Traveling backwards in time is impossible. The idea of time-travel has gained popularity because according to many equations in physics, time is reversible. However, this does not accurately reflect reality.
Impossible due to the second law of thermodynamics: entropy increases in a system and never the reverse. This remains true unless a considerable amount of energy (relatively speaking) is applied to the system to "organize" it, so applying this to the universe would conflict with the first law of thermodynamics.
Scientists who threw down the gauntlet to physics by reporting particles that broke the Universe's speed limit said they were revisiting their contested experiment.
"The new test began two or three days ago," said Stavros Kasavenas, deputy head of France's National Institute for Nuclear Physics and Particle Physics, also called the IN2P3.
"The criticism is that the results we had were a statistical quirk. The test should help address this," The team stunned particle physicists by saying they had measured neutrinos that travelled around six kilometres (3.75 miles) per second faster than the velocity of light, the highest speed possible.
About: Faster Than The Speed Of Light
An international group of scientists has made an astonishing claim - they have detected particles that seemed to travel faster than the speed of light.
It was a claim that contradicted more than a hundred years of scientific orthodoxy. Suddenly there was talk of all kinds of bizarre concepts, from time travel to parallel universes.
So what is going on? Has Einstein's famous theory of relativity finally met its match? Will we one day be able to travel into the past or even into another universe?
In this film, Professor Marcus du Sautoy explores one of the most dramatic scientific announcements for a generation. In clear, simple language he tells the story of the science we thought we knew, how it is being challenged, and why it matters.
New Tests & Criticism
Time Travel Issues
Measured Neutrino Speed
More Time Travel Issues
The neutrinos had been measured along a 732-kilometre (454-mile) trajectory between the European Centre for Nuclear Research (CERN) in Switzerland and a laboratory in Italy.
Through a complex transformation, a few of the protons arrive at their destination as neutrinos, travelling through Earth's crust.
The scientists at CERN and the Gran Sasso Laboratory in Italy scrutinised the results of the so-called Opera experiment for nearly six months before making the announcement.
They admitted they were flummoxed and put out the begging bowl for an explanation. The results have not been published in a peer-reviewed journal.
Arxiv, has had scores of papers submitted to it.
Some point to perceived technical glitches, noting that only a minute flaw in measurement would have had the neutrinos busting the speed of light.
Kasavenas said CERN was making available a special form of proton beam.The idea is to assess a modified measurement technique.
The past is non-existent. The idea of time as a line is only a model. Time is just what we use to describe the interactions between particles as a system changes.
In truth, there is always only the present. The past and future are merely conceptual or predictive.
Certain particles decay in certain circumstances (thus going against conservation of mass). Since they no longer exist in our universe, we would have to create mass to account for their loss in order to then "reverse" the flow of time. As this cannot be done, we cannot travel back in time.
The problem is that many theories about physics have been misunderstood and misconstrued. For some reason, many people have the misconception that with physics anything is possible. This is not true. Take trying to escape our universe for example (which is impossible). If we ever could, at best the laws of physics would differ in a way that wouldn't facilitate our ability to exist.