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Post by trebor on Sept 14, 2010 9:29:02 GMT -4
What point are you trying to make and the VARB? That the field may attenuate/divert incoming gamma rays. May I point out that the Van Allen belt's consist of charged particles trapped within the earths magnetic field. Gamma rays are not charged particles and are not effected by either the VAB's nor magnetic fields.
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Post by JayUtah on Sept 14, 2010 9:52:54 GMT -4
That the field may attenuate/divert incoming gamma rays. So, along with photographic analysis, geology, and perhaps some other topics, we can now add radiation to the list of things about which Rodin knows little of value. The Van Allen belts have no effect on gamma rays, which are electromagnetic radiation. Anyone who passed basic high school physics should know that.. I refer you to the picture in the OP where the gamma radiation is very distinguishable from background.No. It is distinguishable only in this image because the image is the arithmetic pixel-wise sum of several passes of data, at -- obviously -- extremely low spatial resolution. The Moon is indistinguishable from background in each source image, but it is a consistent source of that radiation at that location in the frame, from image to image. Hence when the images are summed, the consistent presence of gamma intensity at that location in the frame sums to a greater value. The background sources shift and vary from one source image to another because they are essentially noise. Hence over the majority of the frame's extent, they do not sum to very great values. even though they are as prominent as the Moon in each source image. Again, a real photographic analyst understands the notion of intensity buildup. Now you're claiming this radiation exists in biologically significant amounts on the Moon's surface. You've been asked multiple times to substantiate this claim. Please do so, or admit that you don't know what you're talking about.
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Post by PhantomWolf on Sept 14, 2010 10:04:57 GMT -4
This isn't quite correct. The Gamma Rays are created when Cosmic Rays hit the Lunar surface. Actually its both I suggest you read the quote again. Both of those sources are emission sources, not reflective sources.
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Post by chew on Sept 14, 2010 10:27:33 GMT -4
You have no idea what that picture means because it does not have a scale on it. Black could mean 0, white could mean .0000001 or 1,000,000. Find the scale that goes with it then maybe you'll have a valid point.
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Post by rodin on Sept 14, 2010 12:29:33 GMT -4
The Van Allen Belts interact with charged particles, but have no effect whatsoever on short-wavelength EM radiation (which gamma rays, x-rays, UV and visible light all are). OK
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Post by rodin on Sept 14, 2010 13:26:22 GMT -4
That the field may attenuate/divert incoming gamma rays. So, along with photographic analysis, geology, and perhaps some other topics, we can now add radiation to the list of things about which Rodin knows little of value. The Van Allen belts have no effect on gamma rays, which are electromagnetic radiation. Anyone who passed basic high school physics should know that.. I refer you to the picture in the OP where the gamma radiation is very distinguishable from background.No. It is distinguishable only in this image because the image is the arithmetic pixel-wise sum of several passes of data, at -- obviously -- extremely low spatial resolution. The Moon is indistinguishable from background in each source image, but it is a consistent source of that radiation at that location in the frame, from image to image. Hence when the images are summed, the consistent presence of gamma intensity at that location in the frame sums to a greater value. The background sources shift and vary from one source image to another because they are essentially noise. Hence over the majority of the frame's extent, they do not sum to very great values. even though they are as prominent as the Moon in each source image. Again, a real photographic analyst understands the notion of intensity buildup. Now you're claiming this radiation exists in biologically significant amounts on the Moon's surface. You've been asked multiple times to substantiate this claim. Please do so, or admit that you don't know what you're talking about. I concede that on reflection it should have been obvious gamma rays are not affected by the Van Allen belts, since obviously the much less energetic light passes clean through. I do understand very well the principle of signal to noise enhancement by repeated sampling. Looking at the OP photograph the background space around the gamma Moon appeared to me to show structure, suggesting it was more than just noise. I have since read up on various gamma ray observation satellites The first Explorer 11 returned 31 gamma ray 'events' (photons?) in 147 hours of useful observation. If this is correct then the structure in the background must be noise since gamma events are so few and far between absent something energetic to focus on. Intuitively one would think the Sun would be a far more powerful gamma ray source than the Moon. The fact the reverse is true piqued my interest. For the record I don't think I ever made the claim that the Moon's gamma radiation was definitely biologically significant (to the extent of being an Apollo dealbreaker for example). I put a question mark in the thread title for a reason .
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Post by blackstar on Sept 14, 2010 14:10:59 GMT -4
It's shame you don't seem to have noticed this image on that page: en.wikipedia.org/wiki/File:LPgravityfield.pngWhich is a visualization of the moons gravitional field, normally as invisible to the human eye as gamma rays. In both cases the data has been processed into a form that can easily visualized and interpreted, more than likely involving an exaggeration of the variations as part of that processing.
