pawan7

Ohh I see. Thanks for all the replies. but my objective is to measure distance using the integration wave of a smart phone such as bluetooth, radio waves and so to calculate the distance between another object which may be hidden under something or behind something, so therefore the light ray idea will not work. Any solution? I think radio waves, infrared, sound, Bluetooth or even Wifi(if there is a ray that exist) is the most suitable?

Ohh okay, So I do want to measure the distance between two objects. The preferable accuracy is a foot or an inch. So the best wave would be sound wave for this accuracy?

So what would be the precision of sound waves used? would it be inches? and would it still work if it is possibly covered by something?

So I want to measure the distance between two objects wirelessly, which should preferably give out the same type of waves to do so. My prediction is that slower the speed of the wave, more accurate we can measure the distance between the transmitting objects. So radio waves or sound waves are much slower than Bluetooth which works at the speed of light? if I'm correct. I'm a complete novice to every form of science, especially physics. So please tell me the most accurate and the most energy efficient way of calculating the distance between two variable objects wirelessly. It does not have to consist of a method of waves. Thank you, Waiting in anticipation