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--------------------- 2631 - DARK MATTER - dark coffee would help?
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- The science of “cosmology” is using a diverse array of high-precision measurements to reconstruct our universe’s history in remarkable detail. The computer being one of the most amazing instruments.
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- When we compare different measurements of the expansion rate of the universe, the patterns of light released in the formation of the first atoms, the distributions in space of galaxies and galaxy clusters and the abundances of various chemical species, we find that they all tell the same story, and all support the same series of events.
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- This line of research has been more successful than we had any right to have hoped. However, the discoveries made in recent decades have raised as many new questions as they have given answered.
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- What is our universe is actually made of? Cosmological observations have determined the average density of matter in our universe to very high precision. But this density turns out to be much greater than can be accounted for with “ordinary atoms“. Is there some other matter that we still don’t know about?
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- After decades of measurements and debate, the overwhelming majority of our universe’s matter, about 84 percent, is NOT made up of the atoms we know and love, or of any other known substance.
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- Although we can feel the gravitational pull of this “other matter“, we simply do not know what it is. This mysterious stuff is invisible. We call it “dark matter.”
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- For almost as long as we have known that dark matter exists, physicists and astronomers have been devising ways to try to learn what it’s made of. They’ve built ultra-sensitive detectors, deployed in deep underground mines, in an effort to measure the gentle impacts of individual dark matter particles colliding with atoms.
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- They have built exotic telescopes, sensitive not to optical light but to less familiar gamma rays, cosmic rays and neutrinos, to search for the high-energy radiation that is thought to be generated through the interactions of dark matter particles.
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- They have searched for signs of dark matter using incredible machines which accelerate beams of particles, typically protons or electrons, up to the highest speeds possible, and then smash them into one another in an effort to convert their energy into matter. The idea is these collisions could create new and exotic particles, including the kinds of particles that make up the dark matter of our universe.
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- Over the past 15 years experiments designed to detect individual particles of dark matter have become a million times more sensitive, and yet no signs of these elusive particles have appeared. And although the Large Hadron Collider has by all technical standards performed beautifully, with the exception of the Higgs boson, no new particles or other phenomena have been discovered.
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- We have more open questions now than we did a decade or two ago. And at times, it can seem that the more precisely we measure our universe, the less we understand it.
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- Throughout the second half of the 20th century, theoretical particle physicists were often very successful at predicting the kinds of particles that would be discovered as accelerators became increasingly powerful. It was a truly impressive run.
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- But our prescience seems to have come to an end, the long-predicted particles associated with our theories have stubbornly refused to appear. Perhaps the discoveries of such particles are right around the corner, and our confidence will soon be restored. But right now, there seems to be little support for such optimism.
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- The search has widened to the larger the spiral galaxy, the faster it spins it should be flying apart. The super spiral galaxies are actually rotating even faster than predicted based on the visible sizes of the galaxies. The fastest of these super spirals whips some of its stars around at up to 1,250,000 miles per hour. By some estimates, that's nearly three times as fast as our Sun circles our galaxy.
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- This means these gargantuan galaxies have higher dark matter to visible matter ratios than smaller spirals, like our Milky Way, to account for the extra rotation speed. The finding also suggests something else: a maximum size for how big a spiral galaxy can get.
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- The rotation rates of spiral galaxies with 10 to 20 times as much visible matter as the Milky Way were measured. These super spirals were found to have unexplainably fast galaxies rotation rates.
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- When one object orbits another, its orbital speed depends on the mass of the central object. Whether a planet orbiting a star or a star orbiting the center of a galaxy, it will orbit faster if the central object has more mass.
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- Most spiral galaxies rotate at speeds proportional to the amount of visible matter, like stars and gas, they contain. The dark matter in these galaxies also contributes to the rotation speed. But the amount of dark matter tends to be proportional to the amount of visible matter, too, so rotation speeds are still proportional to visible mass.
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- But these super spirals rotated much faster than astronomers would have predicted based on their visible mass, meaning they actually have a much higher ratio of dark matter to visible matter.
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- The most massive spiral galaxies, the buildup of dark matter might be stopping more stars from forming. So even as they look to larger clumps of galaxy-hosting dark matter, they probably won’t find spirals that are much larger.
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- Our search in to the unknown is like picking up pebbles of knowledge along the beach while a whole ocean of unknown expands out over the horizon.
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-------------------------------------- Other reviews about Dark Matter
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- 2497 - DARK MATTER - What is it exactly? To explain the Observable Universe we are continuously learning new things. Astronomers have three major unproven theories, Dark Matter, Dark Energy, and Cosmic Inflation. We know something exists with each of these but we just do not know what it is or what causes it.
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- 2401 Science is examining the evidence for Dark Matter making up 80% of all the matter in the Universe. But, we can not find what it is? Matter and Energy are two forms of the same thing according E = mc^2. ALL MATTER is 30% of the total and ALL ENERGY is 70% of the total. Of the 30% of all matter 25% is Dark and only 5% is “Ordinary matter” that we see as our Ordinary Universe. 95% is unknown Dark stuff with 30% holding things together and 70% ever expanding and separating all the matter in its expansion.
