Past Life and Near-Death Experiences

Here are a few articles and blog posts I have unearthed recently explaining and/or debunking these phenomena. I would be interested to learn anything more. The problems as I see it for a supernatural explanation are:

  1. The absence of a known mechanism, especially for re-incarnation as the cause of past life regressions.
  2. Re-incarnation is a very complicated explanation in the absence of a genetic solution.
  3. No physicist to my knowledge has supported quantum theory as a possible explanation.
  4. Tucker, in particular, seems to have leapt from describing a phenomenon to identifying a cause without any intervening process. His predecessor in the field, Stevenson, carefully avoided drawing any such conclusion.
  5. There has been no replication of Tucker’s experiments by other scientists and, therefore, his findings have not been replicated, which is a key aspect of the scientific process.
  6. Near-death experience seems to be governed by one’s culture and religion; in other words Christians often see Jesus whereas Muslims see the prophet Mohammed.

Anyway, see what you think.

Past Life Regression – James P. Cole

Over the weekend I spoke to someone that firmly believed in past life regression, being a topic I was unfamiliar with(except in passing) I decided to do some research into the subject.  There is certainly a wealth of information online about the topic.  The theory basically states that under hypnosis people can access memories of past lives.  There seems to be some clinical evidence that some people under hypnosis do say things that could be interpreted as memories of past lives.  Although in all fairness the data collected isn’t exactly definitive or often particularly credible.  I won’t go into credibility and merits of the particular studies here as they have already been discussed ad nauseum online, suffice to say there is certainly no general consensus on the credibility of any of the studies conducted from both sides of the issue.  Despite the arguments about the credibility of many of the key studies in the area there does seem to be a large amount of anecdotal evidence.

While anecdotal evidence is hardly something to rely on being an open minded guy I decided to do some research into the matter.  Nearly all of the articles I read about past life regression seemed to be written by proponents of reincarnation.  It appeared to me there is a lot of jumping to conclusions and a whole bunch of people trying to use past life regression as evidence for reincarnation.  But as is often the case with these things the people espousing these views have very little hard evidence to link the two theories let alone a testable hypothesis as to how the phenomenon could actually work.

I could find nothing in the way of a solid testable hypothesis as to how these memories are stored and transmitted from person to person and just a lot of wild conjecture.  So for those of you out there trying to link reincarnation and past life regression consider the following:

There has been some clinical data collected showing that under hypnosis people can say things that could be interpreted as memories of past lives.  That is all the definitive information on the matter at this time.

Many people seem to have prematurely concluded that past life regression must be the result of reincarnation.  Reincarnation however is an untested and unproven theory, equally I could say that an invisible unicorn sneaks into your room at night and implants memories of past lives into your brain.  Both these theories would explain past life regression or conversely past life regression could be used as evidence to attempt to validate either of these theories.  Given that there is the same amount of empirical evidence to support the theory of reincarnation and also the theory of unicorn transmitted memories then I have to conclude that they are both equally probable.  No article I could find could offer a decent explanation of how clinical observations past life regression and reincarnation were linked other than nebulous explanations of the “soul” or “some energy” again both theories with no physical evidence.

Seeing as the theory of the “soul” and reincarnation are both unverified theories(with no hard evidence to support them) they should both be treated with a healthy degree of scepticism.  While I found many people attempting to use past life regression as evidence of reincarnation or the “soul” I didn’t find anyone trying to properly explain how these things could work or answer any of the obvious questions that arise from such explanations like:

What is the mechanism by which these memories are stored and passed from person to person?

What form does the “soul” take?

Given that the “soul” can influence our behaviour then it must in some way be interacting with normal matter so how is this interaction taking place?

Given that the “soul” must be interacting with the normal matter in some way it should therefore be possible to design an experiment to measure this interaction and collect hard data on the theory.  So why don’t the proponents of these theories come up with a decent hypothesis and design an experiment to test it?

Surely if you firmly believed in something so seemingly unlikely as reincarnation or the “soul” these would be the first questions you would ask and then try to find answers to these questions, if for no other reason than to have the peace of mind of some credible basis for your beliefs.  If in fact observed instances of past life regression are actually what is being claimed then the phenomenon should be studied and understood.  I read several articles claiming that maybe it is “just beyond logic and science” which shows a particular brand of ignorance that treats science as a static thing, assuming if it can’t provide a definitive answer today it never will in the future.  In the past many things were “beyond logic and science” which can now be accurately explained so it seems wilfully ignorant(and quite frankly lazy) to assume that something not currently understood can never be studied and explained.  If proponents of theories like the “soul” or reincarnation want to be taken seriously then this sort of wilful ignorance will always keep them on the fringes of intellectual credibility.  To be taken seriously proof needs to be provided and to just say “it is real but can never be understood so I can never investigate or provide proof” doesn’t exactly inspire credibility or give anyone any reason to subscribe to your theory over any other and is certainly not going to win over the people sitting on the fence.

