Dark Energy: How Can ~73% Of Universe Exist?

In summary: The answer to this last question is that the particles are not rigid, but have a sort of "fluidity" to them. This means that they can undergo transformations, or "quantum jumps," that allow them to transfer energy and information between the different parts of the particle.
  • #1
Bradfordly1
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How is ~73% of the universe made up of Dark Energy if energy doesn't take up physical space?
 
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  • #2
Bradfordly1 said:
How is ~73% of the universe made up of Dark Energy if energy doesn't take up physical space?
Energy is a propery of a system. E.g. potential energy of a body in a gravitational well of another body, or kinetic energy of a body w/r to some reference frame.
That's why you can define energy (density) of the universe - it's a system that has that property.
 
  • #3
'Dark energy' is a place holder name for something we don't know which appears to be causing accelerating expansion of space.
We don't know what dark energy actually is, but it certainly exists in physical space and not somewhere else.
It isn't baryonic matter of course, atoms, but then other more usual forms of energy are not either.
Does light or electricity occupy physical space?
 
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  • #4
Force carriers, called bosons, are massless and do not occupy space, only massive particles, called fermions, occupy space so there is no limit on the number of bosons that can occupy any given space.
 
  • #5
Chronos said:
Force carriers, called bosons, are massless and do not occupy space, only massive particles, called fermions, occupy space so there is no limit on the number of bosons that can occupy any given space.
Not all bosons are massless. Mesons are bosons and have a mass. But, of course, all bosons are volume less, since they are not subject to Pauli's dxclusion principle.
 
  • #6
I stand corrected. The meson is indeed a boson with mass. Upon further review I noted this discussion at https://www.fnal.gov/pub/today/archive/archive_2013/today13-02-15_NutshellReadMore.html Fermi lab

" The quarks, leptons and bosons of the Standard Model are point-like particles. Every other subatomic particle you've heard of is an extended particle. The most familiar are the protons and neutrons that make up the nucleus of an atom, but there are many others—pions, kaons, Lambda particles, omegas and lots more. The defining feature of these kinds of particles is that they have a reasonably measurable size (which happens to be about the size of a proton).

It is further stated

" Point particles are much more bizarre and are sometimes said to have zero size. This statement has raised more than one eyebrow. How can something have no size at all? And if it has mass, does the zero size mean it has infinite density? (And by the way, as you read on, you'll see the answer to that last one is no.) You begin to see why some people are skeptical when a scientist says a particle is point-like. ...While the quarks, leptons and force-causing bosons of the Standard Model are all currently treated as point-like, there is no guarantee that this will always be true. It may be that as we probe to smaller and smaller sizes, we will eventually find that the particles we thought were point-like are actually extended particles with smaller things inside them. However, because the core particle is surrounded by this extended cloud, determining whether the core is point-like or extended is a real challenge."

For futher discussion that may be of interest see;http://journals.aps.org/prd/abstract/10.1103/PhysRevD.86.034003, Size of the σ meson and its nature.
 
  • #7
But if today's elementary particles are extended objects with smaller things inside, what are those things--pointless or extended? Ultimately either we must accept point particles or have extended objects which are not rigid. If elementary particles are extended and rigid, we have another problem: any force applied on one side cannot be communicated immediately to the other side (because no communication can take place faster than velocity of light) and so the whole particle cannot move together. In other words it cannot be rigid.
 

1. What is dark energy?

Dark energy is a hypothetical form of energy that is thought to make up about 73% of the universe. It is believed to be responsible for the accelerating expansion of the universe.

2. How do we know dark energy exists?

Dark energy is not directly observable, but its existence is inferred from observations of the expansion of the universe. The rate of expansion is found to be increasing, which suggests the presence of a repulsive force, which is attributed to dark energy.

3. What is the difference between dark energy and dark matter?

Dark energy and dark matter are two different concepts. While dark energy is a hypothetical form of energy, dark matter is a type of matter that is believed to make up about 27% of the universe. Dark matter interacts with gravity, while dark energy is believed to have a repulsive effect on the expansion of the universe.

4. How is dark energy related to the Big Bang Theory?

The Big Bang Theory is the prevailing explanation for the origin and evolution of the universe. It is believed that dark energy was present at the time of the Big Bang and has been expanding alongside the universe ever since. The presence of dark energy is necessary to explain the accelerated expansion of the universe predicted by the Big Bang Theory.

5. Can we harness or use dark energy?

At this time, there is no known way to harness or use dark energy. Its effects are only observed on a cosmic scale and are not currently understood enough to be utilized in any practical way. However, research into dark energy is ongoing, and it may hold potential for future discoveries and advancements in our understanding of the universe.

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