Daylight Stargazing Goggles???

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daniel_rey_m

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<p>In my schooldays my favorite book in the school library was a thick one with "Ripley's Believe It Or Not" cases.&nbsp; The only one I still remember, & there were hundreds, was about a boy in XVIIIth- or XIXth-Century France, I think, who could see the stars in broad daylight, but it's only now that&nbsp;I started to wonder whether or not one could develop some artifact that would allow anybody to do that.&nbsp; One could think that, if that were possible, they would've come up with such a thing already, but maybe not.&nbsp; Bionics is constantly finding things in nature that lead to new products & processes, like Velcro & the oxyacetylene torch they use for welding (cp. the bombardier beetle).&nbsp; Maybe there's an animal that can see the stars by day & nobody has realized it can do it.&nbsp; If anyone here ever manages to use this comment as a starting point then please give due credit eventually instead of arguing, if I complain, that ideas are "in the air" & nobody's property & that (s)he never ever read this.&nbsp; I don't want to have to drag anybody into a courtroom....</p> <div class="Discussion_UserSignature"> </div>
 
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MeteorWayne

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>In my schooldays my favorite book in the school library was a thick one with "Ripley's Believe It Or Not" cases.&nbsp; The only one I still remember, & there were hundreds, was about a boy in XVIIIth- or XIXth-Century France, I think, who could see the stars in broad daylight, but it's only now that&nbsp;I started to wonder whether or not one could develop some artifact that would allow anybody to do that.&nbsp; One could think that, if that were possible, they would've come up with such a thing already, but maybe not.&nbsp; Bionics is constantly finding things in nature that lead to new products & processes, like Velcro & the oxyacetylene torch they use for welding (cp. the bombardier beetle).&nbsp; Maybe there's an animal that can see the stars by day & nobody has realized it can do it.&nbsp; If anyone here ever manages to use this comment as a starting point then please give due credit eventually instead of arguing, if I complain, that ideas are "in the air" & nobody's property & that (s)he never ever read this.&nbsp; I don't want to have to drag anybody into a courtroom.... <br />Posted by daniel_rey_m</DIV><br /><br />That would be difficult, since the bright blue sky is in between the stars and your eyes. You would have to filter all or most of the skyglow while still allowing enough&nbsp;of other frequencies from the stars to pass through. A good starting point might be to examine the spectrum of the blue sky. Perhaps you could search for one? <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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lildreamer

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>In my schooldays my favorite book in the school library was a thick one with "Ripley's Believe It Or Not" cases.&nbsp; The only one I still remember, & there were hundreds, was about a boy in XVIIIth- or XIXth-Century France, I think, who could see the stars in broad daylight, but it's only now that&nbsp;I started to wonder whether or not one could develop some artifact that would allow anybody to do that.&nbsp; One could think that, if that were possible, they would've come up with such a thing already, but maybe not.&nbsp; Bionics is constantly finding things in nature that lead to new products & processes, like Velcro & the oxyacetylene torch they use for welding (cp. the bombardier beetle).&nbsp; Maybe there's an animal that can see the stars by day & nobody has realized it can do it.&nbsp; If anyone here ever manages to use this comment as a starting point then please give due credit eventually instead of arguing, if I complain, that ideas are "in the air" & nobody's property & that (s)he never ever read this.&nbsp; I don't want to have to drag anybody into a courtroom.... <br />Posted by daniel_rey_m</DIV></p><p>as MW pointed out - and what your up against ...</p><p>here is a website I find interesting in its way of presenting information</p><p>http://hyperphysics.phy-astr.gsu.edu/Hbase/atmos/blusky.html</p><p>"<font size="1">Blue Sky :</font>The blue color of the sky is caused by the scattering of sunlight off the molecules of the atmosphere. This scattering, called Rayleigh scattering, is more effective at short wavelengths (the blue end of the visible spectrum). Therefore the light scattered down to the earth at a large angle with respect to the direction of the sun's light is predominantly in the blue end of the spectrum."</p><p>then you need to contend with the polarization of light </p><p>wiki is nice place to start</p><p>http://en.wikipedia.org/wiki/Photographic_filter</p><p>&nbsp;</p><p>its probable that you can create such a filter - one to remove blue wavelength and have it polarized as well but that's beyond my level of knowledge or expertise...</p><p>but it would be interesting to find out ....hmmm need to dig........</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>
 
