Fun outside the visible spectrum

[Eternally Noodling]

Using Blue Ghost...

[Eternally Noodling]

How to keep a secret.

[Eternally Noodling]

That's the name of the Noodler's catfish...

Edited February 8, 2007 by Eternally Noodling

[Eternally Noodling]

Firefly and Blue Ghost...to show the flames possible within the "other" spectrum.

 

That's it for now -

 

Next photo...fingers crossed...will be a radio-reactive ink. NOT radio-active...

 

It turns from black to bright green in swirls when using a wireless device near it (such as a mouse or phone)....but turns all green when subjected to radar. The originator of this thread asked me if an ink was possible that would tell him when somebody was checking up on his speed in his car (I think he was joking? yes?). I don't think he knew what that question set off in my mind (I could not sleep as a result). Many experiments and some $ later...and now I just need the camera to behave and capture strange reflections again!

 

3 out of 4 inks never make it to the fountain pen - but many failures are very interesting to a fountain pen nut such as yours truly...

Edited February 8, 2007 by Eternally Noodling

[goldkiwi]

Radio-reactive ink sounds fascinating! I look forward to seeing all your future concoctions!

[Mocksy]

The originator of this thread asked me if an ink was possible that would tell him when somebody was checking up on his speed in his car (I think he was joking? yes?).

Actually, I asked for paint that I could change the color of if I noticed I'd been noticed.

 

Of course I was joking, that is, unless you can do it.

[captnemo]

Has anyone here attempted to illuminate/excite Blue Ghost ink using a UV LED?

 

What were the results?

 

Phil

[a11en]

Working on that... haven't purchased the led's yet- will let you know if I get it done! BTW, you want to look for the super-luminescent LED's, the ones that caution you about using it directly against your eyes- would be my guess... those tend to be the higher power, and have a better wavelength for fluorescence... but I could be wrong...

 

One thing to keep in mind, is that a fluorescent light-bulb with the UV filter is going to emit at a much broader wavelength than a semiconductor p-n junction LED. They will tend to have fairly specific wavelengths. So, it's quite possible to be close, or to slightly illuminate, and waste a good portion of the LED power outside the region of excitation for the fluorophore.

 

Nathan- if you're still reading the thread- can you let us know the range of excitation wavelengths for blue-ghost? That way we can be sure to snag an LED with the best wavelength? [Of course it's quite possible the fluorophore has a range of wavelengths that excite it... so perhaps all UV excites it...] I may have asked you this over e-mail as well... I'm sorry for the repeat question.

 

BTW, love the images, Nathan!!

-Allen

 

ps- I really like the ability to jot down notes in texts and books without adversely marking up the pages... excellent stuff.

pps- I have no idea if I could swing this, but I might be able to do some PL on blue-ghost... that would tell us the wavelengths for sure... [if I have some spare time, I'll ask the laser-lab fellow whether he thinks it might be fun to try it- should be easy at room-T.]

Edited February 8, 2007 by a11en

[captnemo]

One thing to keep in mind, is that a fluorescent light-bulb with the UV filter is going to emit at a much broader wavelength than a semiconductor p-n junction LED.  They will tend to have fairly specific wavelengths.  So, it's quite possible to be close, or to slightly illuminate, and waste a good portion of the LED power outside the region of excitation for the chromophores.

Yes, I am an engineer and quite familiar with the broad spectrum of a UV fluorescent versus the almost monochromatic output of an LED but I didn't want to put people off by getting too technical.

 

That's really why I was asking the question because the ink might only be excited by a particular wavelength that the LED might miss. Hence, an empirical observation from someone would lay the question to rest.

[a11en]

ha ha ha.

 

Yes, this is exactly the trick. I did find a nice source for about 3 different wavelength UV LED's, and my plan has been to buy some... but I just never got around to it.

 

I just fired of an e-mail message to the laser-lab manager and we'll see if we can't run a simple experiment to check for the wavelengths. I'm hoping that he has a tunable UV source... I can't see him not having one. But, he might not want to use it for something this silly. ha ha ha.

 

Perhaps I should entice him with a cheap FP fillled with Blue-Ghost for his own use? I'll let you know if I hear from him, and what he thinks.

 

Cheers!

-Allen

 

ps- it's Fluorophore, not Chromophore in this situation- silly me... [wiki: fluorophore ]

Edited February 8, 2007 by a11en

[captnemo]

  ha ha ha. 

 

Yes, this is exactly the trick.  I did find a nice source for about 3 different wavelength UV LED's, and my plan has been to buy some... but I just never got around to it.

 

I just fired of an e-mail message to the laser-lab manager and we'll see if we can't run a simple experiment to check for the wavelengths.  I'm hoping that he has a tunable UV source... I can't see him not having one.  But, he might not want to use it for something this silly.   ha ha ha. 

Silly? I beg your pardon, sir. This is not silly at all. It would be a practical application for his wowee-zowee tunable UV source! Hmmph!

 

Actually, my guess is that the material in the ink does not have a narrow absorption band but as long as the excitation is above a threshold frequency / energy it will excite and fluoresce. In other words, X-rays would light it up also. I think. Just a guess.

[a11en]

Yes, this is exactly the issue- if we assume that it's similar in nature to a band-gap in a semiconductor, if the energy is too small, it won't excite the fluorphore I believe. since eV land is reverse of nm land, that means we need a shorter wavelength to have higher energy I believe... ugh- I may be failing miserably here.

 

So, if it excites at 365nm, then we can assume anything shorter will have enough energy to excite it. [i sure hope I'm getting this right.]

