I have now been posting on average just over once a day for seven months. It has helped me to recover from some difficult medical times. Now I am going to carry on with life some more so blogging will be light.
Stats on posts are:
September (34)
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Zero-emission cars that run on hydrogenFuel-cell vehicles have long promised several major advantages over those powered by electricity or hydrocarbons. The technology has only now begun to reach the stage where automotive companies are planning launches for consumers, however. Initial prices are likely to be in the range of $70,000 but should come down significantly as volumes increase within the next couple of years.
Unlike batteries, which must be charged from an external source and can take from five to 12 hours depending on the car and charger, fuel cells generate electricity directly, using hydrogen or natural gas. In practice, fuel cells and batteries are combined, with the fuel cell generating electricity and the batteries storing it until demanded by the motors that drive the vehicle. Fuel-cell vehicles are therefore hybrids and will likely also deploy regenerative braking, which recovers energy from waste heat, a key capability for maximizing efficiency and range.
Unlike battery-powered electric vehicles, fuel-cell powered ones have a long cruising range—up to 650 kilometers per tank (the fuel is usually compressed hydrogen gas); a hydrogen fuel refill only takes about three minutes. Hydrogen is clean-burning, producing only water vapor as waste, so fuel-cell vehicles using hydrogen will be zero-emission, an important factor given the need to reduce air pollution.
There are a number of ways to produce hydrogen without generating carbon emissions. Most obviously, renewable sources of electricity from wind and solar sources can be used to electrolyze water—although the overall energy efficiency of this process is likely to be quite low. Hydrogen can also be split from water in high-temperature nuclear reactors or generated from fossil fuels such as coal or natural gas, with the resulting carbon dioxide captured and sequestered rather than released into the atmosphere.
As well as the production of cheap hydrogen on a large scale, a significant challenge is the lack of a hydrogen distribution infrastructure that would be needed to parallel and eventually replace gas and diesel filling stations. Long-distance transport of hydrogen, even in a compressed state, is not considered economically feasible today. Innovative hydrogen storage techniques, such as organic liquid carriers that do not require high-pressure storage, however, will soon lower the cost of long-distance transport and ease the risks associated with gas storage and inadvertent release.
Mass-market fuel-cell vehicles are an attractive prospect because they will offer the range and fueling convenience of today’s diesel and gas-powered vehicles while providing the benefits of sustainability in personal transportation. Achieving these benefits will, however, require the reliable and economical production of hydrogen from entirely low-carbon sources as well as its distribution to a growing fleet of vehicles, expected to number in the many millions within a decade.
Note - Well not a surprise winner and not a new idea. The difference is we are close to seeing mass market fuel cell vehicles and that will change everything.
Source: Scientific American
The answer laid out by Professor John D Norton of Pittsburgh University (more here):
YES
This "yes" depends upon quantum mechanics, in whose founding Einstein played a major role. It is our best theory of matter and is usually applied to deal with matter in the very small, that is, little particles like electrons. It tells us that matter in the very small has properties quite unlike the ones we are used to with ordinary objects.
We are used to the idea that ordinary objects are either particles orwaves. It turns out that in the small, particles are both particles and waves. They have a dual character that is quite preplexing when you first learn of it and, as far as I can tell, that perplexity never really goes away, even if you know a lot about them.
| Take electrons, for example. They are familiar to us from old-fashioned television tubes. The electrons are fired from a glowing element at the back of the tube. They are formed into a beam by deflecting magnetic fields. When the electron is in flight in the beam, it behaves just like a wave. It spreads out in space, has a wavelength and frequency and can produce all sorts of wavelike phenomena, like interference patterns. These are just like the rippled patterns that water waves make on the surface of a pond when pebbles are dropped in. We can only get them because the waves are spread out in space. |  |
 | When these electrons strike the screen of the TV tube, they behave very differently. According to the standard text book accounts of quantum mechanics, they instantly cease to be wave. They collapse to a point, so they are now behaving like a particle. We see that localization through the emitting of a brief flash of light from just one point on the screen. (Many of those flashes combine to make the images we watch.) |
So sometimes an electron behaves like a wave; and sometimes like a particle. So what? The odd part is what decides whether the electron behaves like a wave or a particle. In the standard text book treatments, we decide by the act of observing the electron. An electron left to itself behaves like a wave. The moment we observe it--for example by having it smash into the screen of a TV tube so that we can see where it is from the flash of light produced--then it behaves like a particle.