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daniel_rey_m

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<p class="MsoNormal"><span>It can&rsquo;t be as easy as filtering out the blue light.<span>&nbsp; </span>The filter would block only the blue-light rays coming at the observer.<span>&nbsp; </span>Blue light is scattered in ALL directions by the air particles & the foreground glare caused by the other blue-light rays would still be there.<span>&nbsp; </span></span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>Also, supposing it would work, then one wouldn&rsquo;t be able to see the blue stars.<span>&nbsp; </span>I wonder how patchy a piece of night sky would look like without all its blue stars!!!</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>How, then, could there possibly have been someone who could see through the blue glare?<span>&nbsp; </span>The problem with Ripley was that his purpose was merely to amuse, so maybe he wasn&rsquo;t too rigorous about his sources.<span>&nbsp; </span>The story might&rsquo;ve been hearsay --just a &ldquo;rural legend&rdquo;.</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>Anyway I&rsquo;ll keep daydreaming & researching this until I can come up with my Daytime Starwatch Viewer&copy;&nbsp; (or DSV).<span>&nbsp; </span>I suggest a business partnership with Space.com.<span>&nbsp; </span>People would send around fifty dollars to the present website in order to reserve one unit at once so they would be first to get one, long before the product is available on the market, & I would get half of that.<span>&nbsp; </span>There would be a refund if five years were to go by & still there were no DSVs.</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>I hope the scheme </span><span>doesn&rsquo;t 1</span><span>) sound like a typical rip-off, & 2) somehow break the law.</span></p><p class="MsoNormal">&nbsp;</p><p class="MsoNormal">I still have to investigate all those links...polarization...filters...thank you, Li'l Dreamer....& thank you MeteorWayne the Mod for the filtering hint....</p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>There&rsquo;s also the matter of the possible uses, apart from providing some fun.<span>&nbsp; </span>What about practical uses, besides making the inventor monstrously rich?<span>&nbsp; </span>A DSV&copy; could be sold for navigational purposes if you had a time machine & you could go back far enough but I can&rsquo;t come up with any scientific reasons for developing it in my life & times&hellip;. </span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span><span>&nbsp;&nbsp; </span><span>&nbsp;</span><span>&nbsp;</span></span></p> <div class="Discussion_UserSignature"> </div>
 
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MeteorWayne

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<p>The other factor is the sky glow is not just blue, it is a continuum that peaks at blue but extends throughout the visual spectrum. So you can't just use a narrow band filter to take out a specific blue wavelength, you have to filter most of the visual spectrum to some degree. After that, what's left for stars.</p><p>Venus and occasionally Jupiter&nbsp; are bright enough to be seen in daytime, though I have never succeeded in my attempts. It might be possible to see Sirius as well. Of course the sun and moon are bright enough to exceed the glare :) And rare Supernova and comets have been visible in the daytime, not during my lifetime though. Also, Iridium satellite flares are bright enough, I have seen a few of those; they are very bright (~ Mag -8) though.</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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Mee_n_Mac

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The other factor is the sky glow is not just blue, it is a continuum that peaks at blue but extends throughout the visual spectrum. So you can't just use a narrow band filter to take out a specific blue wavelength, you have to filter most of the visual spectrum to some degree. After that, what's left for stars. Posted by <strong>MeteorWayne</strong></DIV><br /><br />I was going to add the above but MW beat me to it.&nbsp; Just as an illustrative experiment, you might try to find a set of "blue blockers" sunglasses.&nbsp; They did a fair job of knocking&nbsp;down the blue part of the spectrum.&nbsp; Bluejeans looked black and the sky was gray when I had a pair.&nbsp; But I never did see any stars in the daytime sky with them.&nbsp; Now perhaps with a high power scope (narrow FOV) and the proper filtering you might be able to decrease the background level enough to see some brighter stars but that's not exactly your scheme anymore. <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>
 
