Dark matter Dark matter is invisible. Based on the effect of gravitational lensing, a ring of dark matter has been detected in this image of a galaxy cluster (CL0024+17) and has been represented in blue. Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but accounts for most of the matter in the universe. Astrophysicists hypothesized dark matter because of discrepancies between the mass of large astronomical objects determined from their gravitational effects and the mass calculated from the observable matter (stars, gas, and dust) that they can be seen to contain. Although the existence of dark matter is generally accepted by the mainstream scientific community, some alternative theories of gravity have been proposed, such as MOND and TeVeS, which try to account for the anomalous observations without requiring additional matter. Overview Estimated distribution of matter and energy in the universe, today (top) and when the CMB was released (bottom)
Physicists check whether neutrinos really can travel faster than light | Science According to Einstein's theory of special relativity nothing – not even neutrinos – can travel faster than the speed of light in a vacuum. Photograph: Cine Text/Allstar The scientists who last month appeared to have found that certain subatomic particles can travel faster than light have fine-tuned their experiment to check whether the remarkable discovery is correct. Their modified experiments – which are the result of suggestions from other physicists about potential flaws in their research – should be completed before the end of the year. The original experiment, reported last month, involved firing beams of neutrinos through the ground from Cern near Geneva to the Gran Sasso lab in Italy 720 kilometres (450 miles) away. The finding sent the physics world into a frenzy because it appeared to go against Albert Einstein's theory of special relativity. First time around, the Cern scientists fired pulses of neutrinos lasting around 10 microseconds each through the rock to Gran Sasso.
Theory of relativity The theory of relativity, or simply relativity in physics, usually encompasses two theories by Albert Einstein: special relativity and general relativity. Concepts introduced by the theories of relativity include: Measurements of various quantities are relative to the velocities of observers. In particular, space contracts and time dilates.Spacetime: space and time should be considered together and in relation to each other.The speed of light is nonetheless invariant, the same for all observers. The term "theory of relativity" was based on the expression "relative theory" (German: Relativtheorie) used in 1906 by Max Planck, who emphasized how the theory uses the principle of relativity. In the discussion section of the same paper Alfred Bucherer used for the first time the expression "theory of relativity" (German: Relativitätstheorie). Scope The theory of relativity transformed theoretical physics and astronomy during the 20th century. Two-theory view History
Finding a direction of time in exotic particle transformations Unlike our daily experience, the world of elementary particle physics is mostly symmetrical in time. Run the clock backward on your day and it won't work; run the clock backward on a process in particle physics and things are just fine. However, to preserve certain fundamental aspects of space-time the Standard Model predicts that certain reversible events nevertheless have different probabilities, depending on which way they go. This time-reversal asymmetry is remarkably hard to observe in practice since it involves measurements of highly unstable particles. New results from the BaBar detector at the Stanford Linear Accelerator Center (SLAC) have uncovered this asymmetry in time. Researchers measured transformations of entangled pairs of particles, including the rates at which these transformations occurred. A direct consequence of relativity in particle physics is the presence of three related symmetries, known as CPT: charge, parity, and time.
Neutrino oscillation Observations A great deal of evidence for neutrino oscillation has been collected from many sources, over a wide range of neutrino energies and with many different detector technologies. Solar neutrino oscillation The first experiment that detected the effects of neutrino oscillation was Ray Davis's Homestake Experiment in the late 1960s, in which he observed a deficit in the flux of solar neutrinos with respect to the prediction of the Standard Solar Model, using a chlorine-based detector. Solar neutrinos have energies below 20 MeV and travel one astronomical unit between the source in the Sun and detector on the Earth. Atmospheric neutrino oscillation Reactor neutrino oscillation Many experiments have searched for oscillation of electron anti-neutrinos produced at nuclear reactors. Beam neutrino oscillation Neutrino beams produced at a particle accelerator offer the greatest control over the neutrinos being studied. Theory where Since . restored) . .
These Are Some of the Most Ancient and Distant Galaxies Ever Discovered—And They're Glorious Leading Light: What Would Faster-Than-Light Neutrinos Mean for Physics? The stunning recent announcement of neutrinos apparently exceeding the speed of light was greeted with startled wonderment followed by widespread disbelief. Although virtually every scientist on record expects this discovery to vanish once more detailed analysis takes place, dozens of researchers are exploring the question whose answer could shake the foundations of physics: What if this anomaly is real? Neutrinos are ghostly particles that only weakly interact with normal matter; trillions of neutrinos stream through our bodies every second. Last month researchers from the European OPERA (Oscillation Project with Emulsion-tRacking Apparatus) collaboration reported clocking pulses of neutrinos moving at speeds that appeared to be a smidgen faster than light-speed. The credibility of the OPERA scientists who made the supposed discovery of superluminal neutrinos is not in doubt.
