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Físicos apostadores

Acho que estou devendo uma pizza para o Jorge Stolfi. Como disse Giovani Amelino-Camelia, a chance dos neutrinos superluminais realmente existirem era de uma para dez mil, mas apostar nessa possibilidade era por demais tentador, pois participar de uma revolução científica com essa chance é bem melhor do que apenas fazer trabalhos tecnicamente corretos e mesmo elegantes,  mas de significância marginal. 

Phenomenology of Philosophy of Science: OPERA data

Giovanni Amelino-Camelia
(Submitted on 15 Jun 2012)

I observe that, as the physics side of the OPERA-anomaly story is apparently unfolding, there can still be motivation for philosophy of science to analyze the six months of madness physicists spent chasing the dream of a new fundamental-physics revolution. I here mainly report data on studies of the OPERA anomaly that could be relevant for analyses from the perspective of phenomenology of philosophy of science. Most of what I report is an insider’s perspective on the debate that evolved from the original announcement by the OPERA collaboration of evidence of superluminal neutrinos. I also sketch out, from a broader perspective, some of the objectives I view as achievable for the phenomenology of philosophy of science.

Comments: 13 pages, LaTex
Subjects: History and Philosophy of Physics (physics.hist-ph); High Energy Physics – Experiment (hep-ex); High Energy Physics – Phenomenology (hep-ph)
Cite as: arXiv:1206.3554v1 [physics.hist-ph]

After Particle Search, Some Wallets May Lose Mass

By 

When physicists at CERN reported on July 4 that they had discovered a new particle resembling the long-sought Higgs boson, it prompted a worldwide celebration of pride and mystification.

It also prompted a worldwide settling of scores as physicists — inveterate gamblers — examine the data to decide whether it is time to pay up on longstanding bets about the existence of the boson, which has been the object of a 40-year manhunt.

As described by the Standard Model, the theory that now rules physics, the Higgs boson would be tangible evidence of a hypothesized cosmic molasses known as the Higgs field. That field endows some elementary particles with mass, breaking a logjam of mathematical symmetry in the laws of the early universe and thus adding diversity and the possibility of life to the cosmos. Physicists say it will take them at least the rest of the year and maybe longer to ascertain whether the new particle fits the theoretical prediction — in particular that it has no spin, the first known subatomic knuckle ball.

Nevertheless, the British cosmologist Stephen Hawking, who 10 years ago bet the University of Michigan theorist Gordon Kane $100 that the particle didn’t exist, has already told reporters he is conceding defeat. Dr. Kane is awaiting his windfall. “I haven’t heard directly from him,” Dr. Kane said in an e-mail, “but I assume I will soon, in some interesting way.” Read more [+]

Neutrinos, Higgs e LHC no BLOGPULSE

Comparando os dois experimentos do OPERA sobre neutrinos superluminais

OK, OK, sei que é feio o simples cut and paste (o SEMCIÊNCIA ganhou o prêmio Tartaruga no II EWCLiPo por causa disso) mas preciso registrar aqui o ótimo post do Matt Strassler sobre os experimentos do OPERA, para futuras referências.

Of Particular Significance

Conversations About Science with Theoretical Physicist Matt Strassler

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OPERA: Comparing the Two Versions

Matt Strassler 11/19/11Ok, here’s the latest, as I currently understand it, on the OPERA experiment’s measurement that suggests (if it is correct in all respects) that neutrinos might be traveling faster than the speed of light, which in the standard version of Einstein’s theory of special relativity should be the ultimate speed limit that no particles can exceed.

