Science as we know it!

If all the people of the world had a basic understanding of science......

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Why do onions make me cry!?


Flickr/Darwin Bell

The kitchen is a place for tears. At least for me it is. Some days, if I even look at an onion I end up a bawling mess, with red eyes and mascara covered cheeks. But why? Well the answer sounds scarier than you might think – I have sulfuric acid in my eyes!

Because onions spend their pre-pantry life in the ground, they store sulfur from the soil in their cells to prevent underground pest attacks. When you cut an onion, you break these cells in the onion apart, mixing the stored sulfur (known as ACSO) with an enzyme in another part of the cell called allinase. When these two mix, they create tear-jerking compounds called thiosulfinates. As these thiosulfinates waft up towards your face, they mix with the water in your eyes creating sulfuric acid! Understandably, your eye doesn’t like this much and produces tears (massive amounts of tears if you are anything like me!) to water the acid down and stop the irritation to the eye.

So how do we stop mascara running down our cheeks as we prepare dinner? There are heaps of ideas out there ranging from the scientific to the crazy!

  • Run the onion under water to wash the thiosulfinates down the sink so they don’t reach your eyes.
  • Freeze the onion so the ACSO and the allinase aren’t as volatile.
  • Don’t cut the root end of the onion, because it stores more of the thiosulfinates.
  • Try not to lean directly over the onions so the thiosulfinates don’t waft into your eyes.
  • Put vinegar on your chopping board. This is mean to denature the allinase, stopping the reaction.
  • Breathe through your mouth instead of through your nose, so less of the irritants touch the sensitive mucous membranes in your nose.
  • Hold a tissue (or piece of bread) in your mouth as you cut, so the tissue absorbs the thiosulfinates
  • Have an open flame from a match or candle nearby (no idea how this is meant to work! Maybe the flame is meant to suck the gas away like a vacuum?)
  • Wear goggles or sunglasses while cutting.

But the only surefire method – don’t make dishes with onions!

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A Challenge to Make Science Crystal Clear

At 11, Alan Alda was fascinated by the colorful, translucent undulations of a burning flame.

So he asked his teacher, “What is a flame?”

“It’s oxidation,” she said.

The answer dumbfounded him. A flame is indeed oxidation, a type of chemical reaction that occurs when something burns. But the word did not capture why a flame burns orange or why it produces heat, or anything else that the young Mr. Alda really wanted to know about it.

“It’s just giving it another name,” he said by telephone last week. “It’s like saying, ‘Well, a flame is Fred.’ And that really doesn’t get you anywhere.”

Mr. Alda, now 76, pursued acting rather than science — many people still think of him as Hawkeye Pierce from the television series “M*A*S*H” — but his fascination with the universe persisted.

In the 1990s, he led the collaboration that created “QED,” a play about the brilliant, irascible, bongo-playing physicist Richard Feynman, with Mr. Alda playing Dr. Feynman. Also, for 11 years, he hosted the PBS television show “Scientific American Frontiers.”

(via fyeahchemistry)