...What is Dark Matter? The Oxford dictionary defines dark matter as a non-luminous material which assumed to exist in space. But what does this mean? If dark matter is non luminous how do we know it’s there? How can we detect it? These are the kind of questions I will try to answer in this short article. Discovery: In the mid to late 19th century scientists observed that stars orbiting nearby galaxies were rotating faster than expected. The speed calculated indicated that the gravity created by them could not contain the matter within the stars. Therefore meaning that the stars should have been ripped apart from their own gravity. This indicated that there could be some other form of matter that is acting within the galaxy; which could have certain properties that explain the larger amount of gravity e.g. more massive matter. Properties of Dark Matter: Figure 1 Figure 1 Dark matter is hard to “get your head” around as scientists say that you can’t see it; then how can it exist? Dark matter is said to be “non-luminous”, therefore it does not absorb, give off or reflect light, which means we cannot observe the existence of Dark Matter (But we could detect it: See section on “Detection”). Detection: Although we cannot see Dark Matter it supposedly makes up 22% of the universe, compared to 4% of normal matter (See Figure 1). The evidence of how dark matter could exist is from experiments held in particle accelerators, such as the Large Hadron Collider at CERN. As Dark Matter...
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...astro-ph/0301505 UMN–TH–2127/03 TPI–MINN–03/02 January 2003 arXiv:astro-ph/0301505v2 25 Jan 2003 TASI LECTURES ON DARK MATTER∗ KEITH A. OLIVE† William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 USA E-mail: olive@umn.edu Observational evidence and theoretical motivation for dark matter are presented and connections to the CMB and BBN are made. Problems for baryonic and neutrino dark matter are summarized. Emphasis is placed on the prospects for supersymmetric dark matter. 1. Lecture 1 The nature and identity of the dark matter of the Universe is one of the most challenging problems facing modern cosmology. The problem is a long-standing one, going back to early observations of mass-to-light ratios by Zwicky1 . Given the distribution (by number) of galaxies with total luminosity L, φ(L), one can compute the mean luminosity density of galaxies L= which is determined to be2 L ≃ 2 ± 0.2 × 108 ho L⊙ M pc−3 (2) Lφ(L)dL (1) where L⊙ = 3.8 × 1033 erg s−1 is the solar luminosity. In the absence of a cosmological constant, one can define a critical energy density, ρc = 3H 2 /8πGN = 1.88 × 10−29 ho 2 g cm−3 , such that ρ = ρc for three-space curvature k = 0, where the present value of the Hubble parameter has been defined by Ho = 100ho km Mpc−1 s−1 . We can now define a critical mass-to-light ratio is given by (M/L)c = ρc /L ≃ 1390ho(M⊙ /L⊙ ) (3) ∗ Summary of lectures given at the Theoretical Advanced...
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...neutrinos, and the mysterious dark matter. In the present, scientists are still bombard about dark matter and what it really is. Although, scientists do not know what dark matter is, they are certain of what it is not. Dark matter is not in the form of stars and planets that we see and it is known to make up about 25% of the entire Universe. By using the effect of gravitational lensing, astronomers are able to determine that dark matter is not affected by most of the other baryonic matters. They also found that dark matter is the responsible substance that makes up most of the masses in the universe (found in galaxies, dwarf galaxies, and cluster galaxies). Dark matter is also the primary influence of gravitational pulls. The mysterious and magnificent space that seems almost empty to the naked eye has fascinated mankind for as long as history can remember. The universe seems empty because it is made up of gas which is primarily composed of particles such as protons, electrons, photons, neutrinos, and dark matter. Dark matter is known to make up about 25% of the entire Universe but scientists have yet to understand completely about this mysterious subatomic particle. What is dark matter and where did it come from? What is really the natural function of dark matter? Where and how can dark matter be found? These questions have been the ultimate challenge for astronomers for the past decades. Scientists and Astronomers have always known that dark matter influenced the cosmos in...
