May the force be with you

A couple of days ago, I was watching a movie when I start wondering why is there opening credits? My friend argued that it was an obligation by the Directors Guild of America (for American film or course). I then said ... what about Star wars ... and then it the silence came.

So I felt compelled to find the answer. In recent years, many major American motion pictures have done away with opening credits, with many films, such as Van Helsing, Batman Begins, and The Mummy Returns not even displaying the film title until the closing credits begin. George Lucas is credited (or blamed) with popularizing this with his Star Wars films which display only the film's title at the start. His decision to omit opening credits in his films Star Wars Episode IV: A New Hope (1977) and Star Wars Episode V: The Empire Strikes Back led him to resign from the Directors Guild of America. However, Hollywood had been releasing films without opening credits for many years before Lucas came along, most notably Citizen Kane and The Godfather. However, it was with the release of Lethal Weapon 2 in 1989 that the "title only" opening became an established form for summer blockbusters. Clint Eastwood has done away with opening credits (except for the title) in every film that he has directed since approximately 1982.

Coffee Facts

A cup of drip brewed coffee has about 115 milligrams of caffeine, an espresso (and percolated coffee) about 80mg, while instant coffee has about 65mg of caffeine. Decaffeinated coffee is not totally caffeine free, containing about 3mg of caffeine. A can of Coca-Cola has about 23mg of caffeine, Pepsi Cola 25mg, Mountain Dew 37mg, and TAB 31mg. Tea has about 40mg of caffeine, while an ounce of chocolate contains about 20mg.

The first Espresso machine was introduced in 1822 by the French, but it was the Italians who later perfected and distributed it.

Coffee is the world's most popular stimulant: 4 out of 5 Americans drink it, consuming more than 400 million cups a day. Consumption in Scandinavian countries is more than 12kg (26lb) per capita. With more than 25 million people employed in the industry, coffee is second only to oil in world trade.

The word "tip" is also related to coffee. It comes from old London coffeehouses where the waiters' brass boxes were etched with the inscription, "To Insure Promptness." In fact, it was in one such coffeehouses which belonged to a Mr Lloyd that a few cargo insurers got together to start the Lloyd's insurance company.

How to walk on water

Do you ever wonder why water drops have a spherical shape? Because a sphere has the smallest possible surface area to volume ratio. An which force required such ratio ? Surface Tension.

Surface tension is caused by the attraction between the molecules of the liquid by various intermolecular forces. In the bulk of the liquid each molecule is pulled equally in all directions by neighboring liquid molecules, resulting in a net force of zero. At the surface of the liquid, the molecules are pulled inwards by other molecules deeper inside the liquid but they are not attracted as intensely by the molecules in the neighbouring medium (be it vacuum, air or another liquid). Therefore all of the molecules at the surface are subject to an inward force of molecular attraction which can be balanced only by the resistance of the liquid to compression. Thus the liquid squeezes itself together until it has the locally lowest surface area possible.

The photograph shows water striders standing on the surface of a pond. It is clearly visible that its feet cause indentations in the water's surface. And it is intuitively evident that the surface with indentations has more surface area than a flat surface. If surface tension tends to minimize surface area, how is it that the water striders are increasing the surface area?
Recall that what nature really tries to minimize is potential energy. By increasing the surface area of the water, the water striders have increased the potential energy of that surface. But note also that the water striders' center of mass is lower than it would be if they were standing on a flat surface. So their potential energy is decreased. Indeed when you combine the two effects, the net potential energy is minimized. If the water striders depressed the surface any more, the increased surface energy would more than cancel the decreased energy of lowering the insects' center of mass. If they depressed the surface any less, their higher center of mass would more than cancel the reduction in surface energy.

Water Slide

I was looking for an article on surface tension when I felt onto theses facts:
Water is a common chemical substance that is essential to all known forms of life. In typical usage water refers only to its liquid form or state, but the substance also has the solid state, ice, and gaseous state, water vapor. About 1,460 teratonnes (Tt) of water cover 71% of Earth's surface, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds, and precipitation.[2] Saltwater oceans hold 97% of surface water, glaciers and polar ice caps 2.4%; and other land surface water such as rivers and lakes 0.025%. Now, you have to be impressed by theses numbers.

Tomorrow: Why can water stride walk on water?

My Two Cents

I’m sorry for yesterday’s absence, but I’m in some kind of rush at work. So today’s gonna be a quick one: Can a penny dropped from the top of a tall building kill a pedestrian?

A penny isn't the most aerodynamic of weapons. A combination of its shape and wind friction means that, tossed even from the 1,250-foot Empire State Building, it would travel fast enough merely to sting an unlucky pedestrian.

Brain Teasers

Today’s fact is about a popular misconception that human uses only 10% of our brain. This misconception arose from a misunderstanding of neurological research in the late 1800s or early 1900s when researchers either discovered that only about 10% of the neurons in the brain are firing at any given time. Another possible origin of the misconception is that only 10% of the cells in the brain are neurons; the rest are glial cells that, despite being involved in learning, do not function in the same way that neurons do. If all of a person's neurons began firing at once, that person would not become smarter, but would instead suffer a seizure. In fact, studies have shown that the brains of more intelligent people are less active than the brains of less intelligent people when working on the same problem (which does not in any way mean that epileptics are less intelligent).

Fly Me to the Moon

When low on the horizon, the Moon can appear to be larger than when it's higher in the sky. It's all an illusion, scientists say, and it does not involve any enlarging effects of the atmosphere. Rather, it's all in your mind.

Here's how it works: Our brains think things on the horizon are farther away than stuff overhead, because we're used to seeing overhead clouds that are close compared to those on the horizon. In the mind's eye, the sky is a flattened dome. With this dome as a reference, we expect something on the horizon (such as the moon) to be father, and because it is actually no farther than when overhead, our brains goof and imagine that it is larger.

Now, that what I call an all natural enlargement process ;)