Skip to main content

Home/ Diigo In Education/ Group items tagged particles

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
ZeroDivide .

Nova Fabric of the cosmos The illusion of time full video - YouTube - 48 views

www.youtube.com/watch

Time

shared by ZeroDivide . on 03 Aug 14 - No Cached
  • The Evolution of Time and the Carnot Cycle at the Edge of the Universe
  • ZeroDivide . on 03 Aug 14
     
    We are all time travelers... drifting through time at a steady pace, one moment at a time. In what direction are we moving through time? Or does time move through us? How many dimensions of time are there? Though slightly allegorical, three-dimensional time offers physics new parameters, accounting for conventional and exotic physical phenomena, while maintaining the conservation of energy and symmetry groups found in physical law.  I began playing with the idea that all of physics could be reduced to just interactions between spatial and temporal coordinates. I wondered if inertia and momentum might be composed strictly of temporal components. This would require extra time dimensions. Could inertia or momentum be used as indicators of multi-dimensional time? What about charge, spin, and other properties of matter? Answers to some of these questions appeared to reside in neutrino research, specifically neutrino flavor oscillation.  The universality between Thermodynamics and Temporal Mechanics can reduce the fundamental forces of nature into a single expression, a new equivalence principle, which can be used as the generator for the evolution of time. Once Quantum Mechanics is seen through the lens of three-dimensional time, the EPR paradox looses its mystique. The speed of light may be restricted to a set speed limit within each individual frame of reference, however, frames of reference can undergo periods-of-time at varying rates of the passage-of-time. If the positive side of absolute zero is a state of condensed matter, what is on the negative side of absolute zero? Uncondensed matter?  The anti-matter aspect of the Dirac equations may have been misinterpreted. The convention is to assume that "matter" is composed of "particles" distinctly different from "antimatter" composed of "antiparticles". The assumption of one time dimension locks in this interpretation of the Dirac Equations. However, the uniform production of particles and antipa
Gareth Jones

