Oct 29, 2019 Dark matter takes up 27% of the known Universe, while dark energy, a repulsive force that makes the Universe expand, gets 68%. Only 5% of the Universe is the observable world, including us.
This Study Guide consists of approximately 59 pages of chapter summaries, quotes, character analysis, themes, and more - everything you need to sharpen your knowledge of Dark Matter. The geisha mask is used to hide the identity of the man who abducts Jason. It is a symbol of that strange man.
The mass–energy of dark matter and ordinary (baryonic) matter contributes 26% and 5%, respectively, and other components such as neutrinos and photons contribute a very small amount. The density of dark energy is very low ( 7 × 10 −30 g/cm 3), much less than the density of ordinary matter or dark matter within galaxies.
According to NASA, less than 5% of the universe is made of normal matter. That means everything we can observe from Earth is just a tiny fraction of reality.
The rest is dark and unknown; 68% of the universe is dark energy and 27% is dark matter. Two of the biggest mysteries of the universe aren’t nearly as related as their names imply. Dark energy is a property that pushes things apart in space, while a dark substance pulls celestial objects toward it. We don’t know much about either one, although experiments could find the answers, and you never know when scientists will have a breakthrough that would fundamentally change our understanding of the universe.
Dark Matter
There is a physical substance in space that we can’t see, although astronomers can observe its influence. The force of gravity from all visible matter isn’t strong enough to keep a galaxy together, so there must be something else that has mass that we can’t see. A dark and mysterious form of matter fills out the missing parts of the equation. This invisible substance produces an attractive force (gravity) that pulls matter inward and helps hold galaxies together, according to Mental Floss.
Discovery
Previously, astronomers expected the stars at the center of our galaxy to move faster than those on the galaxy’s edge, according to the Hobby Eberly Telescope Dark Energy eXperiment (HETDEX). This seems logical because the center of the galaxy, which is the center of the mass, should have the strongest gravity.
But when astronomers measured the stars that form a bright disk across the Milky Way galaxy, they were surprised to discover that all stars orbit the center of the galaxy at about the same speed. There’s some other invisible matter pulling at the stars from the outside.
Astronomer Fritz Zwicky discovered the substance in 1933, according to Britannica, when he observed that visible matter didn’t provide nearly enough mass to keep the stars from flying off into space. Astronomers have since observed this effect in other galaxies, as well as clusters of galaxies. Calculations now show that a vast “halo” of a dark substance surrounds the Milky Way. This halo may be 10 times as massive as the bright disk, so it exerts a strong gravitational pull.
What Is It Made of?
We still don’t know exactly what it is, but scientists have a few working theories. In the meantime, according to NASA, we’re working on process of elimination. Here are some things that it is not:
Visible matter (we can’t see it).
Dark clouds of normal matter made of particles called baryons. Scientists would be able to detect baryonic clouds because they would observe radiation passing through them.
Antimatter. Scientists do not see the unique gamma rays that are produced when antimatter annihilates with matter.
Galaxy-sized black holes. Astronomers say the gravitational lenses that they see eliminates this possibility. 1 up casino on facebook.
So, what does that leave us? Some possible candidates are dense astronomical bodies called massive astrophysical compact halo objects (MACHOs) or weakly interacting massive particles (appropriately nicknamed WIMPs), according to Mental Floss.
Dark matter likely consists of an exotic subatomic particle that hasn’t been detected yet. Scientists are conducting experiments at the International Space Station and CERN to try to capture these elusive particles, although nobody has succeeded yet.
Dark Energy
While matter attracts (gravity), energy, on the other hand, produces a repulsive force (antigravity) that pushes matter outward. It’s not an object but rather a property of space, and it helps explain why our universe is expanding. According to HETDEX, dark energy shows itself only on the largest cosmic scale.
Discovery
In 1929, legendary astronomer Edwin Hubble observed the “redshift” phenomenon that proved that our universe has been expanding since the Big Bang. For decades, astronomers believed that gravity would cause the expansion to slow down. Then in 1998, astronomers were shocked to learn the opposite.
According to Mental Floss, astronomers were using the Hubble Space Telescope to study distant supernovae, when they observed that around 7.5 billion years after the Big Bang, the universe began expanding at an even faster rate. Family guy brian mushroom trip. According to NASA, no one expected to discover that the expansion was accelerating, and scientists still can’t explain it, but they can tell that it exists because it affects the expansion of the universe.
Dark Matter Symbols
What Is It Made of?
According to NASA, there are several theories for what dark energy is. It may be an inherent property of space. Contrary to popular belief, empty space is not nothing. It has properties; it can expand and possess its own energy, as Albert Einstein suggested with his gravity theory and cosmological constant.
The quantum theory of matter provides a second explanation. This theory suggests that “’empty space’ is actually full of temporary (‘virtual’) particles that continually form and disappear.” However, this theory is highly unlikely, because when physicists attempted to use this theory for calculations, the answer came out wrong, according to NASA.
A third option is that dark energy is a new kind of dynamical energy fluid or field, which some scientists have called “quintessence.” If that’s the case, we still don’t know anything about it, says NASA.
