QUES: Density is also an important physical property of matter. The concept of density combines what we know about an objects mass and volume. Density reflects how closely packed the particles of matter are. When particles are packed together more tightly, matter is more dense. Differences in density of matter explain many phenomena. It explains why helium balloons rise. It explains why currents such as the Gulf Stream flow through the oceans. It explains why some things float in or sink. You can see this in action by pouring vegetable oil into water. You can see a colorful demonstration in this video.
Do you have any questions?
MY QUESTION: Based on the explanation in the article, why do you expect to happen with the water and oil?

QUES: Right after the Pentagon was hit, NEADS learned of another possible hijacked aircraft. It was an aircraft that in fact had not been hijacked at all. After the second World Trade Center crash, Boston Center managers recognized that both aircraft were transcontinental 767 jetliners that had departed Logan Airport. Remembering the "we have some planes" remark, Boston Center guessed that Delta 1989 might also be hijacked. Boston Center called NEADS at 9:41 and identified Delta 1989, a 767 jet that had left Logan Airport for Las Vegas, as a possible hijack. NEADS warned the FAA's Cleveland Center to watch Delta 1989. The Command Center and FAA headquarters watched it too. During the course of the morning, there were multiple erroneous reports of hijacked aircraft. The report of American 11 heading south was the first; Delta 1989 was the second. NEADS never lost track of Delta 1989, and even ordered fighter aircraft from Ohio and Michigan to intercept it. The flight never turned off its transponder. NEADS soon learned that the aircraft was not hijacked, and tracked Delta 1989 as it reversed course over Toledo, headed east, and landed in Cleveland. But another aircraft was heading toward Washington, an aircraft about which NORAD had heard nothing: United 93. United Airlines Flight 93 FAA Awareness. At 9:27, after having been in the air for 45 minutes, United 93 acknowledged a transmission from the Cleveland Center controller. This was the last normal contact the FAA had with the flight. Less than a minute later, the Cleveland controller and the pilots of aircraft in the vicinity heard "a radio transmission of unintelligible sounds of possible screaming or a struggle from an unknown origin." The controller responded, seconds later: "Somebody call Cleveland?"This was followed by a second radio transmission, with sounds of screaming.
Do you have any questions?
MY QUESTION: What was the first flight that was erroneously reported as hijacked?

QUES: Alexander's body was laid in a gold anthropoid sarcophagus that was filled with honey, which was in turn placed in a gold casket. According to Aelian, a seer called Aristander foretold that the land where Alexander was laid to rest "would be happy and unvanquishable forever". Perhaps more likely, the successors may have seen possession of the body as a symbol of legitimacy, since burying the prior king was a royal prerogative. While Alexander's funeral cortege was on its way to Macedon, Ptolemy seized it and took it temporarily to Memphis. His successor, Ptolemy II Philadelphus, transferred the sarcophagus to Alexandria, where it remained until at least late Antiquity. Ptolemy IX Lathyros, one of Ptolemy's final successors, replaced Alexander's sarcophagus with a glass one so he could convert the original to coinage. The recent discovery of an enormous tomb in northern Greece, at Amphipolis, dating from the time of Alexander the Great has given rise to speculation that its original intent was to be the burial place of Alexander. This would fit with the intended destination of Alexander's funeral cortege. Pompey, Julius Caesar and Augustus all visited the tomb in Alexandria, where Augustus, allegedly, accidentally knocked the nose off. Caligula was said to have taken Alexander's breastplate from the tomb for his own use. Around AD 200, Emperor Septimius Severus closed Alexander's tomb to the public. His son and successor, Caracalla, a great admirer, visited the tomb during his own reign. After this, details on the fate of the tomb are hazy. The so-called "Alexander Sarcophagus", discovered near Sidon and now in the Istanbul Archaeology Museum, is so named not because it was thought to have contained Alexander's remains, but because its bas-reliefs depict Alexander and his companions fighting the Persians and hunting. It was originally thought to have been the sarcophagus of Abdalonymus (died 311 BC), the king of Sidon appointed by Alexander immediately following the battle of Issus in 331. However, more recently, it has been suggested that it may date from earlier than Abdalonymus' death.
Do you have any questions?
MY QUESTION: What known alterations were made to Alexander's tomb?

QUES: Bin Laden reportedly discussed the planes operation with KSM and Atef in a series of meetings in the spring of 1999 at the al Matar complex near Kandahar. KSM's original concept of using one of the hijacked planes to make a media statement was scrapped, but Bin Laden considered the basic idea feasible. Bin Laden, Atef, and KSM developed an initial list of targets. These included the White House, the U.S. Capitol, the Pentagon, and the World Trade Center. According to KSM, Bin Laden wanted to destroy the White House and the Pentagon, KSM wanted to strike the World Trade Center, and all of them wanted to hit the Capitol. No one else was involved in the initial selection of targets. Bin Laden also soon selected four individuals to serve as suicide operatives: Khalid al Mihdhar, Nawaf al Hazmi, Khallad, and Abu Bara al Yemeni. During the al Matar meetings, Bin Laden told KSM that Mihdhar and Hazmi were so eager to participate in an operation against the United States that they had already obtained U.S. visas. KSM states that they had done so on their own after the suicide of their friend Azzam (Nashiri's cousin) in carrying out the Nairobi bombing. KSM had not met them. His only guidance from Bin Laden was that the two should eventually go to the United States for pilot training. Hazmi and Mihdhar were Saudi nationals, born in Mecca. Like the others in this initial group of selectees, they were already experienced mujahideen. They had traveled together to fight in Bosnia in a group that journeyed to the Balkans in 1995. By the time Hazmi and Mihdhar were assigned to the planes operation in early 1999, they had visited Afghanistan on several occasions. Khallad was another veteran mujahid, like much of his family. His father had been expelled from Yemen because of his extremist views. Khallad had grown up in Saudi Arabia, where his father knew Bin Laden, Abdullah Azzam, and Omar Abdel Rahman (the "Blind Sheikh").
Do you have any questions?
MY QUESTION:
Where did the four suicide bombers grow up?