- 2931 - DARK MATTER - explorations? - Researchers remain unsure about what exactly dark matter is. Originally, some scientists conjectured that the missing mass in the universe was made up of small faint stars and black holes, though detailed observations have not turned up nearly enough such objects to account for the significant amount of dark matter's influence.
--------------------------- 2931 - DARK MATTER - explorations?
- How did we ever come up with dark matter even existing? How do we think something is there that we can not see?
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- It all started in the 1930’s when a Swiss astronomer, Fritz Zwicky, noticed that galaxies in a distant cluster were orbiting one another much faster than they should have been given the amount of visible mass they had. To explain this he proposed than an unseen substance, which he called ‘dark matter“, might be tugging gravitationally on these galaxies. It was invisible mass.
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- Since then, researchers have confirmed that this mysterious material can be found throughout the cosmos, and that it is six times more abundant than the ‘normal matter’ that makes up ordinary things like stars and people.
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- The current leading contender for dark matter is a hypothetical particle called a “Weakly Interacting Massive Particle“, or WIMP, which would behave sort of like a neutron except would be between 10 and 100 times heavier than a neutron or a proton.
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- If dark matter is made from WIMPs, they should be all around us, invisible and barely detectable. So why haven't we found any yet? While they wouldn't interact with ordinary matter very much, there is always some slight chance that a dark-matter particle could hit a normal particle like a proton or electron as it travels through space.
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- Researchers have built experiment after experiment to study huge numbers of ordinary particles deep underground, where they are shielded from interfering radiation that could mimic a dark-matter-particle collision.
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- The problem? After decades of searching, not one of these detectors has made a credible discovery.
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- Does dark matter consist of more than one particle? Ordinary matter is made up of everyday particles like protons and electrons, as well as a whole zoo of more exotic particles like neutrinos, muons and pions.
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- Some researchers have wondered if dark matter, which makes up 85 percent of the matter in the universe, might also be just as complicated. There is no good reason to assume that all the dark matter in the universe is built out of one type of particle. It could be dozens of different particles?
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- “Dark protons” could combine with “dark electrons” to form “dark atoms“, producing configurations as diverse and interesting as those found in the visible world. While such proposals have increasingly been imagined in physics labs, figuring out a way to confirm or deny them has so far eluded scientists.
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- Do ‘dark forces’ exist? Along with additional particles of dark matter, there is the possibility that dark matter experiences forces analogous to those felt by regular matter. Some researchers have searched for "dark photons," which would be like the photons exchanged between normal particles that give rise to the electromagnetic force, except they would be felt only by dark matter particles.
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- Physicists in Italy are gearing up to smash a beam of electrons and their antiparticles, known as positrons, into a diamond. If dark photons do exist, the electron-positron pairs could annihilate and produce one of the strange force-carrying particles, potentially opening a brand-new sector of the universe.
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- Could dark matter be made of “axions‘? As physicists increasingly fall out of love with WIMPs, other dark-matter particles are starting to gain favor. One of the leading replacements is a hypothetical particle known as an axion, which would be extremely light, perhaps as little as 10 raised to the 31st power less massive than a proton.
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- Axions are now being searched for in a few experiments. Recent computer simulations have raised the possibility that these axions could form star-like objects, which might produce detectable radiation that would be quite similar to mysterious phenomena known as ‘fast-radio bursts‘, FRB’s.
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- What are the properties of dark matter? Astronomers discovered dark matter through its gravitational interactions with ordinary matter, suggesting that this is its main way of making its presence known in the universe.
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- But when trying to understand the true nature of dark matter, researchers have remarkably little to go on. According to some theories, dark-matter particles should be their own antiparticles, meaning that two dark-matter particles would annihilate with one another when they meet.
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- The “Alpha Magnetic Spectrometer” (AMS) experiment on the International Space Station has been searching for the telltale signs of this annihilation since 2011 and has already detected hundreds of thousands of events. Scientists still aren't sure if these are coming from dark matter, and the signal has yet to help them pin down exactly what dark matter is.
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- Does dark matter exist in every galaxy? Because it so massively outweighs ordinary matter, dark matter is often said to be the controlling force that organizes large structures such as galaxies and galactic clusters.
