physics /oss/taxonomy/term/3871/all en The Uncertainty of What Happened When Heisenberg Met Bohr /oss/article/medical-history/uncertainty-what-happened-when-heisenberg-met-bohr <p>It isn’t often that the subject matter of a play on Broadway is science. “Copenhagen” opened on Broadway in 2000 after a run in London’s West End. Its focus was a 1941 meeting in Bohr’s Copenhagen house between Danish physicist Niels Bohr and his former protégé German physicist Werner Heisenberg. The meeting was an informal one so there is no record of the actual discussion, but when questioned later, the two parties had different memories of the dialogue.</p> Fri, 19 Jan 2024 16:39:11 +0000 Joe Schwarcz PhD 9809 at /oss Squirrels can survive a fall from any height, at least hypothetically /oss/article/did-you-know/squirrels-can-survive-fall-any-height-least-hypothetically <p>Squirrels, in theory, can survive a fall from an object of any height due to two factors: their size and their mass. A force (such as the force of gravity) is calculated by multiplying mass and acceleration. The acceleration due to gravity on Earth is always roughly 9.81 m/s<sup>2</sup>, regardless of what object it is acting on. Squirrels are not very heavy—a grey squirrel only weighs about 0.5 kg—meaning that the force acting on a falling squirrel just isn't that big.</p> <p><em>Force = mass*acceleration = 0.5 kg * 9.81 m/s<sup>2</sup> = 4.9 N</em></p> Fri, 28 Oct 2022 10:00:00 +0000 Ada McVean M.Sc. 9275 at /oss Is it true that Archimedes formulated his famous principle based on an observation he made as he immersed himself in a bath? /oss/article/history/it-true-archimedes-formulated-his-famous-principle-based-observation-he-made-he-immersed-himself <p>Archimedes’ principle states that any object, totally or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object. But. it was not the discovery of the principle named after him that sent the Greek mathematician, physicist and inventor running naked through the street yelling “Eureka,” meaning “I have found it.” What he supposedly found was a solution to a problem posed to him by King Hiero of Syracuse who had suspected that a goldsmith tasked with making him a gold crown had substituted some of the gold with silver.</p> Fri, 04 Mar 2022 20:40:18 +0000 Joe Schwarcz PhD 9042 at /oss Is there a difference between real snow and "artificial snow"? /oss/article/you-asked/there-difference-between-real-snow-and-artificial-snow <p>Snow-making machines actually make tiny beads of ice, each one about one ten-thousandth of an inch in diameter. Water is sprayed from a hose together with compressed air. The air is needed because as it quickly expands, its temperature drops since it has to do work by pushing away air molecules. This cooling helps freeze the water. As the water freezes, it releases heat. This should be obvious when we realize that in order to melt ice, we have to add heat. The heat released is then taken up by the expanding compressed air. This is why the "snow-making" pipes are always high in the air. If t</p> Thu, 17 Feb 2022 15:29:52 +0000 Joe Schwarcz PhD 9027 at /oss Why do curlers sweep? /oss/article/technology-you-asked/why-do-curlers-sweep <p>Just about any subject becomes more interesting with a deeper dive. That is certainly the case for curling, a sport that is a mystery to many and unfortunately often the butt of jokes. However, it is a sport that has a rich history, one that features strategy, athleticism, good sportsmanship, and plenty of science!</p> Fri, 11 Feb 2022 22:17:40 +0000 Joe Schwarcz PhD 9022 at /oss Dragonflies Experience as Much G-Force as Fighter Pilots /oss/article/did-you-know/dragonflies-experience-much-g-force-fighter-pilots <p>Gravity and the human body have a finicky relationship. Too <a href="https://en.wikipedia.org/wiki/Micro-g_environment#Health_effects_of_the_micro-g_environment">little</a> gravity and <a href="https://en.wikipedia.org/wiki/Micro-g_environment#Health_effects_of_the_micro-g_environment">humans</a> <a href="https://en.wikipedia.org/wiki/Micro-g_environment#Health_effects_of_the_micro-g_environment">lose bone density, experience extreme nausea and become anemic.</a> Too much gravity and humans <a href="https://en.wikipedia.org/wiki/G-LOC">lose consciousness and die</a>.</p> Thu, 23 Aug 2018 16:20:02 +0000 Ada McVean B.Sc. 7319 at /oss The Luminescent Chemistry of Lava Lamps /oss/article/did-you-know/luminescent-chemistry-lava-lamps <p><span>If you think back to the 60’s and 70’s your memories are probably illuminated by a lamp filled with swirling globs of colourful goop that really </span><a href="https://www.smithsonianmag.com/arts-culture/the-history-of-the-lava-lamp-21201966/">didn’t shed much light at all</a>.</p> <p><span>Lava lamps were </span><a href="https://patents.google.com/patent/US3570156">invented</a> in 1963 by a British accountant, Edward Craven-Walker, and marketed under the name Astro Lamps. The name might have changed since then, but the chemistry largely hasn’t.</p> Thu, 19 Jul 2018 16:54:28 +0000 Ada McVean B.Sc. 7177 at /oss What the Heck Is the Uncertainty Principle? /oss/article/did-you-know/uncertainty-principle <p>If you've watched the <a href="https://www.youtube.com/watch?v=H-AlfuvjPYM">Big Bang theory</a> or taken some science classes you've probably heard of something called the <a href="https://www.youtube.com/watch?v=9mXJK86GCsI">Uncertainty Principle</a>. This theory, which looks like this in formula form: ΔpΔx = h basically states that we cannot know both the speed and the position of a subatomic molecule. Now, at least to me, that has always sounded a little bit like witchcraft. It just doesn't quite sound real- why can't we know both the position and the speed of a molecule?</p> Sun, 15 Oct 2017 17:09:47 +0000 Ada McVean B.Sc. 5185 at /oss