Friday, April 27, 2007

Hawking takes zero-gravity flight

from the bbc:

British physicist Stephen Hawking has completed a zero-gravity flight in a specially modified plane.

Professor Hawking, who suffers from motor neurone disease, was able to float free, unrestricted by his paralysed muscles and his wheelchair.

The two-hour flight over the Atlantic took a series of dramatic dives, allowing the professor to experience 25-second spurts of weightlessness.

The event could be a step closer to Hawking's goal of going into space.

The modified Boeing 727 jet simulated the experience of weightlessness as it took a series of eight plunges.

"It was amazing," Prof Hawking said after the flight.

"The zero-G part was wonderful and the higher-G part was no problem. I could have gone on and on. Space, here I come!" he said.

Initially, the organisers had planned to go through between one and three zero gravity sessions.

In the end eight were completed, and Prof Hawking experienced weightlessness for about four minutes.

What is Gravity?

Gravity holds us to the ground. It governs motion throughout the universe and keeps the Moon in orbit around the Earth, and the Earth in orbit around the Sun. The nature of gravity was first scientifically described by Sir lsaac Newton more than 300 years ago.

Where Does Gravity Come From?

Newton established that all objects, however small or large, have gravity. He noted that small objects have less gravity than large objects and that the force of attraction diminishes rapidly as the objects move apart.
Newton's research led to the Universal law of Gravitation.

Newton's Law of Gravity

Each object in the universe attracts each other body.

The force is proportional to the product of the two masses and inversely proportional to the square of the distance between the point masses:

F is the magnitude of the gravitational force between the two point masses
G is the gravitational constant
m1 is the mass of the first point mass
m2 is the mass of the second point mass
r is the distance between the two point masses

Assuming SI units (sorry united states, but the rest of the world and all of science communicates in metric units not english - and we now have been using metric since the 1970's), F is measured in newtons (N), m1 and m2 in kilograms (kg), r in metres (m), and the constant G is approximately equal to 6.67 × 10−11 N m2 kg−2. (incredibly weak when compared to the other 3 forces*)

*but gravity acts differently than the other 3 forces - see a physics textbook, or wait for me to blog about the four forces and their properties and relationships.

...nice to have something positive to blog about for a change.

i'm a big fan of stephen hawking, and very happy he's managed to achieve this.

i really hope he makes it into space.

No comments: