The clouds are now thicker. I'd settle for a silver lining at this point.

The SAD (Sunlight Attenuator Device) is now fully operational. I've called Houston and they have given me a "go". (ok - it was really "go home" but let's think positive).

The initial test was on a 60 watt clear light bulb. The inner markings and filament reflection off the glass were easily seen. Then I turned it on....(just kidding).

I still think the Sun will look white because of the irradiance curve is so flat down here. Maybe NASA will take it and give it to an astronaut to see what he sees. Blue-green still has a fightin chance considering the irradiance curve the Sun radiates.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

I am now in Orlando with full sunshine but no S.A.D.! [I''l forego the pun] I did not bring it as I heard the weather was bad. [Not to mention the concern I have for it getting out cf calibration during the flight.]

SAD2 will be complete by tomorrow. The SAD2 strobe disk is an aluminum pie pan and the rotating shaft is a tube from a paper towel roll. The S.A.P. (SAD Activating Person) is prepared to operate.

I hope this does not distract you from your interest in other great events such as our landing on Mars.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

Another update.

Today the sun peeked through and I conducted the normal preliminary tests in my lab (bedroom).

FAILURE. The main drive shaft (and only shaft) to the strobe plate de-coupled! Apparently, Elmer's glue is not suitable for aluminum. I had feard this but did not want you t o worry too much.

I am repairing. Should be ready just after sundown, probably.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

The tension is unbearable! ](*,)

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- There must be a new moon out, she said. He's always bad then.

Hey....your name's not George!

Oh, sorry, Eroica. The solitude of a lonely inventor can be stressful.



Update....di-dt, di-dit, di-dit...

Rain.

However. I did test SAD2 (semi-repaired) on the hotel lamp. I saw darkened bands. After climbing high enough to see the bulb.....sure enough....2 little flourscent bulbs. You sawie it coming too, right?

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

S.A.D. 3 will be electric powered. A hand fan or battery powered drill will drive the strobe plate.

I wanted everyone to know in advance to thwart all the anticipated media questioning of future SAD development. Now that they beat Pres Bush down to spilling everything about Moon and Mars trips, I figured they'd be here next.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

Left SAD 2 behind as the aluminum pie pan would probably look like a land mine to the airport radar security. Hope the Smithsonian will forgive me.

Back in San Antone..

Yeah...Sunlight! And it isn't even Spring.

I was the S.A.P. and the Sun's image was.......WHITE. No surprise.

The hand spinning was non-uniform. I went ahead and upgraded SAD into SAD 3. An old variable speed drill held the pencil shaft nicely. The image was reasonably steady at the higher rpm (up to 1200 rpm).

The slot was about .5 mm wide (1 cm long). It was 7 cm from center of strobe plate. This reduced the net sunlight by almost 99.9%! Still the sunlight was very intense but I could see the disk, barely. (Solar angle above horizion was about 45 deg.)

I did not test it closer to the horizion. But will see how the color compares with the color changes near the horizion tomorrow, hopefully.

Try to get some rest, all. You deserve it.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

Update....di-dit, di-dit, di-dit

Finally got a sunset to watch.

No solar hue variation with SAD3. The sun's setting and changing colors seem to match what was seen through SAD3.

This seems to confirm the conventional wisdom that the color changes of the Sun near the horizon are atmospheric related only and not a due to the eye's color cones thresholds possibly being exceeded [when it looks white].

It also may confirm the Sun's color, as seen on Earth, to be white.

Now we need a SAD4 to go up with an astronaut where the Sun's irradiance is nearly twice as intense in the blue and green range as opposed to down here. Reducing the Sun's intensity might make all the difference.

Any advice? Any astronauts want to be a S.A.P.?

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

=D> Well done, George! A positive contribution to the science of astronomy. Give that man an award!

So, if the sunlight is reduced to about 0.1% of its normal intensity, it looks white - is that your finding?

I don't suppose you could reduce it to, say, 0.01%, or even 0.001%? Baader AstroSolar Safety Film reduces the intensity of sunlight by 99.999%. But it does not reduce it equally across the spectrum - blue wavelengths are attenuated much more than red - so it's not much use to us here.

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- There must be a new moon out, she said. He's always bad then.

This is a serious comment, not a joke.... you should publish this. No thoughts as to where.

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At night the stars put on a show for free (Carole King)

Yes. White. Essentially the hue that you see with a quick and analytical glance of the sun is the same hue of color you would see when the intensity is lowered to 99.9%. It is white during most the day. As the sun looks yellowish near the horizon, so also does the view through SAD3.


I can clearly understand why they have to cut out 99% more than I did...it is still very, very bright even through SAD. So, if you add a mirror for light gathering, it would be imperative to cut it down.

I assumed any kind of filter or even glass might alter "true color" viewing, so, the strobe idea makes more sense as it is "pure" sunlight (albeit atmosphericly bleached).

