Hoist with Zeno's Petard

[Metaphor Warning: this posting exists in a superposition of metaphorically analogous similes, or analogous metaphorical similes, or... and?]

So - Zeno's Petard? Well, he could have described a shock wave instead of an arrow... if he'd known about explosives... allow me to allow myself a little creative licence.

Anyway, a new problem has arisen, and the problem is that instead of preventing you from being hoist into the air (because the shock wave can never arrive) the Quantum Zeno Effect turns out to have a sting in its tail (though the venom may turn out to be its own antidote - as we shall see later).

Lawrence Krauss has just put up a rather large "Oops?" sign in his latest paper - where he raises the concern that whereas the universe was ticking along nicely, even if it was potentially in a metastable false vacuum, we may have just buggered it up by noticing the fact. All bets are off - our nice little temporarily stable universe may now be a teensy-weensy bit wobblier.

It's like this... The Quantum Zeno Effect tells us that for small t, the probability of decay is proportional to t squared and if we can't quite bring decay (radioactive, quality of TV programming, moral, etc.) to a complete halt, we can at least slow it down by Obsessive Observation (TM) [Tools: Geiger counter, The Ghost of Mary Whitehouse, and, er, The Ghost of Mary Whitehouse]

Normally decay processes are exponential. Example: a while back a Northern Rock share was worth £12, then it became £6, then £3 - anything that halves at regular intervals is undergoing exponential decay. (I can't bear to provide a link.)

But - and here's the fly in the quantum cosmic ointment - for large t, the decay becomes slow again (a Power Law) - meaning apparently that if the decay hasn't happened by then it's really not likely to decay at all.

But, I hear you cry, that's a good thing! It is indeed - if we are living in a wobbly universe. Or it was, until some idiot went and observed the universe before it has reached the transition point (actually I'm not sure that the timing was that important) from Exponential to Power Law because at that point his observation reset everything (trust a bloke to start fiddling with (qu)bits of fundamental existence) - and we are back on the slippery slope of Exponential decay again.

Oh dear, as I seem to find myself exclaiming more and more these days (as in, "Oh dear. Where are my slippers," or "Oh dear, I've snagged my nice new cardigan,", or even "Oh Dear!The Windows Vista Update - KB938797 if you want to know - that Microsoft recommended for my PC is not, in fact, valid for my PC", etcetera, etcetera, etcetera.)

It may not all end in tears, but (oops - didn't plan this one, honestly) it could all end in tears, rips, splits and general cosmic hyperactivity disorder as the false vacuum (have I explained that one yet? No? Ah.) collapses to a new all time low of vacuity (c.f. UK government data protection assurances (random but relevant link), Northern Rock share valuation, usw.) and Life the Universe and Everything goes "Poof!".

Now I'm in a bit of a quandary as to what to recommend. Live long and prosper but get overrun in the end, or accept that everyone dies young (good or bad - remember to tell the kids "Only the good die young" at the same time you tell them Santa keeps a list of Naughty and Nice) cosmologically speaking.

However, getting back in the saddle of my tame French ovine, if we have indeed put an observational spanner in the cosmic works, we have the answer in hand: the Quantum Zeno Effect, the cause of the problem in the first place.

Whoever made that ill-advised observation of some remote supernova and noticed that the universe is accelerating "outwards" - thereby effecting the observation of a false vacuum - should be glued to his telescope and forced to keep watching... and his children... and his children's children... and his children's children's children (etcetera, etcetera, etcetera ad infinitum - if we want there to be one) to make sure that it doesn't decay. Seems fair to me.

However, two other considerations to take into account.

a) Death of Universe = No Invasion of the Boltzmann Brains (not a bad thing, IYAM)

and (more fundamentally)

b) How in the name of Dick Emery can one part of a quantum system "observe" another part of a quantum system in such a way as to affect the decay probability of the system as a whole?

Answer that if you can! Personally - Oh dear, I really should stop thinking about such things - I'm now more concerned about The Boltzmann Brains From Another Universe observing ours (universe that is) - that really could upset the cosmo-quantum apple-cart and dump several unattractively large flies in our collective soup (ah... you are wondering now, "Did he say ointment or soup earlier?"). The BBFAU may already have observed us - or done so long ago - and it's all over bar the shouting.

Or just perhaps, the plethora of BB's in the multiverse ensures that we are always observed, and thus safe for the foreseeable future.

What was that old Chinese curse? May you live in interesting times.

Here's hoping we live through these interesting times... personally I'm planning to stick around.

Watch me.

[PS A False Vacuum - one which talks about you behind your back]
[PPS If the Quantum Zeno Effect is both doom and salvation doesn't it just cancel itself out, or does it mean it's all kindofuncertain in a satisfyingly-quantum-sort-of-way? Over to you Nicey]