“Dreams of Other Worlds”: WMAP #WSW2013

Houston, we have lift off!

All week long for World Space Week, we have been posting exclusive excerpts from Chris Impey and Holly Henry’s new book, Dreams of Other Worlds: The Amazing Story of Unmanned Space Exploration. Each day has included an excerpt from a different chapter(s) about a different unmanned spacecraft, along with a picture of the craft that doubles as an iPhone background!

Today is the last official day of World Space Week, so we’ll be finishing it out with an excerpt from Chapter 12, which talks about the curvature of space and how WMAP has helped us to interpret it.

We hope we took one small step for blogging about space, and one giant leap into a space adventure!

WMAPWMAP has not only put us “in tune” with the cosmos; it has refined and sharpened our view of the extraordinary event that created all matter and energy 13.8 billion years ago.
WMAP has taken quantities that were poorly known or only hinted at and turned them into well-measured cosmological parameters. The temperature is measured to a precision of a thousandth of a degree. Since space can be curved according to general relativity, the universe can act as a gigantic lens. To do this vast optics experiment we look at the microwaves that have been traveling across space for billions of years. The fundamental harmonic of the microwave radiation sets the size of the “spot.” Radiation from that typical spot size travels through space and the angular size can be magnified or de-magnified depending on whether space has positive or negative curvature, which is like the universe acting as either a convex or a concave lens. WMAP has shown that the spot size doesn’t change so the universe is behaving like a smooth sheet of glass. The inference is that space is not curved; the universe is flat to a precision of 1 percent. This is just as expected from inflation.

Think you know all about these missions? Take our quiz and find out!
Proud of your score? Tweet it! #WSW2013

This post is part of a series, explore additional posts hereWorld Space Week Round-Up #WSW2013 >>