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Question Your World: How Accurate Are Our Measurements of the Universe?

Knowing something is a pretty relative concept. For a long time we knew that the Earth was the center of the universe, later we learned we were wrong about what we once knew. So, accuracy means a lot when we say we know things. Using technology, we've been able to accurately know a lot of things about our natural world. There are still many things big things left to learn about, such as the size of the known universe. How accurate are our measurements of the universe? Find out in this Question Your World radio report produced by the Science Museum of Virginia.

The full knowledge of something is a pretty awesome notion. To have as little room for errors as possible, what a remarkable thought. For example, if you can name all 50 states and at least 49 of their capitals then you know your US geography down to 1% accuracy. That's pretty good. If this was a test you'd do pretty well.

Well similarly there are other areas where knowing something at a level of high accuracy is very important. GPS navigation systems have to be spot on in their spacial assessments to operate at full functionality. The medical side of legal issues needs to be spot on to properly identify the variables involved in making legal decisions. Clearly, there are a lot of places where accuracy becomes very important.

Similarly, a pretty large survey was just concluded and the result is the most accurate assessment to date of something bigger than a GPS system or a court case. The physicists at the Lawrence Berkeley National Laboratory are celebrating their latest announcement, the most accurate data on the size of the known universe. Big stuff. Using a method called Baryonic Acoustic Oscillation the scientists at this lab were able to give us the size of the known universe to a 1% accuracy! This is a remarkable and complex procedure. In order to conduct this survey physicist had to examine the separation of massive amounts of galaxies, observing the oldest and most distant light possible, and factoring the known expansion rate. Once all these factors were collected over decades of compounding research, the big math roll out could begin. Then they were able to understand all the variables and apply them to current expansion rate an answer started to appear. After that work was done they claimed that they results explained the size of the known universe to a 1% accuracy.

So, how big is the known universe? Big! Keep in mind, we have just recently started to be citizens of the cosmos. Our evolution is but a mere blink of the cosmic eye with billions upon billions of years behind us and an unknown amount of time yet to unfold. These discoveries and processes help us better understand what it means to be a part of the universe. When Galileo and the early naturalists started to question the movements of the sun, moon, and planets they set off a chain of events that would one day make it possible for us to understand orbits. A practical application of this knowledge is in front of your eyes right now. These words don't live in your computer, they're being transported to and from space and then redirected to a device that allows you to read this. Understanding gravity and orbital velocity are major pieces in putting a satellite in orbit. Some may think that making a jump from the discovery of a sun-centered solar system is quite different from understanding the size of the universe, but keep in mind it's all about accuracy. The more exact we can be, the more we can establish for our future scientific and technological projects.

We still don't know much about dark energy and dark matter, but this is the most accurate assessment we've been able to pull together thus far. Pretty far out stuff, literally.

Imagine that as a test, naming everything in the universe, it's hard enough to name all fifty states and their capitals!

Article by Prabir Mehta, Science Museum of Virginia

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