in the name of science, i wholeheartedly accept your challenge!
aw…floozy…you’re so open mouthed…er…open minded when it comes to fun things you can do with a girl and spooge.
by the way, i wanna hijack the fuck out of this thread. my favorite euphemisms for “sperm” are “baby batter”, “tadpole yogurt”, “hot man chowder”, and “man ranch”. anyone got more to add to the pot?
All I got to throw in is that scorpians also glow in the dark - bright blue/green. We always take along a blacklight when we’re doing presentations and glow up the scorps.
Hmm…maybe I should be checking the parents instead! 
I’ve had sex under a black light before and I don’t remember my man juice glowing under the light the moment it came out. Old spooge stains show, new wet ones not so much.
Does anyone have access to a black light and a pair of testicles to verify this?
Tonic water. it’s the quinine in it.
Allow me to semi-hijack off onto a tangent about chemistry…
Principally but not exclusively, phosphors are the class of chemical compounds that are responsible for causing matter to glow under black lights (spelled ‘blacklites’ in my OP because that’s how my lamps are labeled). Phosphors do this by absorbing UV light (not seen by naked eye) emitted from a black light and then emitting a sub-violet light (glow that is seen). Despite the name, phosphors do not contain the element phosphorus, which has its own illuminating properties; rather, phosphors are unique transition metal compounds with fluorescent properties. Read more about phosphors on Wikipedia.
Most white paper contains phosphor additives to maximize their whiteness under normal light. Many laundry detergents contain phosphors to brighten clothing. White clothes are so prominent under black light because they reflect the UV light onto the imbedded detergent (from what I understand at least). Darker clothes OTOH absorb most of the light. Glow-in-the-dark objects use phosphors to glow as well.
Although 4 years of studying materials engineering for my undergrad degree has significantly increased my knowledge of chemistry, I am no expert in the chemistry of glowing compounds. Seven is correct that that a fresh squeeze emerging from the love pump has little or no glow under black light. Semen must undergo some drying before the glow is visually evident. It is only speculation on my part that I believe the oxygen in the air reacts with the semen to create phosphor compounds. I searched the Internet for a while and found a number of references to dried semen glowing under black light, but I failed to find any site discussing the chemical compounds in semen that are responsible for the occurrence of glowing. The human body (inclusive of semen) is known to contain trace amounts of several transition metals. If you look at the list of phosphors on the Wikiedia page about them, then you find a number of phosphor compounds containing transition metal atoms and oxygen atoms.
I do not know all the details of the events involving the young lady who I discussed earlier in this thread, but I speculate that she guzzled much of the semen but left a quick drying thin layer on her lips, etc.
Fingernail cuticles and teeth also glow under black light (though not as bright as white paper does), but again I cannot seem the find an internet site that identifies the compound(s) responsible.
Actually, you’re slightly off here. phosphors, in the article you cite, are defined as:
That’s not what things under a “blacklite” do – generally, they’re things that only glow while the blacklite is on them. This isn’t phosphorescence, but fluorescence. They can be studied with a Fluorimeter. I know – I spent several years in grad school doin this, searching for new laser materials.
Does sperm lase?
A 1920s-style sperm ray?
As someone once told me, “Hit anything hard enough and it’ll lase”. Not literally true, but it’s surprising what will. One noted researcher actually wrote a recollection about “edible lasers”.
Not everything that fluoresce will laser under that excitation. The gain for the cavity has to exceed the loss. The expression for the gain coefficient has a product of decay time and bandwidth in it. There are other factors, too, but, in general, broad bandwidth has to be coupled with very short decay times in order to lase (while narroe bandwidth can have longer decay times). Most biological fluorescence tends to be pretty broad, so, unless the decay time is short (which is not often the case), my guess is that it wouldn’t. Of course, if you pump it with, say, and atomic bomb a la Peter Hagelstein, you might get the resulting plasma to lase.
There are easier and much more fun things to do with Precious Bodily Fluids.
I think the OP is jumping to conclusions; plenty of other things fluoresce under UV light and it could be one of these other things that he saw smeared across someone’s chin. Cat urine, for example.
I’ve never been to any such parties, and I’m not even a physicist!
Let me add a couple cites…
As I admitted in post #45, I am not an expert in the chemistry of glowing matter. Rather, my current area of of research involves molecular transport through carbon nanotube membranes.
I do not how much or how correctly the terms ‘phosphorescence’ and ‘fluorescence’ are used interchangeably. This site along with many others contend ‘fluorescent compounds’ are responsible for the black light glow of white paper and laundry detergent. However, this site among others attributes the effect exclusively to ‘phosphors’ in detergent, white paper, and anyting else that glows in black light for that matter.
Cat urine (as well as urine from other mammals) contains fluorescent compound(s). For that matter, anything that glows under black light contains some fluorescent or phosphorescent chemical compounds.
Although the terms are used interchangeably they are quite different. Mainly the difference is in the electron spins during the transition. Fluoresence involves a singlet state, where electron spins are aligned anti-parallel. Phosphoresence refers to a triplet state where the electron spins are aligned in the same direction. Since the change in spin is forbidden during a transition, phosphorescence has a slight “delay” if you will. Things that claim to glow in the dark after being exposed to a bright light are phosphorescent. The state cannot immediately revert to the ground state, so it slowly gives off light (energy). Hence the glow in the dark. Something fluorescent will stop glowing immediately as soon as the energy input is removed.
If you ever have hit a firefly while driving, they glow for 10ish seconds smeared on your windshield. Fireflies phosphoresce so the decay from the excited triplet state to the ground state is slow and not immediate. If they were fluorescent, they’d stop glowing immediately upon impact.
I just want to thank ArchitectChore for starting this thread. Until this week I had not know that semen fluoresced under ultra-violet light. And I just watched the new episode of Drawn Together in which a joke was based on this fact. If not for the SDMB, I wouldn’t have gotten the joke.
