A law of physics that states that light from a point source fall off inversely to the square of the distance. As a example, if a light is 10 feet from your subject and you move it to 20 feet, you'll only have 1/4 the lighting intensity. If you move the light to 40 feet, it will now have only 1/16th the intensity.

This law suggests that the amount of radiation passing through a specific area is inversely proportional to the square of the distance of that area from the energy source. Mathematically, the Inverse Square Law is described by the equation: Intensity = / where is the intensity of the radiation at 1 unit distance and is the distance traveled in those units.

the rate at which radiation flux decreases with distance.

Formula stating that if you double the distance from the light source, the light level goes down by a factor of 4, if you triple the distance, it goes down by a factor of 9, and so on.

Useful when setting up a microphone or speaker, the inverse square law states that, in a free field the intensity of sound drops by 6 dB for each doubling of distance from the source. Now, none of us ever work in a truly free field (no reflective surfaces), but for most applications these numbers are accepted as workable. In real world terms, this means that for each time you double the distance between your sound source and a listener or microphone, the power of the audio drops by 75% - a fairly significant amount! How much is this in terms of volume? Well, it depends on the source you consult, we've seen both 6 dB and 10 dB convincingly listed as doubling or halving the volume (let's just say it's subjective and leave it at that...) - regardless, 6 dB is a very noticeable drop in level! Consider this the next time you place a microphone or speaker: Rather than just cranking up or attenuating the mic preamp or amplifier level for gain control, look at the distance to your source...

Newton's mathematical equation, proving for every given distance traveled from the source, sound levels drop 6 dB.

States that direct sound levels increase (or decrease) by an amount proportional to the square of the change in distance.

The Inverse Square Law defines the relationship between irradiance from a point source and the distance to the measurement surface. It states that the intensity per unit area varies in inverse proportion to the square of the distance between the source and the surface. E = I / d In other words, if you measure 16 W/cm2 at 1 meter, you will measure 4 W/cm2 at 2 meters, and can calculate the irradiance at any other distance. A well defined measurement plane is essential, as is an approximate point source. For a valid 1% approximation of a point source, the ratio of distance to lamp diameter must be greater than 5 : 1.

The relationship between distance and intensity for gamma and X-radiation. The intensity from a point source is inversely proportional to the square of the distance from the source.

Sound levels fall off with distance traveled. Sound level drops off 6 dB from the source point for every doubling of distance.

the intensity of radiation at any distance from a point source varies inversely as the square of that distance. For example: if the radiation exposure is 100 Rem/hr at 1 inch from a source, the exposure will be 0.01 Rem/hr at 100 inches. Ionization the process by which a neutral atom or molecule acquires either a positive or a negative charge.

The law that states that in the absence of reflective surfaces, sound pressure (or light) falls off at a rate inverse to the square of the distance from its source. In other words, every time you double your distance from the sound source, the sound pressure level is reduced by a factor of 4, or 12 dB.

Simply stated, the fact that in an un-obstructed area (like an open field) the sound pressure level will drop to half-pressure (-6 dB) every time the distance to the sound source is doubled.

The energy that is received from a source diminishes with distance in accordance with this law. What it means is that for two identical sources e.g. stars of the same colour and brightness, if one is twice as far away, it will appear four times as faint or if it was three times further away it would be nine times fainter. This law also works with gravity.

The relationship between a intensity of light coming from a source and the distance of the observer from that source. It states that the intensity is inversely proportional to the square of the distance (ie If you are twice as far from a light, it will appear four times as dim).

lighting law which states that light intensity is inversely proportional to the square of the distance from the light source. Iris: the aperture controlling diaphragm.

Force of gravity decreases as the square of the distance increases

The law which states that when radiation (thermal or nuclear) from a point source is emitted uniformly in all directions, the amount received per unit area at any given distance from the source, assuming no absorption, is inversely proportional to the square of that distance.

The relationship that states that electromagnetic radiation intensity is inversely proportional to the square of the distance from a point source.

The equation (E = I / d2) that is used to calculate the illumination at a specified distance from a source of light.

Pertains to any physical condition in which the magnitude of a physical quantity follows an inverse relationship to the square of the distance-- i.e. doubling the distance quarters the quantity in question. Sound pressure waves follow this scheme, and in free field, doubling the distance results in a 6dB decrease.

The physical law that causes light from a flash to fall off in such a way that as flash to subject distance doubles, the light falls off by a factor of four.

A proven statement in physics, repeatable through experimentation. A given physical quantity (as illumination) varies with the distance from the source inversely as the square of the distance. As applicable to flash photography, doubling the flash-to-subject distance reduces the light falling on the subject to one-quarter.

The intensity of radiated energy (such as light energy emitted from a photoelectric sensor, or sound energy emitted from an ultrasonic sensor) falls off by an amount equal to the square of the increase in distance from the source. For example, if the distance from the energy source is doubled, the intensity of the energy decreases to one-fourth of the original strength. Or, if the distance from the source is increased ten-fold, the resultant energy becomes 1/100th of the original strength. The ratio of intensities (I) of emitted energy at distances Da and Db is: Ia/Ib =(Db)2/(Da)2

The law stating that the illuminance at a point on a surface varies directly with the intensity of a point source, and inversely as the square of the distance between the source and the point. If the surface at the point is normal to the direction of the incident light, the law is expressed by fc=cp/d2.

the mathematical relationship of the signal strength and distance, where signal strength is inversely proportional to the square of the distance