How to make florescent ink?

I have Googled and searched Wiki on how to make fluorescent (ultraviolet) inks. I want to know how to make them. I dont want th lemon juice , corn starch, milk or other types of invisible inks. I want to make the stuff the glows under uv light. I searched using uv, ultraviolet, fluorescent inks but couldnt find anything other than the lemon juice and other types of "invisible" writing. Please help if you know where to find or if you know how to make fluorescent (ultraviolet) inks. You can email me at I mean the inks that u can buy for handstampers and that are put in invisible ink markers. I want to make the stuff myself and not have to buy it off the internet.... So while yes there are alot of things that glow under UV, I want it in liquid form.

Posted by WhiteThatch 10 years ago

UV Surface Mount LEDs

I am currently modifying an iBook G3 so that, among other things, it will be fluorescent orange. Currently, when the computer sleeps, a white LED illuminates through the casing. Since the casing will now be fluorescent, I would like to replace the white surface mount LED with an ultraviolet one, so that the case will glow as the computer is sleeping. I was wondering if someone could help me out by telling me where I might be able to purchase an ultraviolet surface mount LED? P.S. The image included will be stenciled and mirrored on each side of the apple on the top of the iBook.

Posted by Ora 10 years ago

UV LEDs for Sanitation

Would UV LEDs be suitable for sanitation purposes? If so, does anyone have information on how many, of what type, and how long exposure is required for different materials? Thanks!

Posted by Weissensteinburg 9 years ago

DIY Tinkerers Making Cool Stuff

This article in the Orlando Sentinel does a nice job of giving an overview of a few people in the DIY community. They even give Instructables a nice mention and then go on to talk about this guy:He has posted more than 50 projects on Instructables, including a sound-activated camera made from a disposable camera and an old computer speaker, and a method for taking ultraviolet photography using a broken black-light bulb.Hmm... who could that be? Link

Posted by fungus amungus 9 years ago

Capturing tiny sparks/flashes of light via video/photo?

Alright, for one of my upcoming Instructables, I need to capture tiny sparks or flashes of light (same thing, just not sure exactly what to call them) on video and take a picture also. I've tried and tried, but no matter how dark the room is, I just can't seem to get it on video. Even if I see it myself, for some reason it doesn't show up on camera. Is it possibly due to the fact that the light I'm trying to capture is ultraviolet light turned into blue light? Thanks!

Posted by Bran 11 years ago

Seeing Auras & Ghosts

I have posted this on other forums without much response. Since some of the best minds use this site, I should get a lively response. Friday, on a TV show called 20/20, they interview some kids that said they see auras and spirits. Do any of you know people who can do that? I have tried to see or photograph auras without success. It seems that these things may be visible either in the ultraviolet or far infrared and require someone with eyes that are more sensitive to these wavelengths. Young kids would be better at that. Infrared and ultraviolet light (UV) are in our environment, even though we can't see it. You would expect that different people would look different under UV, just as they do under visible light. Additionally, some things show fluorescence under UV. Perhaps auras are differing fluorescence by individuals as seen by those with extended visual response. It might be interesting to look at various people under just UV or just infrared (perhaps using night goggles) and note the observations. It would be interesting to have someone view auras through various filters to see how the auras change. Are auras affected by magnetic fields? Would smoke in the air have an effect? Does the aura look better with a dark background? Does getting drunk help? Ghosts are probably more difficult. It is to be expected that God doesn't want us asking them sensitive questions (like "Where's Heaven?"). ~Bob~

Posted by ShutterBugger 8 years ago

Chmistry buffs: IR invisible ink?

Hey all science-type people, I've seen invisible ink pens and things for sale that contain ink that show up in infrared, instead of ultraviolet light.  That's really appealing to me for a number of project ideas because digital cameras pick up IR exteremely well (especially with their filter removed). The problem is I think I'm going to want a lot of it, and those dumb little pens are crazily expensive. So any of you chemistry buffs out there have a secret formula I could make?  I'd prefer something invisible in regular light, but hey, whatever you've got. :) Thanks in advance for your help, -Kurt

Posted by PS118 7 years ago

12-year-old designs advanced 3D solar cell

From Slashdot:12-year-old William Yuan's invention of a highly-efficient, three-dimensional nanotube solar cell for visible and ultraviolet light has won him an award and a $25,000 scholarship from the Davidson Institute for Talent Development. "Current solar cells are flat and can only absorb visible light" Yuan said. 'I came up with an innovative solar cell that absorbs both visible and UV light. My project focused on finding the optimum solar cell to further increase the light absorption and efficiency and design a nanotube for light-electricity conversion efficiency."Much about his young man is eerily similar to many participants here on Instuctables...SlashdotBeaverton Valley Times story

Posted by gmoon 9 years ago

Maxablaster: The homemade 52 million candlepower flashlight.