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daniel_rey_m

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<p class="MsoNormal"><span>It looks like nobody&rsquo;s discussed the subject on a professional level.<span>&nbsp; </span>It could be because 1) such a device has no scientific use, 2) developing it would be too complex & costly, or 3) a consensus was arrived at, according to which it would be an impossible assignment.<span>&nbsp; </span>If someone&rsquo;s working earnestly on it then it&rsquo;s being done secretly, to gain a strategic advantage.<span>&nbsp; </span>In that case then maybe they&rsquo;re already using it.</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>An &ldquo;advanced search&rdquo; (key words: &ldquo;daylight stars&rdquo;) leads to very few useful sources, the best one being a discussion at the BAUT Forum titled &ldquo;Question on seeing stars in the daytime&rdquo; (already three years old).</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>It starts with someone explaining how one could do that (apart from the exceptional circumstances that partly & occasionally allow it, as MeteorWayne suggests).<span>&nbsp; </span>He doesn&rsquo;t consider the fact that Wayne points out: that the diffused glow is not just blue light.<span>&nbsp; </span>Maybe the blue component is so overwhelming that the rest can be ignored?</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>The two key concepts are &ldquo;spectral irradiance&rdquo; & &ldquo;signal-to-noise ratio&rdquo;.<span>&nbsp; </span>In our case the &ldquo;signal&rdquo; is the incoming starlight, the &ldquo;noise&rdquo; (interference) is all that foreground dazzle, & the purpose is to increase the signal/noise ratio (by lowering the value of the denominator).<span>&nbsp; </span><span>&nbsp;&nbsp;&nbsp;&nbsp;</span><span>&nbsp;</span></span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>He says, &ldquo;The sky has a specific & knowable spectral irradiance.<span>&nbsp; </span>What if a filter were made to adjust the blue daytime sky to a low & even spectral irradiance level?<span>&nbsp; </span>(Big &lsquo;if&rsquo;, I&rsquo;m sure.)<span>&nbsp; </span>[That&rsquo;s his own aside, not mine.-d.r.m.]<span>&nbsp; </span>Couldn&rsquo;t we see some stars as a result?<span>&nbsp; </span>Would it not greatly improve the signal to noise ratio, as in electronic filtering?<span>&nbsp; </span>(&hellip;)</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>&ldquo;A bright red star like Antares, or Betelgeuse, with strong reds, would not be attenuated by the filter as much & its light might stand out enough to see with a scope. <span>&nbsp;</span>(&hellip;)</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>&ldquo;I do not know enough about filter manufacturing to suggest the effort would be worth the while.<span>&nbsp; </span>You might have to know the exact spectral irr. for each point in the sky you wish to observe to be truly effective.<span>&nbsp; </span>So, even if the idea is sound, it&rsquo;s likely &lsquo;too much squeeze for the juice&rsquo;.</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>&ldquo;Googling produced nothing for me on this.<span>&nbsp; </span>Is it nuts or what?&rdquo;</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>Then someone agrees with the comment about the red stars & he also suggests using polarizing filters.</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>The use of a long tube to peer through or a telescope is brought up.<span>&nbsp; </span>Mee'n'Mac knows about this.&nbsp; It seems to be a well-known trick.<span>&nbsp; </span>It &ldquo;improves contrast&rdquo; by shrinking the field of vision, which eliminates some of the &ldquo;scattered light&rdquo;.<span>&nbsp; </span></span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>Elsewhere I found the reason why watching from the bottom of a deep well or a chimney wouldn&rsquo;t work.<span>&nbsp; </span>Someone quotes a passage from Tolkein that shows that the author held this false belief, but it has to do with a deep & narrow canyon.</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>Polarizing filters sound particularly promising & maybe they&rsquo;re the key to the solution.<span>&nbsp; </span>Compound eyes in arthropods like bees & ants can perceive polarized light, which makes them see patches in the sky.<span>&nbsp; </span>This helps them find their way around.<span>&nbsp; </span>Maybe some insects & birds can keep a straight course by day because they use otherwise invisible stars as markers?</span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>These filters can also block certain wavelengths.<span>&nbsp; </span>For example, light from a rainbow is polarized light, which is why if you watch one with polarizing sunglasses you&rsquo;ll see that they eliminate a portion of the rainbow.<span>&nbsp; </span>This property could be useful when trying to soften the (mostly) blue glare. </span></p><p class="MsoNormal">&nbsp;</p><p class="MsoNormal"><span><span>I don't know if Mee'n'Mac is talking about this kind of polarizing sunglasses.&nbsp; </span></span></p> <p class="MsoNormal"><span>&nbsp;</span></p> <p class="MsoNormal"><span>The Ripley website has no search tool & no decades-old files either, so I had to send a request hoping they can send me the details about that story.<span>&nbsp; </span>This would allow one to try & confirm it.<span>&nbsp; </span>If true then the contrivance is feasible, theoretically, because it would be proof that the blue luster can be eliminated.<span>&nbsp; </span>Maybe it all hangs on that single case.<span>&nbsp;&nbsp; </span><span>&nbsp;&nbsp;</span><span>&nbsp;</span></span></p> <div class="Discussion_UserSignature"> </div>
 
