Have you ever been to a disco / party where the DJ used a long purple fluorescent tube that made anything white shine in the dark? That was Black-Light i.e. an Ultra-Violet light). Black-lights 'shine' Ultra-Violet light of which there are three kinds; A, B and C. The two most often referred to are B and C. These are the potentially harmful forms of UV, against which you should protect yourself when sunbathing etc.

That depends on you or others in the home. Each of us react differently to moulds. All moulds are allergins. Some moulds have mycotoxins that are harmful. You should consult with a doctor trained in this area. See similar questions...

Black bear "attacks" on humans are both defensive and offensive. Defensive attacks are fairly common, especially in parks, campgrounds, and similar situations where humans and black bears are brought into close contact and bears are habituated or conditioned to humans and human foods. Injuries, typically minor scratches, occur when people crowd, pet, or hand-feed bears and intrude on the animal's personal space. See similar questions...

I have never seen a cockroach glow under black light however other pests in more tropical or desert regions, the scorpions, do glow fluorescently. Scorpions are well known for this behavior. Their generally soft cuticle has fluorescent compounds. There is a famous picture on the cover of Science of a fluorescent scorpion. I once took a walk in the evening desert outside Albuquerque NM with a portable black light. See similar questions...

No, lets rephrase this. The point color (the muzzle, eye rings, belly) is totally separate from the body color. Black body color is recessive whether or not the points are light are dark. Are dark points recessive or dominant? They are recessive to the white points. the white points are dominant, which is why you see them more often. The donkeys with the dark points (termed no light point) have two recessive genes for the dark points. See similar questions...

Black bears undoubtedly evolved as a forest animal and are anatomically and behaviorally adapted to forests. These adaptations convey survival advantage in response to threats of predation on the young. Tree-climbing ability is apparent in cubs when they first emerge from the den and they will quickly climb when a threat appears. The sow need only wait nearby and return after the threat passes, thus protecting both herself and her young without direct confrontation. See similar questions...

Unprovoked attacks on humans by black bears are very rare. Dozens of minor injuries have occurred when people petted or crowded black bears that they were feeding or photographing. Considering their size and strength, black bears show amazing restraint with humans and each other. In the last century, there were only 40 deaths in all of North America that were caused by black bears. See similar questions...

No. A filter ensures than no hazardous Ultraviolet (UV) light reaches the skin. A second filter ensures that the wavelengths which only cause heating of water in the skin are removed. Protective glasses should be used by both the operator and client to reduce the risk of firing the light directly into the eyes. See similar questions...

Without special safety precautions, the laser can be dangerous. However, we ensure patient as well as health care worker safety by: 1. providing safety glasses for everyone in the room; 2. using the lowest effective settings possible; and 3. only allowing the doctor to perform the procedure as per the State Board of Medical Examiners. At the very low energy settings we use to treat spider veins, the danger is minimal. Treatment for vein problems have advanced dramatically over the past 5 years. See similar questions...

It is safer than natural sunlight. Our infrared light and heat has all the benefits of sunlight without the danger of ultra-violet rays. Our infrared light penetrates almost 2” into the body faster then conventional saunas thus implementing health benefits quicker and more beneficially. See similar questions...

Over the life of an incandescent light bulb the filament begins to deteriorate and the particles will settle on the inside of the glass. In return the bulb will take on a grayish appearance and a slight decrease in light output may occur. For fluorescent bulbs only the ends will blacken as the bulb is burned. Each time the lamp is turned on and off the emissions material settles on the inside of the glass. Extreme darkening generally indicates the bulb is about to burn out. See similar questions...

The following colours are UV active (ie. will glow under UV light):- White,Pink,Yellow and Orange. This applies to all product; Beginner, Ultimate performance and the Beaming Poi. See similar questions...

In the case of a black hole, it's best to think of gravity as Albert Einstein described it: a warp in space-time.... More » See similar questions...

Because infrared light has no ultra-violet rays, it is actually as beneficial, but much safer than natural sunlight. It is also more effective than steam because the infrared light penetrates the body so quickly and safely. See similar questions...

Arching light switches can be caused by a number of problems. Have Electricians PLUS check the problem and rectify it if necessary. See similar questions...

There is a patent pending lamp protector installed inside the UV Dental Toothbrush Sanitzier. This lamp protector substantially reduces the amount of UV light leaked out through the holes of UV Dental Toothbrush Sanitizer. The amount of UV light leaked out is not of dangerous level. However, prolonged viewing of the UV lamp through the holes is not recommended as UV light is harmful to our eyes anyway. See similar questions...