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Post by JayUtah on Feb 5, 2006 16:26:33 GMT -4
And actually I was more wondering how he could look up with that space suit, since we have been told that was virtually impossible to do.
No. What's impossible is to crane your head backward enough to block out sunlit terrain and see out of the helmet. Nothing about the helmet prevents you from seeing objects in the sky; you'll just be seeing terrain too.
Now we should get the information how high above the lunar horizon the earth was standing during Apollo 11...
No. Now you should answer the questions put to you instead of dodging them and trying to change the subject. 1.5 inches at a distance of 18 inches is what angular dimension?
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Post by AstroSmurf on Feb 5, 2006 16:29:08 GMT -4
The Earth was bright enough that they didn't have to shield their eyes from every other sunlit surface in order to see it. As for the Earth's altitude, some trigonometry and the location of the Apollo 11 landing site should provide this for you. I'm done doing your homework.
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Post by phunk on Feb 5, 2006 16:30:29 GMT -4
No, now you're misquoting people. You weren't told it was impossible to look up at all. You were told it was very hard to look up high enough to not have any of the lunar surface in your view.
The earth's albedo is like 3x the moon's, and it's like 12x the area, so it's much brighter than the full moon. I wouldn't be suprised if it alone was enough to ruin your dark vision and your view of the stars from the moon.
*edit, typo
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Post by LunarOrbit on Feb 5, 2006 16:34:04 GMT -4
Now we should get the information how high above the lunar horizon the earth was standing during Apollo 11... Are you sure Neil was on the lunar surface and not orbiting the moon in the CSM when he held his thumb up in front of the Earth? I don't think the quote was that specific.
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Post by stargazer on Feb 5, 2006 16:36:32 GMT -4
The Earth was bright enough that they didn't have to shield their eyes from every other sunlit surface in order to see it. As for the Earth's altitude, some trigonometry and the location of the Apollo 11 landing site should provide this for you. I'm done doing your homework. No, you don't have to do my homework, you should try to figure things out yourself. If the thumb-blotting-out-the-earth-story is not what Hufschmid had in mind there is still a science challenge to solve. Maybe it has something to do with the appearance (phase) of the earth during that day they allegedly strolled around on the moon.
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Post by phunk on Feb 5, 2006 16:36:56 GMT -4
Now we should get the information how high above the lunar horizon the earth was standing during Apollo 11... Are you sure Neil was on the lunar surface and not orbiting the moon in the CSM when he held his thumb up in front of the Earth? I don't think the quote was that specific. Also, he didn't say he held his arm fully extended, so his thumb could have blocked a much bigger angle. Trying to use that quote as some sort of evidence is really grasping at straws. *edit, hangover = typos
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Post by phunk on Feb 5, 2006 16:38:16 GMT -4
The Earth was bright enough that they didn't have to shield their eyes from every other sunlit surface in order to see it. As for the Earth's altitude, some trigonometry and the location of the Apollo 11 landing site should provide this for you. I'm done doing your homework. No, you don't have to do my homework, you should try to figure things out yourself. If the thumb-blotting-out-the-earth-story is not what Hufschmid had in mind there is still a science challenge to solve. Maybe it has something to do with the appearance (phase) of the earth during those days they allegedly strolled around on the moon. The only argument I can see hufshmid making would be to attribute a quote about earthrise to someone on the lunar surface, when in fact it was a quote about the view from lunar orbit.
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Post by sts60 on Feb 5, 2006 16:43:05 GMT -4
Yes, that's important because of the "tiny pea", a rather strange description for an object appearing 13,5 times as large as the moon.
No, it's irrelevant. You claimed it was impossible for an Apollo astronaut to cover up the Earth with his thumb. Weaseling about subjective impressions does not change the fact that your claim is flat wrong.
Go get Armstrong's arm length and thumb width.
Already done, as Jay pointed out. Do you have a specific counterclaim?
Of course, if he has Tarzan's thumbs and can't s]tretch his arm out completely because of that space suit
Armstrong was about 5'11" (edit: or within a couple of inches of it)and, from the look of photographs, of average proportions. It was conclusively shown that an average adult human would cover up the Earth from the Moon with an uncovered thumb, held out at arm's length.
(I'm wondering how he could look up at the earth but not the stars)
False statement of another issue. The issue was not being able to look up enough to see some stars; it was being able to look up enough to avoid peripheral vision to Sunlit objects. Your attempt at misdirection is noted.
Oh, and how many stars, exactly? Without a quantitative estimate, you have no idea whatsoever about what someone should see.
he might be able to blot the earth out... You will certainly "solve" that one also.
Already solved, with simple trigonometry and facts which are beyond dispute. You can shut your eyes and plug your ears and shout "Na-na-na" all you want, but the fact is that anyone who takes a few moments can see your claim is wrong.
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Post by JayUtah on Feb 5, 2006 17:16:19 GMT -4
No, you don't have to do my homework, you should try to figure things out yourself.
