Can an infinitely long object fit in an expanding universe?
| Autor: | Aaron Glanville, Tamara M. Davis |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Cosmology and Nongalactic Astrophysics (astro-ph.CO) Inertial frame of reference Age of the universe FOS: Physical sciences Astronomy and Astrophysics Observer (special relativity) Space (mathematics) 01 natural sciences Metric expansion of space Acceleration Classical mechanics Space and Planetary Science 0103 physical sciences Fictitious force 010303 astronomy & astrophysics Astrophysics - Cosmology and Nongalactic Astrophysics Reference frame |
| Zdroj: | Publications of the Astronomical Society of Australia. 37 |
| ISSN: | 1448-6083 1323-3580 |
| DOI: | 10.1017/pasa.2020.25 |
| Popis: | Does space stretch its contents as the universe expands? Usually we say the answer is no - the stretching of space is not like the stretching of a rubber sheet that might drag things with it. In this paper we explore a potential counter example - namely we show that is is impossible to make an arbitrarily long object in an expanding universe, because it is impossible to hold the distant end of the object "stationary" with respect to us (as defined in the Friedmann-Lemaitre-Robertson-Walker metric). We show that this does not mean that expanding space has a force associated with it, rather, some fictitious forces arise due to our choice of reference frame. By choosing our usual time-slice (where all comoving observers agree on the age of the universe), we choose a global frame that does not correspond to the frame of any inertial observer. As a result, simple relativistic velocity transforms generate an apparent acceleration, even where no force exists. This effect is similar to the fictitious forces that arise in describing objects in rotating reference frames, as in the case of the Coriolis effect. 10 Pages, 6 Figures. Minor changes, additional discussion in Sections 2 and 4 |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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