That means that the second picture is incomplete. The electron will only cede its wavelike character if there is someone there observing it. Only then does it collapse.
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That is the odd part. Standard, text book quantum mechanics tells us that the act of our observing the electron has caused it to collapse to a point. This astonishing idea troubled Einstein very greatly and he could never accept it. What difference does it make to the electron if we observe it or not?
What Einstein also saw was that the difficulty could not be confined to minute objects like electrons. If individual particles have this dual wave-particle, then so do collections of particles. Our observing of them will also cause them to collapse. Big objects like steam locomotives, moons and planets are just many, many particles all in one place. They will also have a slight wave character, too small for us to notice, but there nonetheless. And when we observe them, they will collapse!
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His collaborator and biographer Abraham Pais reports
"...during one walk, Einstein suddenly stopped, turned to me, and asked whether I really believed that the moon exists only when I look at it."
Abraham Pais, Subtle is the Lord. Oxford: Clarendon Press, 1982. p.5.
The famous physicist (and inventor of the name "black hole") John Wheeler also reported of Einstein
"...No one can forget how he expressed his discomfort about the role of the observer, 'When a mouse observes, does that change the state of the universe?' "
John A.Wheeler, "Memoir", pp. 21-22 in A. P. French, Einstein: A Centenary Volume. Cambridge: Harvard Univ. Press, 1979, on p. 22.
The question above is a combination of these two remarks and the answer of yes is just standard text book physics.
It is meeting today at the UN headquarters in New York. Over 150 world leaders are attending. A new record and a security nightmare.
The United Nations General Assembly is one of the six principal organs of the United Nations and the only one in which all member nations have equal representation. Its powers are to oversee the budget of the United Nations, appoint the non-permanent members to the Security Council, receive reports from other parts of the United Nations and make recommendations in the form of General Assembly Resolutions. It has also established a wide number of subsidiary organs.
Today both President Obama and President Putina addressed the Assembly and both spoke of Syria. They have different agendas but finally it looks like everyone will concede the general slaughter should stop, Assad might have to hang around for a little while before being retired, ISIS must be dealt with and if all the institutions of Syria are destroyed the vacuum will not be filled with nice happy people. A further tricky bit will be agreeing on which oil pipeline goes where. The US, Europe, Russia and others all have differing ideas.
The UN Assembly summary - At present an expensive and only very occasionally useful talking shop. The best option given the lack of any other.
The details courtesy of Wales Online:
Lucky star-gazers across the UK will be able to see the supermoon lunar eclipse on Sunday night, a phenomenon that was last seen in Britain more than 30 years ago.
The supermoon lunar eclipse occurs when the moon passes through Earth's shadow, which creates the illusion that it's turned a fiery red as light from the sun bends around the Earth. It also means that within the space of a few hours the moon will be at its darkest, then at its brightest and a whole 14 percent bigger, which is bound to look pretty spectacular.
It'll be the first eclipse of its kind since 1982 and Nasa has revealed that we'll have to wait until 2033 to spot another one - time to make the most of it now. The eclipse will last five hours and 11 minutes and start at 1.11am early Monday morning for those of us who live in the UK. But it'll start getting really good at about 3.47am. If you live in Wales there's a big chance you'll be able to view it, but those in England may not be so lucky.
[Via Wales Online] [Image Via Carl]
