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Aircraft do not defy the law of gravity, they produce a sufficient force to overcome gravity, just as you do if you decide to jump in the air.

There are four main forces acting on an aircraft, thrust from the engines, drag on the airframe, gravity pulling down and lift generated by the wings.

Once the size of the lift is greater than the weight of the plane then gravity will be overcome and the plane will rise. Once cruising altitude is achieved the lift force is balanced with the weight and the aircraft stays at a constant height.

The second planet from the Sun is Venus. After the Moon, Venus is the most brilliant natural object in the nighttime sky. It is the closest planet to Earth, and it is also the most similar to Earth in size, mass, volume, and density. These similarities suggest that the two planets may have had similar histories. Scientists are thus intrigued by the question of why Venus and Earth are now so different.

December 2003 answer: It appears that the Egyptians were responsible for the 24 hour day. The Eqyptians were fond of counting in base twelve (instead of base 10 which is commonly used today). This is thought to be because they counted finger joints instead of fingers. Each of your fingers has three joints, so if you count by pointing to finger joints with your thumb you can count to twelve on each hand. This might seem arbitrary, but is actually just a strange as counting in base ten simply because we have ten digits.

The Egyptians divided the clock into 12 hours of daytime and 12 hours of night-time (or alternatively 10 hours between sunrise and sunset, an hour for each twilight period and 12 hours of darkness). This is known because of various sundials from the period which have been found to be marked with hours. Interestingly this means that hours started out changing in length with the seasons (as the amount of daylight vs. darkness changes).

Nightmares tend to occur after several hours of sleep, screaming or moving about is very uncommon, the dream is

usually elaborate and intense, and the dreamer realizes soon after wakening that he or she has had a dream.

One of the most common reasons for bullying is image. Anyone who looks the least bit different from what is considered to be normal will likely face bullying at some point in his life. Kids with freckles, acne, moles, buck teeth and other physical differences will be targeted by bullies.

Kids who go out of their way to sit in the front of the class, answer the teacher’s questions and do well on exams are also convenient targets because they are considered to be “nerds”.

Kids who don’t have the same style of clothing as their peers are often the targets of bullies.

Because he sailed around the western tip of Africa in 1488. thus making possible later trips to India.