Chem discussion

For this discussion, I would like you to take a look at the Wikipedia article titled Orders of magnitude (energy), available at  We discussed this briefly during class. This article is interesting because it gives the energy generated (or consumed) by a wide range of natural and man-made phenomena.  Your goal is to take any two or three of these you find interesting, and show how they put each other in context, i.e., how comparing them allows you to get a better sense of what each of the values mean.

Here’s an couple of examples:

1) The energy to melt 1 g of ice is 3.3 x 10^2 joules.  That’s not very much–we could melt a gram of ice just using the body heat from our hand.  Likewise, adding that much thermal energy to our bodies would be barely noticeable. And yet that’s about the same as the energy in a lethal dose of X-rays.  So it’s striking that an amount of energy that, in the form of heat, seems tiny to us, could actually kill us if delivered in the form of X-rays.

2)  The devastating 2014 Indian Ocean earthquake was the third biggest on record.  In this earthquake, 1,600 km of fault moved by 15 meters. It was so big that it caused the earth as a whole to vibrate by 10 mm! So I would have though that the energy released by this earthquake must be vastly larger than the amount of energy any single human device could release in a short period of time.  I was thus surprised to find that the 50 megaton Tsar Bomba (the largest nuclear device ever detonated) actually released about twice as much energy as the Indian Ocean quake (2.1 x 10^17 J vs 1 x 10^17 J).

You can compare anything you want.  For instance, you might find it interesting that the fuel carried by an Airbus jumbo jet contains about 14x as much energy as the total estimated calories an average human consumes in an 80-year lifetime.  Have fun with this!

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