Tag: cosmic education

It all depends on your point of view

Over the winter, we read Brian Swimme’s The Hidden Heart of the Cosmos as part of the HMC Montessori Training Program. Swimme is one of those people trying to reconcile science and religion, or at least some type of spirituality.

He argues that crass commercialism, embodied by the consumer culture and a lot of television that is excrescent and dis-empowering, has replaced the spirituality that our ancestors sought in the dark, quiet reaches of the night. Then they had the time to contemplate the meaning of life and their place and even purpose in the universe. Now we try to respond to a rapidly changing world with no time to consider the fundamental questions.

I tend to be a bit skeptical about just how useful it is to examine the intersection of the sacred and the scientific. The scientific perspective is a powerful way of looking at the world. Spirituality seems to be one of those fundamental needs of human beings. I’ve never found it difficult to see the wonder in the natural world around me (which is why things like texture photography fascinate me). But when we try to describe the natural world in terms of religion and spirituality, I get a bit uncomfortable. When you’re treading the boundary between what we can observe objectively and what we feel subjectively, it’s all to easy to slip between one and the other. To stretch the scientific truth to accommodate the poetic language or metaphor. And so, it’s the little things that end up bugging me to no end.

Copernicus revolutionized the way western civilization viewed the world and itself, Swimme notes. The Earth was no longer at the center of the universe. The Sun did not revolve around us, we revolved around it. So when you see the Sun going down at sunset, it’s not really going down, the Earth is turning away. Except that it is and it isn’t. If the Earth is rotating you away from the Sun, or if the Sun in going down past the horizon, is just a matter of your point of view.

If you want to describe the motion of the planets, the easiest model to construct is one where the Sun is the stationary reference point at the center of the solar system. But, if you were a glutton for punishment, you could write the equations of motion such that the you were the stationary reference point and everything else moved relative to you. It’s a bit like thinking about yourself on a boat floating down a stream. To an observer sitting on the bank you are moving downstream, but to you, the guy on the bank is moving and you’re staying in the same place.

So I get a little agitated when Swimme points out how remarkable it is to think about the fact that we occupy such a small place in such a large universe. He argues that it should broaden your perspective on the universe, and open your mind to larger questions. But I find it just as remarkable, or perhaps even a little more so, to consider the world where I am not moving, and everything else is spinning in some ridiculously complicated dance around me.

I think of Swimme at times when I’m trying to model solute transport through a fluid. Should I try to follow the motion of individual particles with the fluid. Should I take the broader view of the flow through the system. Or should I try to mix the two approaches. Either way, the math should give the same result, since I’m just trying to describe the same thing from different point of view (of course the problem is in how compatible the different approaches are to being programmed).

I know I’m missing the main point of the Hidden Heart of the Cosmos here because of my own hang-ups, so I’ll post an excellent video interview of Brian Swimme by Bob Wright, the author of Nonzero, so he can better explain himself. (If you can’t get the video to play, you can read the transcript.)

Timeline of life

Timeline of Life on Earth.

This year the theme is life. My central organizing structure is the timeline of life on Earth. I plan to link all of the discussions of taxonomy, phylogeny and genetics to this timeline over the course of the year.

The timeline above will be the first lesson. As with these things the trick is deciding how much detail to keep in and how much to keep out.

What I like is that it gives the general overview of when important things happen while leaving a lot of space for students to investigate. Most of what we’ll be seeing this year happened in the Cambrian and this timeline conveys that this is a very small part of the whole history of life. In fact, it’s only when we cover the biochemistry of genetics that we will be talking about the origins of life.

From the Exploring Earth's Origins website.

The website Exploring Life’s Origins has a great timeline. It also has some really neat sections, with very useful videos, on the formation of protocells and the origin of RNA on the early Earth that lead to life as we know it.

The Magnetic Field?

The one thing I left out that I’m still conflicted about is the Earth’s magnetic field. Recent research indicates it has been around since 3.2 billion years ago and its presence or absence may have had profound effects on life.

The Earth's magnetic field protects us from the solar wind. Image from NASA.

Having a magnetic field protects the Earth from the charged particles spewing out of the Sun, the solar wind. This makes life on land a lot easier since the solar wind’s particles are quite damaging to DNA. However, prior to the magnetic field forming all this damage to DNA may have also accelerated mutation and thus evolution.

Voyager

Voyager approaching the heliopause (from NASA).

The Voyager spacecraft, launched in 1977, are still going and making new discoveries. They are after all the man-made objects that are furthest away from the center of the solar system, beyond the orbit of Pluto, and are now approaching interstellar space.

Where does the solar system end and interstellar space begin? Well, the Sun gives off light, but it also emits a plasma of charged particles (protons and electrons typically) that’s called the solar wind. These charged particles are launched from the Sun pretty fast, but as they get to the edge of the solar system they start to slow down, because the solar system is moving through a magnetic cloud, and, as we all know, charged particles are affected by magnetic fields.

The solar wind, assisted by the Sun’s magnetic field, pushes against the interstellar magnetic cloud, creating a bubble, called the heliosphere (helio=sun, sphere=sphere) that is pretty much the edge of the solar system.

Both Voyager spacecraft are approaching the heliosphere, and we’ve recently discovered that as the solar system moves through the interstellar magnetic cloud, the heliosphere is pushing against the cloud and the cloud is pushing back quite a bit. As a result, the heliosphere is shaped like the bow wave of water around a speeding boat.

It is difficult not to personify these two lonely spacecraft as the get further and further away from home, with no way to get back, but sending signals that tell of their discoveries and ensure their immortality.

The Moon transits the Earth

(from NASA).

Perhaps one of the most amazing sequences of images ever taken. NASA’s Deep Impact spacecraft took these movies looking back at the Earth from 50 million km away. You can see the moon clearly crossing the face of the planet. This really resets your perspective. The full movie is below.

The Big Bang

Good blogging style, like good presentations, should be multi-modal. On the internet we’re limited to text, images and sound/video so we do the best we can. I tend to be text oriented so I try to add an image to each post. In an earlier post on how science works I snagged an image by cédric sorel that he contributed to Wikipedia.

Artist's impression of the Big Bang. By cédric sorel: http://commons.wikimedia.org/wiki/File:Big_bang.jpg

Each time I see this interpretation of the Big Bang I am astonished once again. The textures give the impression of a three-dimensional cut-away, and the detail in the spiral galaxies swirling away from the center just pulls my attention like a strong magnet lines up iron filings.

The image is in the public domain and a high resolution version can be found on the Wikimedia Commons page (http://commons.wikimedia.org/wiki/File:Big_bang.jpg).

The universe … for scale

The American Natural History Museum has a YouTube channel with some interesting science-related videos. The one above, “shows the known universe as mapped through astronomical observations.”

Every satellite, moon, planet, star and galaxy is represented to scale and in its correct, measured location according to the best scientific research to-date.