Not every science lesson starts with specimens or equipment; this one starts with a beautiful painting. We’ll study it and ask questions that will help us think scientifically.
This piece is called Aurora Borealis, and it was painted by Frederic Church in 1865.
Study it for a moment… What jumps out at you? What are you curious about? Do you have some questions? Do you notice how the colors in the sky are reflecting on the surface? Smooth surfaces tend to yield much more faithful reflections, and this is more of a blurry color—we're so used to seeing reflections everywhere that we tend not to notice them. Sometimes it takes an artist's eye to point this out, and that’s certainly noticeable here.
Study the beautiful colors in the sky. Do you notice the lines... do you see the series of lines that appear to be converging? Where have you seen that before? If you've ever seen the Sun streaming through an opening in the clouds showing this sort of radiating shafts of light, or if you've ever noticed that lines of a road (if you're traveling on a long straight road) they appear to converge in the distance.
The place where they seem to converge is the vanishing point, and this is most obvious when you have parallel lines of something such as roads or buildings. We don't typically see vanishing points in natural scenes because there aren't a lot of instances of parallel lines in nature.
Mentally extend the lines to the horizon, and you'll see that they converge. That's evidence that the lines of light we see here are parallel. But perhaps you're thinking, "I thought that light radiated from a source in all directions." That's certainly true with sources such as light bulbs. The light that reaches Earth from the Sun is a little different. The Sun is so immense, and such a tiny sliver of its rays reach Earth that by the time they do, the light rays are reasonably parallel. When you see sunlight bursting through clouds in these radiating shafts of light they appear to convergence because they are parallel.
But this isn't light from the Sun. So we can't use this explanation. This light comes from excited particles in the atmosphere. When particles that are high atmosphere are ionized and excited, they give off light very similarly to those in fluorescent tubes. And since the particles have charges they're affected by Earth's magnetic field. If you see a diagram of Earth's magnetic field, you'll notice that in some places, the field lines are nearly parallel. And that's what you're seeing here. These charged particles are lining up according to Earth's magnetic field lines.
Do you notice the different colors? What colors can you see? Cyan, gold; scarlet; different colors correspond to different energies. If you've had the chance to study flame tests, rocks, stars, or even atoms they all have this characteristic in common—that if they're excited in a specific way they give off light. The light they give off is very particular to what they're made of. And so you can look at the light they're giving off and make a conclusion as to what the substance is. That's how we can identify what stars are made of: we analyze the light coming from the stars and then we conclude, "Oh it must be made of hydrogen or lithium." And that correlates to what's going on here.
We had these images on the walls in our classroom just because they're so fascinating to look at, but when we need to study them, we look at them online where we can zoom in and get to some incredible detail. In fact, the first time I shared this with my students they showed me so many things I had overlooked. They noticed, and perhaps you've noticed it too, that the ship has a light on.
So that causes us to ask more questions, "Who's on the ship? What are they doing? What time of day is it? Is it winter? Is it summer? Could you figure that out? Well, you can infer their location because of the title of the painting—and the title of the painting is Aurora Borealis. Do you know what that means? I've alluded to it here, referring to it as the Northern Lights which is another name for it.
Aurora refers to the Roman god of the dawn and Borealis is the north wind. I think the name is credited to Galileo—in his lifetime there was an unusual display of the Northern Lights and they were seen much further south than normal, and so from his home in Italy, Galileo saw them. And to him, they look like the dawn. They don't come up at dawn; they come up at night, but it looked as though the Sun was rising because of the red glow in the distance and so he called it the northern dawn and that's where the name comes from; Aurora meaning dawn and Borealis meaning north.
What do you notice here? Earlier we wondered about the reflection and, whether this area could be ice or water? Since this is a dog sled, which must run on solid ground, this section has to be ice and not water.
In our classroom we had art like this on the walls sometimes we had a discussion about them like the one we've had here but primarily they serve as a beautiful reminder of how things are connected and how studying one area of interest can often inform another.
If you're interested in adding these types of studies to your classroom, check out the resources here.
And, if studying more about light intrigues you, you can click the link here.
Thanks for joining me on this discussion as we delve into what it means to think scientifically.