6 Mind-Blowing Facts About the Universe

The universe is truly phenomenal in scope, and it exists on a scale that's truly hard to wrap your head around. Even the smartest astrophysicists and cosmologists amongst us still have more questions than answers when it comes to certain aspects of the universe. Still, much is known and a huge amount of progress has been made over the last several decades. Take a look at these 6 mind blowing facts about the universe that you can try to make sense of.

6 Best Facts about the Universe You Don't Know

1. The Big Bang: Most people are familiar with the Big Bang to some extent, but the depth of information know available is mind boggling, taking us back to the tiniest fractions of a second after the Big Bang began (10^-43 seconds). It's important to understand that the Big Bang didn't happen at a place, the Big Bang happened everywhere, causing the tiny "point" that was the universe to explode apart, form particles and matter and then inflate in size. The Big Bang itself is an unexplainable singularity, happening with a universe of zero size and infinite temperature and density, and the cause is unknown.

Now for some mind-boggling numbers to gasp or scratch your head at. Between 10^-43 seconds and 10^-35 seconds, the entire universe expanded to a size 10⁵⁰ times bigger than it was, an unimaginable inflation of 100 trillion trillion trillion trillion times. Within the first 100 seconds of the Big Bang, all of the building blocks for all of the matter in the Universe today were formed.

2. Organization Exists at Every Level: Our solar system is a collection of planets orbiting our sun, stars group together into clusters and the Milky Way is a collection of stars all grouped together by gravity as well. Well, gravity and organization persists at even larger scales as well. Galaxies group together into clusters. The Milky Way is a part of the Local Group, with almost 50 other galaxies. This is a very small galaxy cluster however, for example the relatively close by Virgo Cluster contains 2,500 galaxies.

3. Superclusters and More: Clusters form together into superclusters, which contain tens of thousands of galaxies, with our own being the Local Supercluster. Galaxies and superclusters still show more organization, forming into massive filaments across the universe, with massive voids of empty space in between. For example, the Great Wall is a collection of galaxies spanning 70 Mpc, or mega parsecs. (One Mpc is a million parsecs, and each parsec is 3.26 light years. So a distance of 70 Mpc is well over 225 million light years. For comparison, the Milky Way galaxy is about 30 Kpc across, or about 100,000 light years). The largest structures in the universe are between 200-300 Mpc across.

4. Dark Matter: We cannot see or detect about 90% of the matter across the entire universe, although strides have now been made in "mapping" this matter. This dark matter, so named because it does not emit energy at any wavelength, is still a huge mystery in terms of what it really is. Its presence however is unquestionable, because the interactions on large scales within galaxies, between galaxies and galaxy clusters is impossible with the level of mass that can be accounted for by stars, planets and interstellar dust alone.

5. Dark Energy: Dark energy is the mysterious force that causes repulsion between matter in the universe on the largest scales, leading to the known expansion of the universe. Dark energy is the largest component of the matter/energy in the universe, estimated to account for 73%, with dark matter accounting for 23% and luminous matter such as stars only accounting for 4% of the total!

6. Permanent Expansion or Collapse? The fate of our universe is still up for debate, and possible end results could be a permanent expansion, continuing the expansion we are still going, or eventually collapsing back in on itself. This is basically a function of density of matter and energy within the universe, and is a battle between gravity and dark energy. Gravity of course would bring everything back together, while dark energy as mentioned leads to repulsion. Currently, it is believed that our universe exists at the exact critical density needed to prevent collapse back on itself, creating a basically flat universe that is infinitely expanding.

Source: Chaisson and McMillan, Astronomy Today, Sixth Edition. 2008.