-
Sound travels almost 3 times as fast in helium gas than in normal air because helium is less dense. Contrary to common perception, helium does not make the voice high-pitched, because voice pitch is determined by the vibration frequency of the vocal chords generating the sound. So, while the fundamental pitch of the voice is actually unchanged, what helium does Read more...
-
An ideal gas is a scientific concept underpinning the Ideal Gas Law, of a theoretical gas with strictly defined properties for the purpose of understanding, predicting, and explaining the behavior of real gases under different conditions of temperature, pressure and volume. In an ideal gas: Molecules are spheres which collide elastically with each other and the container walls, so the Read more...
-
A temperature of minus 40 degrees is the same in both Celsius and Fahrenheit. It is the only temperature point on the F and C scales where this occurs. Read more...
-
The light we see from the sun is made up of a rainbow spectrum of colors from red through blue to violet. As light passes through the Earth’s atmosphere, it hits small gas molecules and particles in the air and gets scattered in different directions. This is known as Rayleigh scattering. As blue light has more energy than, say, red Read more...
-
An ion is an atom or molecule carrying an electrical charge because it has an unequal number of protons and electrons. By convention, protons are considered positively charged, and electrons negative and a net electrical charge results whenever there is more of one than the other. An ion with more protons than electrons carries a net positive charge and is Read more...
-
Most commercial aircraft cabin windows are made of three plastic panes, each separated by a small air gap. The tiny hole at the bottom of the window is a bleed hole through the center pane to equalize the pressure inside the window unit with the cabin air pressure. By design, this ensures it is the outermost window pane bearing the Read more...