What is the dark matter?
Frequently Asked Questions in CosmologyWhen astronomers add up the masses and luminosities of the stars near the Sun, they find that there are about 3 solar masses for every 1 solar luminosity. When they measure the total mass of clusters of galaxies and compare that to the total luminosity of the clusters, they find about 300 solar masses for every solar luminosity. Evidently most of the mass in the Universe is dark.
Related QuestionsIs Even the Bible Relative? [Free Republic]The story of dark matter is best divided into two parts. First we have the reasons that we know that it exists. Second is the collection of possible explanations as to what it is. We believe that that the Universe is critically balanced between being open and closed. We derive this fact from the observation of the large scale structure of the Universe. It requires a certain amount of matter to accomplish this result. Call it M.Related Questions
What is the difference between dark matter and dark energy?
Cosmology Primer: FAQDark matter behaves much like a collection of ordinary matter made of particles, except that it's dark. In particular, dense regions of dark matter tend to become even more dense, as the mutual gravitational force of the matter pulls it together. For this reason, we suspect that the dark matter is some sort of new, massive particle, just one we haven't yet discovered in the laboratory (yet).
Related QuestionsWill JWST contribute to the dark matter research?
The James Webb Space TelescopeJWST can not directly see "dark matter," the unseen matter that makes up a large fraction of the mass of galaxies and clusters of galaxies, but JWST can measure its effects. One of the best ways to measure mass is through the gravitational lens effect. As described by Einstein's General Relativity theory, a light beam passing near a large mass will be slightly deflected, because space-time is disturbed by the presence of mass.
Related QuestionsWhat is "missing mass" and "dark matter?
FAQMissing mass and dark matter are two terms coined to explain puzzling observations in astronomy. In observations of distant galaxies, there appears to be more gravitational attraction between nearby galaxies, and between the inner and outer parts of individual galaxies, than can be accounted for by the visible objects (stars) making up the galaxies.
Related QuestionsWill we ever be able to detect dark matter or dark energy directly?
Cosmology Primer: FAQHopefully. Different candidates for what the dark matter particles are lead to different strategies for detecting them, either directly in laboratories here on Earth or indirectly through high-energy particles from space. But numerous efforts are being undertaken, and we might find dark matter in the near future. Dark energy is an even longer shot; if it is a strictly constant vacuum energy, we could never detect it directly, while a dynamical field could conceivably be detected.
Related QuestionsHow do you know that dark matter isn't just ordinary matter that we can't see?
Cosmology Primer: FAQWe can measure the total amount of matter through the gravitational field it creates, both in galaxies and in clusters of galaxies. But we can separately measure the amount of ordinary matter by less direct means. The traditional method is to study the abundances of light elements (hydrogen, deuterium, helium, and lithium) in the early universe.
Related QuestionsCan you prove that dark matter does not exist?
Is Even the Bible Relative? [Free Republic]I'm booking marking this for a more careful reading later. Until recently, I haven't had much time for the forum. But since I've been back, I've made a conscious effort to avoid the C v E threads. The reason, and I'm not embarrassed to say this, is that I'm currently rethinking my views on evolutionism, in large part as a result of research stimulated by these threads. And my obstinacy was equal to anyone's. Go figure. It also seems that the world had a completely different hydrology.
Related QuestionsPhysOrg: Is dark matter composed of sterile neutrinos?
Science LinksFNAL: DZero finds evidence of rare single top quark; Observation marks a step closer to finding Higgs boson PhysOrg: Alternative theory of gravity [TeVeS based on MOND] explains large structure formation -- without dark matter Eureka: Big magnet ready to face the big questions of the universe - World's largest superconducting magnet switches on [ATLAS] PhysOrg: The story of a 27km long machine and the fundamental building blocks of the Universe [LHC at CERN] BBC: US astronomers say they have fou.
Related QuestionsDoes it matter if I do not keep the first or second dimension run in the dark?
GE Healthcare Life Sciences - Frequently Asked QuestionsOn a practical level, it will make very little difference to the results unless very strong light levels are present. It is good laboratory practice to avoid exposing fluorescent dyes unnecessarily to light to reduce the risk of photobleaching. We therefore recommended that you do keep the first and second dimension gel runs in the dark. Light-excluding Ettan™ IPGphor lid covers are available for Ettan IPGphor Isoelectric Focusing Unit (product code: 80-6496-48).
Related QuestionsIs there any evidence that cold dark matter exists?
Ae-Al] Rev. David Holwick's collection of 35,000+ sermon ill...Well, we're talking about exotic matter. There's three kinds of exotic matter: cold dark matter, warm dark matter and hot dark matter...
Related QuestionsNo matter what I do, I keep getting those fine scratches on my dark colored car. What causes them?
