Interesting Facts
By Jon Therkildsen, MSc MBA from University of Århus (2004)
Oxygen masks on most commercial airplanes are not connected to an oxygen source.
Or compressed air.
The panel above each seat contains an insulated mix of chemicals that, when burned, releases oxygen.
They may include a mixture of barium peroxide (a fine powder used in fireworks), sodium chlorate (a weed killer), and potassium chlorate (reacts violently with sugar).
Therefore it is vital to tug the mask thoroughly (as always instructed in those exciting demonstrations), so the chemical process can start, as this mixture/burning is initiated mechanically by the tug. Once it starts, it cannot be stopped until everything has reacted and has burned out. The supply of oxygen then lasts usually around 15 minutes tops.
This is clever, as each bag is autonomous, and will work even if the rest of the plane is missing. It is also worth noting that the chemical mixture and reaction is technically a burning, meaning it becomes quite hot and dependent on the individual designs, you may feel this heat - or even smell a light burning. But not to worry. It is to be expected (read more).
We do not know why ice-skates can slide on ice.
We understand that friction and mass (pressure form weight) create heat energy causing the ice to melt a tiny bit, so it becomes slippery.
The problem is; the math does not add up.
Friction energy alone is not enough to explain why skates fully work, and the energy from the weight of the skater does not adequately cover the difference. And yet, evidently, ice skates slide. Ice is slippery.
Recently we have discovered that ice always has what seem to be liquid or” loose” water molecules on its surface - even under extremely low temperatures. It, of course, provides a piece of the story to why it is slippery - even for a small guy like Thumper.
The problem is; scientifically ice shouldn’t have liquid ”loose” water molecules on its surface (read more).
Thunderstorms are largely a mystery to science.
Yes, we all know lightning is an electric, magnetic current - a flash or powerful burst of charge that flows within clouds or between a cloud and land. But somewhat unknown - or unappreciated, science still has no complete grasp of how the initial spark can even form and not least generate such potent lightning. It is a mystery; it just doesn't make much physical sense (read more).
More fact or interesting snippets will come…
Photos via Google