This refers to three different things. Interestingly, these three things all involve seeing fantastic otherworldly things in the sky.
The Northern Lights has long been the name attributed to the beautiful patterns created in the sky when the Solar Wind interacts with the Earth's magnetic field.
The solar wind is when the sun farts. On a regular basis it guffs out vast quantities of charged particles all around space. It has been reported to the Antisocial Behaviour Unit on many occasions but apparently they do not have resources to deal with it.
When these charged particles get to the earth they stream around the earth's atmosphere along the lines of the magnetic field. Since these lines congregate at the poles, most of the activity happens in the artic circle or the antarctic. However, the southern lights are rarely seen since only a few scientists with frozen beards live anywhere they are visible.
The lights are one of the most fantastic displays on the earth.
The lights have been mistaken, over the centuries, for sprites, pixies, UFOs, gods, subspace phenomena, the second coming of Christ/Mohammed/Elvis, and invasions by Osama Bin Laden. These incorrect interpretations of the phenomenon are sometimes fantastically hallucinogenic and phantasmogorical.
There are numerous strains of the marijuana plant that have been bred for varying degrees of stupidly high THC content. One of those available in the Amsterdam coffee shops is known as Northern Lights. Apparently it was named because it gets you so off your face, you will see the northern lights in the sky even when they are not there, though exactly how this makes it differ from other forms of super strength skunk is a bit of a mystery.
This is the first book in a trilogy called His Dark Materials by Phillip Pullman. It's about a girl who experiments with bestiality, falls through a hole in the sky, meets god, and saves the universe by having underage sex. This first book from the series has been made into something of a popular film called The Golden Compass. In the book, the Northern Lights refers to strange phenomena in the sky in the vicinity of the north pole, but it turns out to be a kind of door into another dimension and the light coming out of it is some sort of magic fairy dust.
1) Christians and other rather religious people have strong opinions about all of these ideas. Skunk is obviously a little offensive to them; the lights in the sky are just a little too close to the ideas of science and religious folk often argue that they are, in fact, gods; and the book offends them because God appears in it and turns out to be kind of a muppet.
2) They all involve pretty patterns in the sky, either in actuality, or just in the mind as a result of psychedelic drug intake. In some parts, people on acid sometimes say "I'm having a Northern Lights moment" to indicate that they are tripping their nuts off and can see nothing except swirls of colour which they believe to be a doorway into another dimension.
An experiment was conducted to combine all three of these concepts into one moment. A 12 year old girl was asked to ride on the back of an over-friendly polar bear somewhere in northern Scandinavia, at night while the lights in the sky were in full view. She was given industrial strength skunk to smoke. The experiment revealed that social services get involved in 100% of these types of situations.