Runtuhnya Teori Einstein (?)

[E = mc²]

artikel di NG sebagai tambahan:

Particles Moved Faster Than Speed of Light?

Neutrinos—ghostly subatomic particles—may have been observed traveling faster than the speed of light, scientists announced this week.

If confirmed, the astonishing claim would upend a cardinal rule of physics established by Albert Einstein nearly a century ago.

"Most theorists believe that nothing can travel faster than the speed of light. So if this is true, it would rock the foundations of physics," said Stephen Parke, head of the theoretical physics department at the U.S. government-run Fermilab near Chicago, Illinois.

The existence of faster-than-light particles would also wreak havoc on scientific theories of cause and effect.

"If things travel faster than the speed of light, A can cause B, [but] B can also cause A," Parke said.

"If that happens, the concept of causality becomes ambiguous, and that would cause a great deal of trouble."

Don't Bet on Breaking Light Speed

Members of the Oscillation Project with Emulsion-tRacking Apparatus, or OPERA, at the European Center for Nuclear Research (CERN) described the unusual neutrino detection in a paper published this week on the research website arXiv.org.

The team shot neutrinos out of a particle accelerator near Geneva, Switzerland, and measured how long it took the particles to travel to a neutrino detector in Gran Sasso, Italy, 450 miles (724 kilometers) away.

Neutrinos are subatomic particles that have almost no mass and can zip through entire planets as if they are not there.

Being nearly massless, neutrinos should travel at nearly the speed of light, which is approximately 186,000 miles (299,338 kilometers) a second.

To the astonishment of the OPERA team, the particles appear to have reached their destination about 60 nanoseconds faster than expected.

A nanosecond may not sound like much, but "the effect is quite large," said Fermilab's Parke, who was not part of the CERN team.

The extra speed would mean that, over a distance of 621 miles (1,000 kilometers), neutrinos travel about 66 feet (20 meters) farther than light travels in the same amount of time.

The results would be "revolutionary" if true, Parke said, but he added that he highly doubts the findings will hold up under closer scrutiny.

"If I was a betting man, I would bet against it," he said. "Your first response is it can't possibly be true, that they must have made a mistake."

Neutrino Speed an Instrument Error?

Parke is not alone in his skepticism. Many physicists have speculated that the OPERA results are due to a measurement or instrument error.

It would not be the first time such an error occurred, said Louis Strigari, an astrophysicist at Stanford University also not on the CERN team.

"There have been several instances where, through no fault of the experimenters, the equipment was not understood as well as it needed to be," Strigari said.

"It just so happens that you learn more as you get more data and you understand the machinery a little better."

Even the OPERA team is cautious about its results and is welcoming other researchers to repeat the neutrino experiment.

"We want just to be helped by the community in understanding our crazy result—because it is crazy," Antonio Ereditato, coordinator of the OPERA collaboration, told the BBC.

Supernova Neutrinos Not So Speedy

Dave Goldberg, an astrophysicist at Philadelphia's Drexel University, said that if faster-than-light neutrinos did exist, they would likely have been observed in nature before now.

For example, in 1987 detectors on Earth identified neutrinos and photons—light particles—from an exploding star. Both types of particles reached our planet at almost exactly the same instance.

According to Goldberg's calculations, if neutrinos travel faster than light by the amount the OPERA team claims, then neutrinos from that supernova should have been detected in 1984—three years before the photons.

"It's possible, but unlikely," Goldberg said, that detectors active on Earth at the time would have missed such an obvious spike in cosmic neutrinos.

Goldberg concedes that supernova neutrinos are less energetic—and would thus be traveling slower—than the neutrinos from CERN's particle accelerator.

However, "assuming Einstein was correct, both types [of neutrinos] would be moving at something like 99.999999999 percent the speed of light," Goldberg said in an email.

"In other words, from a measurement point of view, they'd be going at essentially identical speeds."

Relativity Still Very Close to Right

Even if the OPERA results are confirmed by other scientists, they wouldn't totally invalidate Einstein's theories of general and special relativity, Stanford University's Strigari stressed. Those theories still explain a remarkable range of observed phenomena in the universe.

"I think it's long been understood that the theories we have today aren't the full answers," Strigari said.

"If this observation holds up, then it's probably a good piece of evidence that the theories we currently have need to be reworked."

Drexel University's Goldberg agreed that physicists won't be discarding Einstein's theories anytime soon.

"Even if relativity turned out to be wrong," he said, "it's clearly very, very close to being right."

[arthurus]

Meski percobaan yang dilakukan CERN itu diklaim sangat akurat, beberapa ilmuwan ngetop banyak yang skeptis. Steven Wienberg misalnya yg udah dapet Nobel. Dia menyamakan hasil eksperimen di CERN ini seperti org yang mengaku memelihara peri di kebunnya tapi perinya hanya bisa dilihat kalo malam berkabut

ini paling skeptis duluan
dari Guardian

Professor Jim Al-Khalili at the University of Surrey said it was most likely that something was skewing the results. "If the neutrinos have broken the speed of light, it would overturn a keystone theory from the last century of physics. That's possible, but it's far more likely that there is an error in the data. So let me put my money where my mouth is: if the Cern experiment proves to be correct and neutrinos have broken the speed of light, I will eat my boxer shorts on live TV."

[E = mc²]

^ LOL

kalo yg saya kutip kan Nobelis Fisika dan penulis buku2 sains ngetop, juga lebih ngetop drpd Khalili. Tapi kita tunggu saja deh, Fermilab mau bikin percobaan serupa. tinggal ditunggu, apakah hasilnya sama atau berbeda...

[Urzu 7]

Jadi cuma teori. blom bisa dibuktikan..

[kandalf]

Halah.. itu paling response emosional. Yakin, kalau ternyata memang benar Neutrino lebih cepat, si Khalili gak akan makan celana pendeknya di depan kamera TV.

[E = mc²]

Jadi cuma teori. blom bisa dibuktikan..

kebalik Ju. justru udah "dibuktikan" tapi gak ada teori

[purba]

Weh... Si Khalili juga fisikawan top tuh...

[el sol]

Neutrino bukannya tak bermassa?
Eh.. gak.. kau benar.. Neutrino punya massa.

Setahuku,
kecepatan cahaya sebagai konstanta kalau gak salah berdasarkan persamaan Maxwell. Teori Relativitas khusus memang kalau gak salah dibuat berdasarkan itu.

Ngomong2, selain CERN, yang punya fasilitas akselerasi partikel siapa saja sih?
Bukankah harus ada percobaan ulang yang dilakukan oleh pihak lain untuk membuktikan?

Dari hasil baca2, Fermilab tahun 2007 sudah pernah melakukan percobaan serupa dengan yang dilakukan OPERA, hasilnya pun sama. Tapi pihak fermilab menyangsikan, margin errornya kelewat besar karena sistem pengukurannya nggak akurat, untuk itu perlu diupgrade sistemnya, tahun depan (2012) baru bisa dioperasikan.

Yg gw denger2 akibat bisa lebih cepet dari cahaya, nantinya manusia bisa time travel?

time travel secara teori dimungkinkan, tapi nggak di alam semesta yang kita diami ini.
kalo penasaran google aja, keyword : godel universe atau godel "time travel"