A series of three scientific papers describing the history of the universe’s expansion tell a confusing story, with predictions and measurements slightly inconsistent. (The paper can be accessed here: one, two, three.) This disagreement is not considered a lethal refutation of modern cosmology, but it may suggest that our theory needs to be revised.
Ancient and modern creation stories
Understanding exactly how the world around us came into being Problems that have plagued mankind for thousands of years. People all over the world have invented stories — from the ancient Greek legends of the creation of the earth and other primordial entities from Chaos (first written down by Hesiod), to the Hopi creation myths (a series of different types). (descriptions of the creatures of the created and eventually become human).
Even today, there are competing creation stories, some based on empiricism and the scientific method. The idea is that about 13.8 billion years ago, the universe began in a much smaller, hotter and more compressed state. Expanding ever since. This idea is colloquially known as “big bang,” Various writers use the term to mean slightly different things. Some use it to refer to the exact moment when the universe was born and began to expand, while others use it to refer to every moment since its beginning. , the big bang is still in progress.
The beauty of this scientific explanation is that it can be tested. Astronomers rely on the fact that light has a finite speed. This means that light takes time to traverse the universe. For example, the light we see when the sun is shining was emitted eight minutes before we saw it. It can take billions of years for light from a location to reach us.
telescope as a time machine
Effectively, this means the telescope is a time machine. By looking at increasingly distant galaxies, astronomers can see what the universe looked like in the distant past. We can unravel the evolution of the universe.
Recent measurements use two different telescopes to study the structure of the universe in different space ages.one facility called antarctic telescope (SPT) sees the earliest light possible, emitted just 380,000 years after the universe began. At that time, the universe was 0.003% of its present age. Considering the present-day universe to be the equivalent of a 50-year-old man, SPT sees the universe just 12 hours ago.
The second facility is dark energy research (DES). This is a very powerful telescope on a mountaintop in Chile. Over the years, we’ve explored about one-eighth of the sky and photographed over 300 million galaxies. Many of them are very faint, about one million times less bright than the faintest stars visible to the human eye. This telescope, from now on, allows him to photograph galaxies dating back 8 billion years. Continuing the analogy of the 50-year-old individual, DES can take pictures of the universe from his 21-year-old to the present. (Full disclosure: researchers at Fermilabconducted this study, but I did not participate in the study. )
Light reaching Earth from distant galaxies can be distorted by nearby galaxies. By exploiting these small distortions, astronomers have created highly accurate maps of the distribution of matter in the universe. This map shows stars and galaxies as the best-known regular matter, as well as dark matter, which is a hypothetical form of matter that neither absorbs nor emits light. Dark matter is only observable through its gravitational influence on other objects, and is believed to be five times more abundant than normal matter.
Is the big bang incomplete?
To test the Big Bang, astronomers used measurements made by the Antarctic Telescope and can use theory to predict to the present day. Measurements can then be obtained from dark energy surveys and compared. If the measurements were accurate and the theory explained the universe, they should agree.
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And by and large they do, but not quite. When an astronomer examines, purely from his SPT measurements and extrapolating theory, how “massive” the matter in the present-day universe should be, the predictions are more “massive” than his DES current measurements. You can see that it is lumpy.
This discrepancy is potentially significant and could indicate that the Big Bang theory is incomplete. Moreover, this is not the first time an astronomer has encountered a discrepancy when projecting the same primordial light measurements imaged by his SPT into modern times. Various research groups using various telescopes have found that the present-day universe is expanding faster than expected, from observations of ancient light seen by his SPT in combination with the Big Bang theory. Other discrepancies are Hubble tensionis named after American astronomer Edwin Hubble, who first discovered that the universe was expanding.
The new discrepancy between predictions and measurements of the massiveness of the universe is tentative, but both this measurement and the Hubble tension suggest that the Big Bang theory may need tweaking. There is a nature. Be careful, the contradiction does not go to the level of destroying the theory entirely. However, it is the nature of the scientific method to adjust the theory to explain new observations.