Did you know that in California it is illegal for workers at orphanages to hug the children? I was shocked to hear this. I’m no expert, but conventional wisdom is that children need love, hugs and caring touches (like being carried). Isn’t it obvious  that children without  any “parental” contact will encounter major obstacles to having healthy relationships when they grow up? Its as if you were to cut off their arm to save a finger.

Warning: Inappropriate touching according to California law.

I understand a small number of nasty people in the world target orphans who are among the most vulnerable in our society. But you have to be pragmatic. While it is awful to consider that some orphans will be abused, it is even more awful to contemplate orphans who don’t get any physical love for their entire childhood.

Feeling self righteous, I googled “hug an orphan” and discovered that in some foreign countries, orphan tourism is a favored pastime. Tourists volunteer at foreign orphanages to help out. This is bad for the children, because a steady stream of strange people does not give them a stable environment. They’re like animals in a petting zoo. Worse, some orphanages intentionally make their place look run down and mistreat the children to inspire greater pathos in the tourists. Aie!

OK, now for the science part. Writing a good law about this issue is not science, it is a value judgement. Those of us who enjoy numbers would like to do a risk-assessment, but the outcome will depend on what value you  place on N loving hugs as  compared to n << N nasty events. Unlike science, when it comes to values your mileage may vary (i.e. you might think I’m crazy, which is OK).  My point is that you have to know where to use science (as in deciding whether or not climate change exists) and where we have to rely on moral judgements. To quote Saint Albert “The laws of gravity cannot be held responsible for people falling in love.“

Electromagnetic Spectrum

There are good reasons that almost everything we know about the distant universe came to us through measurements of light (electromagnetic radiation). Since light was present even at the birth of the universe, the field of astronomy predates just about everything. From another perspective, astronomy began when the first creatures looked up from the surface of their planet and asked, where does that light come from?

Since light is so important to astronomy, we should study the limits of light in every possible dimension, from extreme to extreme. There are four dimensions along which light may vary, but we don’t often give much thought to more than one or two. Here I take a moment to outline all the different ways light can exhibit itself.

The first dimension is color, or to physicists, frequency. The image at top describes only the frequency dimension of light. Those things we call radio waves, x-rays, gamma-rays, are all the same thing as light, with different frequencies. To physicists, the difference between what we call everyday light and x-rays (higher frequency) or cosmic microwave background radiation from the big bang (ironically low frequency) light is merely a constant and has no effect on the physics.

Today’s astronomy picture of the day shows us two more dimensions which are used to describe light. From the perspective where our telescope is the center of the universe, we speak of the direction of arrival of light. The direction of arrival is specified with two angles (in astronomy, right ascension, declination) but in human experience we normally approximate these angles as spatial coordinates (up/down, left/right):

With the two dimensions of  this display, and the dimension of color, that’s all there is, right? In truth, there is one more dimension, which we call polarization. Interestingly, evolution has not given our eyes sensitivity to polarization but it is an important physical property of radiation.

To understand polarization, lets go back to the basics. Light is electromagnetic radiation, and our eyes respond to oscillations of the electric field. But the electric field is a vector field, meaning it has a direction. No matter how complicated the light may become, standing outside your door or at the center of the sun, the electric field vector points in only one direction at a time at any point in space. For reasons I won’t mention, light always moves in a direction perpendicular to the direction of the electric field vector, so if light is to move into your eye (or telescope) the electric field vector must be pointing either in the up/down direction or left/right direction as it passes through. These two axes are the two axes of polarization (left/right, horizontal) and (up/down, vertical).

It is easy to see the effects of polarization with polarized sunglasses. Those kind of sunglasses work really well, especially when driving. This is because the light reflected off the hood of your car tends to be polarized in the horizontal direction, so by filtering out horizontally polarized light, you reduce “glare.” The  image below shows how a polarized lenses can alter your view of the world, proving the difference between information carried in two polarizations of light:

Polarized Lenses Remove Glare

When we do SETI, we need to think about all four of these dimensions which can be used to describe the radiation that comes to us from the sky.  In future blogs, I intend to explore these dimensions in more detail and explore all the different ways nature, and ET, can send us information using light.

I presented two papers, one on recent observations using the ATA to search for repeating ETI signals using an autocorrelation method. (All the signals we found appeared to originate from Earth.)

The second was in a cross-disciplinary session with marine biologists (dophins), chemists (understanding the message contained in our DNA), SETI theory and observations, layers (international law regarding transmitting our own signal for others to find), etc.

I was fascinated by recent studies of dolphin language. Can we use our current SETI algorithms to help understand the dolphin language? Or could we develop new methods to study dolphins, and then apply them in SETI? If you’re interested in dolphin language, a starting place is:
http://www.wilddolphinproject.org/
set up by my new friend, Denise Herzing.