Looking in the Wrong Places | Edge.org - 5 views

www.edge.org/...er-looking-in-the-wrong-places

NaturalScience senseperception paradigm

shared by Gareth Jones on 19 May 18 - No Cached
  • We should be very careful in thinking about whether we’re working on the right problems. If we don’t, that ties into the problem that we don’t have experimental evidence that could move us forward. We're trying to develop theories that we use to find out which are good experiments to make, and these are the experiments that we build.   We build particle detectors and try to find dark matter; we build larger colliders in the hope of producing new particles; we shoot satellites into orbit and try to look back into the early universe, and we do that because we hope there’s something new to find there. We think there is because we have some idea from the theories that we’ve been working on that this would be something good to probe. If we are working with the wrong theories, we are making the wrong extrapolations, we have the wrong expectations, we make the wrong experiments, and then we don’t get any new data. We have no guidance to develop these theories. So, it’s a chicken and egg problem. We have to break the cycle. I don’t have a miracle cure to these problems. These are hard problems. It’s not clear what a good theory is to develop. I’m not any wiser than all the other 20,000 people in the field.
  • I’m still asking myself the same question that I asked myself ten years ago: "What is going on in my community?" I work in the foundations of physics, and I see a lot of strange things happening there. When I look at the papers that are being published, many of them seem to be produced simply because papers have to be produced. They don’t move us forward in any significant way. I get the impression that people are working on them not so much because it’s what they’re interested in but because they have to produce outcomes in a short amount of time. They sit on short-term positions and have short-term contracts, and papers must be produced.
  • The field that I mostly work in is the foundations of physics, which is, roughly speaking, composed of cosmology, the foundations of quantum mechanics, high-energy particle physics, and quantum gravity. It’s a peculiar field because there hasn’t been new data for almost four decades, since we established the Standard Model of particle physics. There has been, of course, the Higgs particle that was discovered at the LHC in 2012, and there have been some additions to the Standard Model, but there has not been a great new paradigm change, as Kuhn would have put it. We’re still using the same techniques, and we’re still working with the same theories as we did in the 1970s.
  • ...10 more annotations...
  • That makes this field of science rather peculiar and probably explains why there hasn’t been much progress. But it’s not like we don’t have any questions that need to be answered. There are a lot of questions that have been around for decades. For example, what is dark energy? What is dark matter? What are the masses of the Standard Model particles? And what’s up with the foundation of quantum mechanics? Is a theory that's fundamentally not deterministic, where we cannot predict outcomes, the last word that we have, or is there something more to it? Is there maybe another underlying structure to reality?
  • but we haven't reached the fundamental level. Maybe we will never reach it. Certainly, the theories that we have right now are not all there is. The question is, of course, if we don’t have any guidance by experiment, how do we make progress? And are we doing the right thing?
  • We’ve reached this point where we have to carefully rethink if the criteria that we’re using to select our theories are promising at all. If one looks at the history of this field in the foundations of physics, progress has usually been made by looking at questions that, at least in hindsight, were well posed, where there was an actual mathematical contradiction. For example, special relativity is incompatible with Newtonian gravity. If you try to resolve this incompatibility, you get general relativity.
  • There are various similar examples where such breakthroughs have happened because there was a real problem. There was an inconsistency and people had to resolve it. It had nothing to do with beauty. Maybe beauty was, in some cases, the personal motivation of the people to work on it. There’s certainly some truth to this, but I don’t think it’s good to turn this story around and say that if we only pay attention to this motivation that comes from ideals of beauty it will lead to progress.
  • If we are working with the wrong theories, we are making the wrong extrapolations, we have the wrong expectations, we make the wrong experiments, and then we don’t get any new data. We have no guidance to develop these theories. So, it’s a chicken and egg problem. We have to break the cycle. I don’t have a miracle cure to these problems. These are hard problems. It’s not clear what a good theory is to develop. I’m not any wiser than all the other 20,000 people in the field.
  • The way that research is funded in foundations of physics and in many other fields just puts a lot of things at a disadvantage that are not pursued anymore. Typically, everything that takes longer than three years to complete, no one will start it because they can’t afford it. They can literally not afford it.
  • Who makes the decisions about the funding? Superficially, people say that it's a funding agency, so it’s the university who get to hire people. But that puts the blame on the wrong party. In the end it’s the community itself who makes the decisions. What do the funding agencies do if they get a proposal? They send it to reviewers. And who are the reviewers? They're people from the same community. If you look at how hiring decisions are being made, there’s some committee and they are people from the same community. They have some advisory boards or something, which contains people from the same community.
  • Even if that wasn’t so, what the people in these committees would be doing is looking at easy measures for scientific success. Presently, the most popular of these measures are the number of publications and the number of citations. And maybe also whether the person has published in high-impact journals. So, these are the typical measures that are presently being used. But what do they measure? They primarily measure popularity. They indicate whether somebody’s research is well received by a lot of people in the same community. And that’s why once a research area grows beyond a certain critical mass, you have sufficiently many people who tell each other that what they’re doing is the good thing to do. They review each other’s papers and say that that’s great and it's what we should continue to do. It’s a problem in all communities that grow beyond a certain size.
  • I later came to the United States and then Canada, and that gave me the opportunity to learn a lot about quantum gravity. I also figured out that much of what goes on in quantum gravity is very detached from reality. It’s pretty much only mathematics. Yes, the mathematics is there, but I still don’t know if it’s the mathematics that describes reality.
  • That’s the very reason why we don’t normally think of gravity as a weak force. It’s the only force that is left over on long distances, and the reason for this is that it adds up. It gets stronger the more mass you pile up. More precisely, we should say that the reason we find it so hard to measure quantum gravitational effects is that we either have a particle that has very pronounced quantum properties, like, say, a single electron or something like that, but then it’s so light that we cannot measure the gravitational field. Or we have some object that is so heavy that we can measure the gravitational field, but then it doesn’t have quantum properties. Okay, so that’s the actual problem.
Elaine Vazquez

Solar Storm Smacks the Earth -- And We've Got Video - 3 views

mashable.com/...nasa-solar-storm-video

shared by Elaine Vazquez on 27 Jan 12 - No Cached
  • to a bow wave in front of a fast moving vessel. In the shock, electrons and protons were accelerated to nearly the speed of light and appear in the video clip as streaks of light as they hit SOHO’s detectors
    • Elaine Vazquez
      Elaine Vazquez on 27 Jan 12
       
      What is solar wind?
  • analogous
  • analogous
  • ...2 more annotations...
  • charged particles
    • Elaine Vazquez
      Elaine Vazquez on 27 Jan 12
       
      What are charged particles? I thought I knew, but I actually forgot. I think I'll call my mom later and ask her about charged particles.
  • “the most intense solar energetic particle storm since 2005.”
    • Elaine Vazquez
      Elaine Vazquez on 27 Jan 12
       
      Are things going to get worse? I will be reading to find this out.
Gregory Louie

Students tap into technology - Pittsburgh Tribune-Review - 1 views

www.pittsburghlive.com/...s_612698.html

shared by Gregory Louie on 23 Feb 09 - Cached
  • use their laptops to read "Don Quixote" and Dante's "Divine Comedy" on the Internet
  • Technology is the wave of the future
  • a computer program
  • ...7 more annotations...
  • "Most jobs require computers," noted Brittnee Stephen, 16, as she assembled a slideshow on her HP Mini laptop. "It's good that we're learning it now."
    • Ed Webb
      Ed Webb on 23 Feb 09
       
