Speed of light may have changed recently

The speed of light, one of the most sacrosanct of the universal physical constants, may have been lower as recently as two billion years ago - and not in some far corner of the universe, but right here on Earth.

The controversial finding is turning up the heat on an already simmering debate, especially since it is based on re-analysis of old data that has long been used to argue for exactly the opposite: the constancy of the speed of light and other constants.

A varying speed of light contradicts Einstein's theory of relativity, and would undermine much of traditional physics. But some physicists believe it would elegantly explain puzzling cosmological phenomena such as the nearly uniform temperature of the universe. It might also support string theories that predict extra spatial dimensions.

The threat to the idea of an invariable speed of light comes from measurements of another parameter called the fine structure constant, or alpha, which dictates the strength of the electromagnetic force. The speed of light is inversely proportional to alpha, and though alpha also depends on two other constants (see graphic), many physicists tend to interpret a change in alpha as a change in the speed of light. It is a valid simplification, says Victor Flambaum of the University of New South Wales in Sydney.

It was Flambaum, along with John Webb and colleagues, who first seriously challenged alpha's status as a constant in 1998. Then, after exhaustively analysing how the light from distant quasars was absorbed by intervening gas clouds, they claimed in 2001 that alpha had increased by a few parts in 105 in the past 12 billion years.

But then German researchers studying photons emitted by caesium and hydrogen atoms reported earlier in June that they had seen no change in alpha to within a few parts in 1015 over the period from 1999 to 2003 (New Scientist, 26 June) though the result does not rule out that alpha was changing billions of years ago.

Throughout the debate, physicists who argued against any change in alpha have had one set of data to fall back on. It comes from the world's only known natural nuclear reactor, found at Oklo in Gabon, West Africa.

The Oklo reactor started up nearly two billion years ago when groundwater filtered through crevices in the rocks and mixed with uranium ore to trigger a fission reaction that was sustained for hundreds of thousands of years. Several studies that have analysed the relative concentrations of radioactive isotopes left behind at Oklo have concluded that nuclear reactions then were much the same as they are today, which implies alpha was the same too.

That is because alpha directly influences the ratio of these isotopes. In a nuclear chain reaction like the one that occurred at Oklo, the fission of each uranium-235 nucleus produces neutrons, and nearby nuclei can capture these neutrons.

For example, samarium-149 captures a neutron to become samarium-150, and since the rate of neutron capture depends on the value of alpha, the ratio of the two samarium isotopes in samples collected from Oklo can be used to calculate alpha.

A number of studies done since Oklo was discovered have found no change in alpha over time. "People started quoting the reactor [data] as firm evidence that the constants hadn't changed," says Steve Lamoreaux of Los Alamos National Lab (LANL) in Albuquerque, New Mexico.

Now, Lamoreaux, along with LANL colleague Justin Torgerson, has re-analysed the Oklo data using what he says are more realistic figures for the energy spectrum of the neutrons present in the reactor. The results have surprised him. Alpha, it seems, has decreased by more than 4.5 parts in 108 since Oklo was live (Physical Review D, vol 69, p121701).

That translates into a very small increase in the speed of light (assuming no change in the other constants that alpha depends on), but Lamoreaux's new analysis is so precise that he can rule out the possibility of zero change in the speed of light. "It's pretty exciting," he says.

So far the re-examination of the Oklo data has not drawn any fire. "The analysis is fine," says Thibault Damour of the Institute of Advanced Scientific Studies (IHES) in Bures-sur-Yvette in France, who co-authored a 1996 Oklo study that found no change in alpha. Peter Moller of LANL, who, along with Japanese researchers, published a paper in 2000 about the Oklo reactor that also found no change in alpha, says that Lamoreaux's assumptions are reasonable.

The analysis might be sound, and the assumptions reasonable, but some physicists are reluctant to accept the conclusions. "I can't see a particular mistake," says Flambaum. "However, the claim is so revolutionary there should be many independent confirmations."

While Flambaum's own team found that alpha was different 12 billion years ago, the new Oklo result claims that alpha was changing as late as two billion years ago. If other methods confirm the Oklo finding, it will leave physicists scrambling for new theories. "It's like opening a gateway," says Dmitry Budker, a colleague of Lamoreaux's at the University of California at Berkeley.

Some physicists would happily accept a variable alpha. For example, if it had been lower in the past, meaning a higher speed of light, it would solve the "horizon problem".

Cosmologists have struggled to explain why far-flung regions of the universe are at roughly the same temperature. It implies that these regions were once close enough to exchange energy and even out the temperature, yet current models of the early universe prevent this from happening, unless they assume an ultra-fast expansion right after the big bang.

However, a higher speed of light early in the history of the universe would allow energy to pass between these areas in the form of light.

Variable "constants" would also open the door to theories that used to be off limits, such as those which break the laws of conservation of energy. And it would be a boost to versions of string theory in which extra dimensions change the constants of nature at some places in space-time.

