The Heisenberg Uncertainty Principle states that you can never exactly know the exact location and exact speed of an object. This is an important concept in quantum physics. Watch this Chad Orzel Ted-Ed Video to try to grasp the principle!
Video: Chad Orzel, Ted-Ed
Everyone believes that Pavlov rang a bell and his dogs started drooling? Right, well, err, maybe not.
According to “Ivan Pavlov: A Russian Life in Science” (Oxford), a new biography by Daniel P. Todes, a professor of the history of medicine at Johns Hopkins School of Medicine states that Pavlov “never trained a dog to salivate to the sound of a bell,” Todes writes. “Indeed, the iconic bell would have proven totally useless to his real goal, which required precise control over the quality and duration of stimuli (he most frequently employed a metronome, a harmonium, a buzzer, and electric shock).”
Evidently Ivan was not a pleasant person. Todes presents Pavlov as a volatile child, a difficult student, and, frequently, a nasty adult. Even anti-semitic
For instance, he developed a system of “sham” feeding. This involved removing a dog’s esophagus and create an opening in the animal’s throat, so that, no matter how much the dog ate, the food would fall out and never make it to the stomach.
Via: The New Yorker
No wonder they drooled.