CD solar spectroscope?

[robz (Robert)]

Originally Posted by Rob_K

Same here Geoff, because the lights are so much less intense than the Sun. But still shows the emissions OK.



No credit due here Geoff, all down to Robz I reckon. And when it all boils down, all these 'designs' (and probably anything else you could possibly think of!) have been played with for aeons!!

Weakened and tried to get a photograph of the spectrum but it nearly drove me mad! Did get the attached but it just doesn't do the visual view justice, there are so many more fine lines that didn't come out.

Cheers -

Geoff and Rob_K..............it gives me immense satisfaction that you have both achieved to get such great results

CD's CAN show some detail in solar spectra eh?

I hope that students and others following this thread do indeed find some fascination in what they see.
Light is a fantastic gift to the universe..............full of mystery and surprises.

No credit needed Geoff............just glad you got to see the elusive lines in the end

Regards,
Rob.

[Rob_K]

Cheers Rob, and thanks again!

Geoff, something you should take into consideration - any observing of the Sun comes with risks. You should prep your students in the dangers of observing the Sun directly, which can lead to severe eye damage or blindness without suitable solar filters. There'll always be some clown who wants to use the "spectroscope" as a telescope! It's all about safe observing by indirect means (reflection of a tiny portion of the Sun's light and splitting that into an observable spectrum). No doubt you already have that in hand though.

Good luck with it, and I'd love to hear how it all goes!

Cheers -

[robz (Robert)]

Great reminder Rob_K

And to think that Galileo waited for a very low, reddish sun, through haze/cloud before he could view it directly through his telescope.................. ...........what a LEGEND!!!!!!

[GeoffMc (Geoff)]

Hi Guys,

I tried the needle-DVD spectrometer with one of my students this afternoon: it took her about 8 seconds to see the absorption lines for the first time.

I made one more modification to the design. Frustrated by not being able to see lights clearly, I replaced the needle with the tube from an old eyepiece. This gives just as sharp solar absorption features, is significantly easier to use on the Sun since the image is so much brighter and clearer, and it works on lights. It should also work on flame tests.

So, looks like the first leg of my journey into spectroscopy is almost at an end. Thanks guys, you're outstanding teachers and mentors. I've learned so much in the last week or so and will now pass on this design to students who can see Fraunhofer lines for themselves. And you're right, of course, Rob_K: students do do silly things, so it's a matter of weighing the risks and benefits of anything to do with science teaching, particularly in such a litigious society. Still, that's teaching for you. But what if it inspired a good kid to take up science professionally...? Yep, worth the risk.

All the best,

Geoff Mc

[robz (Robert)]

Good luck Geoff.

Rob