The Carina Nebula: Star Birth in the Extreme
Also known as the Great Nebula in Carina, or NGC 3372, the Carina Nebula is a large, bright nebula that surounds several open clusters of stars - such as Eta Carinae and HD 93129A, two of the most massive and luminous stars in the Milky Way galaxy. Carina is between 6,500 and 10,000 light years from Earth. It appears in the constellation of Carina, and is located in the Carina–Sagittarius Arm.
The Carina Nebula was discovered in 1751-1752 by Nicolas Louis de Lacaille in 1751–52 from the Cape of Good Hope. The nebula is one of the largest diffuse nebulae in our skies. Although it is some four times as large and even brighter than the famous Orion Nebula, the Carina Nebula is much less well known, due to its location far in the Southern Hemisphere.
Floating Water Bridge
Known as the water thread experiment, this phenomenon shown above seems to defy the intuitive laws of everyday physics. The experiment was first demonstrated in 1863 by British Engineer William Armstrong.
Two containers of deionized water, placed in some sort of insulator (glass beakers work fine), must be connected by a thin thread and exposed to a high-voltage charge (one beaker receives the positive charge, and the negative to the other.) At a critical voltage threshold, a water bridge forms between the two containers across the thread - which remains even when the containers are separated!
Typically, the diameter of this bridge is no more than 1-3 mm, but can remain intact as far as an 25mm! The surface temperature, due to the voltage, rises from about 20 °C (68 °F) up to 60 °C(140 °F)! The longest that the phenomenon has lasted is 45 minutes.
Also known as Newton’s balls, the cradle is a device that demonstrated conservation of momentum and energy via a series of swinging, typically metal, spheres. Named after Sir Isaac Newton, the cradle usually consists of a series of identically sized metal balls suspended via a metal frame so that they are just touching while at rest.
The movement of the balls is restricted to the same plane, thus when one is lifted and released, the resulting force travels through the line of balls and pushes the last one upward - ensuring that the energy and momentum are both conserved.
The Physics of Straws
Straws, how complicated can they be? Most people have a few misconceptions about how straws work, but just like everything else - the answer lies with physics.
Upon placing the straw in a regular cup of water, the pressures inside and outside of the straw are equal! You can see this by noticing that the level of the water and in the glass are the same - both reach the same height of the straw.
When you suck on the straw, you are effectively decreasing the pressure in your mouth - and this lowers the pressure at the top of the straw. As soon as this happens, the force of the atmosphere pushing on the water in the glass is higher than the force of the gases inside the straw. Since pressure acts from high to low, the atmosphere forces the liquid water up the straw. In essence, you are not sucking the water into your mouth, but the atmosphere is pushing it!
Explain this to your friends the next time you’re out to eat - then write down a few bogus equations and they’ll think you’re a genius.