But "there is no accepted varying-alpha theory", warns Flambaum. Instead, there are competing theories, from those that predict a linear rate of change in alpha, to those that predict rapid oscillations. John Barrow, who has pioneered varying-alpha theories at the University of Cambridge, says that the latest Oklo result does not favour any of the current theories. "You would expect alpha to stop [changing] five to six billion years ago," he says.

Before Lamoreaux's Oklo study can count in favour of any varying alpha theory, there are some issues to be addressed. For one, the exact conditions at Oklo are not known. Nuclear reactions run at different rates depending on the temperature of the reactor, which Lamoreaux assumed was between 227 and 527°C.

Damour says the temperature could vary far more than this. "You need to reconstruct the temperature two billion years ago deep down in the ground," he says.

Damour also argues that the relative concentrations of samarium isotopes may not be as well determined as Lamoreaux has assumed, which would make it impossible to rule out an unchanging alpha. But Lamoreaux points out that both assumptions about the temperature of the Oklo reactor and the ratio of samarium isotopes were accepted in previous Oklo studies.

Another unknown is whether other physical constants might have varied along with, or instead of, alpha. Samarium-149's ability to capture a neutron also depends on another constant, alpha(s), which governs the strength of the strong nuclear attraction between the nucleus and the neutron.

And in March, Flambaum claimed that the ratio of different elements left over from just after the big bang suggests that alpha(s) must have been different then compared with its value today (Physical Review D, vol 69, p 063506).

While Lamoreaux has not addressed any possible change in alpha(s) in his Oklo study, he argues that it is important to focus on possible changes in alpha because the Oklo data has become such a benchmark in the debate over whether alpha can vary. "I've spent my career going back and checking things that are 'known' and it always leads to new ideas," he says.

Hello Vade

My personal interest is to invite options regarding constructs and theories.
for me...their is no..*Have arrived...absolute conclusion drawn..close book.

Article excerpt:

FAR APART, TWO PARTICLES RESPOND FASTER THAN LIGHT by Malcolm W. Browne
(From the New York Times Science Section, Tuesday, July 22, 1997)

It was as if some ghostly bridge across the city of Geneva had permitted two photons of light nearly seven miles apart to respond simultaneously to a stimulus applied to just one of them.

The twin-photon experiment by Dr. Nicolas Gisin of the University of Geneva and his colleagues last month was the most spectacular demonstration yet of the mysterious long-range connections that exist between quantum events, connections created from nothing at all, which in theory can reach from one end of the universe to the other.

In essence, Dr. Gisin sent pairs of photons in opposite directions to villages north and south of Geneva along optical fibers of the kind used to transmit telephone calls. Reaching the ends of these fibers, the two photons were forced to make random choices between alternative, equally possible pathways.

Since there was no way for the photons to communicate with each other, "classical" physics would predict that their independent choices would bear no relationship to each other. But when the paths of the two photons were properly adjusted and the results compared, the independent decisions
by the paired photons always matched, even though there was no physical way for them to communicate with each other.

Albert Einstein sneered [at] the very possibility of such a thing, calling it "spooky action at a distance." Scientists still (somewhat shamefacedly) speak of the "magic" of "quantum weirdness." And yet all experiments in recent years have shown that Einstein was wrong and that action at a distance is real."

One of the leading experimentalists in quantum optics, Dr. Raymond P. Chiao of the U. of California, Berkeley, hailed the Geneva experiment as "wonderful."

But an underlying enigma of quantum mechanics remains unfathomed.

The connections that persist between distant but entangled particles are "one of the deep mysteries of quantum mechanics," Dr. Chiao said in an interview. "These connections are a fact of nature proven by experiments, but to try to explain them philosophically is very difficult," he said.

Quantum events obey the laws of quantum theory, which governs the behavior of minute objects like atoms and subatomic particles, including photons of light. By contrast with the laws of "classical" physics (which apply to the relatively large objects of the everyday world), quantum physics often exhibits behavior that seems impossible.

One of the weird aspects of quantum mechanics is that something can simultaneously exist and not exist; if a particle is capable of moving along several different paths, or existing in several different states, the uncertainty principle of quantum mechanics allows it to travel along all paths and exist in all possible states simultaneously. However, if the particle happens to be measured by some means, its path or state is no longer uncertain. The simple act of measurement instantly forces it into just one path or state.

Physicists call this a "collapse of the wave function." The amazing thing is that if just one particle in an entangled pair is measured, the wave function of both particles collapses into a definite state that is the same for both partners, even separated by great distances.

Comment.

The Term **Quantum jump is a new play word/fill in the blank word for outcomes.
Clearly....quantum dynamics is a field of study with much comment that it is percived....yet not fully understood.
A field of endeavour with more suprises for sure : )

Specialists in astrophysics and all those big names..have noted that *Comets begin to light up when passing the Orbital quadrants of Jupiter and Saturn.
Both are kicking out electricity and other particle flow.
Is *Quantum jump occuirng here?..I think so.
SOHO captured the Sun burping Plasma off repeatedly toward Comet 2002v1 Neat..at 0.0999 AU. on perihelion.