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- 2214 - Dark Matter is what is holding our own galaxy together. This same observation is repeated with every other galaxy that astronomers have studied. Their math formulas would not work if there was not some unknown gravity pull holding galaxies together.
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- 2082 - Dark matter throws us a curve. Dark matter is one of the most important, least understood building blocks of our universe. This gravitationally inferred matter accounts for 85 percent of the universe’s mass and is believed to form the underlying foundations upon which all galaxies are built. Our current understanding of dark matter is not entirely correct. This should not be a complete surprise considering we have yet to detect direct evidence of the elusive material.
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- 1934 - Can Dark Matter make Blackholes? Gravity alone is not sufficient to create a Blackhole by itself. We also need the electromagnetic forces. We are discovering many new dwarf galaxies. Maybe these discoveries will lead us to the source of Dark Matter?
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- 1888 - What is the Universe made of? What we observe , know , and think we understand is less than 5% of what is out there. The research is accelerating to discover, what is Dark Matter?
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- 1850 - Dark Mater is 23% of the Universe. It is 90% of all matter. Do we need new math to discover this? Is it new mass or is it undiscovered energy acting like mass?
-astronomical observations.
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- 1823 - Dark Matter and the extinction of the dinosaurs? Earth passes through the disk of our Galaxy every 32 million years. How might this event be involved in the evolution of life on Earth?
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- 1820 - Dark Matter - What do we know about it matters. It is 25% of all the mass-energy in the Universe. It does not interact with light but does interact with gravity.
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- 1777 - Dark Matter - New clues keep coming in but the mystery of what Dark Matter is remains a mystery. Soon some new breakthrough in physics will help explain this.
- 1722 - Dark Matter, what is it? If you include Dark Energy than 95% of the Universe is made of this stuff. Remember matter and energy are the same thing, E = mc^2.
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- 1658 - Gravity grows weaker with distance, 1 / r^2, therefore distant objects must orbit more slowly or they would fly off into space.
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- 1636 - What does Dark Matter look like? - #1636 - Dark Matter accounts for 5.4 times as much mass as Ordinary Matter in the Universe.
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- 1594 - 4% Ordinary Matter and the rest is Dark Matter and Dark Energy. Several methods are used to calculate the structure of the Universe and each reaches the same conclusion. 73% is Dark Energy that we do not understand and another 23% is Dark Matter that we can figure out what it is made of. This Review uses simple methods that you can understand to reach these same conclusions.
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- 1585 - Today the space is expanding due to Dark Energy at 47,000 miles per hour per million lightyears, but, it is also accelerating faster and faster.
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- 1596 - Using Redshift calculation to learn how fast the Universe is expanding. This is one step in understanding that 73% of the mass-energy of the Universe is some sort of anti-gravity causing the galaxies to recede away from each other.
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- 1597 - Using the Brightness Method to calculate the distance to galaxies. To illustrate we will again use the familiar star Vega.
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- 1598 - Stars and galaxies would be flying our of their orbits if it were not for unseen mass existing around the galaxies. The previous Review 1597 calculated that 73% of the Universe was composed of Dark Energy, leaving the 27% composed of matter. How did we learn that 85% of that matter was “ Dark Matter” and not ordinary matter?
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- 1599 - We need a breakthrough in physics to explain Dark Matter. Why is 96% of the Universe “ Dark”? What else could explain how these conclusions could not be true.
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- 1576 - - We need a breakthrough in physics to explain Dark Matter. WIMPs should be colliding with us all the time at 536,880 miles per hour. That is how fast the Sun is going through the Galaxy. There have been unexplained WIMP detections that change with the seasons. Change with the Earth’s rotation around the Sun. Going with the wind of WIMPs or against the galactic wind of WIMPS. Dark Matter will soon be discovered.
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- 1535 - Gravitational lensing has come form theory to being an essential tool for astronomers . Hubble Telescope has used the lensing as a magnifying glass to see galaxies back to years after the Big Bang. An announcement will be made shortly, stay tuned.
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- 1517 - What is the universe made of - 5 calculations used to measure Dark Matter.
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- 1485 - Where is the Dark Matter?
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- 1427 - The picture of Dark Matter Collision
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- 1341 - Investigating Dark Matter
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- 1218 - Could Dark Matter be another Universe?
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- 1204 - Dark Matter, wht do we think it is?
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- 1075 - Dark Matter
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- 837 - Weighing Galaxies using Hot Gas?
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- 718 - What could Dark Matter be?- Dark Matter is there, but, what is it? There are at least three candidates being studied: MACHOS, WIMPS, Hydrogen Gas
There are at least three reasons why astronomers believe that Dark Matter is there: Hot Gas, Colliding Galaxies, Rotating Galaxies
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- 692 - Dark Matter and Blackholes.
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- 594 - Dark Galaxy
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- 374 - What is Dark Matter.
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- February 18, 2020 2631
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--------------------- Monday, February 24, 2020 -------------------
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