The smallest dinosaurs were just slightly larger than a chicken. Compsognathus is one of the smallest and was about 1 m (3 feet) long and weighed about 2.5 kg.

Beards are the fastest growing hair. If the average man never trimmed his beard, it could grow to 30 feet over the course of his lifetime.

Magnetic resonance imaging, or MRI, is a more recent brain imaging technique that is rapidly gaining widespread use for identifying brain disorders. This technique uses a magnetic field and radio waves, rather than X rays.