Warning: For the moment not all numbers are double-checked, and there might, in places, be a number that’s off by as much as a factor of 10. But there should be no major errors. Also, I’m going to be restructuring the website a little bit and will add more cross-links between this article and the various OPERA articles and posts that I’ve put up. Apologies if there’s a bit of construction going on while you’re here. Read more [+]

Estamos em um período revolucionário na Física? Neutrinos anômalos, anti-mesons anômalos e Multiverso como ortodoxia

Achei um blog muito bom para seguir o desdobramento da controvérsia sobre os neutrinos aparentemente superluminais:

Of Particular Significance

Conversations About Science with Theoretical Physicist Matt Strassler

Cientistas famosos como Lee Smolin comentam neste blog. Acho que vou começar a seguir o caso dos neutrinos apenas por este blog e evitar as notícias de jornal e de revistas de divulgação. O blog também comenta sobre as tentativas de explicaçãoda anomalia que estão saindo no ArXiv. O status atual, segundo Matt, é que mesmo o paper do ICARUS e o paper de CG não constituem uma refutação dos resultados do OPERA, pois usam pressupostos teóricos que podem estar errados caso a relação de dispersão dos neutrinos seja outra que a da relatividade restrita. E, ao contrário de Jorge Stolfi, Matt não acredita que o problema com o OPERA tem a ver com as medidas de distância e tempo.

Neutrinos and multiverses: a new cosmology beckons

You wait decades for discoveries that could revolutionise physics, then three come along at once

“THE universe is not only queerer than we suppose, but queerer than we can suppose,” as geneticist J. B. S. Haldane once remarked. In recent decades, physicists have done their best to prove Haldane wrong, by supposing some very queer universes indeed.

Their speculations may seem fantastical, but they are well motivated. Physics poses some formidable questions that we are so far unable to answer. Why is the universe dominated by matter not antimatter? Why does our universe appear to be “fine-tuned” with just the right properties to give rise to galaxies, stars, planets, life and physicists?

The existing edifice of physics, built upon the twin foundations of general relativity and quantum mechanics, is clearly in need of renovation. We have been waiting for years for cracks to appear that might tell us how to go about it. But up to now, nature has remained stubbornly unmoved.

In the past few weeks, however, promising cracks have opened up. In September came stunning news of neutrinos travelling faster than the speed of light. Sceptics withheld judgement but now a new analysis has affirmed the initial result (see “More data shows neutrinos still faster than light”). We still await independent verification – doubts have already been cast – but if it holds up the implications are enormous, opening the door to a new and very different picture of the cosmos.

No less tantalising is a report that particles called mesons decay differently from their antimatter counterparts, anti-mesons (see “LHC antimatter anomaly hints at new physics”). If this result stands up, it would go a long way towards explaining why we have more matter than antimatter. More importantly, it would prise open the standard model of particle physics – which cannot explain the result – and point the way to yet more new physics.

The widest crack of all concerns a theory once considered outlandish but now reluctantly accepted as the orthodoxy. Almost everything in modern physics, from standard cosmology and quantum mechanics to string theory, points to the existence of multiple universes – maybe 10500 of them, maybe an infinite number (see “The ultimate guide to the multiverse”).

If our universe is just one of many, that solves the “fine-tuning” problem at a stroke: we find ourselves in a universe whose laws are compatible with life because it couldn’t be any other way. And that would just be the start of a multiverse-fuelled knowledge revolution.

Conclusive evidence may be close at hand. Theorists predict that our universe might once have collided with others. These collisions could have left dents in the cosmic microwave background, the universe’s first light, which the European Space Agency’s Planck satellite is mapping with exquisite precision. The results are eagerly awaited, and could trigger a revolution not unlike the ones unleashed by Copernicus’s idea that the Earth is not the centre of the solar system and Edwin Hubble’s discovery that our galaxy is just one among many in an expanding universe.

These are exciting, possibly epoch-making, times. Our understanding of the universe stands on the brink of being remade once again. The universe may indeed be queerer than we can suppose, but that was never going to stop us from trying.

