Expert: Rocky Alvey & Billy Teets
Bio: Rocky Alvey is the assistant director of the Vanderbilt Dyer Observatory and has been involved in astronomy since 1969.
Filmmaker: Dimitri LaBarge

Duration : 0:4:4

Technorati Tags: Astronomy, nature, science, sky charts, star charts, Telescopes

This video showcases the Zenith Telescope, built by Troughton & Simms in London, England circa 1872. Surveyors used this telescope to mark the boundary between Canada and the United States along the 49th parallel in western Canada.

To learn more about Telescopes, visit the Canada Science and Technology Museum.

http://www.sciencetech.technomuses.ca/

Duration : 0:2:25

Technorati Tags: 1609, 2009, 49th, and, Astronomy, Canada, discoveries, Dominion, earth, education, Exploration, Galileo, Guide, instrument, International, IYA, maps, Museum, navigators, Observatory, Of, optical, orbits, Ottawa, parallel, Program, railway, Resources, revealing, science, Simms, stars, sun, Surveyors, teaching, technology, telescope, Troughton, Virtual, Year, Zenith

Duration : 0:12:49

Technorati Tags: cable, design, generation, hydro, kea, mauna, ntsc, power, product, renewable, sex, shop, shopping, shower, solar, tap, Telescopes, toys, tv, wind

Expert: Jesse Sturgeon
Bio: Jesse Sturgeon has served as a sales and customer service representative for Anacortes Telescope in Anacortes, Wash. for several years. He enjoys introducing people to the science & art of astronomy.
Filmmaker: Curtis Enlow

Duration : 0:2:24

Technorati Tags: Astronomy, binoculars, night sky, science, Telescopes

http://www.opticalvision.co.uk/astronomical_telescopes/sky-watcher/dobsonians

With telescopes, you very much get what you pay for. A £100 telescope will be extremely limited in what it will show you, and you will soon be frustrated and wanting more. Most of the telescopes in this price range are cheaply made toys…the ones on the page above are some of the rare exceptions. Quite frankly I wouldn’t recommend any of the competition. Read some of the recent telescope questions here and you’ll see how frustrating cheap telescopes can be! Anything less than a 150-mm Dobsonian is probably a waste of money, so realistically you’re looking at around £200.

Here are a few web pages with good information on beginner’s telescopes:

http://www.gaherty.ca/tme/TME0702_Buying_a_Telescope.pdf

http://www.scopereviews.com/begin.html

http://observers.org/beginner/j.r.f.beginner.html

For more advanced information, read Phil Harrington’s Star Ware, 4th edition (Wiley).

You’ll get the greatest value for your money with a Newtonian reflector on a Dobsonian mount, such as these:

http://www.telescope.com/control/category/~category_id=dobsonians/~pcategory=telescopes/~VIEW_INDEX=0/~VIEW_SIZE=1000000

http://www.skywatchertelescope.net/swtinc/product.php?class1=1&class2=106

Buy from a store which specializes in telescopes and astronomy, either locally or online; don’t buy from department stores, discount stores or eBay as mostly what they sell is junk. Find your local astronomy club and try out different telescopes at one of their star parties:

http://www.skyandtelescope.com/community/organizations

I strongly recommend that beginners steer clear of astrophotography until they have learned their way around the sky. Astrophotography is by far the most expensive and difficult area of amateur Astronomy.

Many people who buy Telescopes have no idea how to find interesting things to observe. A good introduction to finding things is NightWatch by Terence Dickinson (Firefly). A more advanced book is Star Watch by Phil Harrington (Wiley).

Expert: Rocky Alvey & Billy Teets
Bio: Rocky Alvey is the assistant director of the Vanderbilt Dyer Observatory and has been involved in Astronomy since 1969.
Filmmaker: Dimitri LaBarge

Duration : 0:2:36

Technorati Tags: Astronomy, nature, science, sky charts, star charts, Telescopes

Why are telescopes that detect different types of electromagnetic waves used to observe the universe?