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...known universe is made up of Dark Matter. What is Dark Matter? Why does it take up so much space? How can we use it for the betterment of our universe? There are so many questions that arise when something we know little about makes up so much of where we live. What I Already Know About My Topic: I chose to write about Dark Matter in the universe because it is a very rarely known thing in human understanding. When someone thinks space, they think planets, galaxies, and “Star Wars.” When I took my first high school science class, the very last section we had was about Dark Matter, and I had visibly freaked out to the point that my teacher asked me if I was okay. When it comes to “galactic” science, I tend to know quite a bit more about the subject than those that taught it to me because I was always a “Discovery Channel” child. Dark Matter is an interesting thing that you seldom hear or see anything pertaining to. This is why I have chosen to “teach” you about this potentially catastrophic element. Have you ever just taken a moment to look up at the stars and thought, “Wow, there’s quite a lot of black up there! I wonder what it is?” Well, ladies and gentlemen, that “space” that surrounds us is actually not space at all! It is filled with boundless amounts of an element that doesn’t exist within the Earth’s atmosphere! Surprisingly enough it is filled with a substance called Dark Matter, otherwise known as ‘Anti-matter.” Now you may be filling...
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...Dark matter is everywhere, shooting through you every second of your day. You must ask yourself the question of how a particle so heavy in mass, a particle that can influence whole galaxies in the way they spin and their positioning in the universe, is still yet to be detected? This is down to the fact it doesn’t interact with light at all, it is literally ‘invisible’. Dark matter is the building blocks of the universe, without it, star systems like the Milky Way would cease to exist. Dark matter is an invisible mass that has such a large gravitational pull it can affect the speeds of entire galaxies in a cluster. The majority of the mass from a galaxy is actually considered to be dark matter. For example, “The Coma Cluster of Galaxies” is always moving at extreme rotational speeds. However, we can measure the mass of these galaxies by measuring the speed at which they travel and after the measurement it is obvious there is far too much mass to account for the amount of gas and planets in that cluster therefore, you must conclude that there is something else there making it so heavy. It appears there is actually about ten times as much dark matter in this cluster than there is...
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...Top 10 Biggest Things In The Universe Do you think the pyramids are big? How about the Burj Dubai? Both of those are nothing compared to Mt. Everest. They’re all huge when you look at them from a human or ‘earthly’ perspective. These objects however, are microscopic when compared to some of the things that exist in our universe. Let’s explore them. 10) Largest Asteroid Ceres is the largest asteroid we know of. It is almost 600 miles in diameter which makes it as large as California. It’s massive enough that its gravity forces it to have a spherical shape and also shares the title of ‘Dwarf Planet’. It’s so big, that it contains 25% of the mass of the asteroid belt. If you took all the asteroids in the asteroid belt and glued them together, that new object would only be about 2.5 times as big as Ceres. 9) Largest Planet Located in the constellation Hercules, planet TRES4 is 70% larger than Jupiter in diameter, but has only 80% of Jupiter’s mass. Because of how close it orbits to its sun, it is thought that the intense heat expands the gasses that make up this planet, resulting in an almost ‘marshmallow-like’ density. It’s holds the title of the largest planet we’ve discovered so far. Update: Science is never finished. Since this list was compiled, observations of an exoplanet called WASP-17b suggest that it is even bigger than TRES4. Despite its radius being twice that of Jupiter’s, it only has half the mass. This makes it even “fluffier” than TRES4. 8) Largest Star ...
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...galaxy doesn’t need lots of stars to be big. It can be dominated by the dark matter, just as our own galaxy Milky Way is 95% dark matter by mass. However, a galaxy has been found that is as big as our galaxy but is almost entirely dark matter. Named Dragonfly 44, this galaxy consists of 99.9% dark matter. The galaxy was first detected last year through the use of WM Keck Observatory and the Gemini North Telescope in Manuakea, Hawaii, when the Dragonfly Telephoto Array noticed a region of the sky in the constellation Coma. Albeit being relative near to the earth, this galaxy hasn’t been detected by the astronomers for years as it is very dim. Astronomers determined the amount of dark matter in Dragonfly 44 by using the DEIMOS instrument installed on Keck II to measure the velocities of stars. It took them 33.5 hours over a period of six nights to calculate the mass of the galaxy....