Tempos revolucionários na Física

Nos tempos de estudante sempre reverenciávamos os tempos heróicos da Mecânica Quântica e a coragem de seus fundadores. Mas será que realmente gostariamos de viver naquela época de confusão e queda de paradigmas centrais da física classica? Ou será que seriamos mais conservadores e céticos, esperando ver (confirmações definitivas ou um consenso científico) para crer em vez de acreditar que realmente uma nova física estava surgindo?

Roque propôs que se fizesse um estudo estatistico dos papers do ArXiv sobre os neutrinos superluminais. Pelo que vi até agora, dos 113 artigos sobre o assunto no repositorio, não tem nenhum de algum fisico brasileiro. A equipe de fisicos brasileiros que vai acompanhar o experimento MINOS em 2013 já anunciou que é cetica. 

Será que os brasileiros, por herança cultural lusitana, seriam mais conservadores? Cadê a tão propalada criatividade do brasileiro?  

Essa noticia que saiu agora explicaria o ajuste fino de alpha em nossas redondezas. Se alpha varia continuamente, talvez estivessemos em uma regiao critica de transicao: será que o nosso universo é critico e está na borda de uma transicao de fase entre duas regioes, como no caso de uma rede onde um gradiente de p (num modelo de percolacao)  produz p=p-c na borda entre uma regiao percolante e uma regiao nao percolante?

http://www.dailymail.co.uk/sciencetech/article-2056018/Laws-physics-change-depending-universe.html

Laws of physics ‘are different’ depending on where you are in the universe

  • Laws we know may be ‘like local by-laws’ say scientists
  • Hints universe is bigger than we think – possibly infinite
  • Other parts of the universe may be hostile to life

By ROB WAUGH

Last updated at 12:36 PM on 1st November 2011

The quasar ULAS J1120+0641: Scientists measured the light from distant quasars for the 'signatures' of metal atoms in between us and the distant galactic nuclei - they found that the measurements were different from similar ones on Earth

The quasar ULAS J1120+0641: Scientists measured the light from distant quasars for the ‘signatures’ of metal atoms in between us and the distant galactic nuclei – they found that the measurements were different from similar ones on Earth

The laws of physics may not be as set in stone as previously imagined.

One of the laws of nature seems to vary depending on where in the universe you are, research suggests.

The new analysis of data from Hawaii’s Keck telescope and Chile’s Extremely Large Telescope, could have profound implications for our understanding of the universe.

The ‘constancy’ of physics is one of the most cherished principles in science – but the scientists say that the ‘laws’ we know may be the galactic equivalent of ‘local by-laws’ and things may work quite differently elsewhere.

The discovery – if true – violates one of the underlying principles of Einstein’s theory of General Relativity, and has profound implications for our understanding of space and time.

The findings could mean that the universe is far bigger than we thought – possibly even infinite.

It also means that in other parts of the universe, the laws of physics might be hostile to life – whereas in our small part of it, they seem fine-tuned to supporting it. 

Research carried out at the University of New South Wales (UNSW), Swinburne University of Technology and the University of Cambridge found that one of the four known fundamental forces, electromagnetism – measured by the so-called fine-structure constant and denoted by the symbol ‘alpha’ – seems to vary across the Universe.

The two telescopes at the W.M. Keck Observatory on Mauna Kea on the Big Island of Hawaii. Scientists used data from these, and from the Extremely Large Telescope in Chile to search 300 distant galaxies

The two telescopes at the W.M. Keck Observatory on Mauna Kea on the Big Island of Hawaii. Scientists used data from these, and from the Extremely Large Telescope in Chile to search 300 distant galaxies

The researchers looked at light from distant quasars – huge, bright objects that outshine their host galaxies – to see how the light was absorbed by metallic atoms such as chromium, iron, nickel and zinc on its billion-year journey to us.

The researchers looked at 300 distant galaxies. The experiment found that the atoms in space behaved differently from ones on earth.

‘The results astonished us,’ said Professor Webb. ‘In one direction – from our location in the Universe – alpha gets gradually weaker, yet in the opposite direction it gets gradually stronger.’