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Mee_n_Mac

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;&nbsp; The two key concepts are &ldquo;spectral irradiance&rdquo; & &ldquo;signal-to-noise ratio&rdquo;.&nbsp; In our case the &ldquo;signal&rdquo; is the incoming starlight, the &ldquo;noise&rdquo; (interference) is all that foreground dazzle, & the purpose is to increase the signal/noise ratio (by lowering the value of the denominator).&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp; He says, &ldquo;The sky has a specific & knowable spectral irradiance.&nbsp; What if a filter were made to adjust the blue daytime sky to a low & even spectral irradiance level?&nbsp; (Big &lsquo;if&rsquo;, I&rsquo;m sure.)&nbsp; [That&rsquo;s his own aside, not mine.-d.r.m.]&nbsp; Couldn&rsquo;t we see some stars as a result?&nbsp; Would it not greatly improve the signal to noise ratio, as in electronic filtering?&nbsp; (&hellip;)&nbsp;&nbsp;.... &nbsp; These filters can also block certain wavelengths.&nbsp;&nbsp;....&nbsp;I don't know if Mee'n'Mac is talking about this kind of polarizing sunglasses.&nbsp;&nbsp;&nbsp; Posted by <strong>daniel_rey_m</strong></DIV><br /><br />I think you've got the important concepts down.&nbsp; Decrease the amount of "noise" so as to improve the SNR.&nbsp; Do this by spectral filtering (ie : blocking the blue like my odd sunglasses, and I don't think they were polarized) and reducing the area of the sky seen.&nbsp; Would such a combo scheme work ?&nbsp;&nbsp; Got me .... <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>
 
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kelvinzero

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<p>What about augmented reality goggles.. stream down the last images from 'google-sky' or whatever and superimpose them over what you physically see using global positioning :)</p>
 
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daniel_rey_m

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<p><span><font size="3"><font face="Times New Roman">A.k.a. kevinzero, I don&rsquo;t understand how your ARGs &copy; would work.<span>&nbsp; </span>What you seem to be saying is that you would place images of the night sky (so they already have a &ldquo;Google Sky&rdquo; too??) &ldquo;over what you physically see using global positioning&rdquo;, but the GPS system is used, not to see anything, but to find out one&rsquo;s geographical co-ordinates.<span>&nbsp; </span>Maybe you&rsquo;re talking about the computerized (&ldquo;go-to&rdquo;) telescopes with software that points the thing at whatever you want to see according to the observer&rsquo;s location?<span>&nbsp; </span>Anyway I don&rsquo;t think that kind of hardware needs the GPS.<span>&nbsp; </span>Please explain&hellip;thanks.</font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">I was waiting for the reply from the Ripley&rsquo;s website before making additional comments but maybe they&rsquo;ll never send one, or they&rsquo;re working on it, so I&rsquo;ll have to keep going without that.<span>&nbsp; </span>Now comes&hellip;THE NEXT STEP&hellip;a small step for science, probably, but a giant one for the consumer gadget market&hellip;</font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">&hellip;namely, the researching procedure, the inventor&rsquo;s &ldquo;modus operandi&rdquo;.<span>&nbsp; </span>One would have to put together a light framework with four aluminium rods, like the outline of an oblong box, the rods being the four long edges, a sort of long rack to place the photographic filters in line.<span>&nbsp; </span>Then one has to try very many combinations, sliding them back & forth to change the distance between them, & rotating one of a pair of polarizing filters within a 90-degree angle because this gradually leads to the total blocking of certain wavelengths.</font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">You also need something else that is even simpler & easier to make: a support for the framework.<span>&nbsp; </span>It can be like the ones they use for watching through binoculars while keeping them steady --just a stick with a small tablet at one end, perpendicular to it.<span>&nbsp; </span>Sharpen the other end to a point so you can stick it into the soil while you sit in a chair.&nbsp;<span>&nbsp;&nbsp;</span></font></font></span></p><p><span><font size="3"><font face="Times New Roman"></font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span><span><font size="3"><font face="Times New Roman">It would be necessary to develop a &ldquo;viewer&rdquo; that would work ANYWHERE, not just where the atmosphere is exceptionally clear, free from &ldquo;particulate matter&rdquo; (like summits & the Poles).<span>&nbsp; </span>Otherwise no one except maybe a few research institutes would want to buy it, & you would never recover your invesment & maybe end up going hungry & wanting to trade places with someone, like in the movie with Don Ameche, Eddie Murphy & Dan Ackroyd (maybe I didn&rsquo;t get the names right).<span>&nbsp;&nbsp;</span></font></font></span></p><p><span><font size="3"><font face="Times New Roman"></font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span><span><font size="3"><font face="Times New Roman">This means that you can & MUST set to work wherever you are, but preferrably away from areas with heavy air pollution.<span>&nbsp; </span>If you want to be thorough, though, you&rsquo;ll want to go even further & follow scientific, not just commercial, criteria.<span>&nbsp; </span>Besides, maybe such a device would work only in certain places that are not easily reached, so that if you insist on working in your neighborhood --on a balcony or on a rooftop, or in the nearest backyard or park-- you&rsquo;d never get anywhere.<span>&nbsp;&nbsp;</span></font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">In that case you&rsquo;d have to consider additional factors such as geographical location & altitude, which would imply traveling around like the Jet Set --the &ldquo;frequent-flyer&rdquo; crowd-- until you have enough points to get a free ticket to the Far East, which would be a great contribution to your project.<span>&nbsp;&nbsp;</span></font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">This would compel you to find sponsors, maybe the Nat&rsquo;l. Geographic Society, the Rolex wristwatch company, &/or Bill Gates, & persuade them that this is not just a cute little school science project, but something that will eventually fetch BIG BUCKS & become a milestone in the history of science.<span>&nbsp;&nbsp;</span></font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">Otherwise all you need to do is buy the filters, or better yet, ask a professional photographer who&rsquo;s a relative or an acquaintance to lend them to you.<span>&nbsp; </span>Before making the framework you need to have the filters ready because these come in several sizes.<span>&nbsp; </span>You might come to realize that you need several such frameworks.<span>&nbsp;&nbsp;</span></font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">Good filters are expensive, though, but since you&rsquo;re groping in the dark, who is to say that poor-quality filters are not BETTER for this kind of job, whatever the reason?<span>&nbsp; </span>You might find out that this is so without ever understanding the reason, unless you can ask a scientist or an engineer with the necessary knowledge of optics.<span>&nbsp; </span>You&rsquo;d have to buy bad filters too, then.<span>&nbsp;&nbsp;</span></font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">True, it&rsquo;s starting to sound crazy, but you must leave no stone unturned, even if they start to laugh at you & kick you around on the online forums.</font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">If you don&rsquo;t really care about science for the sake of science then all the expensive flying around wouldn&rsquo;t be part of the budget & the factors on your task list would be 1) the meteorological (atmospheric) conditions (pollution, ion concentration, humidity, temperature, turbulence), 2) the hour, 3) the season, 4) the region of the sky & 5) the tilt of the framework while pointing it at the sky.</font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span></p><p><span><font size="3"><font face="Times New Roman">Maybe now you&rsquo;re finally ready to launch the project.<span>&nbsp; </span>After trying out hundreds of combos it would be gratifying to see, all of a sudden, a few bright points sparkling through the filters&hellip;.&nbsp;<span>&nbsp;</span></font></font></span></p><p><span><font size="3"><font face="Times New Roman"><span>(Sometimes after sending the&nbsp;message the paragraph spacing vanishes&nbsp;& you get&nbsp;a single, massive&nbsp;one.&nbsp; I had to spend&nbsp;plenty of&nbsp;time correcting this & I hope it won't happen again!)&nbsp;&nbsp;&nbsp;</span><span>&nbsp;</span><span>&nbsp;&nbsp;&nbsp;&nbsp;</span></font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span><span><font size="3"><font face="Times New Roman"><span>&nbsp;&nbsp;</span></font></font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span><span><font face="Times New Roman" size="3">&nbsp;</font></span><span><span><font face="Times New Roman" size="3">&nbsp;&nbsp; </font></span></span></p> <div class="Discussion_UserSignature"> </div>
 
