LEDs Saving More Electricity than Solar can Produce

LED lighting can save more electricity than solar will produce, according to LED pioneer Roland Haitz, former chief technology officer, semiconductor products group, Hewlett-Packard (later Agilent).

 

"20 percent of the world's electricity that's generated is used for lighting. Three quarters of that can be saved by using LEDs; 15 percent of today's electricity consumption can be saved," he said at the Economist's Innovation Summit.

He said that there was a lot of noise around green technology and that projects relating to solar cells and wind energy tend to get a lot of government funding. However, he believes that focusing on technologies such as LEDs could make a bigger difference. Solar energy currently accounts for 0.5 percent of the world's supply, although some have predicted that it could  provide as much as 22 percent by 2050.

Haitz is in a good place to comment, as he has had the LED equivalent of Moore's Law named after him. Haitz's Law states that every decade, the cost per lumen falls by a factor of 10, the amount of light generated per LED package increases by a factor of 20 for a given wavelength of light.

Haitz says that LED lighting will be made extremely cheaply, with much better light output than the current 200 lumens per watt which are currently possible, compared with a standard 100 watt incandescent lightbulb which has an efficiency of around 17 lumens per watt.

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Posted in: electricity,environment,LED,light,solar,solar energy

Lasers that Flash in a Quintillionth of a Second

Making Electron Movies with an Attosecond Laser After splitting and then recombining two laser beams from the same origin, the resulting beam would be passed through a gas medium that further intensifies the beam's frequency.

An international team of researchers spanning Australia, North America, and Europe has created a model for a new kind of attosecond laser that should be able to film individual electrons as they participate in chemical reactions. Such high-res, high-speed data gathering has never been achieved before, and if successful the new laser system could have implications for everything from basic chemistry to complex pharmaceutical research and chemical engineering.

Capturing electrons on “film” isn’t easy--imagine the shutter speed you would need to capture something moving so fast that it can rotate a central hub in 151 billionths of a billionth of a second. That’s how fast the electron orbiting a hydrogen nucleus is moving, so in order to capture it in the act you need something with attosecond resolution. In other words, you need a laser capable of pulsing at the attosecond scale.

Attosecond laser pulses have been demonstrated before, but they were too weak to actually measure electron dynamics. For that, you need something both fast and intense. This new laser system satisfies both requirements, and does so with a relatively simple setup.

To get super-short bursts of laser light, you need to combine light waves of different frequencies in a very precise way such that they reinforce each other. This is easier said then done, particularly because it’s hard to get two different laser beams synchronized precisely. To overcome this, the researchers constructed a setup that runs a single laser beam through a beam splitter, producing two beams of different frequencies that are nonetheless the same beam. And because they share the same origin, they remain in sync.

But they’re still not at the attosecond level yet. Several other things have to happen to reach the proper intensities and durations necessary for attosecond-scale measurements. But a paper the team recently published in Nature Photonics outlines the road to attosecond resolutions in such a way that other researchers think its only a matter of time (and, more specifically, a matter of amplification) before we’re looking at individual electrons in a way in which we’ve never seen them before.

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New Solar Cells Producing Electricity From Both Light and Heat

PETE A small PETE device made with cesium-coated gallium nitride glows while being tested inside an ultra-high vacuum chamber. The tests proved that the process simultaneously converted light and heat energy into electrical current. Stanford University

Though the sun offers us a couple options for exploiting its energy -- light and heat -- we've always had to choose to use one at a time, because solar-energy technology hasn't been able to capture both typs of radiation simultaneously. Stanford researchers say that's about to change, however. Their new breakthrough could put solar power on par with oil, price-wise.

Using readily available materials, a team of engineers has come up with the first solar technology to combine photovoltaic and thermal electricity generation.

Called "photon enhanced thermionic emission," or PETE, the process uses cesium to more than double existing systems' efficiency levels. PETE devices could be easily incorporated into existing solar collection systems, and they're cheap to boot.

Photovoltaic (PV) cells get less efficient as they get hot, which is one of the biggest problems in solar efficiency. What's worse, silicon -- used in most PV cells -- can only absorb energy from certain parts of the light spectrum. Ultimately, more than half the solar energy hitting each cell is wasted.
  

The Stanford system exploits the excess heat, turning it into extra electricity.

Researchers led by Nick Melosh, an associate professor of materials science and engineering, coated a piece of semiconducting material with a thin layer of cesium. This allowed the cell to use both light and heat to generate electricity, Melosh says.

The team used gallium nitride in the tests because it can withstand high temperatures, but PETE systems of the future would likely include gallium arsenide, commonly used in household electronics.

The system has to get extremely hot in order to work -- the hotter the better, Melosh says -- so new PETE systems will be a better fit for huge solar farms than rooftop arrays.

They will need to include solar concentrators, but that creates another layer of efficiency, because less semiconducting material will be needed. Melosh says each device would require about a six-inch wafer of semiconducting material.

When used with the heat-conversion process, PETE devices could reach 60 percent efficiency, Melosh says. But as Stanford's news release points out, even 30 percent efficiency would bring solar power in line with the price of oil.

This video from Stanford further explains the process.

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Posted in: electricity,heat,light,solar cells,stanford university

Photons Can't Go Faster Than SoL

Shengwang Du and His Team Measured the Speed of a Photon Hong Kong University of Science and Technology

Hong Kong scientists claim to have proved that a single photon cannot travel faster than the speed of light in a vacuum, making time travel seemingly impossible.

