Debut of The Universe

Have you stopped counting dollars and started counting stars (I feel something so right doing the wrong thing… the wrong thing being this joke)? It would be impossible to count all of them, really. In fact, an estimated septillion stars (that gives you 10²⁴ stars… or a 1 followed by 24 zeroes) are said to exist in the observable universe. And no, dear reader, no one knows how large the universe is. Much of the universe has yet to be explored, though we aren’t aware of how much of it still needs exploring.

We know the universe is bigger than we can imagine, but at the beginning of time, it may have been extremely small. The Big Bang Theory is currently the most well-known and widely accepted theory on the beginning of the universe. It tells us that the universe used to be a singularity, an infinitely dense and infinitely hot point in space, and that the universe is now expanding.

Although the Big Bang Theory seems to provide a lot of answers on how the universe came to be, it is only a theory, and scientists do not have a direct way of proving that the Big Bang actually happened. Scientists can only look for traces or side effects of the Big Bang in search of the truth to the origins of the universe.

The Universe is getting fatter

An important piece of evidence supporting the Big Bang Theory lies in a discovery made by Edwin Hubble back in 1929. Hubble observed galaxies, gathering information on their distance from the Earth. He later noticed a red-shift in most galaxies, meaning most galaxies were moving away from us at a rate directly proportional to their distance from us. Put simply, the farther away a galaxy was, the faster it was moving away from us. This came to be known as Hubble’s Law.

We aren’t in the center of the universe, though, because the universe has no center. It isn’t expanding from a single point but it is expanding as a whole equally in all directions. This expansion is usually linked to the expansion of raisin bread in an oven. As the loaf expands, each raisin will “see” the other raisins moving away. Similarly, each galaxy sees the rest of the universe’s galaxies moving farther apart.

The Big Bang didn’t exactly start with a “bang”. Well, not in the way we usually think. The universe did not explode; space-time expanded, and continues to expand to this day (more on this later). So if the universe didn’t come from an explosion, why do we still call the theory the “Big Bang” Theory? Fred Hoyle, an astronomer and supporter of the Steady State Theory, another theory discussing the birth of the universe, thought the Big Bang Theory was bogus. He was the one who actually coined the term “Big Bang”, because the event happened very suddenly, like an explosion.

The Universe is a gigantic microwave

Naturally, to say the universe is expanding implies that the universe was once smaller. As mentioned earlier, the universe used to be extremely small, extremely dense and extremely hot. This was proven thanks to physicists Arno Penzias and Robert Wilson in 1965.

They were testing a microwave detector (we can’t see microwaves because they are shorter than light waves visible to us) when the detector was making more noise than they expected. They found bird poop in their detector, and thought this caused the machine to malfunction, but the detector continued making a lot of noise even after they cleaned it out. The pair eventually learned the radiation they detected, called Cosmic Microwave Background (CMB) radiation, was leftover heat from the Big Bang. This radiation was 2.74 Kelvin (-270.4℃) in temperature. It definitely doesn’t sound hot, but in the world of physics, 0 Kelvin (-273.15℃) is the absence of heat, therefore 2.74 Kelvin is still “hot”.

The Universe was once like a (super)star

One second after the Big Bang, the universe was filled with hydrogen atoms. These atoms then fused with another to form other light elements, such as helium and lithium. This whole process was called the Big Bang nucleosynthesis. A star’s core behaves similarly, producing the same elements formed during the earliest moments of the universe. Astronomers measured the ratios of these elements and discovered how abundant they were around the universe, with hydrogen being the universe’s most abundant element. Their observations matched the predictions of the Big Bang Theory, yet again strengthening its credibility.

The Universe has stretch marks (read: Gravitational waves)

Scientists have more evidence on how the universe got fatter! On March earlier this year, a Harvard team of astrophysicists working in the South Pole detected gravitational waves, ripples in space-time resulting from the Big Bang. Strong gravitational wave signals were found in the CMB radiation mentioned earlier. These gravitational waves pave the way for the theory of cosmic inflation, the rapid expansion of the universe, which is said to have happened about 10^-34 seconds after the Big Bang.

Despite giving us a better insight on how the universe works, the Big Bang Theory leaves us with unanswered questions. What happened before the Big Bang? Was there really a time before the Big Bang? Is our universe the first universe to ever exist, or is it a remnant of a previously existing universe? How can something as huge and dynamic as our universe come from nothing? These questions continue to baffle scientists, who constantly continue to seek out answers until there’s nothing more to ask.

Has your brain exploded yet? Think of it like this: Your brain is its own universe and experienced its own version of the Big Bang. Your brain didn’t explode; it expanded with knowledge!

Sources:

Hawking, Stephen. A Brief History of Time: Updated and Expanded Tenth Anniversary Edition. New York: Bantam Books, 1996. Print

Jones, Andrew. “What is Inflation Theory?” About.com. n.p., n.d. Web.

<http://physics.about.com/od/astronomy/f/InflationTheory.htm>

Jones, Andrew. “What is Inflation Theory?” About.com. n.p., n.d. Web.

<http://physics.about.com/od/astronomy/f/InflationTheory.htm>

McKinnon, Mika. “Incredible Discovery Provides Evidence for the Big Bang Theory.” Space io9.

n.p., n.d. Web. 17 March 2014. < http://space.io9.com/have-physicists-detected-gravitational-waves-yes-1545591865>

Pasachoff, Jay, and Filippenko, Alex. The Cosmos: Astronomy in the New Millenium. Boston: Cengage

Learning, 2007. Print.

White, Martin. “Big Bang Nucleosynthesis.” Astronomy, UC Berkeley. n.p., n.d. Web.

<http://astro.berkeley.edu/~mwhite/darkmatter/bbn.html>

“How Many Stars are there in the Universe?.” European Space Agency. n.p., n.d. Web 
<http://www.esa.int/Our_Activities/Space_Science/Herschel/How_many_stars_are_there_in_the_Universe>.

Article by Andie 

Artwork by Katrina 

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Science has been Andie’s thing since she was four (she once thought the Milky Way was the gateway to heaven). She doesn’t mind being called a geek—because it’s obviously true—and is now a physicist in the making. She believes her puns, jokes and pick-up lines are amazing, even if everyone else around her doesn’t. Andie constantly thirsts for adventure, and is ready to give almost anything a try.

Katrina's biggest life goals include becoming a mermaid, and figuring out how many cupcakes she can eat without gaining weight. You can follow her on Twitter or Instagram at @kkotrono.