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crazyeddie

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>In my schooldays my favorite book in the school library was a thick one with "Ripley's Believe It Or Not" cases.&nbsp; The only one I still remember, & there were hundreds, was about a boy in XVIIIth- or XIXth-Century France, I think, <span style="font-weight:bold" class="Apple-style-span">who could see the stars in broad daylight, but it's only now that&nbsp;I started to wonder whether or not one could develop some artifact that would allow anybody to do that.</span>&nbsp; One could think that, if that were possible, they would've come up with such a thing already, but maybe not. .. <br /> Posted by daniel_rey_m</DIV></p><p>There already IS such an artifact.....it's called a telescope. &nbsp;Even a small telescope will show you any of the brighter stars in broad daylight, if you know precisely where to point it. &nbsp;Amateur astronomers do this all the time with planets, particularly Venus and Mercury.</p><p>Of course, seeing ALL the stars <span style="font-style:italic" class="Apple-style-span">at once</span> in broad daylight is a different story.......&nbsp;<img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-wink.gif" border="0" alt="Wink" title="Wink" />&nbsp;</p> <div class="Discussion_UserSignature"> </div>
 
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rogerinnh

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<p>There's another approach that hasn't been discussed as yet, although it would not provide realtime observing of the daytime sky.</p><p>If you use a digital light sensor array, as in a digital camera, and take multiple (tens, hundreds?) of pictures of the same portion of sky and then analyze the pictures it&nbsp;might be possibleto detect the very slightly more intense pixels representing the stars and other celestial objects. The general blue-sky foreground could essentially be "averaged-out" of the image, leaving just the background, steady-position, steady-intensity, stars and other distant objects visible in the processed image.</p><p>- Roger Garrett</p>
 
