Cancer Posted November 13, 2007 Report Share Posted November 13, 2007 Re: The Last Word Or get them to think with it. And they'll hate you for trying, too. Quote Link to comment Share on other sites More sharing options...
AliceTheOwl Posted November 13, 2007 Report Share Posted November 13, 2007 Re: The Last Word People usually do. It implies they don't know enough. Quote Link to comment Share on other sites More sharing options...
Cancer Posted November 13, 2007 Report Share Posted November 13, 2007 Re: The Last Word Well, it's worse when they cannot possibly have the answer in memory, and they have to deduce an answer. Ooo, that's the worst. Since there were two thought questions, plus one question where I said in lecture the text is wrong and gave the right answer, plus one where half the question was about something that we covered before the 1st midterm and the other half was part of he introductory material of part of the 2nd lab ... I am a bad, bad instructor. Quote Link to comment Share on other sites More sharing options...
AliceTheOwl Posted November 13, 2007 Report Share Posted November 13, 2007 Re: The Last Word Bad teacher, expecting your students to actually attend and retain! No cookie! Quote Link to comment Share on other sites More sharing options...
Cancer Posted November 13, 2007 Report Share Posted November 13, 2007 Re: The Last Word This explains so much. Quote Link to comment Share on other sites More sharing options...
AliceTheOwl Posted November 13, 2007 Report Share Posted November 13, 2007 Re: The Last Word Hasn't teaching taught you ANYTHING? If you spoon-feed them, they will regurgitate. C'mon, prof! Quote Link to comment Share on other sites More sharing options...
Bazza Posted November 14, 2007 Author Report Share Posted November 14, 2007 Re: The Last Word You can lead a horse to water' date=' but you can't cram information into a college student's head for him. [/quote'] Hey! I resemble that remark. Quote Link to comment Share on other sites More sharing options...
Bazza Posted November 14, 2007 Author Report Share Posted November 14, 2007 Re: The Last Word 3. What is the Doppler Effect, and what does it allow us to measure about astronomical objects? 3. The Doppler Effect is the change in frequency of wavelengths as an object approaches or gets farther away' date=' the way a train whistle sounds higher in pitch as it approaches, then deepens, and gets higher in pitch again as it moves away. Scientists can measure changes in the wavelengths of lights emitted by distant stars, or reflected by distant planets, to tell if they're moving toward or away from us.[/quote'] Partial credit. The Doppler effect lets you measure the speed of something along the line of sight. While looking at it initially (honestly! although I didn't post it), I recalled that the Doppler effect was used by an American astronomer (c 1929) in concluding that the universe was expanding. Let me start again. Hubble saw that astronomical objects were moving away from Earth due to their redshifts (shifiting of light towards the red part of the spectrum in electromagnetic radiation, interpreted as a 'Doppler effect in space'). This enabled Hubble to conclude that the universe was expanding as the objects were accelerating away from Earth like a car going past a pedestrian on a freeway. As we can calculate the rate in which the universe is expanding, we can deduct this constant from the distance from one object to another to arrive at the correct distance Object A is from Object B. If we didn't take into consideration the constant rate of universal expansion the distance we calculated would be incorrect. Knowing the rate of universal expansion and the nature of redshifts allows us to create arbitrary points of observation within the universe, which as stated above allows us to calculate the distance of Object A to Object B eg the point of observation of Object A may be the sun Sirius. Quote Link to comment Share on other sites More sharing options...
AliceTheOwl Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word But of course. Quote Link to comment Share on other sites More sharing options...
Tim Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word Woah! what happened to the rep bar? It turned into a series of "Xhasareputationbeyndrepute" Quote Link to comment Share on other sites More sharing options...
AliceTheOwl Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word Not for me. Quote Link to comment Share on other sites More sharing options...
Tim Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word After I posted that msg, it corrected itself. Quote Link to comment Share on other sites More sharing options...
AliceTheOwl Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word Must've been tweaking the system. Quote Link to comment Share on other sites More sharing options...
Bazza Posted November 14, 2007 Author Report Share Posted November 14, 2007 Re: The Last Word Still is the same for me. Quote Link to comment Share on other sites More sharing options...
Bazza Posted November 14, 2007 Author Report Share Posted November 14, 2007 Re: The Last Word And tomorrow I'll be away from the NGD for 4 days. I'm going to a wedding in Sydney (4 hour plane flight). The wedding is my (ex-)GM so I'm looking forward to it. Also I plan to do shopping while I'm there. Miss you. Quote Link to comment Share on other sites More sharing options...
Tim Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word I think it is on my end. I've been having to try two to three times to load every page. ONce they load, they load quick. It just won't connect on the first try. Quote Link to comment Share on other sites More sharing options...
Cancer Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word The Doppler effect gives you speed along the line of sight. Now, other information teamed with those radial velocity data can give you other stuff. The Hubble flow only works for distant galaxies, and this class is Solar System, so I haven't discussed the velocity-distance thing. Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word And tomorrow I'll be away from the NGD for 4 days. I'm going to a wedding in Sydney (4 hour plane flight). The wedding is my (ex-)GM so I'm looking forward to it. Also I plan to do shopping while I'm there. Miss you. Have a good trip. And please tell us how you managed to squeese four days into one. Quote Link to comment Share on other sites More sharing options...
Cancer Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word Have fun, Bazza. Quote Link to comment Share on other sites More sharing options...
AliceTheOwl Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word And tomorrow I'll be away from the NGD for 4 days. I'm going to a wedding in Sydney (4 hour plane flight). The wedding is my (ex-)GM so I'm looking forward to it. Also I plan to do shopping while I'm there. Miss you. Have fun! Quote Link to comment Share on other sites More sharing options...
Cancer Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word Rep Power: 4340 I have H-gamma rep!!! Hm. Punted the day's roll for PsychLim: Spectroscopist (Strong, Uncommon 8-). Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word . . . aren't you one Ångström short? Quote Link to comment Share on other sites More sharing options...
AliceTheOwl Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word Congratulations. Now I'm tempted to rep you just to take it away. Hmm. Quote Link to comment Share on other sites More sharing options...
Cancer Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word . . . aren't you one Ångström short? It's actually 4340.x, where x is larger than 5. The article rounds up, while I've truncated down. Most astronomers do the same and identify H-gamma as 4340Å, though. Quote Link to comment Share on other sites More sharing options...
Cancer Posted November 14, 2007 Report Share Posted November 14, 2007 Re: The Last Word Congratulations. Now I'm tempted to rep you just to take it away. Hmm. The next two important lines are at 6300 and 6707. Quote Link to comment Share on other sites More sharing options...
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