Today we’re going to be discussing the difference between dark and vacuum energy, but before we dive in, we first need to establish what energy means in scientific terms.
What Is Energy?
In physics, energy is defined as the capacity for doing work, and by “work”, we mean the working against a force.
Energy can exist in numerous forms including thermal, potential, kinetic, electrical, chemical, and nuclear.
Once energy is transferred, then it is appropriately designated according to its updated nature.
The word was first used in this context by the physicist Thomas Young in 1800, though it did not become widespread for some time.
Theories on dark energy and theories on vacuum energy may well offer different explanations and interpretations of some of the same phenomena.
Both are things that cosmologists, physicists, and astronomers are still trying to get to grips with.
There are of course critics of these ideas, as is the nature of the beast with theoretical sciences.
This article will take a look at what each theory is and whether there are any differences between the two concepts of mysterious energy.
What Is Vacuum Energy?
Vacuum energy is theorized to be the underlying background energy that exists everywhere across the universe.
The term refers to a specific case of zero-point energy that is closely related to the quantum vacuum.
There is some disagreement as to the volume of space that this energy takes up, thus causing the cosmological constant problem.
The conflict arises between the two methods of measurement.
When referring to the upper limit of the cosmological constant, estimates show the vacuum energy of free space to be 10−9 joules per cubic meter.
Alternatively, the field of quantum electrodynamics estimates a more significant, 10113 joules per cubic meter.
This field is consistent with the Planck constant and the principle of the Lorentz covariance.
Observations in the effects of vacuum energy have been made in the Casimir effect, the Lamb shift, and spontaneous cosmic emissions.
These observations have led cosmologists to believe that they play a role in the function and resulting behavior of the universe.
What Is Dark Energy?
Dark energy is believed to make up the vast majority of the universe, with estimates that dark energy makes up almost 70 percent of the matter-energy density of the known universe.
Dark energy has been found to be closely related to the vacuum of space, and it is in fact a key property of the vacuum itself.
Who Discovered Evidence Of Dark Energy?
In the late 1990s, astronomers observing supernovae discovered evidence for the existence of dark energy.
So what relevance do supernovae have? These are exploding stars that can be seen across vast distances of observable space.
Supernovae la are searched for specifically as they are both highly visible and also known to explode at consistent rates of energy.
These consistent levels allow astronomers to measure distances and therefore the speeds at which the universe previously expanded.
They theorized that these measurements would show clear evidence that the universe’s rate of expansion was slowing down through time.
They assumed that the gravitational pull of the various stars and formations in the cosmos would contribute to this deescalating rate of expansion.
The Supernova Cosmology Project was launched in 1988 by the American astronomer Saul Perlmutter and his team.
Further development was undertaken in 1994 by Australian Brian Schmidt and the High-z Supernova Search Team.
Fascinatingly, contrary to earlier predictions, the team’s findings in 1998 showed that the universes’ expansion was in fact accelerating.
This left their minds blown, as then, there was no known property or discovery in physics that could explain such an effect being produced.
Astronomers attributed the force that was causing this acceleration as “dark energy”, and it has continued to be known as that to this date.
This has opened up completely new thoughts, theories, ideas, and assumptions as to the nature of dark energy and the universe itself.
It continues to amaze, inspire and frustrate theoretical physicists the world over as they seek to gain a deeper understanding of dark energy’s relationship to the universe, potential, and dangers.
Previously, Einstein’s theory of the ‘cosmological constant’ was the most closely associated with giving a clearer idea of what dark energy is.
His theory, shared in 1917, described the cosmological constant as a constant energy field that is present across the universe.
The discovery of a rapidly expanding universe caused him to abandon this idea and disregard his previous perceptions about this potential phenomenon.
What’s The Difference Between Dark Matter And Dark Energy?
The combination of dark matter and dark energy creates polarity throughout the universe, as they are both opposite and the same, two opposite parts of the same forces.
Dark matter produces gravity, which is an attractive force, whereas dark energy produces antigravity, which is a repulsive force.
Dark matter in effect slows down the universe, whilst dark energy speeds it up.
What Do Physicists Think Now?
In recent times, many cosmologists have returned to using the cosmological constant, believing it to be the most logical way to explain the observations they are making.
Others argue that the acceleration may be the result of an as yet unidentified aspect of nature that has not been knowingly observed or measured.
Thus far, there are yet to be any successful attempts of measuring the acceleration inconsistent in highly detailed ways.
This leaves dark energy as an immensely fascinating cosmic phenomenon that continues to ask more questions than it answers.
What Discoveries Are Next?
An exciting project is under development in a partnership between the Euclid Consortium and the European Space Agency (ESA).
The name, as with many cosmological endeavors, is associated with ancient Greek culture, with it being the name of revered mathematician Euclid of Alexandria.
You may have noticed Roman culture is often used in the naming of planets and other cosmological happenings too.
The team-up between Euclid and the ESA is to develop the Euclid satellite.
It is intended to allow for a deeper understanding of dark energy and dark matter, through taking an astronomically wide range of measurements.
Its mission will see it map the 3D distribution of up to two billion galaxies! Wow.
The satellite will also look to observe and map the dark matter and dark energy that is present in those many galaxies.
The aim is to map up to 10 billion years of cosmic history, and dark matters’ place in that history.
With a deeper understanding of these findings, they hope to find an answer to the mystery of the cosmological constant.
You may associate the term gamma with a scientist named Bruce, who you don’t want to make angry, however, gamma will also play an important role in the Euclid mission.
The satellite will measure gamma from cosmic structures to test the theory of general relativity.
This will show whether the theory holds out when tested at such vast cosmological scales.
Cosmic energy is a phenomenon that drives the universe forwards at unparalleled speeds.
Some wide-ranging concepts and theories look to explain the mysterious, to explore the depths of the universe, that look to find the answers of the great unknown.
Both theories relating to “dark energy” and “vacuum energy” offer an insight into the deepest of mysteries.
With technological advancements and new missions on the horizon, the scientific community eagerly awaits the next step.
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