Peroration on the Fiction of Nothing

The Guest Editorial by Brian Greene in New Scientist is a pretentious peroration in favour of ‘nothing’ – of beliefs that space is empty – and shows the poverty of reductionist physics.

He’s wrong that Isaac Newton saw space as empty, for the latter believed in the aether (or several aethers) as Paul Davies’s article says.  Johannes Kepler had conjectured a force in the Earth that causes the Moon to move, while Newton’s contemporaries contested the algebraic law of gravity on the grounds that action-at-a-distance is non-science.  But not until Michael Faraday (~1850s) did the concept of a field of force, filling space, come to the fore. 

Greene’s empty space is a false concept – space is filled with physical fields, zeropoint radiation / quantum fluctuations and dark energy.  Paul Davies’s article embraces this physics – “the notion that space is a mere void with no physical properties is no longer tenable” – so why did Greene’s editorial ignore it?

As Davies says, fields possess energy and exert pressure.  Recasting of Einstein’s unified field equation with a true (not pseudo) tensor shows gravity is not only geometry (Leonid Grishchuk).  Gravitational wave scientists are seeking to detect physical waves, comprising propagating energy pulses.  The idea of gravity as just geometry – the ‘shape of nothing’, Greene calls it – is plain wrong.

Neutrino fields get Jim’s boxer shorts in a twist

Jim Al-Khalili’s defence of his extreme scepticism of faster-than-light neutrinos departs from the fundamental standpoint of Faraday, Maxwell and (early) Einstein that space-filling fields are physical, as the formulation of Steven Weinberg, Logunov etc. of a real energy tensor for the gravitational field.   He blogs the CERN neutrinos:

##  moved faster than light “were it travelling in a vacuum“

##  “moving through empty space… they don’t interact or bump into anything”

Yet light travels not in a vacuum but through the gravitational field and waves in it, as well as in the electromagnetic (e-m) field.

If neutrinos have mass, they would likewise be travelling in the gravitational field and they would Cherenkov-radiate in that field.  But if they are massless like ‘photons’, they are not perturbations of the electromagnetic field, but would be perturbations of a third space-filling ‘neutrinic’ field.  As that has an energy density, it automatically enters the Einstein-Hilbert unified field equation. Is Jim’s offhand “bring back the aether” dismissing this basic field theory?

So physics can accommodate neutrinos faster-than-light without the drastic overthrow that Jim warns of – and in a way as Alice suspects that might force him to eat his boxers.

Wave neutrinics – new territory of the neutrino

 Alice has a pot at Jim Al-Khalili’s rash promise…..

So neutrinos might – just might – go faster than light. Maybe some neutrinos go faster than some light – maybe. Let’s face it, we don’t really understand neutrinos as much as light. There’s an awful lot of them, and they might – just might – have a little bit of mass – or at least some of them might. 

Say the neutrino field (in all of its varieties) has zero mass, so it propagates at the speed of light. But what is that? The speed of light depends on its frequency, through the refractive index of the medium. Do you retort there is no medium – that the aether went out a hundred years ago? Well there is hardly empty space between Geneva and Gran Sasso.

Also, the full understanding (if that is what we have) of light propagation requires us to distinguish between ray optics and wave optics, even in “empty” space. To a very good approximation we work out how light paths are bent by the Sun’s gravity by applying Fermat’s Principle (ray optics) to the path length. One way of describing this latter calculation (see The Theory of Gravity by A. A. Logunov, 2001) is that the Riemann forward light cone is contained within the Minkowski causality cone. But there is a region of space-time between the two cones, and that region is where there is scope for different frequencies to behave differently.

Now throw in the new varieties of speed-of-light objects and, without needing to wander into any exotic new dimensions, you have some new physics. While holding firm to causality, I would not be sure that Jim Al-Khalili will not have to “eat his boxer shorts on live TV”.

‘The Big Questions’ – do physicists agree?

