Here, we shall talk in greater
detail about dark matter. Dark matter is said to make up 23% of the universe that we live in. 4%
is matter, and 73% is dark energy. Dark matter is stable and does not react
with other particles. It does not absorb light, does not emit light, and it
does not even interact with light. But what we know is, it bends light. We
cannot see it, but we know it is there. A technique called Gravitational
Lensing is used to detect dark matter. Dark matter bends light that
passes through it. So, even if we cannot see dark matter, by observing the
bending of the light, we know it's there. Gravitational Lensing, is precise,
because it shows how much dark matter is, how it is distributed, and where
it is positioned. Gravitational
Lensing measures the distortion of the light rays, passing through
dark matter. Dark matter also acts as a framework, like a skeleton, an
invisible framework, holding the visible matter together. We include a picture
that we drew to give you better understanding of the concepts.
Also, the speed of a galaxy's spin, when
calculated by scientists’, shows that it is not stable, but that
is not possible because an unstable galaxy will be chaotic. It cannot be
stable, unless there is 'something' that holds the galaxy, making it stable.
This ‘something’ is the missing matter, a missing piece and this ‘something’ is
called the dark matter. Dark matter is an invisible mass that is
gravitational interactive and is able to affect the speed of the entire galaxy.
Let's go back to basic, what is matter? Matter is anything that has mass and occupies
space. So does dark matter. It has mass and occupies the space. But we
cannot hold it, or put it in a bottle, because it does not react with any
visible particle known to us. In fact, it can just pass through us
without us feeling anything, or notice anything. It can
just through physical bodies. Another important fact that needs to be paid
attention to is, dark matter
interacts with gravity. Did you know that, in the galaxy, the velocity of the
orbiting of the gas and dust is constant, even though the velocity should,
supposedly further away it is from the center, slows down. What is affecting
the velocity, making it constant? The answer is, of course, dark matter. The
mass of dark matter is keeping the velocity of the galaxy, constant. Dark
matter are surrounding the galaxy, keeping the galaxy whole. Without dark
matter, galaxy would fall apart.
Reviewed and Corrected by :
Prof.Mohd Isa Mohd Yusof,
Senior Lecturer,
Centre of Foundation Studies,
Aras 5,Bangunan FSK 1,5
Universiti Teknologi MARA,
Cawangan Selangor,
Kampus Puncak Alam,
42300 Bandar Puncak Alam,
Selangor,
Malaysia.