 

A quick survey of all blue-fluroscent chemicals that I could find easily shows a range of 230-460 for excitation wavelengths. [pretty broad]... but my bet is on a specific one.. it actually shows a very broad excitation spectrum. You can excite it nicely at 355nm I believe. But, this is only a guess as to what is being used.

 

A quick note to Nathan- please know that this is in no way an attempt to reverse engineer your amazing work- it's only to try and determine excitation wavelengths!!

 

Also- a quite note as well- some compounds can react with protein chains etc., and change their emission wavelength- so my little survey can't take into account fluorescent dies that compound with other materials and subsequently change their wavelength. It's quite possible it's one of those as well...

 

Fun digging, however. Learned quite a bit in my little side-track.

 

My hat's off to Nathan for some very awesome inks!

-Allen

 

ps- If the above is true, getting the lower UV led is what you want to do- and that has the highest likelihood of exciting the flurophore- if the fluorophore is the one I happened across, then it will excite with almost any UV light... perhaps a bit more brightly at specifically at 320 or so... but as I mentioned, it's broad- so 355/60 likely excites it nicely.

 

-I'd like to reiterate- I have no clue if the above is right.-

 

Another side track: The Time Fountain

Edited February 8, 2007 by a11en

[Bill]

Has anyone here attempted to illuminate/excite Blue Ghost ink using a UV LED?

 

What were the results?

 

Phil

I just tried Blue Ghost with a small "forensic" light that uses 4 UV LEDs. No reaction at all. Accompanying documentation does not list the frequency range. I will attempt to find out.

 

The reaction was fine with an older BIB 365nm blacklight. I'm not sure of the bandwidth.

 

Two other light units (with ranges up to 590nm-415nm) produced a moderate reaction at 445nm and a stronger reaction at 415nm. The newest model produced the best results with twin filters of 415 and 440nm. Viewed with a cut-off filter the background disappeared nicely but that would be unnecessary for most FP uses.

 

Keep in mind the above units are designed for human body fluids and fluorescent fingerprint powders, not for reading blacklight posters. The best reaction I got last year was with a $5 skin blemish inspection blacklight.

 

It would seem reasonable that a group of LEDs of 365nm or so should work, eh?

 

Bill

[maryannemoll]

this thread has become even more fascinating with the discussion of uv lights. i remember in those old real crime documentaries on the discovery channel, forensic experts swear by a particular chemical named Luminal that, when sprayed on a surface, a particular kind of light can show exactly where human blood used to be, and it shows in the form of a luminous splotch, even under paint. That made me wonder what substance was in our blood that Luminal could render luminous under special lighting. I have forgotten about the more technical discussion there, sadly.

[captnemo]

this thread has become even more fascinating with the discussion of uv lights. i remember in those old real crime documentaries on the discovery channel, forensic experts swear by a particular chemical named Luminal that, when sprayed on a surface, a particular kind of light can show exactly where human blood used to be, and it shows in the form of a luminous splotch, even under paint. That made me wonder what substance was in our blood that Luminal could render luminous under special lighting. I have forgotten about the more technical discussion there, sadly.

Actually there is an aerosol spray product, commonly used by law-enforcement, that turns blue if the slightest trace of blood is present but I forgot what it's called.

[captnemo]

I just tried Blue Ghost with a small "forensic" light that uses 4 UV LEDs.  No reaction at all.  Accompanying documentation does not list the frequency range.  I will attempt to find out.

Hi Bill,

 

Hmm, that's a little disturbing. This implies the ink is somewhat pickier than I expected about the excitation.

 

Not to ask a stupid question, but are you sure the "forensic light" was actually working? :blink:

 

Phil

[a11en]

Well, 400+ is a bit into the violet I think... I can't remember what is considered the cut-off for UV. Interestingly, a dermatology lamp is likely a "Wood's Light" made with Wood's Glass (Wiki-Wood's Glass). The peak is around 365nm, but it also has a very broad spectrum (some down to 320).

 

It's quite possible that the forensic lights (if LED's) are specific to luminol excitation etc.- actually, its' weird, it looks like luminol doesn't require excitation? Does it really glow without light?

 

Anyways... I think this is telling us that we need to be down around 360 if possible... and lower likely will be even better.

 

Very interesting thread, guys!

-Allen

[dwmatteson]

Actually there is an aerosol spray product, commonly used by law-enforcement, that turns blue if the slightest trace of blood is present but I forgot what it's called.

If I recall my "Chemistry and Crime" class from undergrad (about 14 years ago), the blood-sensitive chemical is called Luminol.

 

I don't recall if it turned blue or if it needed to be fluoresced with a UV light, though. Perhaps time to test the Google-fu....

 

Don M.

 

edit: Decided to test the Wikipedia-fu first and found it there. You're right -- mixed with an activating agent, it glows blue for about 30 seconds after making contact with any location that has been bloodied, even if it's been cleaned. Way cool.

Edited February 8, 2007 by dwmatteson

[jd50ae]

Actually there is an aerosol spray product, commonly used by law-enforcement, that turns blue if the slightest trace of blood is present but I forgot what it's called.

If I recall my "Chemistry and Crime" class from undergrad (about 14 years ago), the blood-sensitive chemical is called Luminol.

 

I don't recall if it turned blue or if it needed to be fluoresced with a UV light, though. Perhaps time to test the Google-fu....

 

Don M.

 

edit: Decided to test the Wikipedia-fu first and found it there. You're right -- mixed with an activating agent, it glows blue for about 30 seconds after making contact with any location that has been bloodied, even if it's been cleaned. Way cool.

If you watched CSI you would know these things.

[southpaw]

When someone finds a good light that works well with Blue Ghost, would you please post details, including where you found it? TIA