Colin Blakemore says (Radio 4 interview by Jim Al-Khalili, 8 Nov.) that physicists agree on the ‘big questions’, while neuroscientists don’t – not even agree that the origin of consciousness is a big question.

Do physicists really agree??

Eg. do we agree that collapse of the wave-function is a big question?  (More grandly - the correspondence between quantum and classical reality).  Proponents of multiverse theories deny it’s an issue. A small group including Steven Weinberg believe otherwise, but most just carry on using the algorithms of quantum mechanics (New Scientist).

2. Do we agree that higher dimensions of space (or space-time) are real, rather than just useful algebraic nomenclature?  No agreement that this is an issue.

3.  Do we agree the existence of gravitons as equivalent to the gravitational field is a big question?  Gravitons are a basic part of the ‘standard model’, though few of us take their existence seriously. 

4. Do we agree with the ‘standard model‘ that fields are equivalent to particles, or do we see fields as ‘real’ in the sense of Faraday – energy distribution in space and transmitting forces through space?  

5. Do we agree that the existence of Black Holes is still in question?  The large majority appears not to accept it’s an open question.

6. The existence of the Higgs ‘God’ particle is one question on which we do largely agree, because without it the standard model is in great trouble.

Why not include string theory in this list? Because it has no clear physical principles and no empirical basis.  Rather than qualifying as a physical theory, it belongs to the sociology of science.

It’s a fundamental of the ongoing Crisis-in-Physics that many physicists do not see and the leading theorists do not agree on what are the ‘big questions’ in physics. Unsurprising that neuroscientist Blakemore is one of the blind.

Let’s dare to question quantum magic!

What a surprise from New Scientist’s editor.  Has caught on to the criticisms from a “small band of rebels” starting from Einstein, who point out quantum mechanics does not describe one of its central tenets, namely collapse of the wave function caused by an observer.  Now Steven Weinberg has come out as a rebel, demanding a formulation that excludes the ‘observer’.  The new relativistic form of continuous spontaneous localisation, described by David Shiga’s article, still requires the trigger of a measuring device.  But external fluctuations could provide a trigger too, so doesn’t this lead back to Planck’s zeropoint fluctuations being essential?  And provide the alternative to quantum magic, so resolving not just a “flaw” as the editorial terms it, but fundamental inconsistency “in the great edifice of quantum mechanics”.

Why not use ns-pulses before Faster-than-Light claim?

New FtL experiment to use nanosecond pulses

The previous experiment with microsecond pulses (1000ns) that measured the average delay time at ~60ns was very dependent on the statistical analysis and sensitive to detection bias (later detections being slightly less probable than earlier ones). Now the CERN scientists hope to shorten the neutrino-generation pulse to 1-2 ns, so can cut out the statistical arguments. The detection numbers will be much lower. But why did the CERN team not do this first, before making their highly contested claim to overthrow the cornerstone inherited from Maxwell and Einstein?

Neutrinos do Cherenkov, don’t they?

CERN theorists seem baffled, but it’s no surprise that standard physics predicts supraluminal (FtL) neutrinos to slow down via Cherenkov radiation analogous to FtL charged particles, although Cohen & Glashow call it bremstrahlung of electron-positron pairs. Cherenkov radiation is best depicted by analogy with the sonic boom of a supersonic projectile – a sonic boom in the electromagnetic field from a supersonic particle. Likewise, a FtL neutrino would generate a sonic boom in the gravitational field and slow down to ‘c’ (not lower as suggested).

Another argument (neutrino-reaction) is that light is slowed below ‘c’ due to transient electron-positron pairs – zeropoint vacuum fields – but neutrinos are not slowed. This forgets that the field energy has an equivalent gravitating mass (E/c²), which decreases ‘c’ below c_vaccuum - FtL neutrinos slowed to ‘c’ by Cherenkov-type emission.

It seems physicists need reminding that the powerful Einstein-Hilbert gravitational field equation includes source terms from field-energy, both gravitational and electromagnetic. Depicting fields as particles – whether gravitons or photons - can readily mislead.