Anyone know the history (and safety) of using obsidian to view the Sun?

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Solarscout
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Anyone know the history (and safety) of using obsidian to view the Sun?

Post by Solarscout »

While on tour of Teotihuacan in Mexico, my guide told stories of the importance of obsidian in the region. She took out a polished obsidian plate, stating how people on these days could observe the Sun through it, as we approached the Pyramid of the Sun!

There were vendors selling round obsidian plates and smaller necklaces for souvenirs.
Anyone else know the history of cultures using obsidian as a natural solar filter? And how safe is this method compared to filters today? We now know that other harmful radiation can get through but it didn't seem to affect the ancients



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Re: Anyone know the history (and safety) of using obsidian to view the Sun?

Post by DeepSolar64 »

Hmm..Never heard of this. Fascinating. I'll have to research it.


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Re: Anyone know the history (and safety) of using obsidian to view the Sun?

Post by marktownley »

In terms of safety the only way to do it would be to get it on a spectrograph and measure transmission.


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Re: Anyone know the history (and safety) of using obsidian to view the Sun?

Post by Solarscout »

I bought this obsidian plate at Teotihuacan after seeing the tour guide's demonstration of viewing the Sun through it. But I didn't do many viewings after realizing that solar rays may actually be damaging my retina without any sensation


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Re: Anyone know the history (and safety) of using obsidian to view the Sun?

Post by Solarscout »

https://rubblerockandgem.com/products/obsidian-mirror

It is basically a round disk mirror like this one. Well, are there any natural substances or minerals that are documented and certified safe for direct solar observation?


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Re: Anyone know the history (and safety) of using obsidian to view the Sun?

Post by rsfoto »

Solarscout wrote: Thu May 25, 2023 11:46 pm I bought this obsidian plate at Teotihuacan after seeing the tour guide's demonstration of viewing the Sun through it. But I didn't do many viewings after realizing that solar rays may actually be damaging my retina without any sensation
Hi Solarscout,

I understand your concerns about viewing the Sun but most of the warnings are when using a telescope ...

Also from time to time it happens that you look directly into the Sun by mistake or cusriosity and you cans till see.

Hour after hour your eyes are bombarded with light front different directions containing UV as well as IR radiation and since you were born you can still see, correct? There are a lot of direct reflections of the sun on windows, chromed surfaces which shine into your eye, everytime you walk around on a Sunny day.

So looking through the obsidian which is a dense black volcanic glass IMHO can be done. Also you will not be looking for hours through it in the same way you will not use the special Eclipse viewers.

IMHO

I will try to get a Obsidian mirror and put in on my Spectrograph and compare the spectrum with a non mirrored sprectrum.

How thick is you Obsidian disk ?


regards Rainer

Observatorio Real de 14
San Luis Potosi Mexico

North 22° West 101°
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Re: Anyone know the history (and safety) of using obsidian to view the Sun?

Post by Solarscout »

It is 0.5 cm thick. I read early astronomers used telescopes filtered with smoked glass to look at the Sun which wouldn't meet safety standards today


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