Skip to main content

Home/ Diigo In Education/ Group items tagged onde

Rss Feed Group items tagged

Jac Londe

Limites d'exposition humaine à l'énergie électromagnétique radioélectrique da... - 6 views

  •  
    Quelle est notre capacité d'absorption des ondes életromagnétiques ?
Jac Londe

All Measures and Formulas - 48 views

  •  
    Everything you need to know about formats and calculations for all kinds of chemical elements and materials
Jac Londe

Onera - 3 views

  •  
    la lumière, observation, détection, identification
Jac Londe

The Electron is round. Incredibly round | ZME Science - 59 views

  • The experiments, which spanned more than a decade, suggest that the electron differs from being round by less than 0.000000000000000000000000001 cm. Just so you can get an estimate, if the electron were as big as the solar system, it would still be spherical to within the width of a human hair.
  • a team from the Imperial College London concluded that the electron is actually incredibly round, thus making the most accurate estimate of its shape.
Jac Londe

Truly random numbers - 41 views

  • At a quantum scale, the motion of electrons and protons is completely and genuinely random, since it doesn’t follow a clear path of cause and effect. You basically have no idea what’s going to happen. If you can measure this somehow, than you’ve got yourself an absolutely random value.
  • “If you want to defeat an adversary who is trying to hack into your system, basically you need large quantities of random numbers,”  Sussman said.
  • “…a truly random number generator will provide impenetrable encryption for communications — be they military transmissions, secure banking, or online purchasing — that underpin the modern connected world.”
  • ...3 more annotations...
  • The researchers used pulses of laser light, which only last a trillionth of a second, that were directed through a diamond. The light comes and goes through the diamond, however when it exists it’s changed, since it has to pass through quantum vacuum fluctuations, the microscopic flickering of the amount of energy in a point in space. Scientists can measure these pulses of light that emerge from the experimental set-up, measurements which are the truly random.
  • random numbers
  • with quantum physics
Jac Londe

Buckminster_Fuller - 1 views

  •  
    In 1927 Fuller resolved to think independently which included a commitment to "the search for the principles governing the universe and help advance the evolution of humanity in accordance with them... finding ways of doing more with less to the end that all people everywhere can have more and more."[
Jac Londe

Thinking about solar? It's easier to start small | Green Tech - CNET News - 12 views

  • Thinking about solar?
  • Green Ray Solar this week is expected to announce UL certification for a solar panel that puts out alternating current, rather than direct current as most solar photovoltaic panels do today. AC panels can be simpler to install and wire together than traditional panels, which makes a piecemeal approach easier,
  • Traditionally, solar panels are tied into a device called an inverter, which converts the direct current from panels into household alternating current. Strung together, several panels produce enough voltage to run an inverter which, sized for a rooftop array, is roughly as big as a computer monitor.
  • ...2 more annotations...
  • A microinverter brings that DC-to-AC function onto each individual panel. Proponents say the technology simplifies installation and improves panel performance.
  • For example, shading on one panel will not affect the output of other panels connected to it, as happens with panels connected to a centralized inverter.
Jac Londe

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

  • 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.
1 - 20 of 24 Next ›
Showing 20 items per page