      The technology is still very visible, if students are talking in terms of 'computers' rather than the skills involved. We don't talk about 'paper' but writing, critical reading etc. Yet here the platform itself is emphasized. Early days, I guess.
  • has just begun incorporating technology
    • Ed Webb
      Ed Webb on 23 Feb 09
       
      Uh, no. They have been using 'technology' forever, in the form of, say, books.
  • students seem far more interested in learning via interactive technology than they had been with a chalkboard and an overhead projector
    • Ed Webb
      Ed Webb on 23 Feb 09
       
      Well, the problem here is that some of that can be ascribed to novelty. Once every class uses 'interactive technology' (yuk) then how much difference will there be? The tools are great. All tools can be useful. But focus on the pedagogy, people!
    • Scott Merrick
      Scott Merrick on 25 Feb 09
       
      I'm for focusing on understanding. I love the word "pedagogy" because most lay people don't really know what it entails--theory (which can be anything institutional or community deems effective or correct), practice (which, as we know, can be summed up with the phrase "mileage will vary"), and some third thing which if I could come up with it I'd have the magic 3 elements in an effective argument. I think effective tools used effectively by effective teachers (there! 3 uses of one adjective!) will remain effective as long as they are used to promote understanding. No argument here, Ed, just sayin'...
    • Ed Webb
      Ed Webb on 26 Feb 09
       
      Perhaps the magic third thing would be 'attitude' or 'state of mind'? Alternatively, perhaps another of those non-transparent terms, 'praxis'. The point I was trying to make, of course, was that it ain't what you use, it's the way that you use it.
  • "I think the kids that have turned school off because it's boring to them will come here and see something familiar,"
    • Ed Webb
      Ed Webb on 23 Feb 09
       
      Boring and familiar seem to me to be closely related, not opposites. I suspect that often when students say their learning environment is 'boring' they mean 'challenging'.
  • Educational technology does not come cheaply
    • Ed Webb
      Ed Webb on 23 Feb 09
       
      The cost of books is astronomical!
  • "Learning is changing,"
    • Ed Webb
      Ed Webb on 23 Feb 09
       
      Was it EVER the case that we could "just deliver a lecture and expect all the kids to get it"?
    • Gregory Louie
      Gregory Louie on 26 Feb 09
       
      Computer technology in my classroom has revolutionized my teaching of biology. Instead of static images on a printed page, or talk and chalk, my students can manipulate 3-D images of DNA, RNA and proteins. These have even been embedded in a research-based learning progression that leads the students to a robust understanding of the foundational elements of molecular literacy. 1. Atoms and molecules are constantly in motion. (A visualization is not possible on a 2-3 printed page.) 2. All atoms and molecules have a 3-D structure that determines how they interact with other particles. 3. Charges and other intermolecular forces play a role in atomic and molecular interactions. My students can see these for themselves, change the number of particles in a box, or the distribution of charge on a large particle or the temperature of the box and other thought experiments which they can follow in real-time. There is no way, I could do that without the computer!
Marc Patton

Conservation of Linear and Angular Momentum During a Collision - 2 views

serc.carleton.edu/...example9.html

Science Teaching_Ideas Teacher_Resources

shared by Marc Patton on 12 Feb 13 - No Cached
  • Marc Patton on 12 Feb 13
     
    This activity is intended as an introduction to the concept of the angular momentum of a particle moving in a straight line.
Martin Burrett

Auditorium - 99 views

www.playauditorium.com

music flash games puzzle

shared by Martin Burrett on 26 Mar 12 - Cached
  • Martin Burrett on 26 Mar 12
     
    This is a fun musical themed logic game where players must direct light particles into containers by placing arrows in the correct places. http://ictmagic.wikispaces.com/Educational+Games
Caroline Dutton

