1. For those who appreciate unspoilt nature, quarries are not places of beauty. They are scars on the landscape, seemingly at odds with the natural world. It can be hard to accept this as you watch the mechanical arm of a digger pushing into the rock face, destroying it like a child stomping on a sandcastle. But these sites of destruction are also the sources of construction - not just of buildings, but of knowledge. To find fossils we need exposures of fossil-bearing rock, and such faces are surprisingly sparse. Where the right sedimentary stones do come to the surface they are mostly coated in a thick layer of foliage. The Earth herself is like a giant green mammal, full of life. It is often only when our industry drives us to dig into her flesh that we find the secret bones of lost worlds are in there, under the skin. Without digging, we would know almost nothing about her—or our — history.

2. At relatively early periods of post-learning (say, minutes to hours to days), retrieval systems allow us to reproduce a fairly specific and detailed account of a given memory. This might be likened to the library model. But as time goes by, we switch to a style more reminiscent of the Sherlock Holmes model. The reason is that the passage of time inexorably leads to a weakening of events and facts that were once clear and chock-full of specifics. In an attempt to fill in missing gaps, the brain is forced to rely on partial fragments. inferences, outright guesswork, and often (most disturbingly) other memories not related to the actual event. It is truly reconstructive in nature, much like a detective with a slippery imagination. This is all in the service of creating a coherent story, which, reality notwithstanding, brains like to do. So, over time, the brain's many retrieval systems seem to undergo a gradual switch from specific and detailed reproductions to this more general and abstracted recall.

3. Imagine a gigantic banquet. Hundreds of millions of people come to eat. They eat and drink to their hearts' content. Then, one day, a man arrives, wearing a white dinner jacket. He says he is holding the bill. Not surprisingly, the diners are in shock. Some begin to deny that this is their bill. Others deny that there even is a bill. Still others deny that they participated in the meal. One diner suggests that the man is not really a waiter, but is only trying to get attention for himself or to raise money for his own projects. Finally, the group concludes that if they simply ignore the waiter, he will go away. This is where we stand today on the subject of global warming and its environmental effects. For the past 150 years, industrial civilization has been dining on the energy stored in fossil fuels, and the bill has come due. Yet, we have sat around the dinner table denying that it is our bill, and doubting the credibility of the man who delivered it. The great economist John Maynard Keynes famously summarized all of economic theory in a single phrase: "There is no such thing as a free lunch."

4. Although it is the middle of the summer, I am sitting here listening to Christmas music. Many people would say that I have a screw loose or that I'm simply just a little odd in the head. The truth is probably a little of both. Actually, I listen to Christmas music throughout the year because it brings me peace and solace. Holiday jazz and classical songs tend to bring about a calming reaction in an otherwise chaotic environment. This is so true during the actual Christmas season. Besides the daily hustle and bustle, people are in a giving and caring mood. They give more to charities. They drop coins in the buckets of bell ringers on every corner. In general, we are all more kind to fellow human beings during the season. That being said, why do we have to contain that kindness for only one part of the year? Why can't we have that Christmas spirit every day of the year? If you take away the commercialism and don't have to fight for gifts at the mall, you are left with just a cheerful attitude. So as you set up for your summer picnic, stop at the stereo and pop in a Christmas CD.