QUES: You know that friction also causes heat. Think about when you rub your hands together. It is friction that makes them warm. But why does this happen? Friction causes the molecules on rubbing surfaces to move faster. Faster moving particles have more heat energy. Heat from friction can be useful. Can you think of other places where you might find friction? Friction also lets you light a match. Heat from friction can also cause problems. It can cause a car to overheat. To reduce friction, oil is added to the engine. Oil coats the surfaces of moving parts. This coating of oil makes them slippery. When things are slippery there is less friction. Have you ever seen a sign that says, slippery when wet? This too has to do with friction. Water, like oil, can reduce friction. The wet surface may allow your shoes to slide more easily.
Do you have any questions?
MY QUESTION: Why do rubbing your hands make them warm?

QUES: Einstein was displeased with quantum theory and mechanics (the very theory he helped create), despite its acceptance by other physicists, stating that God "is not playing at dice." Einstein continued to maintain his disbelief in the theory, and attempted unsuccessfully to disprove it until he died at the age of 76. In 1917, at the height of his work on relativity, Einstein published an article in Physikalische Zeitschrift that proposed the possibility of stimulated emission, the physical process that makes possible the maser and the laser. This article showed that the statistics of absorption and emission of light would only be consistent with Planck's distribution law if the emission of light into a mode with n photons would be enhanced statistically compared to the emission of light into an empty mode. This paper was enormously influential in the later development of quantum mechanics, because it was the first paper to show that the statistics of atomic transitions had simple laws. Einstein discovered Louis de Broglie's work, and supported his ideas, which were received skeptically at first. In another major paper from this era, Einstein gave a wave equation for de Broglie waves, which Einstein suggested was the Hamilton-Jacobi equation of mechanics. This paper would inspire Schrodinger's work of 1926.
Do you have any questions?
MY QUESTION: What did Einstein publish in that showed the statistics of absorption and proposed the possibility of stimulated emission?

QUES: Josie started planning her new garden in the winter. She chose flowers and vegetables that could grow in her area. She looked through the seed magazines. She ordered the tastiest kind of each vegetable and the prettiest kind of each flower. She talked to a friend about her plans. It seemed like the snow would never melt. But Josie didn't have to wait for spring to get started. Six weeks before the last frost, Josie planted seeds indoors. The tiny seedlings pushed up through the soil and began to grow. Finally spring arrived. Each day, Josie moved the seedlings outside for a few hours so they could get used to the cooler temperatures. Josie worked in her garden, digging the soil. She added a special growing mix from the garden store to make the soil better. When everything was ready, she removed the seedlings from their trays and planted them in her garden. The warm sun and rich soil helped her vegetables and flowers grow.
Do you have any questions?
MY QUESTION: What improved the soil in the garden?

QUES: Early in chapter 5 we introduced, along with Khalid Sheikh Mohammed, two other men who became operational coordinators for al Qaeda: Khallad and Nashiri. As we explained, both were involved during 1998 and 1999 in preparing to attack a ship off the coast of Yemen with a boatload of explosives. They had originally targeted a commercial vessel, specifically an oil tanker, but Bin Laden urged them to look for a U.S.warship instead. In January 2000, their team had attempted to attack a warship in the port of Aden, but the attempt failed when the suicide boat sank. More than nine months later, on October 12,2000, al Qaeda operatives in a small boat laden with explosives attacked a U.S. Navy destroyer, the USS Cole. The blast ripped a hole in the side of the Cole, killing 17 members of the ship's crew and wounding at least 40. The plot, we now know, was a full-fledged al Qaeda operation, supervised directly by Bin Laden. He chose the target and location of the attack, selected the suicide operatives, and provided the money needed to purchase explosives and equipment. Nashiri was the field commander and managed the operation in Yemen. Khallad helped in Yemen until he was arrested in a case of mistaken identity and freed with Bin Laden's help, as we also mentioned earlier. Local al Qaeda coordinators included Jamal al Badawi and Fahd al Quso, who was supposed to film the attack from a nearby apartment. The two suicide operatives chosen were Hassan al Khamri and Ibrahim al Thawar, also known as Nibras. Nibras and Quso delivered money to Khallad in Bangkok during Khallad's January 2000 trip to Kuala Lumpur and Bangkok. In September 2000, Bin Laden reportedly told Nashiri that he wanted to replace Khamri and Nibras. Nashiri was angry and disagreed, telling others he would go to Afghanistan and explain to Bin Laden that the new operatives were already trained and ready to conduct the attack. Prior to departing, Nashiri gave Nibras and Khamri instructions to execute the attack on the next U.S.warship that entered the port of Aden.
Do you have any questions?
MY QUESTION:
Why did the team avert from attacking an oil tanker and attempt to attack a warship?