How Phosphorescence Works

phosphorescence

Glow in the dark products work because of a chemical additive which allows the product to absorb energy on one frequency, and reemit it as visible light which is a different frequency. Zinc sulphide and strontium aluminate are the most commonly used phosphors for photoluminescent products as they reemit energy over a considerably long period. When light is shone upon a glow in the dark object, incoming photons excite the phosphor molecules and these molecules then release that energy taken in by releasing photons and creating a dim light glow. Different phosphors release energy at different rates and thus, the slower a phosphor releases energy, the longer it will glow. The human eye is most sensitive to green light in the dark which is why night vision technology was traditionally created with a green tint

Chernobyl, Ukraine Nuclear Meltdown

Chernobyl-nuclear-meltdown

In 1986, the world’s worst nuclear accident occurred, when the Chernobyl nuclear reactor within the Ukrainian Soviet Socialist Republic exploded releasing 400x as much radiation as the nuclear weaponry which was dropped upon Hiroshima, Japan in 1945 towards the end of World War II. The most dangerous classification of radiation which can be emitted after a nuclear meltdown or detonation of a nuclear atomic bomb are gamma rays, which like x-rays are made up of high energy photons which can travel long distances. Most gamma rays pass straight through an observer, but not all do and these free particles cause fragmentation of deoxyribonucleic acid and damage at the cellular level which can ultimately lead to cancer and subsequently death

Thermoluminescence Dating of Pottery

pottery

The dating of pottery artifacts can be accurately performed by using a technique referred to as “thermoluminescence”. Thermoluminescence involves taking a small sample of an artifact of pottery and heating it up using doses of high energy radiation which creates excited electron states in crystalline materials like pottery. In some materials, these electron states are trapped or arrested for extended periods of time by a localized defect, or imperfection. In terms of the quantum world, these states are stationary states which have no formal time dependence, however they are not stable energetically and when the material is heated it enables these trapped energy states to interact with photons to rapidly decay into lower energy states, causing the emission of photons in the process. The photons are measured and dependent of how many escape, a specified measurement of the total age can be determined. This technique can be used on most minerals and is the only method available to provide exact dating in respect to pottery as the results yielded do not have to be compared against a comparison artifact. Certain minerals store energy from the sun at a known rate and this energy is lodged in the imperfect lattices of a mineral’s crystals. Heating these crystals when creating pottery empties the stored energy reserves, after which time the mineral begins absorbing energy again. Thermoluminescence dating is a matter of comparing the current energy stored in a crystal to what should be there had not pottery not been heated during the creation process thereby establishing a “last heated during” marker or date