Sustainable means, you know, providing for the future, yet managing to take care of our needs today.

When it comes to growing sustainably, there's so much that goes into that crop each and every year, a lot of sweat, a lot of love and a lot of hardship and a lot of our farmers incorporate practices into their farms that are environmentally and economically sustainable.

Click on the subscribe button and come with me as I set off

to discover the science behind your salad. This is

Scientific American's 60 Second Science.

I'm Christopher Intagliata.

Rome wasn't built in a day,

and neither was the Roman subway system.

Underground work is slow going because construction crews often unearthed mosaics, frescoes,

marble, and a few years ago they found the wooden foundations of a luxurious porch from a Roman villa.

So local archaeologists called in Maro Bernabe of the National Research Council of Italy.

He's a dendrochronologist, someone who analyzes tree rings which give

age and environmental info.

We have to study wood because it's full, really full of information.

Bernoube and his team found that the wooden planks were oak, but the wood's origin was harder to determine.

So they compared the tree rings and the oak planks to those available in libraries of tree

rings that contained timber from all over Europe.

And they found a match for the Roman lumber from the Jura region of eastern France,

more than 600 miles away.

The researchers also determined that the French timber was harvested in about 40 to 60

CE, and some of it came from trees already up to 300 years old when they were felt.

The details are in the journal Pl Plus One. The discovery is the first definitive

...