EPISODE 4
Professor Brian Cox travels to Australia to investigate size and its implications.
A close encounter with a great white shark and the marsupial red kangaroo demonstrate the adaptations needed to sustain a large size, with the laws of nature determining the pressures upon their forms.
At the smaller end of the scale, Queensland's insects appear to defy physics, with the effect of gravity proving negligible on successively smaller forms and electrostatic force allowing them to climb vertical surfaces.
Going even smaller, the almost unfathomably tiny trichogramma wasp has to fight against the relatively viscous air - something more akin to us swimming in water. Even smaller still, thrombolites of Lake Clifton are colonies of bacteria and the tiniest free-living forms of life. Ultimately, the smaller you go, the more the size of atoms and fundamental particles begin to come in to play.
Size also affects your life and the speed in which you live it. Smaller animals have a much faster metabolism, with a faster heart rate and larger relative food consumption. Brian visits Christmas Island and its crab population to explore this, with its larger 1 metre, terrestrial robber crabs living much longer, but relatively slower-paced, lives.