If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#71
|
|||
|
|||
Full Moon Handheld
In article ,
He's So Funny! wrote: LOL [...] LOL!!!!!!!!!!!!!!!!!!! [...] LOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! [...] LOL!!!!!!!!!!!!!!!!!!!!!!!!!!!! [...] LOL!!!!!!!!!!!!!!!!!! [...] LOL!!!!!!!!!!!!!!!!!!!!!! Did you make all those up yourself? Mike Beede |
#72
|
|||
|
|||
Full Moon Handheld- can't resist pointing something out.
|
#73
|
|||
|
|||
Full Moon Handheld
On 27 Oct, 15:27, He's So Funny! wrote:
On Sat, 27 Oct 2007 08:15:42 -0700, Dr Hfuhruhurr wrote: On 27 Oct, 15:29, Marty Fremen wrote: "Roger N. Clark (change username to rnclark)" wrote: I finally had a night with a steady atmosphere, so I tried imaging the full moon handheld at 1000 mm (real focal length): http://www.clarkvision.com/galleries.../web/moon.rncl ark.handheld.c10.25.2007.jz3f6583f-8s-800.html This was done standing up with no supports and not leaning against anything. The full resolution image can be seen from the above page. Big deal, even a point and shoot can photograph the moon. I took this whilst looking out of the window the other day, handheld, no supports:http://img141.imageshack.us/img141/9...uh0.jpgEatyour hearts out, DSLR users! Incidentally, this is the same view using max. digital zoom and deconvolution filter to overcome diffraction limit and atmospheric distortion:http://img517.imageshack.us/img517/8...closeupcg8.jpg LOLOLOLOL I almost took that as an instant dig. That was teh funny. Doc But you missed the funniest part about this of all! He's so threatened by the superior images being posted all over the internet by P&S camera owners that he even had to bother to try this kindergartner's level of attempt to discredit P&S cameras. LOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I love it! Keep posting your proof of your being threatened by P&S cameras!! If you didn't think they were a rival you wouldn't even bother. LOL!!!!!!!!!!!!!!!!!!!!!! Awww... what's the matter little moron, is the realization of how much money you wasted on those piece of **** DSLRs finally sinking into that only brain-cell you've ever had? LOL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!- ::blank sta: Whooooooossh!! You totally missed that one didn't you?! Doc |
#74
|
|||
|
|||
Full Moon Handheld- Of course it's a great question!
acl wrote:
On Oct 28, 2:23 am, Joe Miller wrote: Don't read this if you are not interested in astronomical phenonmena. I don't want to waste your time. If one looks carefully near the bottom of the picture,the southern edge, one sees that the craters there and only there have shadows in them. How can that be? Ususally the shadowed craters run along a line that goes north-south. The moon's orbital plane is tilted with respect to the earth's orbital plane. This means that the direction the sun's rays shine toward the moon and the direction from which we view the moon are not exactly the same at full moon unless there is a perfectly-centered eclipse of the moon and we are in the exact right place. In this image there is a significant difference between the direction the sun's rays are hitting the moon and how we view it, but in a north-south direction, so the shadowed craters are near the south pole. We get to see "under" the south pole compared to how the sun "sees" the moon. It's not exactly a north-south tilt, but pretty close. That's not often recorded so nicely in pictures. The moon missed getting eclipsed pretty far this month. Very nice picture. Joe Joe, Good observation. The sun-earth-moon angle was 176 degrees, The image was obtained only 1.2 hours from full moon. So the shadows are from the sun being only about 4 degrees off of direct illumination. (This 4 degrees is called the phase angle.) The shadows at the south pole do not result from the fact that the phase was not exactly full. The phase angle isn't the critical thing here. Thee fact that the moon is well off the ecliptic is the important thing