Launched in June of 2001, the Wilkinson Microwave Anisotropy Probe (WMAP) orbits just outside of Earth's orbit around the Sun (in a position called the L2 Sun-Earth Lagrange point, about 1.5 million kilometers [approximately 1 million miles] away from Earth opposite the Sun). This probe is being used to unlock secrets of the universe which we had never imagined.
I've always been a science and mathematics buff — especially when it came to astrophysics and cosmology. I know, that makes me a serious nerd, but I accept that since my interest in these areas seems to be ingrained in my very genetic code and can't be given up or ignored.
So imagine my wonder and awe when I stumbled across the results that have been coming in from a little known satellite NASA launched back in 2001.
To give you an idea of what WMAP has come up with, consider the following factoids.
WMAP has accurately placed the age of the universe at 13.7 billion years old. It's interesting to note that this is not a guess or estimate. The margin for error on the data WMAP has provided is around 1 percent.
WMAP has also determined that the first stars formed much earlier than we had originally theorized. According to the data collected, stars began to form about 200 million years after the big bang.
WMAP has confirmed that the universe is geometrically flat. That's not to say it's only two-dimensional, but it does mean that Euclidian geometry applies over the largest distances in the universe. This negates the theory that space-time is in some way curved (either positively or negatively).
Most interesting of all of the findings from WMAP, the data shows that the composition of the universe is significantly different from what we had imagined.
Matter (anything comprised of atoms, like solids, liquids and gasses) only make up 4% of the universe. That means we (life in general) make up a mere fraction of the universe as a whole — not even enough to blink at in passing.
Cold dark matter makes up approximately 23% of the universe. The findings show that the dark matter, originally thought to be the remnants of burnt-out stars, is more likely not related to normal (baryonic) matter at all but is probably made up of things like neutralinos or axions or other exotic astrophysical or quantum particles which we have yet to identify. It's even possible that this material is formed by weakly interactive massive particles, the cosmological equivalent of exhaust which forms as a result of nuclear reactions.
The final 73% of the universe is made up of something even more exotic called dark energy. The data show that this energy appears to be close to the "cosmological constant" theorized by Albert Einstein. The large amount of this energy in the universe exerts a constant outward pressure on the cosmos resulting in steady expansion. In fact, if more data can be collected, it might be shown that the big bang wasn't a singular event billions of years ago but is instead a steady explosion of the universe as it presses outward, forced to expand eternally by the ever-present pressure of the dark energy.
All of this data combined with other observable cosmological information solidifies the argument that the universe is expanding and that the expansion began a fraction of a second after the big bang. This is called the Inflation Theory — that the universe will expand forever. Given that dark energy makes up about three-quarters of the universe, WMAP data has even provided an estimate on the universe's expansion rate. This number, called the Hubble constant, is 71 kilometers per second per mega-parsec with a margin of error around 5%.
Now I'm sure that all of this seems like gibberish to many, but it's entirely fascinating and extremely exciting to finally have some solid answers to some very old questions. If nothing else, it certainly helps concrete the message that humans really are irrelevant in the scheme of things since we, together with every star, planet, animal, plant, nebula, liquid, gas, solid and other atom-based matter make up only 4% of what is in all practicality an infinitely large universe.