Hello everyone, my name is Visesh from batch 27. In this article I am talking about the composition and behaviour of dark matter and dark energy.
Dark matter :
Dark matter is an invisible and hypothetical form of matter that does not
interact with light or other electromagnetic radiation which we can not touch
it, feel or see it nor detect it but it does exist and has many evidence o and
scientist all around the world believe in dark matter and Almost 27% of the universe
is made up of dark matter. It was discovered by Fritz Zwicky in the 1930s,
Fritz Zwicky was a swiss astronomer who just made a concept of dark matter by
studying the coma cluster , he observed that the galaxies were rotating faster
in the coma cluster than it should based on visible matter then he inferred
that there is an unseen matter which he called
dark matter which was holding the cluster together but it was not enough proof
in the existence of dark matter. Later Vera Rubin, a women American astronomer proved it by further
compelling evidence for dark matter by studying the rotation curves of spiral
galaxies.
Her observations showed that stars at the outer edges of
spiral galaxies were orbiting at speeds that couldn't be explained by the
visible matter alone. This indicated that a large halo of unseen matter, later
known as dark matter, was responsible for the observed gravitational effects,
holding the galaxies intact. Rubin's findings were groundbreaking and helped to
solidify the idea of dark matter within the scientific community.
The dark matter composition is unknown but scientists have ruled out several possibilities. Dark matter is not a baryonic matter, which means unlike ordinary matter which consist of protons and neutrons, dark matter doesn’t have any of them and it doesn’t produce gamma ray radiation when it interacts with matter. One of the leading theories is that dark matter might consist of Weakly Interacting Massive Particles or also known as (WIMPs) which is yet to be detected. the behaviour of dark matter is understood by its gravitational effects on the visible matter, the behaviours are, it doesn’t interact with the light and the electromagnetic radiations and henceforth we can not directly observe it nor detect it, but instead, it presence is inferred through its gravitational influence on stars, galaxies, galaxies clusters and other astronomical objects. Even though dark matter can not be detected nor can be seen, scientist is still studying dark matter and its secrets by using jwst and hubble telescope to study the dark matter and the newest telescope named vera rubin telescope which contains the largest digital camera which helps us to study dark matter.
Dark energy:
Dark energy is a theoretical form of energy postulated to
act in opposition to gravity and to occupy the entire universe, accounting for
most of the energy in it and causing its expansion to accelerate the universe
and almost 68% of the universe is composed of dark energy. Even though dark
energy can not be detected just like dark matter, there are many evidence of
dark energy and the primary evidence for dark energy comes from
the observation that the universe's expansion is accelerating and a unknow
force is cause the accelerating and expanding our universe. Dark energy was
discovered in 1998 by two independent teams of astronomers observing distant
supernovae. These teams were led by American astronomers Adam Riess
and Saul Perlmutter, and Australian astronomer Brian Schmidt and they were
observing type la supernovae.
Type Ia supernovae are known to have a consistent
brightness, allowing astronomers to calculate their distance based on how
bright they appear. By measuring the distances to these supernovae, both
teams discovered that the universe's expansion was not slowing down due to
gravity, as previously thought, but was actually accelerating. Due to this
it revolutionized our understanding of the universe, suggesting that it is
composed mostly of dark energy and dark matter, with ordinary matter making up
only a small fraction.
The hubble telescope was also a crucial part in research on
dark energy. Hubble's observations of
distant supernovae (exploding stars) in the late 1990s provided the first
compelling evidence for the accelerating expansion of the universe. This
acceleration was unexpected, as it contradicted previous models that predicted
a slowing expansion due to gravity. Because of this it said it said that
in 30-50 billion years the universe will end by the Big rip where the universe
expands so rapidly that everything is torn apart including us, our sun, black
hole and even atoms would be torn apart luckily Recent findings suggest that
dark energy might not be constant and could be weakening, which would alter
these predictions.
The composition of dark energy is still a mystery and
scientist don’t know what is it composed of, but one of the leading theory is
that dark energy is the fundamental energy of the space itself, this theory
suggest that dark energy is a content energy that inherit the empty space and
leading to a repulsive force that counteracts gravity and accelerates the
expansion. The dark energy behaviour is a repulsive force, causing the
universe to expand at an accelerating rate. It is believed to be a relatively
uniform energy field that permeates space and will not interact with normal
matter or light directly. While its exact nature is still unknown, it
currently makes up approximately 68% of the universe's total energy density.
Even though it is still unknown and mysterious , scientists are still learning
more about dark energy and dark matter and who knows we might uncover its
secrets with upcoming new technology.
-S.Visesh Vaidhyanath Batch 27.