Space-Time 'foam' smaller than thought

[Delta4Embassy]

Confirming Einstein scientists find spacetime foam not slowing down photons from faraway gamma-ray burst Update

" One hundred years after Albert Einstein formulated the general theory of relativity, an international team has proposed another experimental proof. In a paper published today in Nature Physics, researchers from the Hebrew University of Jerusalem, the Open University of Israel, Sapienza University of Rome, and University of Montpellier in France, describe a proof for one of the theory's basic assumptions: the idea that all light particles, or photons, propagate at exactly the same speed.

The researchers analyzed data, obtained by NASA's Fermi Gamma-ray Space Telescope, of the arrival times of photons from a distant gamma-ray burst. The data showed that photons traveling for billions of years from the distant burst toward Earth all arrived within a fraction of a second of each other.

This finding indicates that the photons all moved at the same speed, even though different photons had different energies. This is one of the best measurements ever of the independence of the speed of light from the energy of the light particles.

One of the attempts to reconcile the two theories is the idea of "space-time foam." According to this concept, on a microscopic scale space is not continuous, and instead it has a foam-like structure. The size of these foam elements is so tiny that it is difficult to imagine and is at present impossible to measure directly. However light particles that are traveling within this foam will be affected by the foamy structure, and this will cause them to propagate at slightly different speeds depending on their energy.

Yet this experiment shows otherwise. The fact that all the photons with different energies arrived with no time delay relative to each other indicates that such a foamy structure, if it exists at all, has a much smaller size than previously expected."

There's an awesome flash-based app online illustrating the relative size of things from space-time itself to the whole universe and beyond with lots of stuff in-between here:

Scale of Universe - Interactive Scale of the Universe Tool

 

[waltky]

Mebbe if we could figger out how to slow time down, we wouldn't age as fast...

Scientists May Have Discovered What Moves Time Forward
February 1, 2016 • What is time? Although such a primary part of our understanding of the universe, the very nature of time is still a debated topic among theoretical physicists. New research is challenging the modern understanding of time evolution based on an observed “jiggling” effect in particles called mesons.

Scientists suggest there may be a deeper origin of time due to the observed differences between the directions of time: the past and the future. The findings were outlined in a paper entitled, “Quantum asymmetry between time and space” and was published in the journal Proceedings of the Royal Society. “Experiments on subatomic particles over the past 50 years show that nature doesn’t treat both directions of time equally,” said lead author of the study, Professor Joan Vaccaro of Griffith University. “In particular, subatomic particles called K and B mesons behave slightly differently depending on the direction of time,” she explained. “When this subtle behaviour is included in a model of the universe, what we see is the universe changing from being fixed at one moment in time to continuously evolving.” “In other words, the subtle behaviour appears to be responsible for making the universe move forwards in time.” “Understanding how time evolution comes about in this way opens up a whole new view on the fundamental nature of time itself. It may even help us to better understand bizarre ideas such as travelling back in time.”

Time graphic.​

The exciting paper, as theoretical as it may be, suggests an asymmetry exists between space and time in the sense that physical systems inevitably evolve over time, whereas there is no corresponding ubiquitous translation over space. This asymmetry, presumed to be elemental, is represented in the laws that operate differently over time and space.

Professor Vaccaro also demonstrates the possibility of a space and time symmetry, meaning the conventional views of time may need to be revisited. “In the connection between time and space, space is easier to understand because it’s simply there. But time is forever forcing us towards the future,” says Vaccaro. “Yet while we are indeed moving forward in time, there is also always some movement backwards, a kind of jiggling effect, and it is this movement I want to measure using these K and B mesons.”

The research hopes to open doors in understanding the underlying fundamental dynamics of the universe, a problem that remains unsolved in science. “If you want to know where the universe came from and where it’s going, you need to know about time” said Vaccaro.

Scientists May Have Discovered What Moves Time Forward