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Post by Jason Thompson on Feb 17, 2011 4:31:53 GMT -4
I've looked for figures on the internet for the dimensions and consistency of the Van Allen Belts and come up with two contradictory quotes. Then keep looking. AGAIN, will you please get it into your head that planning a mission does NOT involve looking on the web with Google for information about the belts, but going to actual publications and peer reviewed journals, some of which may even be in paper form stored in a strange place called a library. Your inability to find the information online is not even slightly relevant to any real mission planning, despite your insistence.
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Post by PeterB on Feb 17, 2011 8:06:47 GMT -4
...let's deal with the van Allen Belts first. A radiographer told me that it depends on the is intensity of the particles and duration you're exposed to them. She asked me for excact figures on what those were and I showed her links to the two pages I quoted a few pages ahead which give contradictory information on the Belts and she shook her head in bemusement saying: "There's no way to be sure from two so widely diverging estimates." Have you visited the link that trebor provided? Here it is again: modelweb.gsfc.nasa.gov/magnetos/AP-8-min-max-76-6.pdfPerhaps you could read the material in it before you say anything else about the Van Allen Belts. Perhaps you could discuss it with your radiographer friend.
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Post by PeterB on Feb 17, 2011 8:18:03 GMT -4
I don't know for sure why, but it's important to understand the political climate of the day to make a guess. There may well have been a situation where rash claims and reckless boasts could have been the order of the day. Kennedy himself was just a couple of years from being assassinated by his own administaration...America and much of the rest of the world was gripped by an endemic hysteria caused by fear of nuclear war and "Reds under your beds". The Soviet Union, America's Cold War Rivals (as they were perceived) were sprinting ahead in the Space Race after the success of Sputnik and Vostok. It's not the kind of atmosphere where level-headed rational types are granted a respectful audience. Kennedy could have been put under pressure from PR, Intelligence and strategic advisers to say something explosive and mega-daring. A goal! A vision! to give the American people the reassurance that they were still in with a chance!... so Kennedy listened to his advisers and made his speech. It might have only been after the passion of it had died down that in the cold light of day the true magnitude of the task he'd taken on board was understood. Four hypotheticals in one theory. Not bad. How about you look at the documented history of the time, courtesy of Wikipedia (Apollo Program): So Kennedy waited eight days after Gagarin's flight before asking Johnson to do some research. Johnson took a week to investigate before reporting back. Kennedy then waited another 4 weeks before making his announcement. Doesn't sound like a rush job to me.
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Post by PeterB on Feb 17, 2011 8:22:48 GMT -4
I've looked for figures on the internet for the dimensions and consistency of the Van Allen Belts and come up with two contradictory quotes. That's worrying if you're planning a space mission today, let along 40 years ago! This post is an answer to all the people, I've lost count how many, who asked me for additional evidence. Was one of those figures from the site trebor linked to? And have you visited your local university yet? Talked to the geologists or physicists there?
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Post by echnaton on Feb 17, 2011 10:48:38 GMT -4
The list seems to have no bounds. But then, isn't that true of everyone? I certainly suspect that there is a near-infinite amount of things I don't know. The trick is knowing how ignorant you really are about the things you think you do know about. To put is perhaps more accurately, the length of the list of what H does not know that he does not know surpasses the length of the list of what he thinks he knows but actually does not. Or vice-versa.
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Post by gillianren on Feb 17, 2011 13:10:57 GMT -4
To put is perhaps more accurately, the length of the list of what H does not know that he does not know surpasses the length of the list of what he thinks he knows but actually does not. Or vice-versa. How about "I have never known him to discuss anything and actually show evidence that he knows what he's talking about"?
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Post by echnaton on Feb 17, 2011 13:26:17 GMT -4
To put is perhaps more accurately, the length of the list of what H does not know that he does not know surpasses the length of the list of what he thinks he knows but actually does not. Or vice-versa. How about "I have never known him to discuss anything and actually show evidence that he knows what he's talking about"? What she said!
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Post by LunarOrbit on Feb 17, 2011 13:48:09 GMT -4
How about "I have never known him to discuss anything and actually show evidence that he knows what he's talking about"? Well he better start soon because I'm not going to put up with it for much longer.
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Post by Data Cable on Feb 17, 2011 14:09:38 GMT -4
A radiographer told me that it depends on the is intensity of the particles and duration you're exposed to them. She asked me for excact figures on what those were and I showed her links to the two pages I quoted a few pages ahead which give contradictory information on the Belts... [emphasis mine] Did these figures for "the Belts" which you purportedly presented to an as-yet anonymous radiographer correspond to the section(s) through which spacecraft actually passed, and the corresponding exposure duration(s), or just some randomly-selected sampling from some part of the region covered by the belts? Let me ask you these questions: What is the temperature of Earth's atmosphere? Is that temperature suitable for human life?
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Post by chew on Feb 17, 2011 15:41:19 GMT -4
HBs: the poster children for the Dunning-Kruger Effect.
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Post by hagbardceline on Feb 17, 2011 16:05:36 GMT -4
what about the continuing disagreement on the nature of the Belts? There is no "continuing disagreement" (or any disagreement) involving any competent scientists, engineers or space historians over whether the Van Allen belts were a show-stopping threat to the Apollo missions. Relating directly to Apollo? Do any space historians, enginers and scientists even consider that Apollo might have been faked when they talk of the radiation? Maybe not, but there is disagreement; I've discovered it myself when trying to find out exactly where the belts were and how big. Well obviously we have satelites in them now so we know... fairly well for their sake , despite the discrepancies between the Wiki article and the other one I posted. But if there are contradictory figures now, what was it like in the 60's? This is why when members say The Belts were not dangerous, I don't contest that, but we're looking at the Betls from a much better view than the Apollo-planners did.
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Post by tomblvd on Feb 17, 2011 16:21:34 GMT -4
Maybe not, but there is disagreement; I've discovered it myself when trying to find out exactly where the belts were and how big. Perhaps you are having trouble with the actual definition of the VA belts. They are in no way a static thing. The term "belts" is actually misleading. "Van Allen Radiation Fields" is probably more descriptive. Given the immense variability of our Sun, there is a good chance that the nature of the "belts" is going to vary all the way from months to hours. There is no way to get a static "measurement" of the VABs. Depending on many variables, the size, shape and content of the belts is going to be very, very different.
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Post by drewid on Feb 17, 2011 16:52:19 GMT -4
Hag. How deep is the sea and how big are waves? I'll take measurements accuate to the nearest .5 meter . thanks.
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Post by tedward on Feb 17, 2011 17:08:18 GMT -4
I think H needs to look up dynamic. And William Anders, prefer his experience to a radiologist with an incomplete question from a biased asker.
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Post by blackstar on Feb 17, 2011 17:10:43 GMT -4
Here's a page for you to look at HagbardCeline, it's a BBC page forcasting the high and low tides at a port: news.bbc.co.uk/weather/coast_and_sea/tide_tables/12/523/Note that over the course of a week those tides change dramatically. If you knew nothing of how tides work you might conclude that the predictions reflect a degree of uncertainty about the nature and behaviour of the tides, rather than being the predictable variations a of system of interacting forces. You might even conclude that no one would be crazy enough to put to sea given such uncertainty, and even be indignant when others question your conclusion, or tell you that you don't know what you're talking about. To put it simply the problem isn't with the values for the Van Allen Belt you've found, the problem is your inability to understand what they mean and put them in context. Now if you choose to believe otherwise that's your affair, just don't be surprised that no one takes your questions seriously when you simply refuse to absorb the explanations being offered to you, and the physical facts that they contain.
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