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Welcome to the Science Podcast for March 27, 2015. I'm Suzanne Bard, filling in for Sarah Crespi.

In this week's show, we have David Grimm up first with some online news stories, and then we hear from Kathy Spatz Whidim about intergenerational transmission of child abuse.

And finally, we'll hear from Angela Colmoney about new advances in immunotherapy featured in this week's special issue of science translational medicine.

Support for the science podcast is provided by AAAS, the American Association for the Advancement of Science, advancing science, engineering,

and innovation throughout the world for the benefit of all people.

AAAAS, the Science Society.

Now we have David Grimm, editor for our daily news site.

He's here to talk about some recent online stories.

I'm Suzanne Bard.

Here's a thought experiment for you.

If you dug a hole all the way through the earth and jumped in, how long would it take to fall to

the other side? Well, physicists have actually calculated this hypothetical, and the previous

estimate was a surprisingly paltry 42 minutes and 12 seconds. First of all, Dave, what forces would allow us to move that fast through the Earth?

Well, when we're talking about traveling through the Earth, we're really talking about the forces of gravity.

And what scientists have sort of traditionally assumed is that just for simplicity, the Earth's a lot like a billiard ball,

...