The future and the past existing simultaneously?
We all agree that the past is influencing the present and the present is influencing the future. If someone says that future events could influence the past, perhaps this person will be considered mentally ill. However, some researchers argue that quantum physics could demonstrate that time may flow backwards.
According to a study published by the Nature Physics journal, time might run from the future to the past and things could exist simultaneously in multiple states. The fact that time is running from past to future and things can exist only in one place at a certain time is just common sense for most people. However, a team of physicists from the Australian National University (ANU) disagree with this. They argue that things are not so simple.
Andrew Truscott, associate professor at the Research School of Physics and Engineering in the ANU says the new study demonstrates it is all about that direct measurement. He says that at the quantum level, reality does not exist unless it is directly observed.
This conclusion -- which seems absurd to many people -- resulted from two experiments, a classic one for quantum physics and another one more recent.
Experimentation and related findings
In a classic experiment for quantum physics called the experiment of the two slots, scientists have noticed for a long time a strange behavior of light particles -- the photons. When they projected light on a screen with two narrow slots, the photons behaved strangely. They passed through the two slots but they didn't leave just one trace with two stripes on the wall as expected. Instead of leaving just two stripes on the wall, they left many stripes. These stripes appeared on the wall beyond the places corresponding to the slots they went through. This outcome would be possible only if the particle would pass through both slots at the same time, so it's in two places at once.
When sensors to track the photons were placed around the slots, these strange waves disappeared. When the sensors have been pushed aside, the waves behaved the same. This experiment suggested to the researchers that we could change reality simply by observing it directly. In other words, reality is not real.
Another strange experiment supports the same conclusion according to which reality does not exist outside observation. It's an experiment proposed by John Wheeler since 1978 that was finally realized recently. This experiment was called the delayed choice cognitive experiment because it was believed that it would never be implemented.
Wheeler proposed the introduction of a second screen in the experiment. This second screen had to be introduced immediately after the photon had passed through the first screen and before it reaches the second wall.This experiment was conducted using a helium atom instead of a photon. Although it's more massive than the photon, the helium atom was expected to have the same behavior, namely to exist in an undefined state and then once observed to behave either as a particle or as a wave. Lasers have been used as a grill. They were placed one in front of the other, and the second one was turned on randomly. The result was more strange than the researchers expected. Surprisingly, when both lasers were on, the atoms became waves, and when the second laser was stopped the atoms became particles. The odd thing is that the decision about the presence of the second laser was random. For the helium atom that passed through the first laser this was not the case. So it's like the atom could see into the future and would know if there will be a second laser or not and this would have caused its present state.