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Post by nomuse on Sept 14, 2010 14:52:02 GMT -4
If I'm remembering correctly, the neutron flux from high-energy cosmic ray interactions with the regolith is potentially more biologically significant. But we're still talking "10x more impact than the shock wave produced by a gnat's wingstroke at ten feet."
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Post by JayUtah on Sept 14, 2010 15:17:29 GMT -4
I concede that on reflection it should have been obvious gamma rays are not affected by the Van Allen belts...It should have been immediately obvious before the thought even finished forming in your mind. You clearly don't understand enough what gamma rays are, what the Van Allen belts are, how they are formed in the lunar surface, and how they are measured. And it wasn't until several people called you on your hogwash that you did any homework. This is why I say you've already made up your mind and are now just searching for pseudo-intellectual propositions to pretend to be the reasons for your belief. I do understand very well the principle of signal to noise enhancement by repeated sampling.No you don't. Image-stacking, the reasons for it, the procedures for doing it, and the effect you get from it, are all common topics in astronomical imaging. This image was presented to you from the beginning as a stacked imaged. When that was reiterated to you, you reasserted the apparently greater intensity of the Moon in the stacked image as evidence of its supposed real-life prominence in the gamma-ray band. That ignorant reiteration shows you don't understand the method by which this image was produced. Looking at the OP photograph the background space around the gamma Moon appeared to me to show structure, suggesting it was more than just noise.Uh, look at the functional resolution of the "structure" versus the spatial resolution of the imaging sensor. Look up the engineering feat required to focus short-wavelength light. Then rethink your theory about the "structure" in the image. Intuitively one would think the Sun would be a far more powerful gamma ray source than the Moon.But it isn't, and there's a good reason why. Isn't it wonderful how real science relies on study, theorization, and testing rather than upon intuition? You have no clue how much absolute energy from gamma-rays is emitted by the lunar surface. You're just waving your hands at one low-resolution photograph. As a matter of fact, the actual biological dosage an astronaut would receive in a year from gamma emission on the Moon is roughly equivalent to the dosage an X-ray technician would receive. For the record I don't think I ever made the claim that the Moon's gamma radiation was definitely biologically significant...Way to backpedal. You used the term "lethal" and you made this statement: "So if we could shield out all other radiation we could survive for days standing on a Sunspot and suffer no long term ill effects?" How can this not be interpreted to mean you were intending to claim the gamma-ray environment on the Moon had a deleterious health effect? Face it -- your claim is well and truly busted. Please just kindly concede that there is nothing about the gamma-ray environment of the lunar surface that would impede the Apollo exploration.
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Post by Jason Thompson on Sept 14, 2010 17:11:45 GMT -4
I concede that on reflection it should have been obvious gamma rays are not affected by the Van Allen belts, No, it should have been obvious before you even typed it into a discussion forum. You don't think, you don't make the effort to understand, in short you have no idea how to do research properly. A point for trying, but you couldn't even get that on a sound scientific footing. Light passes through the atmosphere but more energetic x-rays do not. The point is not the energy of the radiation but the type of radiation, and you didn't even get the terminology right. The van Allen belts do not trap radiation of any kind: they are trapped particle radiation. It is Earth's magnetic field that does the trapping. Then why did you argue against it when it was first mentioned? If I thought you had any idea how to tell 'structure' from random noise that might mean something. You once again demonstrate your inability to research. It looked like structure, so rather than actually checking the source of the image to find out how it was produced you held on to your intuitive conslusion. That's why science is done by scientists, not by average joes and their intuition. And then argued when several people pointed out it was not lethal (or even especially significant). Stop blustering.
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Post by tedward on Sept 15, 2010 3:57:44 GMT -4
I got the distinct impression, going on previous form, that it was an attempt to rub noses in it.
Rodin, are you acknowledging that it is not an issue to a manned landing
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Post by kallewirsch on Sept 15, 2010 6:30:21 GMT -4
Rodin, just one piece of advice for your life.
If you are wrong on a specific subject und you finally find out that you were wrong, then just say "thank you for putting me straigt and showing me where I went wrong."
But stop to bubble around and how the original question wasn't ment they way it was understood and that you ment something very different and so on and so on.
The first is well accepted and doesn't present a problem to anybody. You admitted you were wrong, you learned something and that's it. Case closed - no big deal.
But the later just lets you look foolish.
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