First, electromagnetic waves span a spectrum. It is a chart-like-scale humans (scientists) devised. All electromagnetic waves travel through free space at 300,000 km/sec.
So the waves have wavelength and frequency (so many cycles of propagating waves in a second).
Frequency = 300,000,000 (m/s) / wavelength (m) or
Wavelength = 300,000,000 (m/s) / frequency (cycles/s).
Now a new name was adapted for frequency called ‘Hertz’ (1 cycle/s = 1 Hz).
If you look into any introductory book of higher Physics, the ‘EM’ spectrum is given in the appendix.
At long wavelengths, Radio waves (lengths of several kilometers to 0.3m or 30 cm) can be detected (‘received’ is the word) by Radio Telescopes using a particular repertoire of techniques & technologies. Microwaves (0.3m to 0.0005m or 0.5mm), still radio waves, but with a little bit different techniques can be also received. All our satellite communications systems employ it. Since our atmosphere heavily absorbs them, one needs to put up Microwave antennas above in the satellites.
Then comes the Far Infra Red (FIR) region with wavelengths down to ten millionths (a millionth of a meter is called 1 micron, 1 |u) there are various techniques again. About a century & quarter ago JC Bose did pioneering work for which he was accorded the honour ‘now’ of co-inventor of Radio. But that work needs to be taken up afresh. Then comes the middle IR. Same is the case here. In near IR (NIR) till 0.7 micron, vigorous work is in progress. This band is mainly for ‘Remotes’ for electronic equipment. But in all IR (FIR, MIR, NIR) space applications are limited except taking photos with those filters because atmospheric molecules interact freely producing IR and absorbing, as basically IR is ‘Heat waves’. One must go above the atmosphere for good work to be accomplished. The Optical ‘Fibre’ operates at 0.8 |u and is the mainstay in optical communications.
Then comes the work horse – 0.7 to 0.375 micron band in which we see the colours (VIBGYOR; Violet end near 0.375 micron & Red end at 0.7 micron). It is called the Visible Region. Telescope is meant for this region of spectrum. Eye is the main receptor/sensor for this part in electromagnetic waves. Almost all our knowledge of space is due to this window in the ‘EM’ spectrum and is called Optical window. If you are looking at a star or galaxy (either with aids like a ‘Telescope’ or without) or seeing its picture in all fantastic colours, you are indulging in Space (Astronomy) studies. 99% knowledge, work, analysis, Red-shift theories are all in Optical spectrum, a mere sliver of the spectrum with almost an ‘Octave’ bandwidth (it means the ratio of the highest to the lowest wavelengths is 2 : 1).
Beyond 0.375 micron (as I told you a micron is a millionth of a meter) we have Ultra Violet portion again divided into NUV, MUV & FUV merging with soft X rays of Nanometer (a billionth of a meter). Some UV cameras get sent in all missions in the Space probes and such programmes.
X rays : A telescope ‘Chandra’ is orbiting the Earth now to take pictures at wavelengths (my guess) of a fraction of a nanometer.
After that comes the ‘Gamma rays’ portion the sensors are complicated and expensive. These high energy and still higher energy radiations, being high energy radiations readily interact with the stuff of our atmosphere and the energy gets transferred into the excitation of those molecules thus decimating the ‘information’ content. So, one must go much above the atmosphere to build a telescope. Here (in this part of spectrum Electrons don’t have separate existence as they combine with Positrons to produce Gamma ray quanta).
Beyond these lie the zone of extremely high energy particles expressed in Energy units (we need to switch from the nomenclature of billionths to billionth billionths).
The whole spectrum (to my reckoning, in wavelengths spans the known region of 10^6 meters to 10^-12meter; a range with a ratio of end to end of 10^18 that we call 18 decades or that is about 60 octaves) and every region or octave has a different technique and equipment. You can’t have the same antenna to receive TV signals, Citizen band, satellite communications and data receiving, isn’t it? My effort is to outline here that all this constitutes the domain of ‘electromagnetic waves’.
The idea of a telescope (whether Optical, IR, Visible, Radio or UV) is to point it. I don’t want to venture into it even because it is a different kettle of fish altogether.
I haven’t got into the preliminary details even.

Duration : 0:6:42

Technorati Tags: Antarctic, Antarctica, Astronomy, cold, expedition, Exploratorium, ice, polar, science, scientist, SouthPole, SPT, telescope

How big of a difference would it be?

It is pretty tough to describe, since it depends on a lot of related issues like light pollution, eyepieces, and your own observing skills. As Tina suggested, the only way to really compare these is to try them yourself. We can tell you that the 10 inch has roughly 36% more light gathering capability than the 8 inch, but to translate that into a level of brightness as perceived by your own eye is an exercise in futility. I personally own an 11 inch SCT with premium eyepieces, and under clear skies I can see more than most people can imagine. But some folks can look through my scope at a target that is absolutely stunning to me and see virtually nothing. They don’t quite know how to look; it takes some practice to see what is out there.

So, if I were you, I would check out the views at a local Astronomy club star party. If that is not possible, I would go with the 10 inch.