Hubble finds Universe expanding faster than believed, scientists baffled

Mindy Sparks
February 24, 2018

Scientists now think that we may need new physics to explain the inconsistency.

While their latest findings, which have been accepted for publication in The Astrophysical Journal, suggest a different measurement for Hubble's Constant that's supposedly more precise because of the instruments they have been using.

The latest discovery using the Hubble telescope showed that the Universe is expanding at a faster rate compared to the expected rate when the expansion was first recorded more than a century ago. Intriguingly, the results are forcing astronomers to consider that they may be seeing evidence of something unexpected at work in the universe. Scientists compare the measured distances to the true and apparent brightness of the supernovae to calculate how fast the universe expands with time. A new physics may be needed, according to the new study.

"The community is really grappling with understanding the meaning of this discrepancy", the lead researcher and Nobel Laureate Adam Riess of the Space Telescope Science Institute (STScI) and Johns Hopkins University, said in a statement. Once the required value is obtained, the telescope observes galaxies along with Type IA Supernovae and the Cepheid stars where the former emits an incredible amount of energy born out of exploding star while the latter has an huge brightness which is used as milepost markers.

Two years ago, astronomers at NASA discovered that the universe is expanding five to nine percent faster than expected. The difference between the two values is about 9 percent. However, the recent studies stipulated a value of 73 km/s/megaparsec.

Another estimate proposed by the European Space Agency's Planck satellite stated the Hubble constant at 67 km/s per megaparsec per 3.3 million years.

"Both results have been tested multiple ways, so barring a series of unrelated mistakes", Riess explained.

Riess outlined a few possible explanations for the mismatch, all related to the 95 percent of the universe that is shrouded in darkness. The universe is huge, it is spread to great distance encompassing all the galaxies, supernovas, nebulas, planets, and other celestial bodies and it is expanding at an exponential rate than earlier estimated. Such speedy particles are collectively called "dark radiation" and include previously-known particles like neutrinos, which are created in nuclear reactions and radioactive decays. These tiny subatomic particles are composed of sterile neutrinos that don't contain any electron, proton or neutron. Lastly, it is also likely that dark matter interacts with radiation much stronger than previously assumed. This value would then be at odds with the number derived from the Hubble observations. The scientists concluded that our Universe is stretching with 2.3% uncertainty.

The recent study by Hubble Telescope took six years to complete and three major steps were taken to measure Hubble Constant to high-precision. Astronomers can not use a tape measure to gauge the distances between galaxies.

The first step is measuring the distance of pulsating stars Cepheid variables in the Milky Way. What they did was measure the how the positions of these stars changed with the Earth's every rotation around the Sun.

All this means that the galaxies are moving around at much higher speeds than previous observation studied were able to calculate. Type Ia supernovae are exploding stars that emit brightness that can be seen from long distances.

Other reports by Iphone Fresh

Discuss This Article