[Admin: The following post argues that the inverse square law makes it impossible to see long distances (billions of light years) with a telescope, however is off by several orders of magnitude, primarily because because it neglects the effects of long exposure. See full discussion in the thread that follows this post] ------------------------------------------------------------------------------ How far do you believe the Hubble allows us to see? It's mirror has a surface area of 49,062.5 cm^2 the average human eye has a surface area of 0.38465 cm^2. In comparison with the lens of the eye it has an objective diameter of 357.14 times larger than the human eye. It's surface area is 127,551 times that of the human eye. This means Hubble collects 127,551 times more light than the human eye, so can make objects appear 127,551 times brighter than with the human eye. Now, being the inverse square law of light says that the apparent intensity of the light of a point source is inversely proportional to the square of its distance to the observer. This means that if the distance of a star is doubled its apparent light is reduced four times. If its distance is increased three times its apparent luminosity is reduced nine times. See following link for the inverse square law. http://hyperphysics.phy-astr.gsu.edu/hbase/vision/isql.html Assuming that a star is so far away that it is barely visible to the naked eye, we know that the Hubble telescope can make the star appear 127,551 times brighter. Does this mean that the Hubble telescope enables an observer to see the star if it were 127,551 times farther away? The answer is no. The Inverse Square Law says that the light that we receive from a star is inversely proportional to the square of its distance. According to this law, at that distance, the light of the star becomes 127,551^2 or 16,269,262,700 times dimmer, far too dim for us to see with the telescope. This raises the question: What is the maximum distance an object can be seen through the Hubble telescope? The answer is 357.14 times the distance that the naked eye can see. The reason is that an object 357.14 times farther away, its light becomes 127,551 times dimmer. Since the Hubble telescope can make a star appear 127,551 times brighter, then looking through the telescope the star would be barely visible. Of course this does not take into account long exposures to film or digital media which would increase the distance several times, but not the claimed billions. So would someone taking the inverse square law of light into effect show me how we can see galaxies a claimed 13.7 billion light years away? Remember - magnification spreads out the light received and so does not make a star appear brighter, but actually dimmer. Because this would mean the human eye can see 38,360,306 million light years????? See following link for the furthest object that the human eye can see. http://www.physics.ucla.edu/~huffman/m31.html The very math itself for the inverse square law of light debunks the claim of telescopic distances. But then that is why even professional astronomers will never discuss the inverse square law of light in connection with telescope distances. Every one I have contacted has refused to answer my question without ignoring the inverse square law.