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MeteorWayne

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>There's another approach that hasn't been discussed as yet, although it would not provide realtime observing of the daytime sky.If you use a digital light sensor array, as in a digital camera, and take multiple (tens, hundreds?) of pictures of the same portion of sky and then analyze the pictures it&nbsp;might be possibleto detect the very slightly more intense pixels representing the stars and other celestial objects. The general blue-sky foreground could essentially be "averaged-out" of the image, leaving just the background, steady-position, steady-intensity, stars and other distant objects visible in the processed image.- Roger Garrett <br />Posted by rogerinnh</DIV><br /><br />That really doesn't help if the sky is brighter than the objects behind it. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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daniel_rey_m

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<span><font size="3"><font face="Times New Roman">CrazyEddie, it&rsquo;s discouraging to see you&rsquo;re not interested in the discussion, or you have little time to spare, or both.<span>&nbsp; </span>All you did was read the opening post & then rush to say something.<span>&nbsp; </span>If you had had the patience to read it all you would&rsquo;ve seen that we&rsquo;ve talked about the use of long tubes & telescopes to watch celestial objects during daylight hours.<span>&nbsp; </span>You&rsquo;d even come across the reasons why this is possible with such instruments, but not if you watch from the bottom of<span>&nbsp; </span>a deep well or a chimney.<span>&nbsp;&nbsp; </span>Some people claim to have seen the brighter planets by day even with the naked eye.<span>&nbsp; </span>Having a device you can easily take with you & wear comfortably, that would allow you to see the stars as though it were nighttime, is a different kettle of fish. </font></font></span> <div class="Discussion_UserSignature"> </div>
 
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Mee_n_Mac

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>That really doesn't help if the sky is brighter than the objects behind it. <br />Posted by <strong>MeteorWayne</strong></DIV><br /><br />Maybe, maybe not.&nbsp; In a imager where the pixel isn't aimed at a star you get a reading due to the sky "noise".&nbsp; In a pixel with a star you get (on average) the same background level + a small amount more due to the star.&nbsp; The problem comes in that the sky / background level has variances in it that are larger than the extra due to the star. You could average a number of images to reduce this variance but I don't think it would work in practice.&nbsp;&nbsp;The residual variance willstill be larger than the amount due to the star. &nbsp;Plus there's a fundamental limit in that the small amount more due to the star may, at the gains needed to keep the sensor from blooming, be less than the quantization level.&nbsp; Then no amount of averaging will help.</p><p>Kind of an interesting thread given it's "Hey, what if ...."start !</p> <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>
 
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MeteorWayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Maybe, maybe not.&nbsp; In a imager where the pixel isn't aimed at a star you get a reading due to the sky "noise".&nbsp; In a pixel with a star you get (on average) the same background level + a small amount more due to the star.&nbsp; The problem comes in that the sky / background level has variances in it that are larger than the extra due to the star. You could average a number of images to reduce this variance but I don't think it would work in practice.&nbsp;&nbsp;The residual variance willstill be larger than the amount due to the star. &nbsp;Plus there's a fundamental limit in that the small amount more due to the star may, at the gains needed to keep the sensor from blooming, be less than the quantization level.&nbsp; Then no amount of averaging will help.Kind of an interesting thread given it's "Hey, what if ...."start ! <br />Posted by Mee_n_Mac</DIV><br /><br />I agree :) However, in most cases, other than maybe 0 magnitude stars or brighter, the signal would be buried well beneath the noise level, IMHO.</p><p>Hey, if anybody can process it that way, great. But that would be massive post processing, not really applicable to the thread subject of Daylight Stargazing Goggles...</p><p>MW</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>
 
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crazyeddie

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>CrazyEddie, it&rsquo;s discouraging to see you&rsquo;re not interested in the discussion, or you have little time to spare, or both.&nbsp; All you did was read the opening post & then rush to say something.&nbsp; If you had had the patience to read it all you would&rsquo;ve seen that we&rsquo;ve talked about the use of long tubes & telescopes to watch celestial objects during daylight hours.&nbsp; You&rsquo;d even come across the reasons why this is possible with such instruments, but not if you watch from the bottom of&nbsp; a deep well or a chimney.&nbsp;&nbsp; Some people claim to have seen the brighter planets by day even with the naked eye.&nbsp; Having a device you can easily take with you & wear comfortably, that would allow you to see the stars as though it were nighttime, is a different kettle of fish. <br /> Posted by daniel_rey_m</DIV></p><p>Sorry, didn't mean to discourage you. &nbsp;What you are hoping for is indeed a different kettle of fish, and would be a real technological challenge. &nbsp;What makes the daytime sky bright is scattered sunlight, which emits over a very broad range of wavelengths. &nbsp;If you filter out those wavelengths, you are also filtering out the very same light that the stars themselves radiate. &nbsp;It's hard to see how such a device could differentiate between scattered sunlight and starlight, but I suppose it's possible. &nbsp;Perhaps the goggles could be programmed to allow pinpoint sources to come through the goggles, but eliminate wavelengths coming from random directions. &nbsp;it might take a lot of processing power and sophisticated optics, but it's probably not impossible.</p> <div class="Discussion_UserSignature"> </div>
 
