Rational Thinker

In 1913, Danish physicist Niels Bohr proposed that electrons orbit atoms in fixed energy levels, where any jump between levels emits or absorbs a photon of light with an energy exactly equal to Planck's constant times its frequency. It was a revolution because it solved two problems. Under the previous model, orbiting electrons would quickly spiral into the nucleus, and also, spectral lines could now be accounted for (at least in light elements). But the model had its limits, and a French aristocrat would ultimately formulate a relation that would both show why Bohr's formula works intuitively, but also would...

By the 1750s, we had a pretty decent understanding of electricity. However, the theory was incomplete. This was demonstrated most precisely when Benjamin Franklin put a cork inside a charged metal can expecting it to be influenced by the can. However, the cork didn't move whatsoever. This confusion sparked a chain reaction of events that ultimately led to Coulomb's law, published in 1785.

Man, this video took me a while to make. It just may be my most ambitious project yet. Hopefully I didn't miss anything too important. If I did or made a mistake, feel free to let me know!

Johannes Kepler had the relative sizes of the orbits of our planets in the solar system mapped by the 1630s. The shape of the solar system had been known relatively well, but it was a shape without scale. Determining the size of the solar system was a much more challenging problem, mainly because there was no known way to make such a measurement. However, that all changed with the development of parallax and taking advantage of an even more fascinating phenomenon: the transit of Venus.

In 1875, French chemist Paul-Émile Lecoq de Boisbaudran discovered the element 'Gallium' after isolating it from a zinc blende ore. However, shortly after his publication, he received word from a Russian chemist with the name of "Mendeleeff" that claimed he had predicted such an element to exist 6 years earlier. This is the story of how that Russian chemist - and a fellow German chemist - turned rival - uncovered the periodic law of the elements and formulated them all into one cohesive unit, transforming chemistry forever.

Before the modern days of organic and inorganic chemistry, there was an old theory called "Vitalism" that had made its way into chemistry. Pioneered into the field by the one and only Jöns Jacob Berzelius, this theory postulated that only living things can create organic compounds through acts of the 'Vital Force.' But cracks in this theory started to form when his pupil, Friedrich Wöhler, synthesized a compound that is found in the most unexpected of places: human urine.

You might think DNA was always the frontrunner by biologists to be the master blueprint of life. However, that couldn't be further from the truth. This video documents how DNA went from experimental backmarker to the frontrunner of a heated scientific race that used betrayal and abuse of power to reveal a winner... and rewrite history.

Helium is a very common element in our universe. However, due to its characteristics, it's very rarely found on Earth. This video shows how scientists in the 19th century overcame this obstacle, over the course of decades, and isolated and discovered the rare gas. Hosted by Simplecast, an AdsWizz company. See https://pcm.adswizz.comfor information about our collection and use of personal data foradvertising.

For over two centuries, Newton’s law of gravity accurately predicted the motions of all the planets in the solar system. But that all changed in 1859, when French astronomer Urbain Le Verrier discovered a strange anomaly regarding mercury’s orbit. This led to a problem in Newton's reality that didn't have an answer until Albert Einstein proposed General Relativity in 1915. Einstein accurately modeled Mercury's orbit with GR, but it wasn't enough for his theory to be accepted as fact. He needed to predict a testable anomaly that had been previously unobserved, and one of his predictions was light bending arou...

In 1895, German physicist Wilhelm Conrad Röntgen discovered a new type of radiation. It was invisible and penetrating to some materials, but not others. He called the radiation "X-rays," and the phenomenon took over the science world. The very next year, a French physicist named Antoine Henri Becquerel, while studying these rays and trying to link them to phosphorescence, accidentally stumbled upon a new phenomenon that would ultimately shape the following century.

The 1920s were an era of intense discovery and progress in the world of physics. Concepts such as matrix mechanics, the Schrödinger model of the atom, the Heisenberg uncertainty principle, and more dominated this era of progress. All of these concepts had a particular trait in common with one another: they showed that probability was the driving force behind reality. Many physicists, most notably among them, Albert Einstein, were not so willing to accept this idea to its fullest. Einstein brought his concerns with him, along with his challenging thought experiments, to the 5th Solvay Conference in 1927, where h...

In the late 19th century, cathode rays were the dominant topic of discussion in the world of physics. Scientists all over the globe were debating over what the nature of those rays were and what that implied for our reality. In 1895, a German physicist by the name of Wilhelm Conrad Röntgen joined this debate, but in his experiments, found something else entirely... something that would change the world forever.

