Tuesday, February 10, 2009

Greatest astronomer, help for a research paper

A TVA member recently asked Who is the greatest astronomer of all time? Criteria is wide open.
It is difficult to choose a greatest astronomer. One can start by comparing what various astronomers did with the equipment they had. For example, Tycho Brahe did his work before the telescope, and his data were used by later astronomers. Even Hipparchus, from ancient Greece, managed to figure out that Earth precesses. This was quite a feat for the time. Not long ago I read a book of the discovery of parallax. The astronomer who solved the problem, I recall, had to evade conscription into Napolean's army. Another example of rising above the times.
Another TVA member wrote: "The greatest observer was William Herschel. Nobody else is even close. He discovered Uranus, the first planet beyond the classical five (plus Earth) that had been known since humans first looked up from the savannahs of Africa. In addition, Herschel observed and recorded thousands of deep-sky objects. His list formed the basis of the New General Catalogue, or NGC, which is still the basic set of objects investigated by both professional astronomers and amateurs. His sister, Caroline, should receive some joint recognition, since it was she who wrote down his observations as he teetered on a ladder at the eyepieces of his homemade reflectors. The most important astronomer was Galileo Galilei. Probably someone else -- probably someone did -- would have turned a telescope to the sky, but he's the one who did it and simultaneously had the scientific awareness to write down his observations. With his first few observations, Galileo overturned thousands of years of superstition and speculation and started mankind on the road to learning what's really up there."
In addition, I would add this article from Nature:
http://www.nature.com/news/2009/090206/full/news.2009.81.html
The article also mentions using citation as a metric. Many theories get published, but knowing what is current and valuable requires some sense of the amount of citation it gets in credible publications. The scientific community follows the citations, but the popular media and public often don't, which leads to common misconceptions on certain topics (e.g., global warming and evolution).

Tuesday, February 3, 2009

Comet Lulin 31 Jan to 3 Feb

The image above shows comet Lulin in the morning sky from 31 Jan 09 to 3 Feb 09. (Click the image for a larger view.)
The widefield view was taken with a 28mm focal length lens. The mosiac of closeups on the right were taken with a 3" refractor, focal length 380 mm (~F5.2). The photos from 2 and 3 Feb were taken with ISO 800 and 45 sec exposure. The images from 31 Jan and 1 Feb were shorter exposures, so any impression that the comet has brightened in these photos is due to inconsistent exposure times.

Tuesday, January 27, 2009

Lighting Guidelines for Flatland

In the hypothetical two-dimensional world of Flatland, exterior lighting is a simple task. First, you identify the perimeter of your building. Then, you attach lights on the sides pointing outward.


This is about as much thought giving to the lighting of this building withing Lake Elsinore, about 35 miles from Palomar Observatory (which is visible from this location).


The exterior lighting is bright and points outward. Very little is shining on the property. The result is that motorists have to contend with the hazard of glare and are unlikely to observe any vandalism taking place.

It probably has the worst ration of glare, light pollution, and energy waste to beneficial light of any building in our community.

Thursday, January 22, 2009

Displaying a flag is patriotic; bad aim is not

How not to light a flag is shown in these pictures.


I took this photo while standing approximately at a right angle to the direction of the light fixture. The image is distorted because I'm using about an 18mm focal length lens. This wide field shows how over-sized the beam is for the flag being lit. The area has adequate downward lighting from fully shielded low pressure sodium lights, making this institution very Palomar Observatory friendly, until the installation of this light.



I took the second picture while standing in front of the flag pole. The flag, presumably, the
target of the floodlight, is behind and above me. The shadow of me and my camera and tripod are visible in the front center, giving an idea of how wide the beam is. I did not use a flash for this exposure.


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In the fight against light pollution, flags are not a big problem. The amount of upward light illuminating our nation's symbol is small compared to unaimed light from other sources. But with any lighting task, it is the failure to light only the target that is the problem. Here, a sliver of the light blasting the sky serves the intended purpose. The rest is bad aim, light pollution, glare, wasted energy, and an obstacle for Palomar Observatory.

The right to light a flag at night should be protected within any lighting ordinance, but there should be a reasonable attempt to light just the flag. Also, as with any uplighting application, there are two components to emphasizing the uplit object. The goal is to achieve contrast, not necessarily illumination. By darkening the background, creating a palette for contrast, you can use less light on the target. Any sense of contrast, which makes upward illumination effective, is lost in the above example.

Another consideration is that any time we automate our lighting, it can promote complacency. Automatic security lighting can make homeowners complacent, thinking the light has them protected. In the case of flags, we replace what could a flag raising or lowering ceremony with the autopilot of a timer (This comment applies only to able-bodied persons and businesses).




Above: Two examples of patriotism on autopilot, though in fairness, the owners of the flag on the right replaced it not long after I stopped and took the photo.)

I suggest that any business conducting a flag ceremony between 7-8 am and 4-5 pm, will get more attention than if they brightly lit a flag all night.

Wednesday, January 14, 2009

Earth, Orbit, and Climate

http://brightstarstemeculavalley.org/animations/earthOrbitAndClimate.html

I’ve always admired botonists for keeping their own scientific definition of “fruit” while the common world speaks of fruits vs vegatables. Commonly, fruit is a culinary distinction, applied to an estimate of sugar content and flavor in produce. Thus, tomatoes are vegatables. To a botonist, however, fruit is the fleshy tissue enveloping the seed, thus, tomotoes, avacadoes, and zuchinni are fruits. For me, learning this distinction was like being admitted into a secret order.