A homemade 52 million candlepower flashlight. So that's what engineers get up to in their spare time.The article says 38, but apparently Ralf has already upgraded to 52 with his newer setup.The 45-year-old Dutch optics engineer has been building his own lights since he was eight, but his recent 38-million-candlepower creation, the Maxablaster, is more like a miniature star. To start, Ottow stripped out the innards of a powerful commercial flashlight and switched in a mercury arc bulb, which generates light by creating an ultra-hot plasma between two closely spaced electrodes inside the gas-filled central chamber of the lamp. That results in a brighter, more focused beam but also kicks out more ultraviolet light (hence the sunburn, a product of early testing). So he added a specially coated reflector and designed, ground, and coated a new glass window that would trap UV rays while still pumping out light.Powered by a pack of 54 batteries, the Maxablaster can put a bright spot of light on a cloud four miles high and illuminate a house from just as far. But Ottow doesn't use it to spook his neighbors. It's not a torch you'd walk your dog with," he says. "It would probably cook your dog." link

Posted by fungus amungus 10 years ago

Google Celebrates 57 Years of a Great Invention

Google's new picture depicts a barcode saying "Google" to celebrate 57 years of the bar code. For a brief history from Wikipedia about the barcode;"In 1932 business student Wallace Flint of Harvard Business School wrote a thesis promoting an "automated grocery store" using punch cards, which customers would hand to a clerk, who would load them into a reader, causing flow racks to deliver the desired products, after which an itemized bill would automatically be produced. In spite of its promise, punch card systems were expensive, and the country was in the midst of the Great Depression, and the idea was never implemented.In 1948 Bernard Silver (1924 - 1962), a graduate student at Drexel Institute of Technology in Philadelphia, overheard the president of a local food chain asking one of the deans to research a system to automatically read product information during checkout. Silver told his friends Norman Joseph Woodland (1921-?) and Jordin Johanson about the request, and the three started working on a variety of systems. Their first working system used ultraviolet ink, but this proved to fade and was fairly expensive.Convinced that the system was workable with further development, Woodland quit his position at Drexel, moved into his father's apartment in Florida, and continued working on the system. His next inspiration came from Morse code, and he formed his first barcode from sand on the beach when "I just extended the dots and dashes downwards and made narrow lines and wide lines out of them." To read them, he adapted technology from optical soundtracks in movies, using a 500-watt light bulb shining through the paper onto an RCA935 photomultiplier tube (from a movie projector) on the far side. He later decided that the system would work better if it were printed as a circle instead of a line, allowing it to be scanned in any direction.On 20 October 1949 they filed a patent application for "Classifying Apparatus and Method", in which they described both the linear and bullseye printing patterns, as well as the mechanical and electronic systems needed to read the code. The patent was issued on 7 October 1952 as US Patent 2,612,994. In 1951 Woodland and Johanson moved to IBM and continually tried to interest IBM in developing the system. The company eventually commissioned a report on the idea, which concluded that it was both feasible and interesting, but that processing the resulting information would require equipment that was some time off in the future.In 1952 Philco purchased their patent, and then sold it to RCA the same year. In 1962 Silver died in a car accident."Full story about Google's choice of picture here here.

Posted by Kryptonite 8 years ago

HCl obtention from bleach and acetic acid (vinegar).

I have always been curious to know if it is possible to obtain hydrochloric acid (HCl) from chlorine-based bleach and acetic acid (vinegar). I found a lot of answers saying that it was impossible and dangerous because you wouldn't obtain HCl; instead, you would get chlorine gas, which is a very dangerous fume that can cost your life. However, I found an answer saying that it was possible to synthesize it, but not directly from bleach. First, you have to mix equal quantities of bleach and acetic acid to obtain hypochlorous acid (HClO) and then you have to add a transition metal oxide (iron oxide, copper oxide, etc.) to get HCl and oxygen gas.  Filled with curiosity and keeping in mind that safety is the priority, I decided to try it out by mixing equal portions of bleach (NaOCl) and acetic acid (C2H4O2), obtaining an aqueous solution of hypochlorous acid (HClO) and sodium acetate (C2H3NaO2).  NaClO + C2H4O2—> HClO + C2H3NaO2 Then, I added copper oxide (rusty pennies) since I know that copper by itself reacts very slowly with HCl, so I could leave it there until the copper oxide had completely reacted with the HClO (leaving clean pennies).  Little but numerous bubbles started to come out which I thought to be the oxygen gas leaving the hypochlorous acid. I waited there until there were no more bubbles coming out which meant that the reaction had finished. To prove that it was HCl, I decided to add Aluminium foil and see if it reacted accordingly. However, nothing happened, so I tried the whole process of mixing bleach and vinegar again but when I got to the part of adding the metal oxide, I did not add copper oxide. Instead, I left it outside in the sun to react since I know that ultraviolet radiation causes fast disproportionation, forming HCl and oxygen gas.   HClO —> HCl + O2 After all the bubbles had finished coming out, I added Aluminium foil to prove that it was HCl. However, noting happened, and again, I obtained the same product as the last time.  I immediately stated to think of possible products that I could have obtained and the reasons why my reaction hadn't worked properly. It was then when I remembered that in the very first reaction (the one of the vinegar and the bleach) I had obtained a side product that I had completely forgotten about; sodium acetate (C2H3NaO2). And I suspect that this side product could have affected the whole process.  And that is my question; was it really the sodium acetate that one that affected the experiment or could have it been something else?

Posted by Joseluismi 10 months ago

Ionizing vs. non-ionizing radiation, units, and safety (updated)

Note: This was originally intended as a reply in the Americium-241 Science forum topicWhen people talk about "radiation," they are referring to many different things, and are probably thinking of some things that don't even apply. "Radiation," the invisible energy given off by radioactive materials, can be either "subatomic" particles or electromagnetic. The most common particles emitted are "beta rays," high-energy electrons, and "alpha particles," helium nuclei. Some sources can emit neutrons, protons, or "positive beta rays" (anti-electrons, or positrons), but those are much less common.The units we use to measure radioactivity are becquerels (Bq, decays per second) or curies (Ci, 3.7 x 1010 decays per second). Since the effects of radiation depend on their energy, another unit of interest is absorbed dose, the energy deposited per unit mass of target, measured in grays (Gy).Safety experts classify radiation into "ionizing," meaning there is enough energy to knock electrons out of atoms or molecules, and "non-ionizing." Infrared and ultraviolet light are non-ionizing, as are neutrons. Alpha particles (helium nuclei), beta particles (electrons) and gammas (as well as lower energy X-rays) are all ionizing radiation. The three have substantially different effects on biological systems, even at the same absorbed dose. Consequently, for radiation safety purposes, scaling factors are applied to produce numerical measures (sieverts, Sv) of "effective" or "equivalent" dose, that can be compared across different kinds of sources.Here's a small table with information for some commonly encountered sources. Isotope Source Activity Dose rate Am-241 smoke detector 35 kBq (1 µCi) 11 µSv/yr @ 1m Te-99m MRI contrast 740 MBq (20 mCi) 1.6 Sv/hr @ 1cm C-14 atmosphere, body 0.23 Bq 10 µSv/yr K-40 bananas, body 4.4 kBq 200 µSv/yrWhat you should see clearly from this is that the natural radioactivity in your body is comparable or larger than that in a common smoke detector. At SLAC, the limit for exposure to sources at the lab by most staff (including me) is 20 µSv/yr (5 mrem).As I noted above, neutrons are sometimes lumped in with ionizing radiation in non-technical "radiation safety" classes (we call them "the photon is your friend" training :-). That is not really accurate -- neutrons don't interact with electrons(*), and so cannot ionize directly. They can interact with hydrogen nuclei (protons), knocking them out of complex organic molecules, and leave behind ionized fragments and free radicals. The can also be absorbed by otherwise stable nuclei, making them radioactive; those new nuclei may in turn give off ionizing radiation.Neutrons lose energy much more slowly in passing through material, and so can penetrate much farther than ionizing particles or gammas. The nuclear interaction [ cross-section] is much more important here than dE/dx (ionization) energy loss. Materials rich in carbon and hydrogen (for example, paraffin) are far more effective at neutron shielding than dense metals like lead.(* for the expert readers) Yes, there is n-e scattering through W and Z exchange, but the cross-section and energy scales are completely irrelevant to this discussion.

Posted by kelseymh 9 years ago