New Hubble Constant Measurement Adds to Universe Expansion Rate

 The Hubble Constant is a unit of measurement used to determine the expansion of the universe. Since the Big Bang, the cosmos has been increasing significantly. Due to the new Hubble Constant measurement, scientists have now estimated the universe to be approximately 13.8 billion years old, NASA revealed in “New Hubble Constant Measurement Adds to Measurement of Universe’s Expansion Rate.” Procured by using NASA’s Hubble Space Telescope, this new measurement may lead to a changed perspective on the universe’s fundamental properties.

X-ray photo by NASA/CXC and optical photo by NASA/STS

NASA stated that scientists announced this new measurement by using the Hubble Telescope to assess the brightness of a red giant star and determined that the universe’s expansion rate is around 70 kilometers per second per megaparsec. Recently, scientists have used the Cosmic Microwave Background, a model based on the structure of light leftover from the Big Bang, to predict how the universe may have evolved into the expansion rate that can be measured today. As defined by the article stated earlier, they calculated a value of 67.4 km/sec/Mpc, in significant disagreement with the rate of 74.0 km/sec/Mpc measured with Cepheid stars. To better explain, the most common use of velocity to measure a galaxy’s speed is km/s; for the distance of a galaxy it is a megaparsec (Mpc); therefore, the unit for The Hubble Constant is km/sec/mpc. The mismatch has prompted astronomers to question whether they truly understand the stars they are measuring and the cosmological models of the universe; improvements may be necessary.

Moreover, alongside the expansion rate, there are other implications. According to NASA, if expansion slows, we can infer there is something within the universe causing the growth rate to slow, possibly dark matter. However, if growth accelerates, it is probable that dark energy is pushing the increase. This new information on physics allows physicists to not only improve future studies but also determine more accurate predictions about Earth, space, and even the universe as a whole. As new research points to a difference between predictions and observations, scientists are considering whether they need to develop a new model to explain the physics of our universe.