Biocentrism (cosmology) Biocentric universe (from Greek: βίος, bios, "life"; and κέντρον, kentron, "center") — also known as biocentrism — is a concept proposed in 2007 by American doctor of medicine Robert Lanza, a scientist in the fields of regenerative medicine and biology, which sees biology as the central driving science in the universe, and an understanding of the other sciences as reliant on a deeper understanding of biology. Biocentrism states that life and biology are central to being, reality, and the cosmos — life creates the universe rather than the other way around. It asserts that current theories of the physical world do not work, and can never be made to work, until they fully account for life and consciousness. Critics have questioned whether the theory is falsifiable. Hypothesis Lanza has said that he intends to publish aspects of biocentrism in peer-reviewed scientific journals. Synopsis of Lanza's book Biocentrism Reception See also References
7 Superpowered Animal Senses You Won't Believe Are Possible The human imagination is pretty limited when it comes to animal senses. We call people with good vision "eagle eye," and believe that toucan's can smell cereal because they have big noses. It turns out the animal kingdom has plenty of creatures whose senses go beyond what we can conceive without our head exploding. Silvertip Grizzlies Can Smell You From 18 Miles Away (And Across Time) Humans use smell to get us excited about pie before we actually put it in our mouths, and not much else. His nose is a time-traveler. It knows who walked down the street last night at 11PM, what the soles of their shoes were made of, the brand of cigarette they were smoking. ... and tell you Ingrid had a secret admirer last spring when they fixed the sidewalk. Fortunately for the sake of this article, and unfortunately for the sake of everyone who's afraid of bears, the silvertip grizzly's sense of smell is seven times stronger than that of the bloodhound. Jumping Spiders Can See Four Primary Colors Wrong.
Neutrinos: Everything you need to know - physics-math - 27 September 2011 Read more: "Neutrinos: Complete guide to the ghostly particle" "…We don't allow faster-than-light neutrinos in here," says the barman. A neutrino walks into a bar…" As reports spread of subatomic particles moving faster than light and potentially travelling through time, such gags were born. But apparently super-hasty motion is not the only strange thing about neutrinos. What exactly are they? First predicted in 1930 by Wolfgang Pauli, who won a Nobel prize for this work in 1945, they are produced in various nuclear reactions: fusion, which powers the sun; fission, harnessed by humans to make weapons and energy; and during natural radioactive decay inside the Earth. If they are so stealthy, how do we know they are there at all? Most commonly, experiments use large pools of water or oil. Where are these experiments found? Other detectors pick up naturally-produced neutrinos. , is buried under Antarctic ice. What's cool about neutrinos? Anything else? Do they have any practical applications?
How old do I look? How old do I look? Can you tell how old something is just by looking at it? You will find out when you play "What's Older?" We will show you five pictures of similar things, such as people, buildings, or cars. The things in the pictures are all different ages. In each group, arrange the pictures by age, oldest on the left, youngest or newest on the right. When you solve a puzzle, you can start your collection of beautiful mini-posters from the GALEX space telescope mission. Signs of aging Some people are good at telling other people's ages. Astronomers can tell the ages of galaxies—or least the ages of the galaxies' light. What clues do astronomers use to tell the age of a galaxy? Cosmic time stamp Light travels in waves, like energy moves through the ocean in waves. No matter what, light always travels at the same speed in space. No matter what, light always travels at the same speed in space: 300,000 kilometers (or 186,000 miles) per second (in round numbers).
Neutrinos: faster than the speed of light? By Frank Close To readers of Neutrino, rest assured: there is no need yet for a rewrite based on news that neutrinos might travel faster than light. I have already advertised my caution in The Observer, and a month later nothing has changed. If anything, concerns about the result have increased. The response to my article created some waves. I already mentioned some of the problems with the experiment – how it measures the time and the distance involved at huge accuracy, and then takes the ratio to get a speed. This aspect of my personal mystery typifies the problems that the actual experimenters have. A neutrino is detected in Italy, 500 miles from CERN, and the time is recorded. More theoretical perhaps, but from a Nobel Laureate, Sheldon Glashow, comes evidence of an inconsistency in the evidence for super-luminal neutrinos. Ultimately though, as I said in The Observer article, it is experiment that decides and it doesn’t matter how many theorists say nay.