Malm's Carnauba Wax and Polish outshines anything!This is probably one of the most asked questions we get. Actually, You cause those scratches! It happens when you try removing dirt from the paint by washing and drying the car. It can also happen when polishing or waxing or anytime you touch the car! Dirt is constantly falling on the paint. Some gets thrown on when driving on wet roads. Dirt is composed primarily of tiny particles of sand. When you wash the car, that sand gets into your sponge, rag, brush or wash mitt.
Related QuestionsWhy is the image too dark?
NASA - JPL Solar System SimulatorIf the "extra brightness" box is unchecked, check it. Each monitor is different, and many have differrent distributions of brightness to the naked eye (this is called "gamma").
Related QuestionsCan I sail after dark?
Frequently Asked Questions (FAQ) about Bareboat ChartersIn most cases Bareboat insurance regulations do not permit you to sail after dark. Exceptions are made in some areas for purposes of making a night crossing in order to make a daylight landfall.
Related QuestionsHow do we move in the dark room?
Dans le Noir?Visitors aren't allowed to move by themselves in the dark room as it could put the waiters at risk (remember the waiters/guides are blind and need clear walkways to work around the tables). If you wish to move or need to leave the dark room to go to the restrooms for instance, you just have to call your waiter; they will assist you anytime.
Related QuestionsAre the toilets in the dark?
Dans le Noir?Would be fun but, no toilets aren't in the dark! The toilets are located on ground floor level and first floor lounge and are fully lit.
Related QuestionsWhat about being in the dark?
Float IrelandThat's up to you. There's a light switch; you control the lights all the time. You can leave them on all through your float session. You can have music playing all through too if you like, and you can choose the music in advance. Floating is the best and fastest way to relax and many people find that silence and the dark help relax even more. But it's up to you, either way, floating is wonderfully relaxing and enjoyable.
Related QuestionsWhat is matter?
Cosmology & Particle Physics FAQThe schoolbook definition would be: Matter is what takes up space and has mass. Matter as we know it is composed of molecules, which themselves are built from individual atoms. Atoms are composed of a core and one or more electrons that spin around the core in an electron cloud. The core is composed of protons and neutrons, the former have a positive electrical charge, the latter are electrically neutral.
Related QuestionsRalphs Restitution Fund - Frequently Asked Questionsaction of the Court exists between the United States Attorney???s Office for the Central District of California (???USAO???) and defendant RALPHS GROCERY COMPANY (???RALPHS???). This action arises out of the Indictment in United States v. Ralphs Grocery Company, CR 05-1210-PA.Related Questions
What's the matter?
Encephalon DiveHallelujah! If the sea will draw out its dead and the dead and hell will draw out its dead, then the dead will be delivered at the mercy of their each individual deed/act.
Related QuestionsDo I have to ferment Kombucha Tea in the dark?
Kombucha FAQ Part 1fa miscellaneous - Frequently Asked Quest...No. It doesn't appear to make any difference. Kombucha can be fermented in full daylight, total darkness, or anywhere in-between. Some people living in far Northern climates such as Alaska, have reported very good results when fermenting their Kombucha Tea in full morning and afternoon sunshine during the winter months.
Related QuestionsWhy 'Dark Reader'?
Dark Reader - FAQVery simple: switch on a UV box in a darkened room and the walls (not to mention your teeth!) glow purple. Switch on the Dark Reader and the room remains just that - dark. It is important to remember that is not the amount of light but the quality of light that is important when looking at fluorescent DNA bands in a gel. With a UV box you are looking at bright DNA bands against a blazing UV background (that is not doing you or your DNA any good!).
Related QuestionsWhy are one or of more the WebCam images dark?
Bonaire WebCams - FAQIf some of the WebCams are dark and others speckled or gray or featuring cool light effects (especially the North BeachCam and DowntownCam), then it's very likely that you're looking at Bonaire at night. Bonaire is on Atlantic Standard Time (GMT-4) year round, and darkness runs from around 7-8pm until 5-6am. If it's daytime and the cameras are dark, then we might have a hardware problem and you should check the news column on the home page to see whether this is an on-going issue at the time.
Related QuestionsAre the chefs blind? Is the kitchen in the dark too?
Dans le Noir?The chefs are not blind and kitchen is lit, the Head chef and his team must be able to equally use each of their senses to deliver great cuisine. They are preparing creative and exciting dishes that play with flavours, using fresh and tasty ingredients for patrons to enjoy a unique culinary experience.
Related QuestionsWhat influenced His Dark Materials?
The Golden Compass | The HDM FAQ | His Dark Materials | Brid...Pullman's main influence for His Dark Materials is the 17th century epic poem 'Paradise Lost' by John Milton. He also cites Blake, Virgil, and Homer as influences, and Von Kleist's essay, 'On the Marionette Theatre'
Related QuestionsWhat are those dark donut shapes?
Cassini-Huygens: FAQSmall donut-like dark spots in images are actually out of focus dust specks on the filter wheels, lenses or other parts of the optics of the cameras. Because there is no way to clean the cameras in space, more of these spots may appear as the Cassini mission progresses.
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