Even the most serious minded attempt to explain curved space and black holes leaves me vaguely puzzled. And I had never understood Einstein’s contention – presuming that he made it – that nothing could move faster than light. Why? It appeared to me more of a theological statement than a measaured fact. Why? Of course, I can see it has ramifications for our observation of the universe, but why should it not be possible? I have wondered about this article of faith from time to time.
Now CERN have apparently measured some sub-atomic particles moving a bit faster than light. How jolly clever of them. I still don’t understand why they should not have been able to do that, and don’t feel anything much has changed now they have. What do we need now to adjust in our understanding of the universe? I just went to the Post Office, and it was still there.
Yes, I know Bonnie Tyler is singing “night”.
Mary, thanks. Yep, they look like publicists to me.
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Vronsky, it’s not your fault that there’s a poor article in the Grauniad. I just thought I should point out that it’s mostly nonsense. On the other hand, the one I linked by Bryony Worthington to seems a bit over-optimistic, though not as bad as Eifion Rees, which could almost be disinformation.
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Regarding abundance; yes, there’s only about three times as much thorium as uranium, but (1) natural uranium is only 0.2% U235, the bit that “burns”, and (2) a molten salt reactor should use 99% of the energy, whereas the reactors we have use less than 5%.
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Regarding radioactivity, it’s silly to try to get the radioactivity in waste down to nothing. Even burning coal releases radioactivity, and the target is to get radioactivity in waste down to background levels.
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Above I said that our existing reactors use less than 5% of the energy. The rest of it still comes out, as radioactivity over the next few tens of millennia. That’s the “radioactive waste” problem; the fuel rods have to be removed from the reactor long before they’re “burnt out”.
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The idea that attracts me is using molten salt reactors to “burn up” that existing waste; we really ought to do that anyway, rather than just burying it and hoping for the best. It would make masses of electricity in the process. Old weapon cores could go in the pot, too. Yes, the stuff that’s left over takes 300 years or so to get down to background levels, but the alternative is to try to secure 100,000 tonnes of “spent fuel” for tens of thousands of years.
If I remember correctly as an object accelerates towards light speed it increases in mass. Thus, to further accelerate it you need to add even more energy up to the point that, at the speed of light, you would need to add infinitely more energy to accelerate any further.
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Note that the mass of a photon is believed to be 0. If this turned out to be not quite correct and the photon actually has a small mass then the ‘speed of light’ would become a misnomer, and ‘c’ would just be a physical constant. Relativity is not affected if this is the case, though, I think.
Paul:
Your explanation doesn’t work. When light passes from one medium to another its velocity changes. When light passes from glass (say) to air or vacuum its velocity increases. If it had any mass at all that sudden change in velocity would require energy, so where does that energy come from? You also used the phrase “to further accelerate it”, you cannot accelerate light, light does not undergo acceleration.
Full marks though for at least understanding the difference between a theoretical constant and an experimentally determined value.
Some propaganda for nuclear tonight on Bang Goes the Theory on BBC1. We were told by a female professor that the deaths associated with the Chernobyl explosion were equivalent to the number who die each year falling out of bed, just over 100!!
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Note Fukishima was a ‘scare’. Outrageous reporting. The BBC could not recognize the truth if it hit them in the face. The format of the porgramme was infantile.
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Next on:
Today, 19:30 on BBC One Synopsis
In the aftermath of the Fukushima radiation scare, the team turns its attention to nuclear power. Jem climbs into a reaction chamber to explain how a nuclear power station works and what happened in Japan. Meanwhile, Dallas investigates the clean-up operation for radioactive waste, and Liz looks at what radiation does to the human body.
The professor is Prof Gerry Thomas, Chair Molecular Pathology Imperial College. London. She said this in March!! What is her agenda?
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Japan: Nuclear panic is ‘over-reaction’ say scientists Thursday 17 March 2011
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As fear spreads in Japan, radiation expert Professor Gerry Thomas tells Channel 4 News: “We are panicking that poor, savaged population about radiation that is not going to harm them.” As helicopters throw water onto the reactor at the Fukushima Daiichi nuclear plant, panic is spreading across across Japan and the wider world. The UK and the United States have chartered planes for people who want to leave the country and France is also advising people to either leave or head to southern Japan.
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But some nuclear experts say that the risk of a radiation leak is being exaggerated. Professor Gerry Thomas is Chair in Molecular Pathology at Imperial College, London and an expert in radiation impact. She says that the precautions taken so far should be sufficient to protect people near the site, telling Channel 4 News: “There is no significant release of radiation yet, it’s really only the workers that are at risk. We are not looking at an accident anything like Chernobyl. The Japanese have done everything by the book by removing people from the vicinity.”
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Gregory Jaczko, who heads the US nuclear regulator, disagrees. He told Congress that the public should get at least 50 miles away from the stricken plant. The Japanese cleared a radius of 12 miles.
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The EU’s energy chief Gunther Oettinger went further, telling the European Parliament: “There is talk of an apocalyspe and I think that word is particularly well chosen.”
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‘Unhelpful response’
Professor Thomas says the response from foreign governments and the media is unhelpful: “I think it’s totally irresponsible and one thing we should have learnt post-Chernobyl is not to spread panic and make claims that turn out to be wrong. The psychological damage being done now to the Japanese is huge. At Chernobyl we told local people that they would get cancer and die and they are still living with the fact that we gave them false information.”
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She believes misinformation about what happened at Chernobyl is partly to blame for the current panic: “The media has got Chernobyl so wrong it’s unbelievable. At Chernobyl there was a massive release of iodine that shot high into the atmosphere and got carried on the wind. We are not likely to have anything like that in Japan.’
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“Tens of thousands of people have lost their lives. Even if the worst case scenario happened and there was an accident ten times the size of Chernobyl, you wouldn’t have as many deaths as that. We are missing the point here and we are panicking that poor, savaged population, about radiation that is not going to harm them.”
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On Wednesday, as people in Japan bought up supplies of potassium iodide supplements to protect their thyroid glands, radiation expert Professor Richard Wakeford told Channel 4 News that people were wasting their money: “This sort of panic-buying is entirely unnecessary. I can’t believe the doses experienced in Japan at the moment could pose a serious risk in food and water.”
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http://www.channel4.com/news/japan-nuclear-panic-is-over-reaction-say-scientists
Fukushima
http://karlgrossman.blogspot.com/2011/09/government-by-anonymous-officials.html