Before I hear the cries of “Well you can’t disprove the theory of the soul or reincarnation” I will say this:  The onus of proof is on the person making the claim.  It is not my responsibility or the responsibility of scientific researchers to disprove every theory that anyone comes up with, it is the responsibility of the person making such extraordinary claims to provide evidence to back up their theory.  In addition to this I could not find a testable hypothesis as to how the “soul” or reincarnation could work so even if I did have the resources or inclination to test its veracity there is nothing for me to test.

Anyway this is a big topic(I could write many more pages on this) and I have digressed quite a bit but seeing as nearly everything I read on the topic seemed to be desperately grasping at straws to try and link the “soul” and reincarnation to past life regression I felt that I need to at least cover the topics.

In my initial thoughts on a mechanism for how memories could be transmitted across lives genetic memory seemed like the most obvious answer.  Genetic memory is the idea that some behaviours and instincts can be transferred genetically, there are many examples of this such as nest building in birds.  To be honest it seemed like a pretty unlikely answer(for many reasons I won’t go into here) but it was the only explanation that immediately sprung to mind.  I figured that if some epigenetic factor could somehow encode memories into a person’s genes they could be transferred to their offspring and therefore across lives.  After some research I discounted this idea as many people report remembering dying in past lives and so there is no way this information could have been passed to their offspring, also you would only be able to access memories of people related to you.  It would be fairly easy to design an experiment to verify or disprove the theory using identical twins separated at birth(to try and account environmental factors) who should theoretically share identical past life memories.  I could not find anything about anyone actually doing such an experiment.  So while genetic memory is in well documented in nature it can’t explain past life regression adequately.

So what are the other explanations for past life regression?  There are a few, none of which have been conclusively proven.  One is that it’s just made up, people have dreams that feel very real, I could dream  I was a Roman soldier or a scullery maid in the past but I would not see that as evidence that I actually was.  So it is clearly possible for the brain to create very realistic feeling scenarios that are not based on fact so this could just be what is happening to these patients under hypnosis.

Another is that the hypnotist asks very leading questions while the patient is in a hypnotised state to try and lead them towards saying things that could be interpreted as talking about actual past lives.

But as I said there is no conclusive evidence for any of theories put forward(including reincarnation and the “soul”).  So the short answer is no one has a proven explanation for the clinical observations(although to be honest I am even a little suspicious of the clinical evidence).

“Ha Ha, I got you, science doesn’t know everything!” I hear the new age anti-intellectuals cry.  Well no one claimed it did.  Equally new age hippy “spiritualism” doesn’t explain everything either.  I find people who fervently espouse unverified “spiritual” explanations to as yet unresolved questions  a strange bunch, they seem to view science as a static thing(much like their own beliefs) and tend to think if science doesn’t explain something today then it never will and has somehow failed and it must be some mystical supernatural force that science can’t define.  This is such a bizarre and short sighted conclusion to jump to and shows such a massive lack of curiosity, understanding and knowledge of history that I find it difficult to fathom.  Less than 80 years ago we didn’t know the mechanism for how hereditary traits are passed from parents to their offspring and I’m sure there were many people saying “see, science can’t explain it therefore it must be the work of [insert crazy theory here]”.  But with more research better experiments and brilliant minds we slowly but inevitably peel back the layers and discover the underlying principles of the world around us.

To think that scientific discovery has gone as far as it ever will or can, and will never explain certain things that many around us point to as evidence of the supernatural, will inevitably, like many before you,  leave you looking the fool.  So for those of you who jump upon unexplained(and often unverified)clinical or experimental data to try and shore up your outlandish, unproven and untested theories I say this: fervent belief in something without evidence poisons the mind, society and advancement of the human condition and will ultimately leave you open to justifiable ridicule.

So until someone can come up with a verified and tested explanation of the observed clinical data I can’t make a call either way as to whether clinical observations described as past life regression are in fact memories of past lives.  But if I was a betting man my guess would be that whatever the answer it lies within the boundaries of physics, neuroscience and physiology.



Jim B. Tucker – critique

While Ian Stevenson focused on cases in Asia, Tucker has studied American children.[21]
Tucker reports that in about 70% of the cases of children claiming to remember past lives the deceased died from an unnatural cause, suggesting that traumatic death may be linked to the hypothesized survival of personality.

Unnatural death doesn’t necessarily mean traumatic, and my question is, are the supposed causes of death reported by the children themselves, or do they identify the person who is then investigated as to causes of death? The only thing you could conclude from such comparisons is an apparent correlation between children claiming to be the reincarnations of the deceased and the accuracy with which they could describe such events, which doesn’t really imply anything beyond the immediate relationship, so this is a rather meaningless statistic.

