Large Hadron Collider may be shut down - from the future

As the LHC supposedly gears up, Harvard physicist Kevin Black, based at CERN, investigates rumors that the particle accelerator may, in fact, soon be shut down—by ripples from the future.

From Kevin Black:

I came across a bizarre paper recently suggesting that the LHC might be shut down. Not because of the funding cuts that have been threatening particle physics projects around the world, nor because of law suits accusing the LHC of threatening life on Earth. (Not even because we at the LHC have recently been accused of having far too much fun rapping.)

No, the paper suggested that future effects caused by the production of particles, such as the Higgs, could ripple backwards in time and prevent the LHC from ever operating.

If it hadn't been written by two very well respected and accomplished theoretical physicists, I would have stopped reading at the title alone:"Test of Effect from Future in Large Hadron Collider; A Proposal". To be completely honest, the title reads like titles that occasionally appear in my inbox—“Relativity Principle Untenable," "Quantum Mechanics a Hoax," and other nerdy versions of the emails from the supposed attorney of my long-lost Nigerian uncle who apparently has died and left me millions of dollars, if I can only send him $50,000 so that he can get it to me.

But I didn't stop. I read the article. I read it for another reason other than the somewhat awkwardly sounding title and not just because the authors, Holger Nielsen, of the University of Copenhagen, and Masao Ninomiya, of Kyoto University, are somewhat famous. I read it because when I come across such things it tends to remind me of the first time I learned about quantum mechanics. To be honest, if it hadn't come from a professor at a university and a published text book I would have thought that the whole thing was some sort of a scam as well. I mean, really? Sometimes it acts as a wave and sometimes it acts as a particle? The first time I heard about wave/particle duality I was expecting to be asked to send the authors money (perhaps to Nigeria?).

So what did the article say? Well, it started out with a reasonable enough point. One of the basic assumptions of classical physics is that time flows in one direction and that when describing a physical system one needs to know the equations of motion and the initial conditions in order to predict the future behavior of a classical system.

However, quantum mechanics changes this a bit. Classical mechanics can be formulated in such a way that one sets up an “action” integral. The solution to the physical system can be expressed as the path that minimizes the action integral. It turns out that in quantum mechanics one needs to not simply take one path—but take the sum over all possible paths. For example, if you want to work out how a photon gets from a lightbulb to your eye, you need to take into account not just its straight-line trajectory, but contributions of all possible paths it could have taken, including paths where the photon bounces round the room. It's a bit strange, but it seems to work and 60 years+ of detailed experiments have confirmed this description over and over again to remarkable quantitative precision.

The authors of this paper claim to show that other terms can be added to the quantum mechanical action that are consistent with current theory and experiment. However, some of these possible terms include conditions in the future that need to be taken into account and summed over. That is to say, what happens in the future could (according to this paper) affect what happens in the present.




Read the article for more. It's definitely an interesting read, but what do you guys think? It does seem a bit far fetched, but this is being proposed by two very prominent theoretical physicists. Also, when it comes to quantum physics, there are some strange laws that dictate how things work.