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rogerinnh

Guest
<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Maybe, maybe not.&nbsp; In a imager where the pixel isn't aimed at a star you get a reading due to the sky "noise".&nbsp; In a pixel with a star you get (on average) the same background level + a small amount more due to the star.&nbsp; The problem comes in that the sky / background level has variances in it that are larger than the extra due to the star. You could average a number of images to reduce this variance but I don't think it would work in practice.&nbsp;&nbsp;The residual variance willstill be larger than the amount due to the star. &nbsp;Plus there's a fundamental limit in that the small amount more due to the star may, at the gains needed to keep the sensor from blooming, be less than the quantization level.&nbsp; Then no amount of averaging will help.Kind of an interesting thread given it's "Hey, what if ...."start ! <br />Posted by Mee_n_Mac</DIV></p><p>Perhaps you could set the shutter timing of the images so that the shutter isn't open long enough for blooming. Or, how about a new kind of digital image sensor that automatically closes the shutter (stops recording incoming light) when any one pixel reaches saturation (and also records the amount of time it took to reach saturation)?</p><p>&nbsp;</p><p>And, yes, it would take a lot of images and a lot of post-processing, but that tiny extra amount of light from the star should still be able to "shine through" the background noise.&nbsp; And, no, this approach does not result in a simple daylight scope for real-time viewing. But it should allow for digital daylight imaging.<br /></p>
 
