The Big Bang took place approximately 13.8 billion years ago, giving birth to the universe as we know it. Before the explosion, all of the material that currently makes up the entire observable universe, including trillions of galaxies, all fit into a space that measured less than a centimeter across. Now, the observable universe is far larger, measuring 93 billion light-years across, and it is still continuously expanding and shows no signs of stopping.
Ever since humanity started to become interested in the mysteries of the universe, we all have had many questions about the circumstances under which the Big Bang happened, especially regarding what came before it. Although many questions about the universe remain unanswered, scientists do know some things.
Most Groundbreaking Discoveries About The Universe That Scientists Revealed
The Continuous Expansion of the Universe
In 1929, Edwin Hubble made the most groundbreaking astronomical discovery in history: the universe is expanding. Before this, many details about the universe were myths or simply theories. Hubble’s discovery paved the way to help humanity gain a better understanding of the universe’s origins.
To make this discovery, Edwin Hubble measured the shift of red wavelengths of light seen in very distant galaxies. He knew that the farther away the observed object is, the more pronounced the redshift will be. Hubble discovered that red wavelengths increased linearly as he observed galaxies farther away, indicating that the universe is continuously expanding in all directions.
Hubble calculated the rate of expansion, known as the Hubble Constant. Using this value, scientists were able to determine that all of the material in the universe used to be packed into a tiny space. The first moment of expansion was named the Big Bang.
Cosmic Microwave Background (CMB)
In 1964, two researchers from New Jersey were developing a new radio receiver. The antenna they were using kept picking up a strange buzzing, no matter where it was pointed. As it turns out, what their antenna was detecting was cosmic microwave background radiation.
This radiation appeared 380,000 years after the Big Bang when the universe had already cooled down and photons were able to travel freely in space. This discovery helped scientists understand that during the first stages of the formation of the universe as we know it, the expansion rate was faster than the speed of light.
No extra dimensions so far
After scientists discovered the gravitational-wave, they were able to search for additional dimensions. As theorists claim, if other dimensions exist, gravitational waves should be able to cross into them.
A couple of years ago, while observing the collision of two neutrons, scientists detected gravitational waves. They measured how long it took them to travel from the stars to our planet, and they no evidence indicating the existence of an extra dimension was found.
Bo has over six years experience as a teacher, advocate and speaker. He has a B.S. from Cornell University, and a Ph.D. in Human rights from Harvard University Graduate School.