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General discussion, chatting and admin contact => Science, research and news in other fields than electronics => Topic started by: Physikfan on November 06, 2017, 08:52:00 PM

Title: Beetle in a Geißler tube
Post by: Physikfan on November 06, 2017, 08:52:00 PM
The two pictures show a beetle in a Geißler tube:
(DC source, 9 kV, cathode top, anode bottom)


(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fgalerie.experimentierkasten-board.de%2Fdata%2Fmedia%2F201%2FP1190850400x751.jpg&hash=35b377083c500c4030503bf872880989)
Exposure normal, with room lighting, fluorescence on the glass wall

(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fgalerie.experimentierkasten-board.de%2Fdata%2Fmedia%2F201%2FP1190851400x815.jpg&hash=310f3ee318867f521968a8cb1ce4b35f)
Exposure 2 f-stops underexposed, room dark, fluorescence on the glass wall

(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fgalerie.experimentierkasten-board.de%2Fdata%2Fmedia%2F201%2FP1190857400x344.jpg&hash=6fcca2d28a973a253a6dd7a7c1352f52)
Exposure 2 f-stops underexposed, room dark
Title: Re: Beetle in a Geißler tube
Post by: Mads Barnkob on November 07, 2017, 10:22:25 AM
Interesting colours on the beetle, I know that some insects have patterns and markings that only show under UV, but the big differences between colours on the beetle here surely suggest that it was doped/contaminated with different materials to make it glow in different colours?

It is a sealed tube right? That glass blower actually put that beetle in-there when making the tube or can you open it up and put samples in, evacuate and fill with gas?
Title: Re: Beetle in a Geißler tube
Post by: Physikfan on November 10, 2017, 08:05:47 AM
Beetle in daylight without discharge:

(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fgalerie.experimentierkasten-board.de%2Fdata%2Fmedia%2F201%2FP1190864400x344.jpg&hash=a65a7a3a00c86060a59c67cffd4c6ffd)
Title: Re: Beetle in a Geißler tube
Post by: Physikfan on November 11, 2017, 07:52:55 PM
Hi Mads Barnkob

"Interesting colours on the beetle, I know that some insects have patterns and markings that only show under UV, but the big differences between colours on the beetle here surely suggest that it was doped/contaminated with different materials to make it glow in different colours?"

The beetle is an artefact, you see the colours of different fluorescent materials.

"It is a sealed tube right?"

Yes, the tube is more than 100 years old.

"can you open it up and put samples in, evacuate and fill with gas?"

No, but I will try to get a tube which can be evacuated and filled with a gas.

Regards

Physikfan
Title: Re: Beetle in a Geißler tube
Post by: Physikfan on November 12, 2017, 04:31:28 PM
Bottom of the beetle in daylight without discharge:

(https://highvoltageforum.net/proxy.php?request=http%3A%2F%2Fgalerie.experimentierkasten-board.de%2Fdata%2Fmedia%2F201%2FP1190869400x290.jpg&hash=966a2a8b804a3e72ce4b38d9a14460b7)
Title: Re: Beetle in a Geißler tube
Post by: futurist on November 19, 2017, 03:59:26 PM
I thought it's a real beetle, now it makes much more sense :)
Title: Re: Beetle in a Geißler tube
Post by: shrad on October 22, 2019, 02:51:27 PM
I have a couple Y2K commemorative lamps with the same kind of fluorescing material with E27 sockets... sad they are not the other form ones like this beetle, but they are nice too

I'll try to make a picture when I have the opportunity to put one out of their box...