Just about everyone has heard of the “Big Bang Theory”. No, I’m not talking about the show (which everyone says I should watch but I’ve never gotten around to). I’m talking about the scientific model that explains the beginning of our universe and how we went from nothing, to everything we see around us.
The Big Bang model postulates that the universe started out as a very dense “singularity”, a point of matter so dense that the laws of physics, as we know them, break down. Using a lot of complicated math, scientist took the laws of physics as far back as they could and determined that the singularity must have existed about 13.8 billion years ago. Now because the laws of physics didn’t really apply then we can’t be 100% sure that what we think happened is what happened. This is just the theory that makes sense right now with every thing we know and observe.
In 1968 and 1970 physicists, including the famous Stephen Hawking, took Einstein’s Theory of Relativity and used it to include measurements of space and time. They and found that, just like matter and energy, space-time was also finite and had a beginning. This means that when people ask “but what was there before the Big Bang?” there is no answer that can be described because there was no “what” or “where”. Everything began with the Big Bang, even time.
Because there was no “what” or “where” the physical laws we need to describe and understand the universe around us were not valid before it’s creation (there was no before) therefore scientist may never know what occurred before the moment the universe came in to being.
At one time scientists were divided about Big Bang Theory but observations have been in favor of the theory and the known physical laws can be used to show that after the “bang” the universe was dense and hot, really, really hot. In the first second after the universe began, the surrounding temperature was about 10 billion degrees Fahrenheit! Particles such as neutrons, electrons and protons formed and decayed or combined as the universe expanded and cooled.
One interesting fact about this early “soup” was that it would have been impossible to look at, light could not penetrate it. It would take another 380,000 years for the creation of neutral atoms that would allow the the light through.
Some other weird stuff happened too but for the most part everything continued to expand and cool and most of the formed particles didn’t survive. What was left was distributed unevenly and began to clump together and would eventually form the galaxies we see now.
This theory has been the dominate model of the creation of the universe but is by no means complete. We still have a lot of questions the most obvious being what was the original cause of the big bang itself. We are getting closer to the answers with the Large Hadron Collider relaunching. In fact, there have been reports that the LHC might disprove The Big Bang Theory completely and that would be very exciting!
I doubt we will ever know exactly how the universe came into existence but I also doubt we will ever be able to stop trying to figure it out either. It is in our nature to pursue these questions. We have to know where we came from.
Image: Butterfly Emerges from Stellar Demise in Planetary Nebula NGC 6302
NGC 6302, also called the Bug Nebula, Butterfly Nebula, is a bipolar planetary nebula in the constellation Scorpius. The structure in the nebula is among the most complex ever observed in planetary nebulae. The spectrum of NGC 6302 shows that its central star is one of the hottest stars in the galaxy, with a surface temperature in excess of 200,000 K, implying that the star from which it formed must have been very large (cf. PG 1159 star).
The central star, a white dwarf, was only recently discovered (Szyszka et al. 2009), using the upgraded Wide Field Camera 3 on board the Hubble Space Telescope. The star has a current mass of around 0.64 solar masses. It is surrounded by a particularly dense equatorial disc composed of gas and dust. This dense disc is postulated to have caused the star’s outflows to form a bipolar structure (Gurzadyan 1997) similar to an hour-glass. This bipolar structure shows many interesting features seen in planetary nebulae such as ionization walls, knots and sharp edges to the lobes.
The Wide Field Camera 3 (WFC3), a new camera aboard NASA’s Hubble Space Telescope, snapped this image of the planetary nebula. WFC3 was installed by NASA astronauts in May 2009, during the servicing mission to upgrade and repair the 19-year-old Hubble telescope.
NGC 6302 lies within our Milky Way galaxy, roughly 3,800 light-years away in the constellation Scorpius. The glowing gas is the star’s outer layers, expelled over about 2,200 years. The “butterfly” stretches for more than two light-years, which is about half the distance from the Sun to the nearest star, Alpha Centauri.
The central star itself cannot be seen, because it is hidden within a doughnut-shaped ring of dust, which appears as a dark band pinching the nebula in the center. The thick dust belt constricts the star’s outflow, creating the classic “bipolar” or hourglass shape displayed by some planetary nebulae.
By NASA, ESA and the Hubble SM4 ERO Team [Public domain], via Wikimedia Commons