Professor Dave Explains
Proving the Pythagorean Theorem
One easy demonstration that proves the validity of the Pythagorean theorem.
Getty Images
Caudal Regression Syndrome Victim Doug Forbis
*EXCLUSIVE* Doug Forbis, 24, doesn't have legs but that hasn't stopped him being an all-round action man. Doug was born with the severest form of a very rare condition called sacral agenesis or caudal regression syndrome which means his...
Getty Images
Kenny Cunningham Meets President Lyndon B. Johnson
Kenny Cunningham of Colorado Springs, CO sits on President Lyndon B Johnson's desk representing the Cerebral Palsy Association / man helps Cunningham with his canes to get comfortable on desk / President Johnson holds Cunningham's arm...
Getty Images
A researcher places a giant leech on his leg.
A researcher places a giant leech on his leg.
Getty Images
A giant leech crawls on a researcher's leg.
A giant leech crawls on a researcher's leg.
Getty Images
A giant leech crawls along a researcher's leg.
A giant leech crawls along a researcher's leg.
Getty Images
A researcher maneuvers a giant leech on his leg.
A researcher maneuvers a giant leech on his leg.
Getty Images
Small crab spider on the plant stem.
Small crab spider sitting on yellow-green stem of plant. Macro shot.
Getty Images
Ice skating performance
/ female ice skater dancing in the spotlight / penguin on stage with ice skater / skaters dressed up as a dog on the ice rink / clowns dive between the dog's legs / skater in bear costume in tub ship. Ice skating performance on January...
Getty Images
Children enjoying swing ride in comfortable orthopedic shoes, carefree time
Children enjoying swing ride in comfortable orthopedic shoes, carefree time
Getty Images
Mixed race man athlete warming up doing jumping jacks before running or work out
Mixed race man athlete warming up doing jumping jacks before running or work out on stadium. Fitness and healthy lifestyle concept.
Getty Images
Last prisoners leave as Alcatraz closes
Alcatraz closes for good / view of prison from the bay / men getting onto boat / empty cell block and prison guard / inside a prison cell / prisoners exit building in handcuffs and leg irons / prisoners getting onto boat many covering...
Getty Images
Mixed race man athlete warming up doing jumping jacks before running or work out
Mixed race man athlete warming up doing jumping jacks before running or work out on stadium. Fitness and healthy lifestyle concept.
Getty Images
BCU Cat Flea (Ctenocephalides felis) feeding, on human skin, Profile
BCU Cat Flea (Ctenocephalides felis) feeding, on human skin, Profile
Getty Images
BCU Cat Flea (Ctenocephalides felis) feeding, on human skin
BCU Cat Flea (Ctenocephalides felis) feeding, on human skin
Getty Images
Doctor examing patient's leg wound
/ CU of patient's leg with cloth covering wound, doctor removes cloth to see exposed wound, re-covers wound with gauze on January 01, 1955 (Footage by Getty Images)
Getty Images
People working out a YMCA gym
TS feet on stair climber, woman on treadmill, array of tv monitors in front of her, man works on back muscles, young man does pull ups, man does leg pushes
Getty Images
Electrocardiogram
Young man laying on bed, portable electrocardiogram machine in wooden case on adjacent table, doctor enters frame, removes, attaches wires to terminals on patient's arms, legs and chest / doctor operating portable electrocardiogram...
Getty Images
Older elderly asian women
Older elderly asian women patients knee pain sitting on wheelchair
Getty Images
POV of person walking on pedestrian path. Man wearing boots walks forward
POV of person walking on pedestrian path. Man wearing boots walks forward
Getty Images
chicken fast food on fire slow motion background.
chicken fast food on fire slow motion background.
Getty Images
chicken fast food on fire slow motion background.
chicken fast food on fire slow motion background.