Lastly, perhaps Einstein’s theory of gravity is not correct, and that’s why dark energy doesn’t fit into our equation of the universe. All of our current knowledge and understanding of the universe depend on Einstein’s theory being true, so if dark energy exposes an error, then we’re back at square one. It would upend our entire understanding of the universe.
Mysteries Remain
All this is to say, we still don’t know much about these “dark” aspects of space. One is a thing, another is a property, and they are both invisible and illogical. That’s why dark matter and dark energy are two of the most exciting areas of science, and scientists around the world are racing to find the answers to the dark parts of space. At this point, what we know is a process of elimination and circumstantial evidence. We know what they’re not, we see the effects, and there is evidence that they exist.
Space is often seen as the ultimate symbol of nothingness, but in reality, space isn’t empty at all. It’s just full of dark things and dark forces that we don’t understand yet.
Fire
Fire symbolizes the relationships within the Fitzgerald family, evidenced in part by Picoult’s choice of Carl Sandburg’s poem “Kin” as the epigraph for the opening chapters. The poem describes fire’s ability to warm as well as to consume, just as the relationships we see in the family, particularly that of Anna and Kate, can both nourish and destroy. Anna and Kate emotionally sustain each other, for instance, even as Anna undergoes painful medical procedures in order for Kate to survive. At the same time, Kate feels increasingly wasted and consumed by her struggle to remain alive, and to a great degree no longer wants to be sustained. Moreover, Anna compares her decision to file the lawsuit for medical emancipation with giving fuel to a fire. Another of the epigraphs Picoult chooses, the poem “First Fig” by Edna St. Vincent Millay, talks about a candle burning at both ends. The family, like that candle, is metaphorically burning itself out.
More than any of the other characters, Jesse and Brian display particular preoccupations with fire. Jesse turns out to be the arsonist setting fires all over the city, while Brian, a career firefighter, earns his living putting fires out. Although Jesse and Brian approach fire in different ways, fire means essentially the same thing to both of them. They view it as a destructive and essentially uncontrollable force, and in that sense fire to them serves as a symbol of Kate’s cancer and the effect that cancer is having on their family, which is figuratively burning out. Just as Brian puts out actual fires at work, he tries at home to put out figurative fires, such as the emotional problems Anna has in response to Kate’s health and Jesse’s negative behavior in reaction to Kate. Jesse’s destructive acts, notably his setting fire to several buildings, stem from his overwhelming sense of guilt over his inability to save Kate. His feeling of powerlessness regarding Kate’s cancer turns into rage, which he releases by burning down buildings. For Jesse, fire also serves as a way to gain his father’s attention, albeit indirectly. Jesse feels neglected because his parents focus so much on Kate, but by setting fires he can literally call his father’s attention any time he chooses.
Stars and Dark Matter
Stars and dark matter function as separate, but related, symbols in the novel. Because stars emit light, we can see where they are and how they move. But dark matter, as Brian explains to Julia, can’t be seen. We only know it exists because we can measure the gravitational effect it has on the visible objects, including stars, around it. Similarly, the references to stars in the novel, which come predominantly from Brian, relate to the general situations characters find themselves in. When Brian talks about twin stars, for instance, and how the light from one star can be so bright that it obscures the light of the other star, the metaphor clearly points to the relationship between Anna and Kate. Because her illness draws so much of their parents’ attention, Kate figuratively obscures Anna’s presence. In another example, we learn that Brian and Sara named Anna after the constellation (and galaxy) Andromeda, said to be located in the sky between her mother and father. Anna, similarly, has one parent on either side of her in her court battle, with one supporting her decision and one fighting it. Furthermore, in Greek mythology, Andromeda’s parents sacrificed her to save their country, much as Anna’s parents force Anna to make sacrifices to save Kate, and to a large degree, their family.
Dark matter, on the other hand, refers to the hidden motivations influencing the behavior of the characters. For Anna, that motivation is her desire to fulfill Kate’s wish to die, which prompts Anna to file the lawsuit at the center of the novel. For Jesse, the metaphor pertains to his feelings of guilt over not being able to save Kate and his desire for more attention from his parents, both of which lead him to start setting fires. For Campbell, the wish to hide his epilepsy motivates him, causing him to lie about his need for a service dog and providing the reason he ended his relationship with Julia when they were younger. In each case, the characters try to keep their motivations hidden, but those motivations still show themselves in the behavior of the characters, just as an observer can detect the presence of dark matter by its effects on its surroundings.
Kate’s Central Line
Types Of Dark Matter
More than her baldness or the scarring on her skin, Kate’s central line, meaning the catheter protruding from her chest that serves as the main port into Kate’s body for her treatments, symbolizes her cancer. Repeatedly in the novel, characters note the presence of Kate’s central line. For instance, when Kate receives her first dose of cord blood, harvested from Anna’s umbilical cord just moments after her birth, Sara watches the doctors connect the bag to the central line. The most notable episode involving Kate’s central line occurs when Kate, Anna, and Sara shop for Kate’s prom dress. Kate becomes frustrated because the dresses are cut too low. When the saleswoman, thinking Kate’s concern is that she doesn’t want to show too much skin, suggests a dress that will cover what she calls “a fair amount of cleavage,” Kate becomes angry. Kate opens the top of her blouse revealing the catheter sticking out from her chest and asks the saleswoman if the dress will cover it.