Scientists continue to argue about the speed of expansion of the universe, which has become one of the most discussed topics in cosmology. It is known that the universe expands with acceleration, but the causes of this phenomenon remain a mystery. One of the theories is the existence of the so-called “dark energy” – a hypothetical form of energy acting as anti-gravity. However, the nature of dark energy is still not clear, and attempts to measure the rate of expansion lead to conflicting results.
Over the past months, new studies have been published, challenging the previously existing consensus. Disagreements in the expansion speed data, which are called the “tension of Hubble”, have become the central theme of the debate among cosmologists and astrophysicists. The problem is that different measurement methods give different meanings.
One of the methods using the data collected by the Observatory Planck by studying the cosmic microwave – the first light emitted in the universe – shows that the expansion speed is 67.4 kilometers per second for megaparseck. This means that if two galaxies are at the distance of one megaparsec (approximately 3.26 million light years), they will be removed from each other at a speed of 67.4 kilometers per second.
However, measurements using variable stars Cefeid, carried out using the Hubble space telescope, give a different value – 73 kilometers per second for Megaparsk. These discrepancies are doubtful in the standard cosmological model, which suggests that the expansion speed should be the same for both the early universe and for the present.
New observations, such as data from the telescope James Webb (JWST), only complicated the situation. Although the Webb telescope confirmed the results obtained using Ceephoid, the problem of the “double expansion speed” remains unresolved.
Recent research, including the map of the Universe, compiled using the Desi tool, show that the speed of expansion of the universe from 8 to 11 billion years ago consistent with the data