that allows us to see around to the "dark side of the moon" under the south pole. Even if the picture were taken at exactly full moon (phase angle 180 degrees), with this geometry you would have still seen the shadows at the south pole. The fundamental point I was making was that those south-pole shadows were not the result of the phase of the moon in the normal sense. Indeed, the moon being at perigee help at a tiny bit, and if the picture had been taken from the south pole of the earth, it would have revealed a tiny bit more of the "dark side." Would you mind if I showed this picture to my astronomy classes? Explaining the shadows would be a good exam question, but maybe too hard for an elementary class of non-scientists who think arithmetic is higher math. But wouldn't it actually be a good question because it doesn't need anything except a) a rough mental image of the relative positions of the earth, the sun and the moon and b) some pictorial thinking (well, also knowledge that light travels in straight lines!)? I mean, what's the best way to test if they actually listened to what was being taught than asking them to do some (perhaps directed) thinking about it and conclude something interesting? Those that can't do it, well, let natural selection take its course! That's just the kind I like to give on my exams. If you really understand the basic underlying principles, you can figure something out you didn't know before. It teaches students that scientific understanding can lead to new knowledge, to the ability to understand something not seen before. My exams are open book and open notes. I'm not the least bit interested in anyone memorizing anything. It's just that the geometrical thinking in this problem might be a bit much for most, but not all a my students during an exam. It would be better as a homework problem. Joe |
#75
|
|||
|
|||
Full Moon Handheld- I'm sorry Clarke, but you are wrong,
You still do not understand my basic point. If the moon were exactly
full, with "full" properly defined, you would still have seen shadows at the south pole. That's all I was trying to say. Think about it. In my haste I used "phase angle" differently from you and the accepted definition. I simply meant the fraction of a lunation that the moon had undergone expressed in angular terms. I used "off the ecilptic" as shorthand for the fact that that there was a signicant angle between the line of sight from your camera to the moon and the line defined by the center of the earth's shadow, which always lies on the ecliptic. I guess I was being too abstract or indirect here. The line defined by the center of the earth's shadow is extremely close to parallel to the line going from the sun to the moon, the direction of illumination of the sun's rays on the moon. We see the moon at a slightly different direction from the way the sun illuminates it. The point is that the plane of the moons's orbit is quite tilted with respect to the ecliptic plane. But I'm done with this. If you think those shadows at the south pole are caused by the moon not quite being full, you are wrong. If it were just a case of the moon not being full, how can the shadowed craters extended both east and west of the south pole? Sorry you don't quite get what I am talking about. Enough of this. Joe An extreme example of this effect was shown by a picture of Saturn on APOD. From earth, Saturn is essentially always "full." The picture there showed Saturn at something like half-illumination, immediately telling one that it was not taken from earth. The picture was taken from a direction very far from being parallel to the sun-Saturn direction.By being far enough off the sun-moon line, as you were when you took your picture, you could "see" around the south pole to the dark side. Where you are compared to how the sun illuminates things is critical. I don't know how to make it clearer without a diagram. |
#76
|
|||
|
|||
Full Moon Handheld- Of course it's a great question!
