Astronomy/Milky Way and more

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Expert: - 7/26/2008


Question
Tom:  I have not written to you before, but I am very impressed by your previous answers.  And since you have responded to so many intelligent questions, I regret having to ask a dumb one:  Since we exist in the Milky Way, how can we know what it looks like from far away?  I have seen representations that look like photographs, but such a vantage point would be millions of light years away.  What am I missing?  Thank you.   Larry

Answer
Hi Larry,
Thanks for the very nice comments and compliments.
Your question is not dumb at all, in fact a very intelligent one, logically.

Yes, you are exactly correct....ours is an "educated guess" since
we are in it. That has been a problem since the 1920's once we
realized (by Edwin Hubble) that we are in only one of billions
of galaxies.
Well, they do it by measuring distances as best they can, plus star
populations, and HII regions with radio telescopes which are
excellent indicators of spiral arm gas. (The famous 21 cm line
of hydrogen spin/flip).
Then with a little intuition, they design a model.
We know it's a spiral and not an elliptical because of the stellar
ages and not all population type II low metallic stars. Then they go from there.
That's the best we can do for now, but it's better than nothing,
I guess.  But we think we're right about living in a barred spiral
now with several major arms in the spiral.
Hope this helps,
Clear skies,
Tom Whiting
Erie, PA  

Astronomy

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Tom Whiting

Expertise

Astronomy has been my hobby/pasttime for over 50 years.  Currently own 3 telescopes, the largest of which is a 30 inch Newtonian truss Dob that is portable.I taught Astronomy/Meteorology at the University Level for 13 years before retiring in 1995. Being retired and home most of the time, I am able to answer all questions relatively quickly, unless it's a new moon weekend with good observing conditions.  No astrology questions please, or questions about alleged UFO picture identifications.

Experience

Experience: Astronomy has been my hobby and study for over 50 years. We currently now own a 30 inch portable telescope (Updated - Pennsylvania`s largest portable telescope). It can be seen on our website at:http://www.velocity.net/~bwhiting and also attend several regional starparties during the year, and have been on 5 total solar eclipse expeditions.

Organizations: President, Erie County Mobile Observers Group for over 15 years.

Publications: Wrote the "Over Erie Skies" newspaper article in our local newspaper for 11 years (1975-86).

Education: Masters Degree- Taught at the University level for 13 years. Retired 20 years -USAF Pilot - KC-135 with 180 combat missions;  Also Eagle Scout, Philmont staff 2 Yrs, Order of Arrow Lodge Chief, Ham Radio (inactive).

Awards: two discoveries: The mini-coathanger asterism in Ursa Minor (the little dipper) And the mini-ladle- another asterism in the bowl of Ursa Minor. Clients: Currently President of the ECMOG as mentioned above.

Education/Credentials
BS  Metallurgical Engineering Grove City College, PAMaster's Degree, Gannon University, Erie, PA Also retired USAF pilot, 20 years.

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