Prof.Bożena  Czerny (Center for Theoretical Physics, PAS): Distance measurement in astronomy
Channel: Centrum Fizyki Teoretycznej PAN
Date: 2023-06-07

Prof.Bożena  Czerny (Center for Theoretical Physics, PAS).
Distance measurement in astronomy.
By now we know the geography of the Solar System due to multiple satellites travelling across the space. However, this direct probing does not go beyond the position of Voyager 2, the rest of the knowledge about the Universe relies predominantly on our skills to measure the distances up to the edge of the Universe, as this is the way to establish sizes, masses and luminosities of objects. These skills are on ona hand based on physics, on the other hand the achieved results can be used to test physics in extreme conditions, at extreme distances, and therefore also on time. The argument seems circular, and the standard methods of distance measurements also rely on apparently circular arguments through the form of the distance ladder. Some shortcuts skipping the distance ladder are possible, and my group is working on one of such shortcuts, based on quasars, but such shortcuts are based on physics which must (?), should (?) do (?) apply at large distance scales. So the name of the game is actually self-consistency of the picture of the Universe we built. I will try to present some of these steps, but I will not be able to cover all the loops.

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