‘The discovery, if confirmed, has profound implications for our understanding of space and time and violates one of the fundamental principles underlying Einstein’s General Relativity theory,’ Dr King added.

The scientists used distant quasars - huge, bright galactic nuclei - to 'illuminate' metal atoms in between them and earth. Analysing the light found that they behaved differently from atoms on Earth

The scientists used distant quasars – huge, bright galactic nuclei – to ‘illuminate’ metal atoms in between them and earth. Analysing the light found that they behaved differently from atoms on Earth

The first hints that alpha might not be constant came a decade ago when Professor John Webb and other colleagues at UNSW and elsewhere, analysed observations from the Keck Observatory, in Hawaii. Those observations were restricted to one broad area in the sky.

However, now Webb and colleagues have doubled the number of observations and measured the value of alpha in about 300 distant galaxies, all at huge distances from Earth, and over a much wider area of the sky.

The new observations were obtained using the European Southern Observatory’s ‘Very Large Telescope’ in Chile.

‘Such violations are actually expected in some more modern ‘Theories of Everything’ that try to unify all the known fundamental forces, said Professor Flambaum.

‘The smooth continuous change in alpha may also imply the Universe is much larger than our observable part of it, possibly infinite.’

‘Another currently popular idea is that many universes exist, each having its own set of physical laws,’ Dr Murphy said. ‘Even a slight change in the laws of Nature means they weren’t ‘set in stone’ when our Universe was born.

‘The laws of Nature you see may depend on your “space-time address” – when and where you happen to live in the Universe.’

Professor Webb said these new findings also offer a very natural explanation for a question that puzzled scientists for decades – why do the laws of physics seem to be so finely-tuned for the existence of life?

‘The answer may be that other regions of the Universe are not quite so favourable for life as we know it, and that the laws of physics we measure in our part of the Universe are merely ‘local by-laws’, in which case it is no particular surprise to find life here,’ he said.

Read more: http://www.dailymail.co.uk/sciencetech/article-2056018/Laws-physics-change-depending-universe.html#ixzz1ecjm6rEb

Bolão dos neutrinos – nova rodada

Ivan entrou no bolão e apostou comigo os R$ 100. O término do bolão ficou marcado para o dia 21 de dezembro de 2012. Caso você queira participar, inscreva-se abaixo. As opções são:

A. A anomalia dos neutrinos superluminais decorrem de um erro sistemático de natureza experimental não levado em conta pelos pesquisadores da colaboração OPERA.

B. A anomalia será explicada por uma aplicação não trivial de física teórica  já conhecida (consensual).

C. A anomalia será explicada por uma proposta de física nova que não viola a simetria de Lorentz.

D. A anomalia será explicada por uma proposta de física nova que viola a simetria de Lorentz.

Façam suas apostas. Como na divisão do bolão o ganho é maior para quem apostar na hipótese mais improvável, uma análise de custo-benefício racional me diz que o melhor é apostar no item D. Está apostado!

New results show neutrinos still faster than light

Read more: ”Neutrinos: Complete guide to the ghostly particle

One of the most staggering results in physics – that neutrinos may go faster than light – has not gone away with two further weeks of observations. The researchers behind the jaw-dropping finding are now confident enough in the result that they are submitting it to a peer-reviewed journal.

“The measurement seems robust,” says Luca Stanco of the National Institute of Nuclear Physics in Padua, Italy. “We have received many criticisms, and most of them have been washed out.”

Stanco is a member of the OPERA collaboration, which shocked the world in September with the announcement that the ghostly subatomic particles had arrived at the Gran Sasso mine in Italy about 60 nanoseconds faster than light speed from the CERN particle accelerator near Geneva, Switzerland, 730 kilometres away.

Tighter bunches

Theorists have been struggling to reconcile the September result with the laws of physics. Einstein’s theory of special relativity posits that nothing can travel faster than light, and many physicists believe the result could disappear in a puff of particles.

