Parts of Canada “missing” gravity?

By:Bosco Noronha

For over 40 years scientists have been researching on why large parts of our country have been labeled “missing“ gravity, particularly the Hudsons Bay area. This phenomenon has been discovered in the late 1960s when the earth gravity field was being charted.

What is gravity?

 We don't really know. We can define what it is as a field of influence, because we know how it operates in the universe. And some scientists think that it is made up of particles called gravitons which travel at the speed of light.

Although we do know how it behaves.

Sir Isaac Newton (1642 -- 1727) was the first to asseverate gravity as a fundamental force of nature. He came up with the very well-known formula that, gravity is proportional to mass. Newton's "law" of gravity is a mathematical description of the way bodies are observed to attract one another. The gravitational equation says that the force of gravity is proportional to the product of the two masses (m₁ and m₂), and inversely proportional to the square of the distance (r) between their centers of mass.

F=Gm₁m₂ / r²,

Where G is the gravitational constant: 6.6726 x 10^-11 m³ kg^-1 s^-2

There’s a problem with Newton’s theory of gravity, and that’s that it just allows us to predict how things move under its influence. It doesn’t say anything about why gravity exists or even how it works, it just allows you to calculate things. Newton knew this, he essentially just said that its down to God, in fact he said that the most beautiful system of the sun, the planets and the comets could only precede on the dominion and council of an intelligent being, in other words “I’ll give you the tools to calculate how the objects move through space, but don’t ask me how or why that is, that’s down to God”. But to understand gravity we need to bring it out of divine hands and into our own.

Modern physics describes gravity using the general theory of relativity by Einstein, in which it is a consequence of the curvature of space-time governing the motion of inertial objects. Einstein determined that Gravity is the warping of space-time continuum. Space time is basically a type of 3 dimensional fabric surrounding our universe and all matter.

So why is the Hudson’s bay area lacking in gravity?

One theory centers on a process known as convection occurring in the Earth's mantle. The mantle is a layer of molten rock called magma and exists between 60 and 124 miles (100 to 200 km) below the surface of the Earth. Magma is extremely hot and constantly whirling and shifting, rising and falling, to create convection currents. Convection drags the Earth's continental plates down, which decreases the mass in that area and decreases the gravity.

Another theory concerns that the Laurentide Ice Sheet, which covered much of present-day Canada and the northern United States. This ice sheet was almost 2 miles (3.2 km) thick in most sections, and in two areas of Hudson Bay, it was 2.3 miles (3.7 km) thick. It was also very heavy and weighed down the Earth. Over a period of 10,000 years, the Laurentide Ice Sheet melted, finally disappearing 10,000 years ago. It left a deep indentation in the Earth. Thus lack of mass means lack of gravity.

So do you get the gravity of the situation?

If you would like to know more about space-time check out this link:

http://videos.howstuffworks.com/tlc/29805-understanding-gravity-video.htm#mkcpgn=snag1