Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and causes many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. It can also damage skin and/or give a painful sunburn.
Short-wave ultraviolet light damages DNA and sterilizes surfaces with which it comes into contact. For humans, suntan and sunburn are familiar effects of exposure of the skin to UV light, along with an increased risk of skin cancer. The amount of UV light produced by the Sun means that the Earth would not be able to sustain life on dry land if most of that light were not filtered out by the atmosphere. More energetic, shorter-wavelength "extreme" UV below 121 nm ionizes air so strongly that it is absorbed before it reaches the ground. However, ultraviolet light (specifically, UVB) is also responsible for the formation of vitamin D in most land vertebrates, including humans. The UV spectrum, thus, has effects both beneficial and harmful to life.
The lower wavelength limit of human vision is conventionally taken as 400 nm, so ultraviolet rays are invisible to humans, although some people can perceive light at slightly shorter wavelengths than this. Insects, birds, and some mammals can see near-UV (i.e., slightly shorter wavelengths than what humans can see).
Angela rated this item 5 stars
Wonderful gift to share with Kids.
Hopefully, this is an item whose raison d'etre we never need to exploit. They arrived safely and quickly and seem of high quality. We've only done minimal testing, but so far they seem to work as advertised. Thank you!
Honestly, I haven't really used this for what I purchased it for yet, but if it doesn't work for that, it works well for just an invisible note or whatever. I love it!
These work phenomenally with a UV light, the only thing I would note is that the ink will fade over time if exposed repeatedly to sunlight.
Everything we sell is verified authentic. We only deal with the most reputable collectors, and consult with our trusted network of scientists and experts.
All orders of $50 or more qualify for free shipping in the US.
We accept most cards, PayPal, After Pay, Apple/Google/Meta Pay, and crypto.
Change your mind? No problem. Enjoy easy returns within 30 days.
We toss a random science sticker in every online order