This one was hard for me to wrap my head around:  so, Earth used to be much smaller than it was. Geochemists at the University of Maryland can tell this from studying Earth’s mantle — the rocky layer between our planet’s metallic core and its outer crust. But back in those wild days of planet formation — that is, ten to twenty million years after the formation of the Solar System — we were getting knocked around quite a bit. And some of those collisions made our planet bigger. At some point back then, researchers posit, Earth smashed into another planet-sized body whirling through space… and thus our bratty little sister orb, the Moon, was born. But despite the many collisions, a part of Earth’s mantle stayed solid, and is part of our planet to this day. Lucky for us it worked out this way:  “Prior to this finding, scientific consensus held that the internal heat of the early Earth, in part generated by a massive impact between the proto-Earth and a planetoid approximately half its size (i.e., the size of Mars), would have led to vigorous mixing and perhaps even complete melting of the Earth.” Complete melting of the Earth! It sounds like an action-adventure movie. But when the UM researchers found volcanic rocks in Russia that were 2.8 billion years old (yep, billion with a b), they found complicated differences in isotopic composition that indicated that Earth’s mantle (or at least part of it) was able to withstand that early battering. In other words, we’ve never had a complete meltdown. Good to know.

Even in our sluggishly-recovering economy, U.S. corporations have money. Approximately $508 billion, in fact — and that’s their excess cash holdings, meaning the money they don’t need for normal operations. And while that may be less than the $2 trillion figure that gets thrown around, it’s still more than three percent of our country’s GDP. “Spending even a fraction of these cash reserves on capital investment could substantially boost economic growth and employment,” says Jeffrey Werling, who heads the University of Maryland’s Inforum Research Center. That doesn’t mean giving each American her share of the excess cash ($1,623 each!). Instead, the UM economists crunched some numbers and found that if that money was spent wisely over the next three years, it could boost the workforce by adding 2.4 million jobs in the next two years — thus reducing the employment rate by 1.5 percent. A nice added effect would be to bump the U.S. GDP up by 1 percent in 2012, 1.5 percent in 2013, and 1.6 percent in 2014. Or corporations could work together to create an “Infrastructure Bank,” which would support investing in infrastructure projects throughout the country. According to the economists’ models, this could boost investment in local, state, and federal structures by as much as $250 billion by 2016 and adding 1.1 million new jobs. How would you spend the money?