It was interesting to note that the image was becoming quite weak as the sun neared the horizon due to the amount of reduction through SAD3. I tried SAD on Sirius, as it was high and bright, but it was not visible. The moon was visible through SAD.

The quality of the solar viewing was not clean enough to note detail such as sunspots, although, a future SAD might improve enough to see them. A filter works easier in this case, however.

Thanks much! That comment makes it all worth the "colorful" effort.

The real value of SAD will be whether or not it makes sense to send it up with an astronaut who will take the few minutes to give it a try. This, I presume, would mean convincing someone with pull that the hypothesis makes sense. Specifically, the hypothesis being that the true color of the sun can not be determined until the observer is outside the atmosphere and with the ability to attenuate the solar visible light intensity to a more reasonable level for the human eye.

Since the irradiance of the sun in the blue and green range above the atmosphere is almost twice that as the irradiance below the atmosphere, there is a fair chance that we might have a blueish or greenish or blue-greenish or something other than white star. I think humanity is ready for this super advanced information. It would also be cool to see the BA add it to his future, hopefully, new book.

If you can reword this to make it "more better", let me know.

Any way I can show you the S.A.D. 3? I can easily get a jpg on it but don't know what to do after that as I do not have a working website at this time. Of course, you know what to expect as it is fairly "sad".

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

The SAD3 in space would be nice. However, what if Hubble took a look at the "Sun's Twin" - 18 Scorpii. This star is very close in temperature to the Sun. If it's absorption lines match then it may be another way to get a handle on the Sun's color.

Another possibility, but likely weak in true color accuracy, would be to heat an object close to a blackbody to the Sun's 5700 deg. C temperature. The Sun is not too far off from a blackbody radiation curve in the visible portion. I can't imagine what we would heat-up that would be accurate. I still don't understand the hole in the furnace trick for that matter. It is also possible the Sun's absorption lines would make a difference in the true color afterall.

Therefore, a S.A.D. and a S.A.P. might be the best method afterall.

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

As someone who regularly heats things to 1200 to 1400C, heating something to 5700C would be no easy thing to do.

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At night the stars put on a show for free (Carole King)

We've got a plasma unit that gets close but I do not think it would be worth the effort due to the amount of effort and absorption within the spectrum problems.

It would be nice to hear..."Oh,yeah, we do this all the time and whatever we heat to this looks blue". Not likely, heh?

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

I found an interesting site that shows the Sun's color to be blueish.

This site displays color rendering based on blackbody curves.

I do not know why the "peachy pink" site varys with this result.

Naturally, I favor the blue sun site over the yellow or peachy pink sites. It also uses Fortran which I always liked (except for the careless "do loops").

Since the Sun's spectrum is so strong in blue and green, this analysis makes more sense to me.

It's possible other sites are post atmosphere "bleaching" in their color rendering.

So the quest continues!! 8) \/

Has Hubble, Cassini or others taken any "natural" or "true color" shots of G class stars?


[The report that 18 Scorpii (our supposed solar twin) was yellow-orange did not thrill me. I wonder what evidence they use to make that claim.]

If I listed other G2 stars, would anyone check them out in their scopes???

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.

Or, you could make a different device (you could even use the same materials!), by putting a pinhole in the pie tin (or a piece of paper, cardboard, etc.) and projecting the Sun onto a white surface (but you'd better hope it's an honest white!) like you do for looking at sunspots or eclipses. That would give you variable attenuation too, by changing the distance between the two; you could make it as bright as you can stand to (hopefully) get the best cone response.

-----------------------

Going back a bit, during the sky & cloud color discussion, I was wondering: what about the green color of the clouds you see just before hail and/or tornados? What brings that about? I've found that far odder than the blue sky or a perceived yellow Sun.

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GhiaPet Home Page

I had an idea recently. While the sky's blue colour is due to Rayleigh scattering, shorter-wavelength light is also scattered, as can be seen near sunset and sunrise. However, this very same process is still happening during the day, but since the length of atmosphere traversed is less, the "scattering angle" is similarly less.

The end result of this is that the sky will look yellow, but only very close to the sun, giving us the impression that the sun itself is yellow.

Comments?

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"We do not require reality to conform to the expectations of the ignorant"

This is actually a good idea. I understand that Kodak makes "gray" paper, or some other name, that reflects visible light evenly.

However, this will cost more than the 19 cents allocated for the project. :wink:


I do not know. I have always assumed it was the presence of hail stone which added some sort of refractive factor to give green the advantage. However, I have been in these storms and no sign of hail.

My guess would be that this green cloud condition ocurrs near sunset so much of the blue has already scattered away which makes green the winner when enhanced by the cloud properties. It would be easier to make this claim if the rest of the sky was green.

I am still reading up on scattering and have a long way to go. My 19 cent SAD may be worth more than what I actually know. 8-[

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Lighten up! This is a stellar board! Author: duh.

"The Sun, with all the planets revolving around it, and depending on it, can still ripen a bunch of grapes as though it had nothing else in the universe to do..." Author: Galileo supposedly.