Date:

Theory that challenges Einstein’s physics could soon be put to the test

Scientists behind a theory that the speed of light is variable – and not constant as Einstein suggested – have made a prediction that could be tested.

Einstein observed that the speed of light remains the same in any situation, and this meant that space and time could be different in different situations.

- Advertisement -

The assumption that the speed of light is constant, and always has been, underpins many theories in physics, such as Einstein’s theory of general relativity. In particular, it plays a role in models of what happened in the very early universe, seconds after the Big Bang.

But some researchers have suggested that the speed of light could have been much higher in this early universe. Now, one of this theory’s originators, Professor João Magueijo from Imperial College London, working with Dr Niayesh Afshordi at the Perimeter Institute in Canada, has made a prediction that could be used to test the theory’s validity.

Structures in the universe, for example galaxies, all formed from fluctuations in the early universe – tiny differences in density in certain regions. A record of these early fluctuations is imprinted on the cosmic microwave background – a map of the oldest light in the universe – in the form of a ‘spectral index’.

Working with their theory that the fluctuations were influenced by a varying speed of light in the early universe, Professor Magueijo and Dr Afshordi have now used a model to put an exact figure on the spectral index. The predicted figure and the model it is based on are published in the journal Physical Review D.

- Advertisement -

Cosmologists are currently getting ever more precise readings of this figure, so that prediction could soon be tested – either confirming or ruling out the team’s model of the early universe. Their figure is a very precise 0.96478. This is close to the current estimate of readings of the cosmic microwave background, which puts it around 0.968, with some margin of error.

Professor Magueijo said: “The theory, which we first proposed in the late-1990s, has now reached a maturity point – it has produced a testable prediction. If observations in the near future do find this number to be accurate, it could lead to a modification of Einstein’s theory of gravity.

“The idea that the speed of light could be variable was radical when first proposed, but with a numerical prediction, it becomes something physicists can actually test. If true, it would mean that the laws of nature were not always the same as they are today.”

The testability of the varying speed of light theory sets it apart from the more mainstream rival theory: inflation. Inflation says that the early universe went through an extremely rapid expansion phase, much faster than the current rate of expansion of the universe.

These theories are necessary to overcome what physicists call the ‘horizon problem’. The universe as we see it today appears to be everywhere broadly the same, for example it has a relatively homogenous density.

This could only be true if all regions of the universe were able to influence each other. However, if the speed of light has always been the same, then not enough time has passed for light to have travelled to the edge of the universe, and ‘even out’ the energy.

As an analogy, to heat up a room evenly, the warm air from radiators at either end has to travel across the room and mix fully. The problem for the universe is that the ‘room’ – the observed size of the universe – appears to be too large for this to have happened in the time since it was formed.

The varying speed of light theory suggests that the speed of light was much higher in the early universe, allowing the distant edges to be connected as the universe expanded. The speed of light would have then dropped in a predictable way as the density of the universe changed. This variability led the team to the prediction published today.

The alternative theory is inflation, which attempts to solve this problem by saying that the very early universe evened out while incredibly small, and then suddenly expanded, with the uniformity already imprinted on it. While this means the speed of light and the other laws of physics as we know them are preserved, it requires the invention of an ‘inflation field’ – a set of conditions that only existed at the time.

Imperial College London

- Advertisement -
spot_img
Mark Milligan
Mark Milligan
Mark Milligan is multi-award-winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 7,500 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education, the BCA Medal of Honour, and the UK Prime Minister's Points of Light Award.
spot_img
spot_img

Mobile Application

spot_img

Related Articles

Excavation uncovers traces of the first bishop’s palace at Merseburg Cathedral Hill

Archaeologists from the State Office for Monument Preservation and Archaeology (LDA) Saxony-Anhalt have uncovered traces of the first bishop’s palace at the southern end of the Merseburg Cathedral Hill in Merseburg, Germany.

BU archaeologists uncover Iron Age victim of human sacrifice

Archaeologists from Bournemouth University have uncovered an Iron Age victim of human sacrifice in Dorset, England.

Archaeologists find ancient papyri with correspondence made by Roman centurions

Archaeologists from the University of Wrocław have uncovered ancient papyri that contains the correspondence of Roman centurions who were stationed in Egypt.

Study indicates that Firth promontory could be an ancient crannog

A study by students from the University of the Highlands and Islands has revealed that a promontory in the Loch of Wasdale in Firth, Orkney, could be the remains of an ancient crannog.

Archaeologists identify the original sarcophagus of Ramesses II

Archaeologists from Sorbonne University have identified the original sarcophagus of Ramesses II, otherwise known as Ramesses the Great.

Archaeologists find missing head of Deva from the Victory Gate of Angkor Thom

Archaeologists from Cambodia’s national heritage authority (APSARA) have discovered the long-lost missing head of a Deva statue from the Victory Gate of Angkor Thom.

Archaeologists search crash site of WWII B-17 for lost pilot

Archaeologists from Cotswold Archaeology are excavating the crash site of a WWII B-17 Flying Fortress in an English woodland.

Roman Era tomb found guarded by carved bull heads

Archaeologists excavating at the ancient Tharsa necropolis have uncovered a Roman Era tomb guarded by two carved bull heads.