Physicist suggests speed of light might be slower than thought

This image shows the remnant of Supernova 1987A seen in light of very different wavelengths. ALMA data (in red) shows newly formed dust in the centre of the remnant. 

Hubble (in green) and Chandra (in blue) data show the expanding shock wave. 

Credit: ALMA/NASA

Physicist James Franson of the University of Maryland has captured the attention of the physics community by posting an article to the peer-reviewed New Journal of Physics in which he claims to have found evidence that suggests the speed of light as described by the theory of general relativity, is actually slower than has been thought.

The theory of general relativity suggests that light travels at a constant speed of 299,792,458 meters per second in a vacuum.

It's the c in Einstein's famous equation after all, and virtually everything measured in the cosmos is based on it, in short, it's pretty important. But, what if it's wrong?

Franson's arguments are based on observations made of the supernova SN 1987A, it exploded in February 1987.

Measurements here on Earth picked up the arrival of both photons and neutrinos from the blast but there was a problem, the arrival of the photons was later than expected, by 4.7 hours.

Scientists at the time attributed it to a likelihood that the photons were actually from another source.

But what if that wasn't what it was, Franson wonders, what if light slows down as it travels due to a property of photons known as vacuum polarization, where a photon splits into a positron and an electron, for a very short time before recombining back into a photon.

That should create a gravitational differential, he notes, between the pair of particles, which, he theorizes, would have a tiny energy impact when they recombine, enough to cause a slight bit of a slowdown during travel.

If such splitting and rejoining occurred many times with many photons on a journey of 168,000 light years, the distance between us and SN 1987A, it could easily add up to the 4.7 hour delay, he suggests.

If Franson's ideas turn out to be correct, virtually every measurement taken and used as a basis for cosmological theory, will be wrong.

Light from the sun for example, would take longer to reach us than thought, and light coming from much more distant objects, such as from the Messier 81 galaxy, a distance of 12 million light years, would arrive noticeably later than has been calculated, about two weeks later.

The implications are staggering, distances for celestial bodies would have to be recalculated and theories that were created to describe what has been observed would be thrown out. In some cases, astrophysicists would have to start all over from scratch.

More information: Apparent correction to the speed of light in a gravitational potential, J D Franson 2014 New J. Phys. 16 065008 DOI: 10.1088/1367-2630/16/6/065008 

ROK Agrees To India's ISRO Space Launch Use Suggestion

ROK Agrees To India's Space Launch Use Suggestion

South Korean President Lee Myung-bak on Thursday agreed to Indian External Affairs minister S.M.Krishna's suggestion to launch ROK satellites on Indian launch vehicles.

A statement issued on behalf of both leaders said: "Referring to the MOU of cooperation, signed last January between the Indian Space Research Organization (ISRO) and Korean Aerospace Research Institute (KARI), Krishna suggested that ROK satellites could be launched on Indian launch vehicles. President Lee agreed with the suggestion and asked his officials to do the necessary follow-up."

On Thursday, Krishna called on the President Lee Myung-bak at the Blue House, the official residence of the President.

The two leaders had a constructive and fruitful 40-minute meeting in a warm and cordial atmosphere.

President Lee and Krishna underscored the importance of increasing people-to-people exchanges to bolster the Strategic Partnership between the two countries including in the fields of education, tourism and youth.

Krishna suggested that a bust of Gurudev Rabindranath Tagore , who had described Korea as the 'Lamp of the East', be installed at a prominent location in Seoul.

Warming to the theme, President Lee said that he would make a strong recommendation to the concerned city authorities to identify a suitable location for installing the bust of Gurudev in 2011, the 150th birth anniversary of the Nobel laureate.

President Lee, during the meet, fondly recalled his landmark visit to India in January this year, as the chief guest at India's Republic Day celebrations.

He appreciated Krishna's visit to Seoul for the 6th Joint Commission meeting (JCM), soon after his own, which would give further impetus to bilateral relations and the initiatives announced during his visit to India.

Later in the evening, Krishna interacted with prominent members of the Indian community. He apprised them about the Strategic Partnership between the two countries.

Krishna observed that bilateral ties were on the cusp of a major take-off and exhorted the Indian community to assist the process, as well as, to make the best use of emerging opportunities for greater trade and investment.

Krishna will be co-chairing the 6th India-ROK JCM with his ROK counterpart on Friday. (ANI)