The Story of Our
UNIVERSE
In the beginning, the universe was smaller than a grain of sand, an infinite singularity that did not exist in time. Then the singularity began its expansion and in literally no time it went from the size proton to a watermelon. And though there was no sound, the new universe began expanding... in a bang.
Inflation
blem was shrugged off, shelved and labeled the horizon problem.
Then another enigma arose. When one places a wooden beam on a rod, if the beam is even the slightest bit heavier on one side, it will aggressively fall that direction until it falls off the beam (shown right). Curvature works similarly. If the universe is less than 0.4% curved (the flattest we can accurately measure) and the modern laws of gravity were true since the big bang, then to have that curvature now have an original curvature of less than 10-62%. This is as much of a mystery as the horizon problem and someone needed to solve it.
In 1980, physicist Alan H. Guth looked at these problems that so many physicists were ignoring for fear that all the centuries of work were wrong and accepted the challenge. Thus came the theory of inflation.
scared physicists. Could the massively complex standard model be wrong? For years the pro
Ever since the beginning, the universe has been expanding faster than celeritas. This does not break special relativity as the speed of light only acts as a cosmic speed limit for objects moving through space, not space itself moving. However, the energy moving through our universe has never had enough time for one end to reach the other. Earth's particle horizon (the furthest light to reach us) alone is 93 billion light years across but the universe is only 13 billion years old, not nearly enough time for one side of the horizon to interact with the other side of the universe as clearly shown by this aging. Furthermore, the CMB shows us that all of the energy in the universe has almost the exact same temperature and has been since the microwaves were released 13 billion years ago when the universe was only 1/1000 of its current size.For years this puzzled and even
​
​
This theory not only keeps the universe almost precisely flat but also allows the two sides to have the exact same temperatures. There is some evidence of this theory. If inflation is correct, the universe is still expanding and what we can see right now is only a small piece of the whole thing. We can measure its expansion because we can see the photons from other galaxies red-shifting a lot more than valid for how far they tell us they've traveled. There is only one explanation for this. The galaxies are slowly moving away from each other, space is expanding.
So when will protons be the size of the Earth? Actually, if inflation is correct, never. Imagine a big
Big Bang has just happened. It expands for less than a quadrillionth of a second before it comes to a halt and the energies begin mixing around. Everything is causally connected (Both sides have seen each other). Then, blow it up thousands of times the speed of light until it's about the size of an orange 1026 times greater in just 10-32 seconds. In which two sides are not causally connected.
Now normal expansion begins.
bubble with a bunch of smaller bubbles inside. The bigger you blow the bubble, the further the inner bubbles travel until soon they can see each other, but that doesn't mean they're expanding. The only motion is the bubble's size and the movement of the smaller bubbles within the big bubble.
The Cosmic Microwave Background
When big bang sent quintillions of elementary particles into space. One would assume they would immediately bind into atoms, but space was so hot that they stayed a plasma, not letting light through and there by filling the entire universe with a dense, black fog. For 80,000 years, the universe stayed above the critical approx. 3000 degrees K for atoms to form, but when it finally cooled, the trapped gamma rays were released, they began travelling the
The CMB currently
The CMB when first released
cosmos, and though their wavelengths have been stretched into microwaves, they still travel today, making up what's called the Cosmic Microwave Background or CMB. This has become a vital resource for unlocking the secrets of our universe and still dominates our understanding, allowing us to look back to the very first stages of the universe.
Dark Energy and the Expanding Universe
When the universe was born it was all energy. In less than a sextillioth of a second, matter was created. In a quintillionth of a second, the had gone from the size of a proton to that of an orange. Now, our universe still continues to expand. But how far will that expansion go before the negative pressure, the gravitational pull of the amount of stuff inside of something, outways the positive pressure?In the late 1990s, physicists added up the total mass of the universe, matter, energy, and dark matter and by solving the Friedmann Equations, found that the kinetic energy fueling the expansion rate exceeds escape velocity, or the speed needed to escape a particular mass. There is not enough stuff in the universe for it to turn in back in on itself. This should mean that the universe
is inverted like a parabola or it is round like a bubble as shown here. Both of these were very possible, but when a team of astronomers measured the curvature by creating a hypothetical triangle between stars, the sides added up to 180 degrees.
The spatial geometry is completely flat, the expansion exponentially slow to a stop in infinite time. This is totally inconsistent with the left side of the Friedmann Equations which deem that the universe should expand exponentially at a hyperbolic curve with these values. Were Milton Friedman's world renown equations wrong? Actually, it’s just that there's a little something called the cosmological constant that makes the left side align with the right. This constant describes a property of constant density - no matter how much the universe expands. The physics world calls this dark energy. While in an expanding universe, matter and energy that we know so well slowly spreads across the universe until it’s so thin it’s almost negligible.
Meanwhile, dark energy actually grows, filling the empty space. The cosmological constant deems that dark energy actually accelerates expansion, causing the universe to be self-sufficient and dominating. This constant also describes that, at a certain point in time, matter's density will dilute below that of dark energy and this vacuum originating substance will take over expansion entirely.
So when will this happen? The scales just tipped. Currently, about 68% of the universe is made up of dark energy. How is that close? As stated above, the density of matter is slowly decreasing with the amount of dark energy. Which means about 10% of the universe's life ago, or about a billion years, the amount of matter vs dark energy was 50:50. Now, not only the expansion rate is accelerating, but also the dilution rate, in only a few billion years, our universe will be only dark matter. Even worse, about 28% of the 32% of the amount of the universe governed by matter is actually dark matter. If normal energy is growing extinct then in only a couple billion years, the atoms that make us all up will likely cease to exist.