Shift:

Cassini-Huygens
Instruments
RPWS: Radio and Plasma Wave Science
The major functions of the Radio and Plasma Wave Science (RWPS) instrument are to measure the electric and magnetic fields and electron density and temperature in the interplanetary medium and planetary magnetospheres.

The RPWS instrument will be used to investigate electric and magnetic waves in space plasma at Saturn. Plasma is distributed by the solar wind, and it is also contained by the magnetic fields (the magnetospheres) of bodies such as Saturn and Titan. The Cassini RPWS instrument will measure the AC electric and magnetic fields in the interplanetary medium and planetary magnetospheres and will directly measure the electron density and temperature of the plasma in the vicinity of the spacecraft.

RPWS will study the configuration of Saturn's magnetic field and its relationship to Saturn Kilometric Radiation (SKR), as well as monitoring and mapping Saturn's ionosphere, plasma, and lightning from Saturn's atmosphere.

RPWS Scientific Objectives

To study the configuration of Saturn’s magnetic field and its relationship to Saturn Kilometric Radiation (SKR)
To monitor and map the sources of SKR
To study daily variations in Saturn’s ionosphere and search for outflowing plasma in the magnetic cusp region
To study radio signals from lightning in Saturn’s atmosphere
To investigate Saturn Electric Discharges (SED)
To determine the current systems in Saturn’s magnetosphere and study the composition, sources, and sinks of magnetospheric plasma
To investigate the dynamics of the magnetosphere with the solar wind, satellites, and rings
To study the rings as a source of magnetospheric plasma
To look for plasma waves associated with ring spoke phenomena
To determine the dust and meteoroid distributions throughout the Saturnian system and interplanetary space
To study waves and turbulence generated by the interaction of charged dust grains with the magnetospheric plasma
To investigate the interactions of the icy satellites and the ring systems
To measure electron density and temperature in the vicinity of Titan
To study the ionisation of Titan’s upper atmosphere and ionosphere and the interactions of the atmosphere and exosphere with the surrounding plasma
To investigate the production, transport, and loss of plasma from Titan’s upper atmosphere and ionosphere
To search for radio signals from lightning in Titan’s atmosphere, a possible source for atmospheric chemistry
To study the interaction of Titan with the solar wind and magnetospheric plasma
To study Titan’s vast hydrogen torus as a source of magnetospheric plasma
To study Titan’s induced magnetosphere

No I was talking about over all cast or absortion of spectra.

Think of radio waves....it takes more energy to produce longer wavelengths at a given intensity over distance but they also carry farther and are less affected by objects, trees mountains ect. Shorter wave lengths at a given intensity over distance need even more energy or amplitude behind them to be detected at the same distance than longer wave radiation because they are more easily effected by reflections and multipath interferences...the higher the frequency the shorter the wavelenghth and the higher the energy it takes to propagate over the same distance due to inteference.

It seems to me then that bluer light has shorter wavelengths than redder light and would be more affected than redder light by distance and the particulate/gaseous densities of the space it has to travel to get here. Another words think of a light filter in which only the longer wavelenths at a given intensity get thru more efficiently at a vs. the shorter wavelenths at the same intensity. What can mess up the figures is whether or not there are a larger number of stars producing light at a higher frequency AND very high intensity in a galaxy billions of lightyears distant, these may appear more bluer shifted than others in the same vacinity. Red light to be visible at a certain distance takes more originating energy (due to the longer wavelengths) than blue light at the same distance but bluer light is more effected by the densities of the medium it travels thru than red light would be, so more originating energy would be needed for the blue light source to maintain equal visibility with that of red. For a more practical point...think about a misty foggy night. Red tail lights cut thru better than the yellows and blues. Low beams with its yellower cooler spectra are better to use on a foggy night than brighter bluer whiter light as all that extra light "reflects" back and blinds you with the glare...unless one has one of those million lumen fog lamps often used in "jacklighting" deer(with much higher originating energies therefore higher intensity) that can cut thru the fog by overwhelming its reflectivity.

I'm not saying the blue/red shift tool isn't a useful measure for guaging speed and direction for closer objects, I'm questioning the tools by which we guage the distance and speed of objects farther out than say a thousand light years or so!

I know the scientists extrapolate these equations based on observation of our own sun and planets and derive distances...ect. It is astounding to me that we could figure out that our average distance to our sun was infact 93 million miles even before we sent out probes that would behave exactly as the theoretical equation stated they would...at the exact distances theorectically pre-calculated. So if they say Proxima Centauri is 4.3 light years from us I believe it. I'm having more trouble believing the figures for objects much farther away...especially when it comes to speed and direction!

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