Cosmic dust produces data

Weekly column from Ken Tapping at the Herzberg Institute (DRAO)


These days we are fairly used to hearing about new telescopes and instruments that are, or are about to revolutionize astronomy. We are actually building some of those things ourselves. However, there is another revolution happening that is producing a dramatic change in our ability to do science. This is driven by the tools we now have to obtain, transport and process data. We can obtain data from sources all over the world, compare it with data from our own experiments and combine these diverse data to make nice images and plots for conferences and publications without leaving our desks. These days itís easy to forget the situation scientists worked with not that long ago.

A couple of years ago we collaborated with a local museum to show astronomers’desks through history. One of them showed what Galileo’s desk might have looked like. However, one particularly interesting one was the desk of a radio astronomer in the 1950’s. This was a time of dramatic progress in radio astronomy.

Of course there was no computer or computer terminal. On the desk there was a notebook, in which the astronomer wrote down the information he or she was extracting from the data. The output from the radio telescope was a wavering inky line running along a paper strip chart, output from a chart recorder. These devices hold paper that rolls out at a precise rate. A needle moves across the width of the chart by an amount depending upon the strength of signal received by the radio telescope. A pen is attached to that needle, so that looking along the chart shows how this signal has changed with time. Using tools such as a ruler or planimeter, the astronomer took key measurements from the chart and wrote them in the notebook. An occupational hazard of using these chart recorders was smothering oneself with the almost indelible ink. This was known as “Chart Recorder Disease”.

It was common practice to look at a photograph taken using a large optical telescope of the area of sky observed with the radio telescope, hopefully to identify the source of the radio emissions. This meant more careful measuring with rulers, to mark the position of the radio source on the picture. Once again, what ended up in the notebook was only a tiny part of the information buried in the photo.

These days, observational or other data, whether images, signal strength recordings or more abstruse information all comes tabulated in computer files. We even have standard formats so that we can use the same analysis tools on all of them. We can squeeze out more scientific juice from the data than ever before. Moreover, thanks to the Internet, we have access to far more data, and have a larger community with whom we can compare notes.

Moreover, because data handling is now so easy, it is more accessible. Whether you are a front-line scientist, an aspiring high school researcher, or just interested, you can access and analyze information in ways that would amaze scientists of only a few decades ago. Just fire up that search engine!

Mars and Saturn are low in the Southwest after dark. Saturn is close to the star Spica. Jupiter rises before midnight and Venus around 3a.m. The Moon will be new on the 15th.

Ken Tapping is an astronomer with the National Research Council’s Dominion Radio Astro-physical Observatory, Penticton.