I have posted in this blog about how the chemical and physical characteristics of an element can be dramatically altered by other elements with which it combines. A case in point is sodium chloride (table salt), which is an innocuous chemical. However, as the video from the BackyardScientist below demonstrates, molten sodium chloride can be quite explosive when added to water. However, this reaction seems to be a physical reaction not related to the explosive properties of elemental sodium. It may have to do with the way the water is heated and converted to vapor very fast within the blob of the molten salt as it goes under the surface of the water.
Nowadays if someone questions that smoking is bad for your health they would be met with looks of befuddlement or derision. The cigarette is one of the deadliest products ever to be marketed, causing the death of millions throughout the world and killing nearly half a million people in the United States each year. But we have to remember that the acknowledgement of this fact by our society was the result of a hard fought battle by scientists, health advocates, clinicians, government officials and many others against a massive denialism campaign waged by tobacco companies. So today, as a reminder, I am posting 2 videos.
The first video shows what goes into you when you smoke cigarettes.
The fact that smoking doesn't kill you sooner is a testament to the defense mechanisms and the regenerative properties of our bodies. However, smoking does end up harming most of the people who indulge in this habit, and one of the main sites of its harmful effects are the lungs as shown in the video below.
Most people associate smoking with lung cancer, but smoking also increases the risk of coronary heart disease, stroke, and cancer in other locations besides the lungs. The good news however, is that if you quit smoking, your body can repair much of the damage caused by smoking, and you can live longer and be a healthier person.
Just a reminder.
I Visited the Science Museum of Virginia in Richmond and stopped by one of its main attractions: The Grand Kugel. The Grand Kugel is a 29 ton granite sphere (kugel is the German word for ball) that is seemingly floating on flowing water. The friction between the sphere and its base is so low that you can move the kugel with your bare hands!
The physics of how this is possible has been studied. The kugel doesn't really "float" on the water, rather the water is pumped under pressure from below the kugel producing an upward force that matches the weight of the rock and creates a lubrication effect. In this sense the Kugel behaves like a big ball bearing. Due to the momentum it gains once it is set in motion, the Kugel can go on for hours before stopping.
There is a force called the Coriolis force that affects the flow or air and water in our planet. This force is responsible for the opposite directions in which storms and ocean currents rotate in the northern and southern hemispheres. This happens because as the Earth rotates, air and ocean currents also move with it, and at different latitudes these currents have different speeds due to the earth being round (someone in the equator, for example, is moving faster than someone in the poles). These currents are then deflected sideways when they move to areas of the earth that are rotating at higher or lower speeds. The force is named after the French mathematician Gaspard-Gustave de Coriolis who studied forces in rotating systems.
One of the most repeated pieces of misinformation in the internet is that the Coriolis force can affect the direction in which the water in your toilet rotates. The truth is that the distances water travels in a toilet are so small that the angle of the water rushing into the toilet and the toilet's geometry overwhelm any effects of the Coriolis force. But the effect can be detected in small volumes of water under the right conditions.
Destin from SmarterEveryDay and Dereck from Veritasium teamed up to make twin YouTube videos documenting the Coriolis effect using a kiddie pool of water. The top video was made in the city of Huntsville in Alabama, North America, and the bottom video was made in Sydney, Australia. These two dudes explain their results and the Coriolis force very well, so I will leave it up to them.
One last thing. Destin and Dereck want you to synchronize the videos to play at the same time. You can do that by clicking "start" on both videos and then briefly stopping and starting the one you clicked first to bring it in synch with the second one when the guys flash the numbers on their computers. Enjoy!