Health - 0 views

www.cleancookstoves.org/...health-impacts.html

clean cookstoves health research project 2013

shared by Caroline Dutton on 12 Feb 13 - No Cached
  • The World Health Organization (WHO) estimates that exposure to smoke from the simple act of cooking is the fifth worst risk factor for disease in developing countries, and causes almost two million premature deaths per year – exceeding deaths attributable to malaria or tuberculosis.
  • Women in developing countries are also at risk of head and spinal injuries, pregnancy complications, and maternal mortality from the strenuous task of carrying heavy loads of firewood or other fuels. Frequent exposure to cookstove smoke can also cause disabling health impacts like cataracts, which affect women more than men, and is the leading cause of blindness in developing countries.
  • Rudimentary wood-fired cookstoves and open fires emit fine particles, carbon monoxide, and other pollutants at levels up to 100 times higher than the recommended limits set by WHO
  • ...5 more annotations...
  • A randomized-control study in Guatemala led by the University of California, Berkeley, found that halving exposure to indoor air pollution with a chimney stove brought about a reduction in severe pneumonia, and that larger reductions in exposure had more pronounced effects. A systematic review of all available studies on the link between solid fuel use and child pneumonia has found an almost doubling of risk for those exposed.
  • Burns from open fires and unsafe cookstoves are another insidious risk faced by poor households dependent on kerosene, open fires, and unstable metal or clay cookstoves, contributing to a substantial percentage of the estimated 300,000 burn deaths that occur annually
  • While the link between exposure to cookstove smoke and a wide range of health problems such as pneumonia, chronic obstructive pulmonary disease, and lung cancer is well established, the current body of evidence linking cookstoves with other potentially important health effects is compelling but less documented
  • Nearly all of the existing evidence is based on observational studies that compare groups using open fires and traditional cookstoves with those using cleaner fuels, with very little being directly obtained from studies that directly measure the effects of interventions.
  • More evidence is needed to demonstrate that the levels of exposure reduction delivered by clean cookstove and fuels will result in declines in related illnesses and deaths.
  • Caroline Dutton on 12 Feb 13
     
    This is the Global alliance for Clean Cookstoves website. They offer much information about the issues surrounding the topic and their action plan for affecting change!
Jac Londe

Startup turns carbon dioxide into fuels - 1 views

phys.org/...rtup-carbon-dioxide-fuels.html

co2 dioxyde carbon carbon dioxide fuels science

shared by Jac Londe on 18 Jun 12 - No Cached
  • Today, carbon dioxide (CO2) is a hot topic. Scientists around the globe are searching for ways to store, dispose of, or prevent the formation of the greenhouse gas, which is a major driver of global climate change. Liquid Light hopes to take this concept one step further and harness waste CO2 as a source of carbon to make industrial chemicals and fuels.
  • Take CO2 and mix it in a water-filled chamber with an electrode and a catalyst. The ensuing chemical reaction converts CO2 into a new molecule, methanol, which can be used as a fuel, an industrial solvent or a starting material for the manufacture of other chemicals.
  • Bocarsly likes to call the process "reverse combustion" because it is like running a burning reaction backwards. Instead of burning fuel and oxygen to produce CO2, the CO2 converts back into fuel and oxygen.
  • ...2 more annotations...
  • Cole set up a flask containing a solution of CO2 and a pyridinium catalyst dissolved in water. In place of sunlight, which emits a broad spectrum of wavelengths of light, she shined on the flask a blue light-emitting diode (LED) because it gives off certain wavelengths that are highly efficient at driving the reaction. In the flask she placed an electrode that is activated by particles of light, or photons. "We used a semiconductor electrode that would allow us to substitute light for electricity," said Cole.
  • The Princeton scientists did some additional studies, and made a surprising discovery: They could turn CO2, which contains only one carbon, into a compound with a carbon-carbon bond, which vastly increases the possibilities for creating commercial applications.
Jac Londe

Scientists capture first direct images of theoretically predicted magnetic monopoles - 19 views

www.physorg.com/...es-theoretically-magnetic.html

images capture scientists science onde

shared by Jac Londe on 25 Oct 10 - No Cached
  • first direct images of
  • magnetic monopoles
  • Image representing 12 micrometer x 12 micrometer of artificial magnetic metamaterial where monopoles can be seen at each end of the Dirac strings, visible as dark lines. The dark regions correspond to magnetic islands where the magnetization is reversed. (Image courtesy of Paul Scherrer Institute)
  • ...3 more annotations...
  • “A magnetic monopole is a ‘hypothetical’ particle that is a magnet with only one single magnetic pole,” says UCD Theoretical Physicist, Professor Hans-Benjamin Braun from the UCD School of Physics, who co-led the study with Dr Laura Heyderman from the Paul Scherrer Institute in Switzerland.
  • “Some of the most important theories explaining how quantum matter behaves in the universe are based on their existence, but they have eluded direct imaging since they were first theoretically conceived in the 1930s.”
  • Initially conceived by the British-Swiss theoretical physicist Dirac in 1931, monopoles were proposed to occur as emergent quasiparticles in so called pyrochlore spin-ice systems by Castelnovo, Moessner and Sondhi in 2008.
Jac Londe

Confirming Einstein, scientists find 'spacetime foam' not slowing down photons from far... - 13 views

phys.org/...scientists-spacetime-foam.html

einstein scientists quantum onde particles photons

shared by Jac Londe on 24 Mar 15 - No Cached
  • Jac Londe on 24 Mar 15
     
    One hundred years after Albert Einstein formulated the general theory of relativity, an international team has proposed another experimental proof. In a paper published today in Nature Physics, researchers from the Hebrew University of Jerusalem, the Open University of Israel, Sapienza University of ...
1 - 11 of 11
Showing 20▼ items per page