Astronomical error

Measurement of distances in astronomy requires considering optical properties of media through which light propagates. We show that currently adopted method of determining large distances in the Universe systematically overestimates astronomic distances and prevents properties of the intergalactic medium from being discovered. We show that distance measurement errors of the current method increase exponentially with the measured distance and that cosmological conclusions based on distances from high-red-shift supernovae, such as the conclusion that the Universe accelerates its expansion, are likely to be incorrect, because they are based on large systematic and exponentially growing errors. In view of presented findings many astronomic observations may need to be re-interpreted.