if we reach there because now we're talking about tens of centimeters of penetration by using safe light now we're talking about potentially whole body human imaging using known as a radiation with rich contrast information so very very exciting I'll touch upon this topic later on and this is ability to time reversal now of course the ultimate limit is the absorption limit if you take all the scattering centers away out of the body you all you have left is absorption right so that's gonna limit your light penetration likely if