Astronomers should have done the same when revisiting the classification of Pluto. Astronomers are smart enough to keep their own definition of planet and minor planet while letting “planet” be applied to Pluto, Eris, and Ceres. Planets should be for the people, to make them happy so they fund observatories and turn their lights down.

I recently learned that climatology has it’s own “precession”. Astronomers know precession as Earth’s wobble, the changes in direction of north over a cycle of 25,800 years. Right now north points to Polaris, but this is constantly changing.

A foundation of climatology is the influence of changes in Earth’s orbit (it’s precession, tilt, and eccentricity) and how these correlate with glacial cycles going back millions of years.

I started illustrating these orbital changes and quickly discovered that the precession values I read in climatology research do not clearly correlate with precession of the Earth’s poles. So, I asked the writer of the science blog Open Mind how precession was measured. His answer:

The quantity called "precession" in climate is the product of the eccentricity and the sine of the angle between the longitude of perihelion and the longitude of the equinox; it's an indicator of the magnitude of the impact on high-latitude climate forcing due to precession of the equinoxes (in the astronomical sense).
To this, I was thinking 1) which equinox, fall or spring? Or does it matter? and 2) how do I calculate the sine? I didn’t ask these questions; this scientist kindly took the time to give a novice a good answer and deserved better than “Huh?” So, I decided to teach myself the skills needed to make sense of the answer. Thus, I created my Orbital Viewer.

If you look at the obital viewer, please read all the caveats, essentially that it illustrates the concepts showing orbital changes as simple clockwork. It does not recreate the orbits accurately and especially cannot to be used to discredit the science of climatology. Any errors are mine, and do not threaten the scientific concensus on global warming. It’s an illustration, but one that moves.

Astronomy is a wonderful way for each of us to become an amateur scientist. Some amateur astronomers make original contributions to science. But most of us, the commoners, we find something that has already been discovered and enjoy that we found it for ourselves. Amateur astronomy is for the people (and real amateur astronomers who contribute to science are smart enough to keep their own distinction). Besides, the best way to save the skies for amateurs, contributing amateurs, and professionals, is to convert the masses into amateur astronomers.

It’s very exciting to see a parallel in climatology. The internet is making it possible for us to read the work of real scientists, and to ask them questions. In my amateur study of climatology I’ve become addicted to the blogs RealClimate, Open Mind, Rabbett Run, Brave New Climate and the list is growing as I learn more and want more answers. (It should be noted that so far I’m still climbing up the learning curve. The more I learn about climatology, the more I know what I don’t know.)

Unfortunately, there has been a deliberate effort to discredit climatology for its prognosis on global warming (an therefore its indictment of fossil fuels, our energy use, and thus the foundations of our economy an and high standard of living). This effort is assisted by 1) climatology having many uncertainties that honest scientists speak openly of, 2) the media loving extremes (e.g., we’re going to die vs it’s a leftist hoax) as extremes sell more papers, books, and advertising, 3) and the general public not only lacking a deep scientific understanding but not knowing where to look for one, and 4) a large number of people who simply will not read any science.

A good scientist rarely makes a good propogandist, a weakness that has fallen prey to the misrepresentation of climate science by propoganda machines and by “anti-amateurs” who use skepticism and sophistry to make a name for themselves. The propogandists need only get attention, funding, or sell their books to be rewarded in their efforts. As some of the effort has been to delay regulation of greenhouse gases, more scientists are discussing their work through blogs. They offer an opportunity for any of us to become amateur climatologists. The blog realclimate.org started this way.

And so I begin the first in a series of illustrations on climatology. The goal is to share an understanding of the science and to invite people to become amateur climatologists. It is also clear to me that much (not all) of the accidental misunderstanding of global warming comes from the fact that people don’t read science. So I hope the illustrations help to this end. And last it is fun. I’m not perfect. I’ll make mistakes and will document corrections. Readers are welcome to ask questions. If I get some good ones I can’t answer, then it’ll be fun to ask some real climatologists.

Tuesday, November 4, 2008

Geological timeline

Geological Timeline

Over the past 10 years I've been illustrating what I read in science journals. I make these illustrations so I can remember the concepts, but just as important, so that I can later find my notes -- a picture helps me with both, however, using my collection of booklets is becoming cumbersome, especially after each booklet is flagged with dozens of colored tags. I need a more responsive format so I've started converting the illustrations to an interactive web format, programmed in Flash, which you can see here.

This is the start of a long process, where I add a few entries when I can. I also need to polish the user interface. I'll make errors with both, so this blog post provides a means for anyone to correct an error I've made. (Use the above link to see the Geological Timeline.)

Sunday, July 20, 2008

Lunar Month Sequence for June 2008



On http://www.brightstarstemeculavalley.com/ I posted an interactive Flash that shows 26 photos of the moon taken from June 5 to June 26. You can see the moon change apparent size and see its approximate location in orbit. This post is made to offer a means for anyone to make comments, ask questions, or offer corrections or suggestions.

(The project can be seen at this page: http://www.brightstarstemeculavalley.org/pages/Astronomy.html)