One of the pleasures of Scientific American is the way it invites us to journey to the frontiers of knowledge, accompanied by the scientists who are working on the boundaries. In this issue's cover story, “Tiny Plants That Once Ruled the Seas,” researchers Ronald Martin and Antonietta Quigg conjure the idea of stepping into an imaginary time machine, with the dial turned back to 500 million years ago. There we witness the watery ways of early life on the earth, when clamlike creatures and trilobites dominated the seas. We watch as the millennia then unfold before us in subsequent eras, with marine life diversifying with remarkable speed. What was the root cause that enabled the early blooming of species?

In their feature, starting on page 40, Martin and Quigg point to a tiny font for such richness: microscopic phytoplankton. These “modest plants” increased the nutrient content available, which “fueled the rise of the modern marine fauna.”

The quantum realm, where particles can be in two places at once and information seems to travel faster than light speed, also beckons armchair travelers in Hans Christian von Baeyer's article, “Quantum Weirdness? It's All in Your Mind,” beginning on page 46. Von Baeyer takes us on a tour through a new version of quantum theory, which suggests that quantum information may exist only in the mind. At times, it seems that the strangest and most wondrous travels both start from and end in our own internal worlds.

ONLINE: Editors on Video

For the past year Scientific American has offered shows on Space Lab, a channel originated by our partners at YouTube. Now we will supply all of Space Lab's programming on YouTube. Here's what you will find each month. First, the Countdown, a biweekly show hosted by science journalist Sophie Bushwick, brings you the top space news. You can watch It Happened in Space for Amy Shira Teitel's fact-filled historical videos. And in our Ask the Experts, you can have your burning questions answered by the pros.

Want more? Check out our Instant Egghead short videos, which explain everyday science phenomena such as why we get “brain freeze” from cold drinks, the life cycle of a bruise and why chimps are stronger than humans.

Find them all on YouTube and at www.ScientificAmerican.com. —M.D.