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- A long-standing mystery in particle physics are the puzzling results of a European experiment known as DAMA/LIBRA. This detector, located in an underground mine below the Gran Sasso mountain in Italy, has been searching for a periodic oscillation in dark matter particles.
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- This oscillation should arise as the Earth moves in its orbit around the sun while flying through the galactic stream of dark matter surrounding our solar system, sometimes called the dark matter wind. Since 1997, DAMA/LIBRA has claimed to see exactly this signal, though no other experiment has seen anything like this.
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- A signal from the beginning of time has led some physicists to suggest that dark matter might have an electrical charge. Radiation with a wavelength of 21 centimeters was emitted by stars in the universe's infancy, just 180 million years after the Big Bang.
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- It was then absorbed by cold hydrogen that was around at the same time. When this radiation was detected in February, 2020, its signature suggested that the hydrogen was much colder than scientists had predicted.
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- Astrophysicists hypothesized that dark matter with an electrical charge could have drawn heat away from the all-pervasive hydrogen, sort of like ice cubes floating in lemonade, But this conjecture has yet to be confirmed.
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- Can ordinary particles decay into dark matter? Neutrons are regular matter particles with a limited lifetime. After around 14.5 minutes, a lone neutron unmoored from an atom will decay into a proton, an electron and a neutrino. But two different experimental setups give slightly different lifetimes for this decay, with the discrepancy between them about 9 seconds.
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- Earlier this year, physicists suggested that if 1 percent of the time, some neutrons were decaying into dark-matter particles, it could account for this anomaly. OK, but the science remains dark. We really can not explain dark matter’s existence.
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- If you can figure it out please let the rest of us know.
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------------------------------- Other reviews available:
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- 2897 - DARK MATTER - produces many new theories? When something seems a little mysterious or we just don’t understand what is going on we like to describe it with the adjective ‘dark’. This is one of the reasons why the term ‘dark’ matter got coined which was first proposed to explain the anomaly observed in the rotational velocities of galaxies.
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- 2886 - DARK MATTER - mysteries? When something seems a little mysterious or we just don’t understand what is going on we like to describe it with the adjective ‘dark’. We do not understand 95% of the universe we live in. The 5% that is left is everything we know about and are still learning about.
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- 2861 - DARK MATTER - how we know it is there? - The big idea of dark matter is that there’s something other than these known particles contributing in a significant way to the total amounts of matter in the Universe. We look at the motions of these objects, we look at the gravitational rules that govern orbiting bodies, whether something is bound or not, how it rotates, how structure forms, and we get a number for how much matter there has to be in there.
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- 2823 - DARK MATTER - needs to be a new 2020 discovery? Researchers remain unsure about what exactly dark matter is. Originally, some conjectured that the missing mass in the universe was made up of small faint stars and black holes, though detailed observations have not turned up nearly enough such objects to account for dark matter's influence.
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- 2790 - DARK MATTER - to discover what it is? - There is a race to discover “dark matter“. Dark matter is that elusive substance that has mystified science since the 1930s, when astronomers first realized galaxies needed some kind of invisible gravitational glue to hold them together. No one knew what it was, so it was named “dark matter“.
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- 2768 - DARK MATTER - What is the Universe Made of? Since 1970 astronomers have believed Dark Matter existed because studying the orbits of galaxies and stars around galaxies could not be calculated based on the stars and matter they could see. Either Kepler’s and Newton’s formulas for the laws of gravity and motion were incorrect, or there was matter there that they could not find.
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- 2767 - DARK MATTER - confirmed by new measurements? - The first Fast Radio Burst detected came from a galaxy that is about 4 billion light-years away from Earth. Using dispersion measurements for these FRB’s, astronomers are able to make a rough calculation of how much dark matter the radio waves passed through before reaching earth.
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- 2718
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- 2631 - DARK MATTER - dark coffee would help? Astronomer’s 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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- 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.
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- 1934 - Can Dark matter make blackholes?
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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?
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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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- December 9, 2020 DARK MATTER - explorations? 2931
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--------------------- --- Thursday, December 10, 2020 ---------------------------
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