A sage once said— some insist it was Buddha, some say Rumi, others Beth Day or Mary Ann Pietzker or the Quakers or Sai Baba or Eleanor Roosevelt or their grandmother. It doesn’t much matter who— that Before you speak, your words must pass through three gates.

The first gate is called “Is it true?”
The second gate is called “Is it necessary?”
And the third gate is called “Is it kind?”

Now we live in foolish times when the presumptive nominee of his Party for President of the United States in the 2016 election says, “I will build a great wall,” the hell with gates, because when it comes to speaking–

First, it doesn’t matter if it’s true or not. No one cares.
Second, it doesn’t have to be necessary. It only has to help you win.
And third, kindness is for losers and liars and people with fat ugly faces.

“If you like pancakes or Belgian waffles, you probably know about sap,” writes F. Ronald Young in his book Fizzics: The Science of Bubbles, Droplets, and Foams. [i] “In winter time the sugar maple tree, stores sugar deep within its roots. Come spring, the tree pumps the sap upward, to bring water from its roots to its budding leaves. The good people of Quebec, the biggest producers of maple syrup in the world, know this and tap the sap to produce the sweet sticky syrup we love. But the atmosphere can support a column of water no more than 10.4 meters high, and some trees are much taller than this. The imposing giant redwoods of California can attain heights of more than 100 meters. So how can the sap rise to the top of a giant redwood?” asks Young.

“The answer is that there can be a negative pressure in the column of the sap. When water evaporates through pores in the leaves, negative pressure is apparently created in the thin capillaries that bring water to the leaves. It is this negative pressure from above, rather than a positive pressure from below, that causes the sap to rise.”[ii]

Finally, an explanation that makes some sense as to how from all the other possible candidates this sap has arisen — negative pressure. After all, how can you question an expert on bubbles?

[i] F. Ronald Young, a retired senior lecturer in physics from Watford Technical College, is an authority in bubble-related science and author of Cavitation and Sonoluminescence.
[ii] Apologies to redwoods lest someone literalize my point.