On Oct 29, 11:56 pm, Joseph Miller wrote:
acl wrote: On Oct 28, 2:23 am, Joe Miller wrote: Don't read this if you are not interested in astronomical phenonmena. I don't want to waste your time. If one looks carefully near the bottom of the picture,the southern edge, one sees that the craters there and only there have shadows in them. How can that be? Ususally the shadowed craters run along a line that goes north-south. The moon's orbital plane is tilted with respect to the earth's orbital plane. This means that the direction the sun's rays shine toward the moon and the direction from which we view the moon are not exactly the same at full moon unless there is a perfectly-centered eclipse of the moon and we are in the exact right place. In this image there is a significant difference between the direction the sun's rays are hitting the moon and how we view it, but in a north-south direction, so the shadowed craters are near the south pole. We get to see "under" the south pole compared to how the sun "sees" the moon. It's not exactly a north-south tilt, but pretty close. That's not often recorded so nicely in pictures. The moon missed getting eclipsed pretty far this month. Very nice picture. Joe Joe, Good observation. The sun-earth-moon angle was 176 degrees, The image was obtained only 1.2 hours from full moon. So the shadows are from the sun being only about 4 degrees off of direct illumination. (This 4 degrees is called the phase angle.) The shadows at the south pole do not result from the fact that the phase was not exactly full. The phase angle isn't the critical thing here. Thee fact that the moon is well off the ecliptic is the important thing that allows us to see around to the "dark side of the moon" under the south pole. Even if the picture were taken at exactly full moon (phase angle 180 degrees), with this geometry you would have still seen the shadows at the south pole. The fundamental point I was making was that those south-pole shadows were not the result of the phase of the moon in the normal sense. Indeed, the moon being at perigee help at a tiny bit, and if the picture had been taken from the south pole of the earth, it would have revealed a tiny bit more of the "dark side." Would you mind if I showed this picture to my astronomy classes? Explaining the shadows would be a good exam question, but maybe too hard for an elementary class of non-scientists who think arithmetic is higher math. But wouldn't it actually be a good question because it doesn't need anything except a) a rough mental image of the relative positions of the earth, the sun and the moon and b) some pictorial thinking (well, also knowledge that light travels in straight lines!)? I mean, what's the best way to test if they actually listened to what was being taught than asking them to do some (perhaps directed) thinking about it and conclude something interesting? Those that can't do it, well, let natural selection take its course! That's just the kind I like to give on my exams. If you really understand the basic underlying principles, you can figure something out you didn't know before. Yes, that's the point isn't it. Most of them won't like it probably (but then again, they probably shouldn't be there in that case). It teaches students that scientific understanding can lead to new knowledge, to the ability to understand something not seen before. My exams are open book and open notes. I'm not the least bit interested in anyone memorizing anything. It's just that the geometrical thinking in this problem might be a bit much for most, but not all a my students during an exam. It would be better as a homework problem. Joe |
#77
|
|||
|
|||
Full Moon Handheld- Clark, my apologies!
Joseph Miller wrote:
First I apologize for adding an "e" to your name. I don't know why I did that. Second, with a little more time to read things, I realized that I was putting words in your mouth. You never did say that the shadows at the south pole were only a result of the moon not being full. I was mislead by your making a point out the fact that the phase was not exactly full. The fundamental trap I fell into was interchanging phase angle (a technical term with a precise definition) and angle of phase- the sun-earth-moon angle. The fundamental point remains. When you took your picture the phase angle was well off zero, with a lot of it in a north-south direction. The phase angle at full moon will be effectively zero when the full moon is on the ecliptic (and an eclipse takes place), but if the fulll moon is far from the ecliptic, a significant north-south phase angle can be observed. Joe |
#78
|
|||
|
|||
Full Moon Handheld
Then began 'He's So Funny! ' to curse and to swear:
Note: Vulgar posting not quoted. This is a family news group in which children and young adults read. It is *your* social responsibility as an adult to demonstrate proper Usenet etiquette. Please refrain from cursing and swearing. -- Gabriel Gowdel |
#79
|
|||
|
|||
Full Moon Handheld
Then began 'He's So Funny! ' to curse and to swear:
Note: Vulgar posting not quoted. This is a family news group in which children and young adults read. It is *your* social responsibility as an adult to demonstrate proper Usenet etiquette. Please refrain from cursing and swearing. -- Gabriel Gowdel |
#80
|
|||
|
|||
Full Moon Handheld
Then began 'He's So Funny! ' to curse and to swear:
Note: Vulgar posting not quoted. This is a family news group in which children and young adults read. It is *your* social responsibility as an adult to demonstrate proper Usenet etiquette. Please refrain from cursing and swearing. -- Gabriel Gowdel |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Full Moon | Wayne J. Cosshall | Digital Photography | 24 | January 6th 07 05:43 AM |
Full Moon 2 | RichG | Digital Photography | 1 | January 4th 07 08:01 AM |
The Moon handheld | Frank ess | Digital Photography | 5 | January 30th 05 12:31 AM |
The Moon handheld | dj NME | Digital Photography | 0 | January 29th 05 04:00 PM |
The Moon handheld | dj NME | Digital Photography | 0 | January 29th 05 04:00 PM |