I'm not so amazed. I have heard that most astronomers do not know anything about electrical engineering principles, and I guess you are proving that out.

IIRC, @rjhuntington is an electrical engineer. I'm gonna go with his explanation of magnetic fields and electric currents...

[rjhuntington]

04:48 AM on 07/08/2011

There is no such thing as "magnetic reconnection". That term is a fanciful invention by people who ought to know better and is an attempt to explain electrical phenomena without invoking electricity. It is a silly concept to an electrical engineer. Magnetic field lines do not "break".

A field can be collapsed by stopping the electric current supporting the field or opening the circuit, which has the same effect. A collapsing magnetic field can produce explosive effects depending on the anmount of energy stored in the field.

"Resistivity" is not a magnetic property, it is a property of materials that refers to the ability of the material to conduct electric current.

Charge in motion is indeed electric current by definition. In space, currents magnetically arrange themselves into twisted pairs of plasma conductors insulated from each other by what are called "double layers" (a feature of plasma). The conductor pairs are held close by the magnetic fields produced by the currents.

Such twisted pairs of plasma conductors are known as Birkeland Currents, after the discoverer, Kristian Birkeland, who showed that such currents are what power the auroras. The solar wind, another example of electric current consisting of charged particles in motion, is the power source for the auroral Birkeland currents.

[ThinkCreeps]

03:35 PM on 07/06/2011

C'mon Mr Headline - `How the northern lights are created'? Was it intelligently designed too?

[MCJanes]

05:40 PM on 07/06/2011

I, for one, am petitioning my school district to have the northern lights taught as representing the souls of unborn children and the torches of long-departed ancestors in addition to this "sciency" stuff, so the children can decide for themselves which they believe.

[jlbissette13]

12:36 AM on 07/07/2011

Hilarious!

[DeanWormer]

05:05 PM on 07/07/2011

Sure, make fun of the Native Americans.