By studying
supernovae, Ewin Hubble was able to determine that the universe is expanding, but
how fast is the question. Scientists were amazed to learn that gravity is not slowing
down the expansion, which was the original theory, but rather the universe is accelerating rather quickly. This new concept was discovered when
scientists observed some strange results from the supernovae with the Hubble
Space Telescope. The stars appeared dimmer than expected, which means they were
farther away from us than they should have been at that specific time. This
observation created the theory called dark energy.
Contributing to
68 percent of the universe, dark energy is hypothesized to be the repellent
force that counteracts gravity. The scientists came up with the idea of dark
energy to explain why the Universe is accelerating because gravity is clearly
not preventing the expansion. Since it was found that atoms make up 4 percent
of the universe, there also appears to be another component, dark matter, which
makes up about 21 percent of the universe. Dark matter is assumed to exist
throughout the Universe, but does not emit or reflect light. Therefore,
scientists use gravitational lensing to estimate the existence based on its
gravitational effects.
Although much is
unknown about our universe, dark energy is the most accepted theory for the
accelerating expansion. But what does that mean for the fate of our Universe? The
expansion of the Universe depends on the density of dark energy. So based off
of this idea, if this energy remains the dominant composition of the Universe
then the Universe will continue to grow exponentially. It seems that dark
energy is taking over the power of gravity, but since it is still only a
theory, it is difficult to exactly define the fate of the Universe. We will
always be learning new things and forming new ideas about our Universe.
Hey Maggie! I liked reading about your post on dark energy. What we do know is that gravity is pulling everything together, but this dark energy is another force that we must consider, a theory of how the universe is able to expand. I thought it was extremely interesting that the theory proposes a relationship between gravity and dark energy. We learned that as the distance between galaxies increases, the gravitational force decreases, and if you think about conservation of energy, this dark energy is able to play a greater role and have a greater force on the galaxies. Although they have almost opposite effects, it was peculiar to realize how intertwined the two forces are.
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