加载中...
COLLECTED BY
Organization:
Internet Archive
These crawls are part of an effort to archive pages as they are created and archive the pages that they refer to. That way, as the pages that are referenced are changed or taken from the web, a link to the version that was live when the page was written will be preserved.
Then the Internet Archive hopes that references to these archived pages will be put in place of a link that would be otherwise be broken, or a companion link to allow people to see what was originally intended by a page's authors.
The goal is to
fix all broken links on the web.
Crawls of supported "No More 404" sites.
This is a collection of web page captures from links added to, or changed on, Wikipedia pages. The idea is to bring a reliability to Wikipedia outlinks so that if the pages referenced by Wikipedia articles are changed, or go away, a reader can permanently find what was originally referred to.
This is part of the Internet Archive's attempt to
rid the web of broken links.
The Wayback Machine - https://sup1a9wrlpyh5li9ro.vcoronado.top/web/20150419140349/http://www.dapep.org/DAPT/EM-Wiki/aurora-borealis.html
Aurora Borealis
Aurora Borealis also known as The Northern Lights, is a luminous glow in the northern hemisphere.
Background information:
- The Northern Lights have been mentioned in many cultures throughout history. The Inuit have ancient folklore that talks of the Northern Lights as the souls of the dead passing on to heaven. In mideaval times, the Northern Lights were seen as the souls of warriors passing. In 1621, French scientist Pierre Gassendi keyed the term Aurora Borealis after Aurora, the Roman Goddess of dawn, and Borealis, the Roman God of the north wind.
- The Lights can be seen in many forms. They include arc (evenly curved arch of light with a smooth lower edge that may extend from horizon to horizon), band (similar to an arc, only folded or kinked on its lower edge), patch (small, cloud like area of auroral light), corona (rayed arcs or bands seen from directly underneath, so the light seems to beam out like a sunburst in all directions), ray (thin beam or shaft of bright light that hangs more or less vertically. A ray is actually a tight curl, or eddy, of light seen from the side), veil (large, featureless expanse of light that sometimes covers the entire sky. It may be white or, in exceptional cases, red)
Arc 
Band 
Patch 
Corona 
Ray 
Veil
How Aurora Borealis occurs:
- Aurora Borealis originates from the sun. Large explosions on the surface of the sun throw thousands of particles into the solar system. These particles form a plasma cloud that escapes into open space. After two to three days the plasma clouds reach the Earth, where they are captured by the Earth's magnetic fields.
- The electrons in the Earth's atmosphere travel along the magnetic field lines. These electrons are guided to the northern poles, which is where Aurora Borealis is seen.
- The Aurora Borealis is caused by charged particles striking atmospheric molecules. Once the collision occurs, the electrons store energy, which is known as excited. The electrons are considered to be excited in this formation because they are being raised to a higher energy level.
- An electron can go to a ground state, or non-excited state by sending off a photon. This sending off creates the intense lights we see.
- The colors that appear during the Northern Lights show reflect the level of excitation of the different gases:
- oxygen = greenish-white
- nitrogen molecules = red-violet
- nitrogen ions = blue-violet
- The light in the Aurora Borealis also includes infrared light, ultraviolet light, and x-ray radiation light.
- The motion of the charged particles is confined by the magnetic field. These particles can only move parallel to the magnetic field causing the lights too look like rays.
When can you see Aurora Borealis Occur:
- Somewhere on Earth, Aurora is occuring. Whether it is Aurora Borealis (in the northern pole) or Aurora Australis (in the southern pole).
- Conditions that allow easy viewing:
- calm solar winds
- dark and clear sky
*the sun and clouds are the biggest obstacles when it comes to viewing aurora.
- Best places to see Aurora Borealis is during the winter in Alaska, Canada, and Skandinavia. Around the winter solstice is the best time because this is when the night sky is the darkest. Best time is the three to four hours around midnight.
Picture of where the Northern Pole is located.
Picture of what the Aurora Borealis looks like.
Resources:
Aurora Borealis. C.A.A.E. Churchill, Manitoba, Canada. Retreieved April 29, from http://www.aurora-inn.mb.ca/borealis.html
Hewitt, Paul G. Conceptual Physics Tenth Edition. San Francisco: Pearson Addison Wesley, 2006. 584.
Lummerzheim, D. (2008). Aurora FAQ. Retrieved April 27, 2008, 2008, from http://odin.gi.alaska.edu/FAQ/#often
Petterson, Frank. "Aurora Borealis - the Northern Lights." Tromso: University of Tromso, 1996. http://www.imv.uit.no/english/science/publicat/waynorth/wn1/contents.htm
Arc 
Band 
Patch 
