Showing posts with label Helium. Show all posts
Showing posts with label Helium. Show all posts

Jul 15, 2016

Helium

We usually think of helium as that stuff that goes in balloons, but it is much more. It is formed by the slow and steady radioactive decay of terrestrial rock and is the second most abundant element in the Universe, but very rare on Earth. Helium is used for keeping  satellite instruments cool and to clean out rocket engines. It was also used to cool the liquid oxygen and hydrogen that powered the Apollo space vehicles.

Helium is used as a cooling medium for the Large Hadron Collider  and the superconducting magnets in medical MRI scanners. It is often used to fill party balloons, weather balloons, and airships because of its low density. Helium-neon gas lasers are used to scan barcodes at supermarket checkouts.

A mixture of 80% helium and 20% oxygen is used by deep-sea divers and others working under pressurized conditions.

It also makes for fun differences with our vocal cords. When you inhale helium, you are changing the type of gas molecules in your vocal tract and increasing the speed of the sound of your voice and changing the timbre. Your voice sounds higher pitched. In contrast, heavier gases like xenon and sulfur hexafluoride slow the speed of sound and lower your resonant frequencies.

Aug 21, 2012

Wordology, Aluminum

Aluminum is the older term, while aluminium was created later by the British to make it sound more like the other elements. Here is a timeline:

1808: Sir Humphrey Davy isolates the metal for the first time. He calls it alumium
1812: Sir Humphrey decides to change the spelling of his element: he renames it to aluminum (the term adopted in the United States)
1812: British scientists dislike the new name and change it to aluminium to match the other classic sounding elements, such as Magnesium, Helium, Potassium, etc.

That's my symposium on aluminum. - Incidentally, the Greek symposium was originally a drinking party and forum for men of good family to debate, plot, boast, or simply to revel with others.