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Larry454
64 years old, retired aerospace engineer, former US Air Force pilot, active father and husband. I enjoy spending time with my family, amateur astronomy, playing in a bluegrass band, golf, model railroading, and going up north to watch the sun set over the lake. I keep busy providing enrichment classes on amateur astronomy, the life and work of Einstein, the nature of comets, as well as conducting occasional planetarium shows at a local college.
Do Special Relativity effects apply to total recession velocities or to "peculiar velocities"?
I understand (thanks largely to help from this forum) that the primary source for the recession red shift in distant galaxies is the expansion of the space between us and not the relative velocity of the separating objects within that space. It then seems to me that the relativistic effects (time dilation, etc) resulting from this separation apply only to the latter interpretation of the term "velocity" - i.e the peculiar velocity and not the total recession velocity. This would mean that a distant red shift does not necessarily imply significant time dilation differences - only "time cone" perception differences due to the distances involved. Is this correct? Thank you.
2 AntwortenAstronomy & Spacevor 1 JahrzehntWhen we measure really distant red shifts...?
How do we know how much of the observed Doppler Effect is due to recession through space vs. the stretching of the space between us? Or does it matter?
5 AntwortenAstronomy & Spacevor 1 JahrzehntWhen it comes to extraterrestrial visitation, who is more incoherent?
The person who understands science and claims that aliens are not visiting based on known laws of physics, thereby showing potential bias against the possibility of some unknown technology that he does not personally possess, or...
The person who has no understanding of physics and assumes that whoever these aliens are, they must be really advanced, and we are just too dumb to understand how they can manage to violate most of the known laws of physics simultaneously. This of course requires no evidence or justification.
Most of you are familiar with my position on this question, but I am interested in reasoned responses on both sides.
13 AntwortenAstronomy & Spacevor 1 JahrzehntDo you find it ironic when actors and politicians pretend to understand energy?
8 AntwortenPoliticsvor 1 JahrzehntTo all my friends who sincerely disagree with evolution -?
Is it important to actually read the material before you become confrontational? Have you ever read anything by Darwin? Gould? Wade? Shubin? Does it make sense to understand what you are disagreeing with? Or do you interpret evolution primarily as it is presented to you by others?
I do mean friends. I have no animosity toward any of you, although I must admit that I have minimal patience for intentional ignorance or for feigned knowledge.
17 AntwortenReligion & Spiritualityvor 1 JahrzehntWhy are gravitationally lensed galaxies blue in color?
I have seen multiple color photographs showing distant yellow galaxies with the clear arcs of more distant galaxies beyond them. (ref. recent book "Einstein's Telescope" by Evalyn Gates). As you might expect, the light arcs from the distant objects form circumferential patterns surrounding the closer galaxies. But what is unusual to my eye is that virtually all of the arcs are blue in color, especially when compared to the closer galaxies that are actually creating the lens. This seems sort of reversed from what I would expect. I would think that the more distant galaxies would favor the red end of the spectrum, while the nearby objects would tend toward the blue, or at least the neutral green portion of the visible spectrum. I understand that it takes a whole lot of red shifting to create visible results, but this appears to be a pattern that, if anything, seems to be contradicting my expectations. Anyone understand this? Is it because the more distant galaxies represent younger stars? If so, why do all lensing galaxies appear to have younger stars than all lensed galaxies?
6 AntwortenAstronomy & Spacevor 1 JahrzehntDoes everybody understand that when meteor showers occur, they can be seen from anywhere on Earth?
Just thought I'd ask, since there seems to be a lot of confusion.
9 AntwortenAstronomy & Spacevor 1 JahrzehntWould anyone else like to see the jerks removed from the galleries?
I am not a very good golfer, but I still love to play, and I have been playing and watching since the Palmer days. Watching the Players' Tournament and some other recent matches has me pretty discouraged. Every shot, especially by the big names, is followed instantaneously by screaming drunks shouting inane and trite phrases like "IN THE HOLE!!!" And they are always within 10 feet of whoever is making the shot. They don't care about the skill or the beauty of the course or the effort required to get there. They only care about yelling loud enough so THEY can be heard above and before everyone else.