It has been demonstrated today that we do. You have been invited to figure it out for yourself too, but it seems you either won't or can't.
If the thumb-blotting-out-the-earth-story is not what Hufschmid had in mind...
Regardless of whether it's what Hufschmid had in mind, you still have that claim on the table. Substantial refutation has been offered to your claim that Neil Armstrong wouldn't have been able to block out the Earth with his thumb. You have asked for and received dimensions with which to compute an answer for your claim.
Please either perform the computation or withdraw the claim.
...there is still a science challenge to solve.
The only "science" challenge to solve is reading Eric Hufschmid's mind to determine what his argument might be. Until he actually makes an argument I feel no obligation to offer any preemptive refutation.
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Post by sts60 on Feb 5, 2006 17:23:36 GMT -4
stargazer, do you withdraw your "Armstrong's thumb" claim, or not? If not, why not, exactly? No, I don't withdraw it. As I said, I can also cover the moon with my thumb at full arm's length leaving very little space on both sides. I definitely cant cover 3,67 moons even if I wear two pairs of thick gloves one on the other. Armstrong freely made that up without thinking about it first. We have shown that the average human thumb width covers an arc distance four times that of the full Moon. This directly refutes your claim that your thumb will "just about" cover the Moon; your thumb, unless you are deformed, is roughly four times wider when held at arm's length than the Moon's disc. Four times wider than the Moon's disc means that your thumb uncovered would "just about" cover the Earth's disc as seen from the Moon. When I hold out my arm as if to block out the Moon with my thumb, which is 1" wide, about 28" from my eyes. The angular width of my thumb in such a pose is 2*tan^-1 (1"/28"), or 2 degrees. That's really sticking my arm all the way out. Do the following experiment to conclusively prove or disprove your claim: 1. Measure the width of your thumb (W) 2. Stick your arm out. thumb up, and use the ball of your thumb to hold a measuring tape against the wall. 3. With your other hand, pull the tape up beside your eye, and read of the length (L). 4. The following formula gives the angular width, A, of your thumb: A = (360/pi)*arctan(W/L) degrees What is the result? BTW, when I held out my thumb, at full arm's length, a little while ago, I could tell even with the brief glimpse that it was several times wider than the Sun's disc. And the Sun's disc is just about the same angular diameter as the Moon's.
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Post by Retrograde on Feb 5, 2006 17:55:41 GMT -4
We have shown that the average human thumb width covers an arc distance four times that of the full Moon. This directly refutes your claim that your thumb will "just about" cover the Moon; your thumb, unless you are deformed, is roughly four times wider when held at arm's length than the Moon's disc. You people keep forgetting to square it like stargazer did. The thumb can block an object sixteem times the size of the moon. N
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Post by sts60 on Feb 5, 2006 18:18:30 GMT -4
Another experiment for you, stargazer:
1. Cut out a paper circle about 9/16" wide and tape it to the wall at eye level. 2. Back up so that your eyes are 10 feet away. The circle will appear just over 1/2 degree wide. [ width in degrees = 2*180/pi*arctan ((9/16")/120") ]
Hold up your thumb with your arm fully extended. Compare it to the paper. Is it just as wide or is it several times wider?
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Post by PeterB on Feb 5, 2006 18:37:17 GMT -4
Stargazer said:
Did you close one eye when you did this?
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Post by Jason Thompson on Feb 5, 2006 19:05:24 GMT -4
If stargazer has to use his entire thumb to blot out the Moon, how come I can do it easily with the tip of my little finger?
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Post by stargazer on Feb 5, 2006 19:07:46 GMT -4
You're either lying, not very observant, or are the most disproportioned person alive.
None of the above.
Ok, so I did some body measuring. My thumb measured at the widest place measures 2,3 cm. When I stetch my arm out it is 71,5 cm away from my eye. My visual angle is thus: 2*arctan(1.15/71.5) = 1.843 degrees.
The Moon's radius is 1,738 km and its average distance from Earth is 384,403 km. That's correct but to be exact we have to measure the exact disctance at the time, it does make a difference.
Therefore, its angular diameter is, 2*arctan(1738/384403) = 0.518 degrees. This is 28 percent of the width of my ungloved thumb. Well maybe I was a bit unobservant here and the problem is it was only a half moon.
The Earth's radius is 6,378 km; therefore its angular diameter as viewed from the Moon is, 2*arctan(6378/384403) = 1.901 degrees. Again we have to know the exact distance. With the average distance this is more than the width of my thumb.
Now, if the "astronaut's" glove is really 1,5'' (3,81 cm) that is enough to blot out the earth. So there is no point here, I admit that. Nevertheless I find Armstrong's quote suspicious because of the "tiny pea". Will have to look up what the exact position of the earth relative to the moon was on that day. I'm still curious what Hufschmid is up to. Does anybody have all of Armstrong's words on the "moon"?
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