LF: Can the past be changed by the FUTURE? Bizarre quantum experiment suggests time can run backwards

Title: Can the past be changed by the FUTURE? Bizarre quantum experiment suggests time can run backwards
Source: Daily Mail Online
URL Source: http://www.dailymail.co.uk/sciencet ... ggests-time-run-backwards.html
Published: Feb 9, 2015
Author: Ellie Zolfagharifard
Post Date: 2015-02-09 19:31:34 by cranky
Keywords: None
Views: 3863
Comments: 8

But if time were like space, shouldn't the future also influence the past and the present?

A remarkable new study suggests that it just might – and the evidence has been shown in the world of quantum mechanics.

Scientists in the US have devised a series of new experiments to probe the quantum mechanical properties of single particles.

These particle have a state that is not merely unknown, but totally undefined before it is measured.

The act of measurement itself that forces the particle to collapse to a definite state - as evidenced in the infamous Schrödinger's cat thought experiment.

Professor Kater Murch at Washington University has found that by knowing the future outcome of a particle, its state in the past altered.

SCHRODINGER'S CAT EXPERIMENT

Schrödinger's cat is a thought experiment created by Austrian physicist Erwin Schrödinger in 1935.

In the hypothetical experiment a cat is placed in a sealed box next to a radioactive sample, a Geiger counter and a bottle of poison.

If the Geiger counter detects that the radioactive material has decayed, it will trigger the smashing of the bottle of poison and the cat will be killed.

The experiment was designed to show the flaws in something known as the ‘Copenhagen interpretation’ of quantum mechanics.

This states that a particle exists in all states at once until observed.

If the Copenhagen interpretation suggests the radioactive material can have simultaneously decayed and not decayed in the sealed environment, then it follows the cat too is both alive and dead until the box is opened.

The theory follows another postulated by scientists back in December. They proposed that at the moment of the Big Bang (illustrated), a 'mirror universe' to our own was created that moves in the opposite direction through time - and intelligent beings in each one would perceive the other to be moving backwards

COULD TIME MOVE BACKWARDS IN A MIRROR UNIVERSE?

The latest experiment follows a similar theory put forward postulated by scientists back in December.

They proposed that at the moment of the Big Bang, a 'mirror universe' to our own was created that moves in the opposite direction through time - and intelligent beings in each one would perceive the other to be moving backwards through time.

The radical theory was proposed by Dr Julian Barbour of College Farm in the UK, Dr Tim Koslowski of the University of New Brunswick in Canada and Dr Flavio Mercati of the Perimeter Institute for Theoretical Physics, also in Canada.

Their research attempts to answer questions that remain about the ‘arrow of time’ - which is the concept that time is ‘symmetric’ and everything moves forwards.

They say that at the time of the Big Bang not one but two universes formed – both moving equally in each direction through time, but opposite to each other.

This universe would not be exactly the same as ours, though; it would have evolved and changed in its own way, completely separate to our own.

However, it would be subject to the same laws of physics, so it would likely have planets, stars and galaxies just like in our version of the cosmos.

If this proves true in our 'classical' world, it would mean that what we're doing now has been influenced by the decision made by a future version of us.

This all remains theory, but physicists have created devices that allowed them to measure these fragile quantum systems to see if this really is the case in the quantum world.

Professor Kater Murch at Washington University used this technique to look at the quantum state of two particles at different stages in their evolution.

A few microwave photons – or particles of light – were sent into the box, where their quantum fields interacted with the circuit.

'We start each run by putting the qubit in a superposition of the two states,' Professor Murch said.

'Then we do a strong measurement but hide the result, continuing to follow the system with weak measurements.'

They then try to guess the hidden result, which is their version of the missing page of the murder mystery.

'Calculating forward, the probability of finding the system in a particular state, your odds of guessing right are only 50-50,' Murch said.

'But you can also calculate backward using something called an effect matrix. Just take all the equations and flip them around. They still work and you can just run the trajectory backward.

'So there's a backward-going trajectory and a forward-going trajectory and if we look at them both together and weight the information in both equally, we get something we call a hindsight prediction, or 'retrodiction.'

When the physicists check it against the stored measurement of the system's earlier state it is right nine times out of 10.

This suggests that in the quantum world time runs both backward and forward whereas in the classical world it only runs forward.

Professor Murch told Dailymail.com that it's as if you left your keys somewhere in the house, but couldn't remember where.

In the quantum world, they could exist in every room of the house simultaneously.

When you eventually find them in the kitchen, in the classical world it is clear that they were there all along, in the quantum world the uncertainty is intrinsic, but Profesor Murch was able to show that indeed hindsight can be applied to make a better guess about where they were in the past.

In the same way, the improved odds in the current experiment imply the measured quantum state somehow incorporates information from the future as well as the past.

And that might implies that time, notoriously an arrow in the classical world, is a double-headed arrow in the quantum world.

'It's not clear why in the real world, the world made up of many particles, time only goes forward and entropy always increases,' Professor Murch added.

'But many people are working on that problem and I expect it will be solved in a few years,' he said.

A better example is the Double Slit experiment. Matter exists on a probability wave until it's observed. Then it collapses into discreet particles. At T=1 it is a wave. At T=2 (when observed) it is a particle. Knowing it's a particle at T=2 says nothing about its state at T=1.

I think the point of the article is that time moving in the opposite direction in the opposite universe would appear to be time moving forward for occupants in both universes.

Liken it to passing traffic on the opposite lane of a two way street. You see yourself moving forward, as do the occupants in cars going in the opposite direction. But from your vantage point, they are going the "wrong" direction (in time) while you are going the correct direction. And their perception of you is the same.

Assuming I could "see" their universe, sure. But time is relative to me as it is to them.

To take an event in my time and my universe and somehow define it by theirs is ludicrous.