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daniel_rey_m

Guest
<p>The Ripley people finally replied:</p><span style="font-size:10pt;color:navy;font-family:Arial">His name was Kaspar Hauser. He was from Baden, Germany&hellip;You have a good memory! The book was published in 1929! The item is on page 118 and looks just like you described it.</span><span style="font-size:10pt;color:navy;font-family:Arial">&nbsp;</span><span style="font-size:10pt;color:navy;font-family:Arial">Thanks for your kind words regarding the late Mr. Ripley (d. 1949) </span><span style="font-size:10pt;color:navy;font-family:Arial">&nbsp;</span><span style="font-size:10pt;color:navy;font-family:Arial">Edward Meyer&mdash;VP Exhibits & Archives</span><span style="font-size:10pt;color:navy;font-family:Arial">Ripley Entertainment Inc</span> <p>My request:</p><p><span style="color:#444444"><font size="3"><font face="Times New Roman">Dear Sirs,</font></font></span><span style="color:#444444"><font size="3"><font face="Times New Roman">&nbsp;</font></font></span><span style="color:#444444"><font size="3"><font face="Times New Roman">In high school, about 40 years ago (c. 1967), I found a hard-cover Believe It Or Not book in the school library, and now, all of a sudden, I urgently need the details concerning a case I came across in that book.&nbsp; Decades ago I left my hometown and I never went back, so I can't go see for myself whether or not it's still there.</font></font></span><span style="color:#444444"><font size="3"><font face="Times New Roman">&nbsp;</font></font></span></p><p><span style="color:#444444"><font size="3"><font face="Times New Roman">It involved someone who could see the stars during the daylight hours too.&nbsp; I think it was a boy in France in the XIXth Century.&nbsp; If one were to thumb through the book the page would be easy to find.&nbsp; I remember a large drawing with a close-up of his head and he was looking up at a sky with a glaring Sun and a few twinkling stars.</font></font></span><span style="color:#444444"><font size="3"><font face="Times New Roman">&nbsp;</font></font></span></p><p><span style="color:#444444"><font size="3"><font face="Times New Roman">At an online forum we've been discussing a hypothetical device that would allow anybody to do that.&nbsp; If the case turns out to be true, rather than a local folk tale, then it's possible to design it, in principle.</font></font></span><span style="color:#444444"><font size="3"><font face="Times New Roman">&nbsp;</font></font></span></p><p><span style="color:#444444"><font size="3"><font face="Times New Roman">Having the boy's name and location would give me the chance to research and confirm the story.&nbsp; That's why this request is so important, and I thank you in advance for any help you can offer, and thank you, Mr. Ripley, wherever you happen to be right now, for all those wonderful illustrations and for making my childhood much more entertaining than it would otherwise have been.</font></font></span><span style="color:#444444"><font size="3"><font face="Times New Roman">&nbsp;</font></font></span></p><p><span style="color:#444444"><font size="3"><font face="Times New Roman">Expectantly Yours,</font></font></span> </p><p>---------------------------------------------------------------------------------------------------------------------------------</p><p>This was surprising since I already knew about Kaspar Hauser & I even saw&nbsp;the German movie, "The Enigma of Kaspar Hauser", years ago.&nbsp; I've found no evidence of his being able to see the stars by day, though.&nbsp; What they do say is that he had an uncommonly sharp eyesight:</p><p>"At first, he was able to see in the dark perfectly well, and much better than in the light of the sun, which was very painful to him. He very frequently amused himself at others groping in the dark, when he experienced not the slightest difficulty. On one occasion, in the evening, he read the name on a door-plate at the distance of one hundred and eighty paces. This keenness of vision did not, however, retain its entire vigor, but decreased as he became more accustomed to the sun."</p><p>He'd been forced to spend 12 years in his early childhood in a dark cell.&nbsp; Maybe this sharpened his night vision?&nbsp; If sunlight irritated him then it would be unlikely that he could see the stars during the daylight hours, or maybe the story hasn't been told correctly.</p><p>Before getting the message from the Ripley's website I'd written this one:</p><p><span style="font-size:10pt;font-family:Verdana">CrazyEddie: &ldquo;(&hellip;) scattered sunlight (&hellip;) emits over a very broad range of wavelengths. &nbsp;If you filter out those wavelengths, you are also filtering out the very same light that the stars themselves radiate.&rdquo;</span><span style="font-size:10pt;font-family:Verdana">&nbsp;</span></p><p><span style="font-size:10pt;font-family:Verdana">MeteorWayne: &ldquo;You would have to filter all or most of the skyglow while still allowing enough&nbsp;of other frequencies from the stars to pass through.</span><span style="font-size:10pt"><font face="Times New Roman">&rdquo;<span>&nbsp;&nbsp;</span></font></span><span style="font-size:10pt"><font face="Times New Roman">&nbsp;</font></span></p><p><span style="font-size:10pt;font-family:Verdana">MeteorWayne: &ldquo;(&hellip;) the sky glow is not just blue, it is a continuum that peaks at blue but extends throughout the visual spectrum. So you can't just use a narrow band filter to take out a specific blue wavelength, you have to filter most of the visual spectrum to some degree. </span><span style="font-size:10pt;font-family:Verdana">After that, what's left for stars.&rdquo;</span></p><p><span style="font-size:10pt;font-family:Verdana">So you see, CrazyEddie, you&rsquo;ll just have to sit down & read it all to avoid more needless repetitions.<span>&nbsp; </span>Anyway, it was nice of you to atone for your sins & be so encouraging this time, because it looks like we&rsquo;re going up a dead-end street.<span>&nbsp; </span>I urgently need a reply from the Ripley people. I can&rsquo;t go back to my hometown 40 years later (I never went back) & see if they still have the book in the school library.</span></p><p><span style="font-size:10pt;font-family:Verdana">If the story is true then the eyes that could see the stars by day must&rsquo;ve had a substance that would let the beams of starlight go through but not the scattered sunlight, or that would enhance their intensity, & in the latter case the retina is involved.</span></p><p><span style="font-size:10pt;font-family:Verdana">One would have to examine the structures that light goes through before arriving at the back of the eye.<span>&nbsp; </span>It&rsquo;s a set of three: first there&rsquo;s the &ldquo;anterior chamber&rdquo; between the cornea & the lens that is filled with the watery &ldquo;aqueous humor&rdquo;, then comes the lens, &, finally, there&rsquo;s the big space in the center of the eyeball, called the &ldquo;vitreous chamber&rdquo;, filled with a thick gel, the &ldquo;vitreous body&rdquo;.</span></p><p><span style="font-size:10pt;font-family:Verdana">The contrivance, then, might have to be a set of chambers filled with transparent gels & sols, rather than a solid-filter &ldquo;club sandwich&rdquo;, or it might have to be a light-beam enhancer.</span></p><p><span style="font-size:10pt;font-family:Verdana">If the former, this would have to be a task for a biologist.<span>&nbsp; </span>(S)he&rsquo;d have to work with non-human animals if nobody (maybe prison authorities?) is willing to donate eyes for this kind of non-critical research, or if the researcher felt it would be morally objectionable to use human eyes, but would the eyes of other species be adequate in this case?</span></p><p><span style="font-size:10pt;font-family:Verdana">One could use those organic substances to fill the chambers in the DSV, supposing they&rsquo;re inert & need no refrigeration, or, that not being so, that one could add preservers to them.</span></p><p><span style="font-size:10pt;font-family:Verdana">This brings up a question: what do they do with all those millions of eyes in the slaughterhouses?<span>&nbsp; </span>Are they thrown away?<span>&nbsp; </span>All of a sudden one suspects that they&rsquo;re used as offal & they go into wieners, just like the snout, the lips & other revolting refuse they would otherwise have to discard.</span> </p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>
 
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