Wednesday, August 24, 2011

This Post Intentionally Left Blank


Wow... the things that keep me up at bed time!

Saturday, July 30, 2011

Janus Christ!

Recently I have been doing research related to a type of constructed object called a Janus particle.
During the course of this research I get to play around with very cool equipment, like lasers, confocal microscopes, magnetic fields, laser traps etc.

Janus particles are named after the Roman god of change or transition, and is usually represented by a figure with two faces.
Likewise, Janus particles are constructed with two faces, each having a different physical property.
Many interesting and useful properties can be explored in such systems.

My task was to study such systems, comprised of silica spheres approximately 2 to 3 microns in diameter. In studying such systems  I get to observe so very cool physics, and to see surprising images.

One afternoon, after a long and trying period of gazing through the objective of our polarizing microscope, I came across the following particle

"Woah! This is better than that grilled cheese Jesus I read about!"

Now wait a minute... I am studying a particle named for a Roman god, and instead I see something that looks strikingly like Jesus?

Is God trying to tell me something?
If he is, I do not have a clue what it is, or why He chose such an obscure medium. Of course, this is a personalized message if there ever was one. Only I could see such an object at that particular place or time!
Now I know how those NASA scientists must have felt when they saw the face on Mars!

Or, perhaps natural selection has simply programmed my visual cortex to recognize patterns that look like faces, and cultural bias has programmed me to find such a recognition in a surprising location to be the work of a higher power?

I sit for a while, focusing and refocusing on the particle,and as I watch, I notice the image is sort of shaking its head at me.
"A message from God!" Perhaps He must be very disappointed that I would dare assert such things as evolutionary biology and cultural biases as to why I saw Him in His glory... in a microscope image of a silica sphere imbedded in 5CB liquid crystal.

Or, perhaps the shaking and nodding of the head is due to thermal fluctuations... Brownian motion? Humm... now the image seems to be nodding its head.

I debated weather to show these images, as I was ill at ease with the idea that people may decide to make a pilgrimage to my lab in order to see the face of Jesus. (Kidding)

Like most people, I get a thrill and goosebumps when I see a face suddenly and spontaneously appear in a cloud, or a shadow pattern, or in the random alignment of light and color in a glass pane. A parasympathetic response to perceived danger, or the cognitive dissonance of seeing a face where none should exist.
As a scientist, I can step back and appreciate the physics and biology that goes into having perceived the face in the first place. I can think about the cultural programming I have undergone, and must overcome in pursuit of science, that goes into perceiving something of the numinous in a play of light.
This cultural programming leads to some falling to the comfort of religion to explain the face, while leading to others invoking aliens, or spirits.

In any case, when I see a sheep in the clouds, or a face in a cheese sandwich, I can enjoy the thrill, and the subsequent analysis of what I am seeing without resorting to religion or superstition.
Some say this is my loss, and that I am missing out on deeper understanding.
That is something I don't quite see.

Sunday, June 5, 2011

Fermi Problem: Why Are Christian Radio Stations So Loud?

My wife likes to listen to a small shower radio during her morning routine, and she laments the fact that she can only get one decent classical station in, and none of the popular music she likes. However, the Christian radio stations come in loud and clear, as do a few particularly awful country stations, and a long string of Spanish language stations. (Neither of us are fond of modern country music it seems.)

We were discussing this phenomena, that the stations we did not like seem to come in very strongly across the dial, but the "good" stations had short range or were weak in comparison.

"Perhaps the reason why the bad stations are clearer is because fewer people listen to them, and are sucking up all the good stations." My wife commented.

I found this a bit funny and started smiling. "It does not work that way!" I stated confidently, but then I though about it a bit...

"Why do you think that?" I asked?

"Well, my cell phone gets worse signals in areas with lots of users, and the WiFi networks get slower when there are a lot of people using the connection." Why not radio stations.

Why not?
Do radio stations have a set bandwidth, like the cell phone towers or WiFi hubs?
Well, not really. The power a radio station puts out is attenuated mostly by distance from the tower, and the amount of matter absorbing, scattering and reflecting the radio waves.
Also, given the fact that a receving radio antenna is sucking down all the radio stations at once, and it is the tuner that is filtering out the unwanted stations, one could make the claim that an receving antenna would attenuate all the stations equally. One could get picky about how antenna lengths are better at resonating with particular frequencies than others I supposed.

But one may still wonder... does a receiving antenna that is actively tuned to a particular frequency absorb more power from the signal than one that is not active, or tuned to another station?
And if so, how much power?

----- Start Fermi Problem ------

Estimate how many radios there are within 20 miles of a transmitter in any given city.

Estimate how much power a single receiving antenna attenuates from the signal.
When it is active? When it is not tuned to the station?

Calculate the difference in power a receiving antenna would observe at 20 miles if suddenly all the other antennas were to physically disappear!

----- End Fermi Problem -----

There are probably many other reasons for a perceived signal to noise ratio for certain types of stations. And this is a fun topic to think about.

Perhaps country music just seems louder to those who do not want to hear it.
Perhaps country music stations cater more towards a demographic that travels more during the day, and thus they are simply transmitted at a higher power than popular music stations.

Perhaps Christian radio stations like to be louder to catch your attention! After all, they are trying to get their message out and save your soul!

But more listeners would seem to be a very small contribute to relative signal strengths, at least from a physics standpoint.