The result also unsettled those within the OPERA collaboration. Stanco was one of 15 team members who did not sign the original preprint of the paperbecause they thought the results were too preliminary.

One of the main concerns was that it was difficult to link individual neutrino hits at Gran Sasso to the particles that left CERN. To double check, the team ran a second set of measurements with tighter bunches of particles from 21 October to 6 November.

In that time, they observed 20 new neutrino hits – a piddling number compared with the 16,000 hits in the original experiment. But Stanco says the tighter particle bunches made those hits easier to track and time: “So they are very powerful, these 20 events.”

More checks

The team also rechecked their statistical analysis, confirming that the error on their measurements was indeed 10 nanoseconds. Some team members, including Stanco, had worried that the true error was larger. What they found was “absolutely compatible” with the original announcement, he says.

That was enough for Stanco to put his name to the paper, although he says six or seven team members are still holding out. The team was planning to submit the paper to a European physics journal on Thursday.

They are still running other tests, including measuring the length of a fibre-optic cable that carries information from the underground lab at Gran Sasso to a data-collection centre on the surface. The team is also trying to do the same test using another detector at the lab called RPC. That test will take another several months.

Even though he agreed to sign the paper, Stanco says: “I’m not so happy. From a theoretical point of view, it is not so appealing. I still feel that another experiment should make the measurement before I will say that I believe this result.”

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Desafio aos físicos céticos: Bolão dos Neutrinos

OK, OK, acho que ganhei o ultimo bolao dos neutrinos, dado que em poucos dias o ArXiv recebeu mais de trinta papers sobre os neutrinos superluminais.

Então lanço um novo desafio aos meus amigos físicos céticos.

Bolão de R$ 100 reais, basta assinar nos comentários para participar.

Duas opções:

A. De 01 de novembro a 21 de dezembro haverá mais papers no ArXiv com a opinião de que os resultados do OPERA refletem física nova, ou melhor, envolverão a frase: Caso os resultados do OPERA se confirmem, a minha ideia é que isso se deve a tal e tal fisica nova não convencional, envolvendo quebra de simetria de Lorentz.

B. Nesse período, a maios parte dos artigos tentará explicar os resultados como erro metodológico do OPERA.

C. Nesse período, a maior parte dos papers  tentará compatibilizar, usando idéias próprias dos autores, os resultados do OPERA com a Relatividade, em vez de assumir quebra de invariância de Lorentz (estão excluídos aqui os papers do item B, ou seja, tentarão explicar as medidas, assumidas como corretas, usando-se diversas ideias que não erros sistemáticos do OPERA).

Bom, a minha aposta é no item A.

Eu vou também chutar aqui uma ideia (que não é minha): Devido as interações das partículas com o vácuo quântico, cada tipo de partícula tem uma velocidade limite c_i, por exemplo c_gamma = c,  c_proton, c_eletron, c_neutrino etc, todas muito proximas mas nao exatamente iguais.

Dai fica a pergunta: quais sao as evidencias e experimentos que realmente constrangem |c-c_i| < epsilon_i, e quanto vale epsilon_i experimentalmente para cada partícula? Putz, acho que essa ideia dá um paper!

Sim, eu sei que isso é anátema e heresia para os relativistas. A física teórica perderia sua beleza, não poderíamos mais fazer c =1 nas nossas equações etc. OK, OK, sim… é isso que se chama de “quebra de paradigma” na epistemologia de Thomas Kunh…  E percebem porque foi tão difícil para o pessoal abandonar o conceito de éter e a visão newtoniana (que tinha durado 300 anos!).

Se idéias extraordinárias precisam de evidências extraordinárias, então a Relatividade Geral só deveria ter sido aceita em 1960, por que as evidências anteriores (especialmente as do desvio da luz estelar perto do Sol) não eram nada extraordinárias, mas sim cheias de erros e ruído…