These findings are consistent with Einstein’s claim that the speed of light is the “traffic law of the universe” or, otherwise put, that nothing can travel faster than light. Of course, humanity’s dream of time travel has long relied on the hope that Einstein was wrong. We got a glimmer of hope back in 1999 when scientists found superluminal (faster-than-light) propagation of optical pulses in some specific medium, the team said. Unfortunately, this was later revealed to be a visual effect, and the photons involved couldn’t actually transmit information.

Since then, there has been a debate surrounding whether or not a single photon might actually be able to travel faster than the speed of light. This experiment, conducted by a team at the Hong Kong University of Science and Technology and led by Professor Shengwang Du, measured the ultimate speed of a photon using controllable waveforms. An explanation, from the press release:

"HKUST's team used a demonstration which required not only producing single photons, but separating the optical precursor, which is the wave-like propagation at the front of an optical pulse, from the rest of the photon wave packet. To do so, Prof Du's team generated a pair of photons, and then passed one of them through a group of laser-cooled rubidium atoms with an effect called electromagnetically induced transparency (EIT). For the first time, they successfully observed optical precursors of a single photon.

The team found that, as the fastest part of a single photon, the precursor wave front always travels at the speed of light in vacuum. The main wave packet of the single photon travels no faster than the speed of light in vacuum in any dispersive medium, and can be delayed up to 500 nanoseconds in a slow light medium. Even in a superluminal medium where the group velocity (of an optical pulse peak) is faster than the speed of light in vacuum, the main part of the single photon has no possibility to travel faster than its precursor."

What that means for us: probably no time travel. Du says their results "confirm the upper bound on how fast information travels with light. By showing that single photons cannot travel faster than the speed of light, our results bring a closure to the debate on the true speed of information carried by a single photon." That indicates, in turn, that time travel is not possible, and that decades of beloved science fiction may not be entirely based on fact.

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Posted in: light,photons,speed,travel

Equation of God

              

                 Behold the, somehow, God Equation! Scientists working in the UK have discovered robust evidence that the creation of the earth and moon was a deliberate act. The researchers found that the earth, moon, and beyond were engineered according to a specific equation. They have dubbed it the God Equation.  

         The equation, which looks like this:

                  Shows a constant, unchanging relationship between the speed of light, the ratio between the circumference and diameter of a circle, and the radio frequency of hydrogen in space. Artificial intelligence engineer David Cumming, CEO of the Edinburgh-based company Intelligent Earth, recently discovered the equation, and said: "I am a scientist and as such I didn't at first really believe it myself. But physics is physics, and maths is maths, and you can't argue with it."
                 The discovery of the equation began with research by engineer Professor Alexander Thom (1894-1985) of Oxford University, into the properties of megalithic constructions such as Stonehenge. He found that their construction did not follow existing measurement systems, but did fit in to a pattern of specific lengths which he called megalithic yards. Two independent researchers Christopher Knight and Alan Butler, based in York, then showed that the megalithic system of measurement was directly derived from characteristics of the Earth's movements through space.

                     
                
                   Linking this system of measurements with known constants such as π (pi, the relationship between the circumference and diameter of a circle), Hl, the radio frequency of the hydrogen fine transition in space, Ω (0.0123456789 representing all the characters of the base 10 number system), and the speed of light in a vacuum C0 (C0 = 299,792.458km/sec), and building on research by Knight and Butler, and the work of Professor Alexander Thom, former Reading University doctoral researcher Cumming followed a research programme that resulted in his discovery of the God Equation. The God Equation shows a direct link between the speed of light, the radio frequency of hydrogen in space, pi, and earth's orbit, rotation and weight. As the possibility of the Earth having the exact required characteristics to fit the equation by chance is remote, and the equation has, in theory, been in existence since the beginning of the Universe, this means that the Earth's orbit, rotation and weight must have been engineered to fit this equation.

                    Cumming states: "Although the ratio of a diameter of a circle to its circumference has been known for thousands of years, we have only recently discovered the hydrogen line, the speed of light, and rediscovered the megalithic measurement system. The advance of science, combined with the uncovering of ancient knowledge passed down through the ages, has only now made the discovery of the God Equation possible."

 Well, overwhelming, except for a few little problems.

                   
                  For instance, the term Hl has units of MHz; the other parameters seem to be dimensionless; and C has units of km/sec. This does not compute. That seems like a rather fundamental error in a very simple equation that must have been formulated by a couple of the geniuses of the age, don't you think?
Oh, wait…there's that mysterious Ω term — maybe we're just missing its units. Except…"0.0123456789 representing all the characters of the base 10 number system". Oh, come on. I call shenanigans on that one. That's completely arbitrary and contrived.

                 How do you get earth's orbit, rotation, and weight from π?
So I plugged in all those numbers anyway, and did the calculation works out to a value for C of 361,448.9 MHz. This is a bit off.
                 Oh, but there's more! There's a footnote to the email I was sent that mentions that you have to calculate the speed of light in megalithic yards, derived by some esoteric calculation from the dimensions of Stonehenge. A megalithic yard = 0.82966 meters, which then gets you to the right number for the speed of light.
Not bad for a formula with three terms, one of which is pulled out of someone's ass, and the whole thing requiring a magic fudge factor to bring it into line with neolithic technology.

For more read entire article here: http://scienceblogs.com/pharyngula/2009/12/the_god_equation.php

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Posted in: creation,god equation,light,space