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...other pictures taken on NASA’s Astronomy Picture of The Day. The appearance of this galaxy was especially fascinating. I was drawn by the image’s bright spots and blue and pink colors. The image is a combination of a visible light image by the Hubble Space Telescope in 2002, an X-ray image from the Chandra Observatory of the hot gas in pink in 2014, and computer generated dark matter in blue through gravitational lens distortions. The bright spots in the image are galaxies within and beyond the cluster. Remains of radiation from the Big Bang along with electrons from hot gas in the galaxy cluster creates the warping seen from earth. Hubble's high resolution shows the distortion in space caused by gravity. This warps the background of galaxies in the image. The more mass in the cluster the larger the distortions. The long vertical galaxy in the image is far more distant and the light is being stretched as it travels towards us through gravitational lens caused by the massive cluster. The pink color across the image is the hot gas that was slowed down by the collision. The blue color across the picture is dark matter...
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...Modern Cosmology Cosmology, or modern astronomy, has deep roots in the Big Bang theory, which seeks to explain the beginning of the universe, the structure of the objects within it, and the laws that govern it. The Big Bang and string theory are two highly respected theories in science for the universe. In the history of astronomy, very little discoveries have been more important than the introduction of the new heliocentric cosmology. It was common belief up until the 1500s that the Earth was the center of the universe-- with everything else orbiting around it. With the 1500s, however; a new idea came to light. Nicholas Copernicus suggested in his book “On the Revolution of the Heavenly Spheres,” that the Sun was the center of the solar system. Later, into the early 1600s, Johannes Kepler was an advocate Copernicus’ heliocentric universe. Kepler is responsible for discovering that planets revolve around the Sun in elliptical orbits—which is the first of his three laws of planetary motion. His second law, according to "Johannes Kepler: The Laws of Planetary Motion" (n.d.), is “the line joining the planet to the sun sweeps out equal areas in equal times as the planet travels around the ellipse,” (para. 14). "Johannes Kepler: The Laws of Planetary Motion" (n.d.), also states that the third of Kepler’s laws is “the ratio of the squares of the revolutionary periods for two planets is equal to the ratio of the cubes of their semi-major axes,” (para. 15). Kepler also proposed that...
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...protons and other baryonic matter only make up about four percent of the known universe.1 So this leaves a huge chunk of over ninety percent unaccounted for. What is this mystery matter that is so crucial to the fabric of the Universe but at the same time is eluding the general public? The mystery ingredients are: Dark Energy and Dark Matter. To be more exact dark matter makes up 23% of our Universe and dark energy makes up 73%.1 Since the beginning of time people have always wondered what is out there in the universe and how it came to be. As the years went by and as technology evolved, astronomers started to answer some of these questions but only to bring up more new questions to be answered. When astronomers first figured out that the universe was expanding, they thought it was in a state of deceleration after it had been expanding for billions of years from the Big Bang. However to their disbelief, when they looked at very faraway supernovae and galaxies, they noticed that the universe was not decelerating but in fact accelerating.1 So this discovery led to the major question of what is the driving force behind the acceleration of the universe. There are many theories out there that try to predict the cause of the acceleration but the one that is most widely accepted is the theory of dark energy. The first person to actually come across dark energy was in fact Einstein. He didn’t even know at the time when he figured this out that it was dark energy. At the time he called...
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...starting point for gathering particle data was the Cosmic Microwave Background, relic radiation left over from the Big Bang. The supercomputer Titan created the data and put it in a format that could be downloaded onto weaker machines, for our purposes. This data was then consolidated and manipulated so that the evolution of features of the cosmos could be seen on a small, detailed scale, which allows for close observations and analysis. The results yielded depict many examples of the innate relationship between ionization and energy density, as well as how these features are related to temperature and photon density. Using a stereoscopic display, dark matter collapse was simulated in 3D so that the details of the connection between gravity and energy, mainly how the gravity of dense regions affects structure formation by causing dark matter to collapse and form halos, could be seen from an advantageous perspective. Overall, these simulations allow us to better understand how the cosmos has evolved over billions of years in order to give rise to stars and planets capable of supporting life. 1. Introduction All of the energy that forms the universe was at one time concentrated at a single point. This extremely concentrated point of energy expanded in what is known as the Big Bang. Blumenthal et al. (1986) Hyperinflation caused the tiny inhomogeneities in the original concentrated point to be amplified on a massive scale. Therefore, even though the young, expanding universe was...
