Monday, August 22, 2011

Light funnels

Astronomy is a particularly elegant science. We can learn about the Universe, and all of the things within it, by collecting light. That is the only way that we can know about objects that are too far to visit directly; light. Light is the substance of astronomy. With light alone, we can determine what elements are in the Sun, for example, as well as find out the exact temperature of the Sun. If we were forced to go there and take a sample, or drop in a thermometer, it would be significantly harder! Because astronomers deal in light, and the information contained within, they obviously want to collect as much light as possible. And this is where telescopes come into play.

Most assume that telescopes are designed to magnify, to "make things look closer." This is sometimes a useful factor, but the real purpose of a telescope is to grab as much light as possible. They are light buckets, or perhaps we can say light funnels. The human eye has an opening of, at most, 10mm. This is great for seeing a few thousand stars in a dark location, as well as one or two other galaxies beyond our "island universe." But with 100 or 200 or 300mm of light collecting diameter (in the form of a mirror or lens), amateur telescopes greatly enhance the amount of information collected. Add in digital cameras and long exposures, and the potential is orders of magnitude better. Research grade telescopes are many times larger and more powerful still. The largest single optical telescopes, now being designed or built, will have diameters of more than 30 meters! They will be able to revolutionize our understanding of the Universe.

It is my pleasure to contribute to this blog because, beyond being a hobby, I think astronomy is the single most important science that we can conduct. Furthermore, this is to be the century of astronomy. Many of the greatest questions about the origin and evolution of the Universe are within our grasp for the first time. We will answer these questions, and many others, and perhaps find them replaced with new questions in turn. If you have stumbled upon this page, and astronomy for the first time, consider this your invitation; join us!

To begin, an astronomer needs nothing more than eyes and some star charts. In time, you may chose to purchase a pair of binoculars, then an inexpensive telescope, followed by more telescopes, a ccd camera, and so on. If the astro bug bites you, be prepared; you will never be able to stop. Visit the sponsor links to the right if you are ready to buy astronomical gear. (But take it slow; no need to rush into buying a telescope until you know what you want.) Feel free to post any questions about astronomy or telescope purchasing in the comments here.

To conclude, let me share two links. One is my personal, tangentially related blog about space exploration and rocketry:

High Power Rocketry

The other is a link for the largest optical telelscope ever planned: a 100 meter telescope called OWL (Overwhelmingly Large.)



Sunday, June 5, 2011

Meade 16-Inch LightBridge (f/4.5) Truss-Tube Dobsonian

This telescope is one of the most powerful telescope to buy
This telescope is a reflector telescope.
This telescope has a red dot finder scope.
The optical lens diameter is 406mm(16 inches).
The focal length is 1829mm(72 inches).
The eye piece is 26mm(one inch).
The field of view is 70"(seventy arc seconds(1.166 arc minutes(0.01944 degrees))).
     Our moon is 1800"(1800 arc seconds(30 arc minutes(0.5 degrees))) in diameter.
     Jupiter is 29.8"-50.1"(29.8-50.1 arc seconds(0.49-0.835 arc minutes)) in diameter.
     Saturn is 14.5"-20.1"(14.5-20.1 arc seconds(0.24-0.335 arc minutes)) in diameter.
The resolution is 0.38 arc seconds.
The highest magnification 800X.
The Total weight of the telescope is 128 lbs.