Everyone wants to have a good time at these events. Nobody minds cheering and enthusiasm. Jack's walk up 18 at Augusta was a classic. But its not the WWF. I think it's beyond obnoxious. It wrecks it for everyone else - even the folks watching on television. I think they should be escorted to the road. No warnings, no second chances, just gone.
Anyone else feel as i do?
7 AntwortenGolfvor 1 JahrzehntWhy does a scriptural explanation of science never include math and physics?
Whenever I hear folks state that they are absolutely certain of their scriptural explanations for scientific issues (Quran, Bible explanations for physical observations) I always ask for something - anything - that anyone with a science or math education can use to understand what they are talking about. I always get no response or some fuzzy wuzzy words discussing philosophical stuff. To a scientist or an engineer looking for logic, such talk is meaningless.
My conclusion is that the ones that are the most certain and self - assured about their scriptural versions of science and mathematics do not understand science or mathematics. Interesting.
13 AntwortenAstronomy & Spacevor 1 JahrzehntFolks who think that there are alien spacecraft in our skies - Do you understand modern physics?
Especially Special Relativity - which is sort of basic and over 100 years old now.
Do you think it's important?
15 AntwortenAstronomy & Spacevor 1 JahrzehntExperienced amateur astronomers: Do you use a computer (GoTo or PushTo) to find your targets?
I am interested in knowing the rough proportions of those who rely on computer finders vs. those who find objects with a Telrad, finderscope, star-hopping, etc.
If you do not, why not? If you do, why? Are you limited by time? light pollution? Do you find that searching for objects is a frustrating or rewarding part of the hobby? Or do you just like the gadget nature of the computer finder? If you use a computer finder on a regular basis, do you find that you do not know the sky as well as your friends who do not?
I am not talking about tracking, auto guiding, or astrophotography, although I suppose that if you have the equipment for that stuff, you may just be spring loaded to use it for finding a target as well...
I will pick best answer based on logic and attitude, and not on whether I happen to agree. Thanks a lot..
8 AntwortenAstronomy & Spacevor 1 JahrzehntWhy do folks like to vote "thumbs down?"?
I generally stopped using that button after I made a few regrettable errors (maybe some of you folks don't make any errors). Unless someone is advocating violence or obnoxious behavior, I am generally willing to let folks speak their minds without jumping on the "thumbs down." I may disagree, but at least I am articulate enough to disagree using words and complete sentences and not just pound on the keyboard. Seems sort of immature.
3 AntwortenYahoo Answersvor 1 JahrzehntQuestions on astrophotography?
I have owned a C-11 on a german equatorial mount for several years now. It tracks beautifully, and I am considering expanding into photography. Pretty sure I want to go with a CCD approach, but my concerns are:
1. Color or monochrome with multiple exposures and filters? I've heard color is getting better in terms of fine detail - any experiences worth relating?
2. Do I need to take a laptop to the site? I have one, but it might get messy. What are the advantages / disadvantages?
3. What do I need for guiding?
I don't know much about it. I will also be working with my club and my telescope dealer friend, but every opinion helps. My long-term interests are in the area of deep-sky objects, although some lunar / planetary shots would be great and would obviously be easier in terms of exposure time, tracking fatigue, etc..
Thanks for your help!
5 AntwortenAstronomy & Spacevor 1 JahrzehntOK - What happens to time if part of the the universe does not exist in a vacuum?
Einstein arrived at some of his ideas by picturing himself riding on a beam of light. What if that beam were slower due to passing through a medium? Would that affect simultaneity across the boundary of the medium? Wouldn't distant stars be seen in the more distant past? We know that time runs slower on the outside of a rotating disk than it does on the inside. Does time run at a slightly different rate underwater? This has no effect on relativity - in fact, I am trying to live within the confines of relativity.
2 AntwortenPhysicsvor 1 Jahrzehnt