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...Week 4 Assignment Lincoln Flelcher Sci/151 April 25th, 2016 Ellis Hodgdon Week 4 Assignment In this here paper we will touch base on some of the topics and questions that's been asked at random. First, we will begin with; Cosmology is the study of the universe as a whole. Describe the foundation of modern cosmology. Secondly, what is The Big Bang Theory and is a part of cosmology. Explain the Big Bang theory and provide an example of one experiment scientists performed that supported it. The third is The Milky Way just one galaxy that resulted from the Big Bang. Describe the structure of the Milky Way and how dark matter influences it. When was dark energy discovered? How has that discovery changed people's view of the universe? Fourth and lastly, What is a theory of everything? What does it aim to do to people's understanding of the universe as a whole? It is said that there are three founding fathers to what we call Modern Cosmology. Father one was Nicholas Copernicus. Copernicus brought forth the idea that it was not the earth that was the center of the universe, but the Sun instead and that everything, the moon, the planets, everything evolved around it. Second was Johannes Kepler. It was Kepler who made the discovery that the earth, the moon and all the other planets were indeed in orbit about the sun in ellipses. According to Counterbalance Foundation (1995), "This was the first of his three famous laws of planetary motion, which describe mathematically how the...
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...Andrew Erbland RELS 376-02 Science, Religion, and Their Relationship To describe the relationship between science and religion, I must first define the two individually. To me, science is a systematic process of making observations through experiments and evaluating the results to draw conclusions. It uses a specific method in which one first poses a question. Then with research and other information, a hypothesis is constructed to be tested with repetition. The results will indicate whether the hypothesis is true or not. If false, the data collected is recycled to form a new hypothesis for testing again. This process insures that all information and facts are collected first and then are used to construct scientific laws and theories. For if a theory is constructed first and then backed by correlating data, then it is not science at all. Science uses the totality of the circumstances to draw these conclusions and does not pretend to confirm laws that can not be proven. Religion on the other hand does not hold such a factual process to avoid false judgments. Much of its foundation is based on faith and belief in what is passed down generationally, typically containing a view that some superhuman or divine power has developed what we see and interact with around us. It is often difficult to distinguish the so-called right belief because nothing can be proven by objective observations or factual events. I’ve come to agree with William James’s definition of religion as what...
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...Time Management (A) Lesson pacing in the classroom is extremely important. The reason it is so vitally important is because it lends purpose, direction, and structure to the classroom. Teachers, of course, need to develop lesson plans which meet certain educational objectives. Teachers could accomplish this with a nice long lecture with a follow-up question/answer session. However, they also need to keep the students engaged, interested, and retaining the information. Teachers don't really want a Ferris Bueller's Day Off classroom scenario..."Anyone?...Anyone?", nor do students. Okay, that's fine. A teacher could incorporate tons of interaction and many different activities into the lesson. Here's lies the rub...they need to do all of this in 45 minutes. Lesson pacing ensures that the teacher can accomplish all of these classroom needs. (B) One might think that if a class includes English Language Learning (ELL) students, then the pacing of the lesson would need to slow significantly. However, this is not necessarily the case. Of course it will need to slow some to allow for language clarification and to allow the ELL students time to translate in their heads. The pacing really just needs a little change-up. Direct instruction should be in more simplified language and with more interaction. The use of visual aids and graphic organizers should be incorporated into direct instruction. Direct instruction also need not be given in one big chunk...
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...Dark Energy, Dark Matter In the early 1990's, one thing was fairly certain about the expansion of the Universe. It might have enough energy density to stop its expansion and recollapse, it might have so little energy density that it would never stop expanding, but gravity was certain to slow the expansion as time went on. Granted, the slowing had not been observed, but, theoretically, the Universe had to slow. The Universe is full of matter and the attractive force of gravity pulls all matter together. Then came 1998 and the Hubble Space Telescope (HST) observations of very distant supernovae that showed that, a long time ago, the Universe was actually expanding more slowly than it is today. So the expansion of the Universe has not been slowing due to gravity, as everyone thought, it has been accelerating. No one expected this, no one knew how to explain it. But something was causing it. Eventually theorists came up with three sorts of explanations. Maybe it was a result of a long-discarded version of Einstein's theory of gravity, one that contained what was called a "cosmological constant." Maybe there was some strange kind of energy-fluid that filled space. Maybe there is something wrong with Einstein's theory of gravity and a new theory could include some kind of field that creates this cosmic acceleration. Theorists still don't know what the correct explanation is, but they have given the solution a name. It is called dark energy. What Is Dark Energy? Universe Dark...
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