In 600 BC, Greek philosopher Thales of Miletus noticed that the gemstone amber attracted light objects when it was rubbed against a cloth. Unbeknownst to him, he had discovered the phenomenon of static electricity. But how did humanity progress from this knowledge of a certain gemstone to powering machines with batteries? The answer lies in two centuries of innovation starting shortly after the beginning of the scientific revolution. This video doesn't cover everything, but does cover the most important steps during the early era of electricity, starting from William Gilbert and ending with Michael Faraday.Keywords for search: Otto von...

The gravitational constant, or at least what it represents, is a fundamental part of our universe. It represents the strength of gravity and, to our knowledge, remains unchanged throughout space and time. But how did our knowledge of this come about? It all started with the Principia, but Newton did not introduce the constant G. This video takes you through the historical process of discovering G and integrating it into the science landscape.

The first liquefaction of helium in 1908 by Dutch experimental physicist Heike Kamerlingh Onnes was revolutionary. For the first time, scientists could push the boundaries of extremely low temperatures and see what happens to materials. 3 years after that feat, Onnes wanted to test something new: what happens to a metals electrical resistance as you reach those critical temperatures? 3 theories existed before Onnes tackled the problem, one by Lord Kelvin, one by James Dewar, and one by Augustus Matthiessen. However, when it came time to experiment, he collected data that matched none of the 3 existing theories. His discovery shocked the world...

After the discovery of beta radiation by Ernest Rutherford in 1898 and the formulation of the mass-equivalency relation by Einstein in 1905, scientists realized that beta radiation was behaving in an odd way. The expected kinetic energy of the beta particles was less than expected and spread out over a spectrum as opposed to the expected single value. Some thought energy conservation was being violated, but a few scientists thought outside the box and proposed a new elementary particle, the neutrino, that would keep energy conserved and save the physics of beta decay.

Henry Moseley was a British physicist known for his discovery of Moseley's Law, which relates the atomic number to the "characteristic X-ray" of each element. Before Moseley's discovery, the atomic number was merely an arbitrary number given to elements, and was not the way elements were sorted on the periodic table.

The weights of atoms and molecules are quite precise today, but has quite a long and complicated history. This video dives into the very beginning of that history, right when modern atomic theory was beginning to surface. John Dalton is the inventor of relative atomic weight, and his ideas were instrumental in getting atomic theory off the ground and running. Not only does this video cover Dalton's contribution, but also two scientists after him that destroyed his initial theory less than a decade after he published it.

In the 1780s, an Italian physicist named Luigi Galvani made a shocking discovering when experimenting with the remains of frogs. He found that when he touched a the nerves of a frog with a lancet, and at the same time, discharged electricity from an electrostatic machine nearby, the frog legs would kick. This would spark a century-long slew of discoveries and theory that would eventually lead to the discover of the invisible radiation known today as radio waves.

Technetium is quite an interesting element and has just as interesting of a history. Many had tried to discover it and failed, and this is because of how unstable all of its isotopes are. The only way to discover the element was to make it ourselves, and that was finally done in 1937.

In 1887, physicists Albert Michelson and Edward Morley discovered a new phenomenon that would come to be known as the fine structure of spectral lines. These spectral lines split into two or more components, and other effects like the Zeeman and Stark effects also showed cases where spectral lines split. The quest to answer why this happened took almost 40 years and would end with the discovery of a new characteristic of an electron known as "spin".

Ever since the discovery of the proton in 1919 by Ernest Rutherford, scientists had been on a mission to break atoms apart, splitting them into their smaller components in hopes of changing elements into others. This was first successfully done by two of Rutherford's pupils, John Cockcroft and Ernest Walton, in 1932 after their invention of the world's first particle accelerator.

In the 1770s, a revolution in chemistry had just begun, starting in Uppsala, Sweden. A young apothecary named Carl Wilhelm Scheele began a series of experiments that led to the eventual downfall of an entire theory of fire that had dominated chemistry for a century. This theory was known as the theory of phlogiston; phlogiston was an invisible substance that released from materials when they burned and was absorbed by air or other substances. Scheele supported phlogiston from his results, but his went unpublished for five years, leading to another chemist, Joseph Priestley, getting credit for the discovery of...

Absolute zero is the theoretical limit to how cold temperature can reach. The quest to calculate the value of it started in the 1700s, but wasn't accurately done so until the mid 1800s by British physicist William Thomson.