He further indicates that the time between death and apparent re-birth is, on average, 16 months, and that unusual birthmarks might match fatal wounds suffered by the deceased.[22]

On average the time is 16 months, well this doesn’t say much, out of ten people its possible that the times varied wildly with outliers and it could average out to 16 months; what are the standard deviations of the distribution, this is more of an indicator of spread and therefore how meaningful the statistics are. Unusual birthmarks MIGHT match fatal wounds, and they might not as well… no report here as to what percentage of birthmarks matched wounds, and that would only be percentage of people WITH birthmarks, which is probably not very high. Even if birthmarks match fatal wounds, so what, it is purely coincidental until you can identify some kind of mechanism which might somehow transmit these wounds to the body of the child. Completely meaningless statement here.

Tucker has developed the Strength Of Case Scale (SOCS), which evaluates what Tucker sees as four aspects of potential cases of reincarnation;[23][24] “(1) whether it involves birthmarks/defects that correspond to the supposed previous life; (2) the strength of the statements about the previous life; (3) the relevant behaviours as they relate to the previous life; and (4) an evaluation of the possibility of a connection between the child reporting a previous life and the supposed previous life”.[25]

(1) We’ve already said why this is rather meaningless; (2) This doesn’t really mean anything, a child can do some research about the deceased, most likely they read about it in the paper or something. And how do you rate the strength of their statements? No mention of this here, I would personally clarify this to be “knowledge of private information that only the deceased would know; (3) Relevant behaviours, so similarities between the deceased and the child? This would be coincidental also. Why is there no mention of personality tests being conducted, surely this would be a good way to correlate the two people if it is supposedly personality which is being passed on; (4) A connection, well we all share many connections with each other, similar interests, habits, etc… this means nothing.

All in all, there doesn’t seem to be much here to support any kind of assertion of reincarnation. The SOCS is meaningless and measures nothing but coincidences. I see no reason to take this seriously until the researcher himself takes it seriously enough to conduct a credible study.

From: Dimebag

Here’s the thing… that children do apparently report memories that the adults around them interpret as “past lives” is a real phenomenon. It’s conceivably worth investigating. You’ll almost certainly learn nothing about “past lives” and a lot about the way adults interpret and manipulate children, but an objective investigation isn’t out of the realm of possibility.

What’s out of the realm of possibility is Tucker’s version of “quantum consciousness”, which is such flagrant stupidity that he should not only have his grant revoked, but his PhD, his driver’s license, and his frequent shopper’s card at the Kroger.

OK, I shouldn’t go that far. This is science “journalism”, and it’s entirely possible that it’s the fault of the article writer that makes him sound like a lunatic. Speculating that there’s some kind of quantum woo-woo in the unsolved problem of consciousness isn’t completely idiotic, though it clearly screams “wishful thinking”. It does feel as if there ought to be some kind of “quantum license” you should be forced to get before an academic is allowed to use the word in a sentence. And it’s not administered in the psychology department.

So, just to review the bidding: it’s only kind of a waste of time and money for this guy to run down claims of reincarnation-implying statements by children. At least, as long as he is considering alternative hypotheses like “manipulation” and “confirmation bias”, which Occam’s Razor considers vastly more likely than whatever quantum hoojiggy he’s got in mind.

The question asks for “flaws” but without a description of the methodology, I can’t say one way or the other. The fact that the article doesn’t have such a description is a strong indicator that the “science journalist” is incompetent, but hey, we already knew that. That may or may not indicate more incompetence in the vicinity, but it’ll be hard to tell. Should he try to publish his results, we’ll find out then. I doubt it will be pretty.

From: Joshua Engel


Near Death Experience explained – Scientific American (synopsis, with permission). Charles Q. Choi.

Near-death experiences are often thought of as mystical phenomena, but research is now revealing scientific explanations for virtually all of their common features. The details of what happens in near-death experiences are now known widely—a sense of being dead, a feeling that one’s “soul” has left the body, a voyage toward a bright light, and a departure to another reality where love and bliss are all-encompassing.

Approximately 3 percent of the U.S. population says they have had a near-death experience, according to a Gallup poll. Near-death experiences are reported across cultures, with written records of them dating back to ancient Greece. Not all of these experiences actually coincide with brushes with death—one study of 58 patients who recounted near-death experiences found 30 were not actually in danger of dying, although most of them thought they were.


A variety of explanations might also account for reports by those dying of meeting the deceased. Parkinson’s disease patients, for example, have reported visions of ghosts, even monsters. The explanation? Parkinson’s involves abnormal functioning of dopamine, a neurotransmitter that can evoke hallucinations. And when it comes to the common experience of reliving moments from one’s life, one culprit might be the locus coeruleus, a midbrain region that releases noradrenaline, a stress hormone one would expect to be released in high levels during trauma. The locus coeruleus is highly connected with brain regions that mediate emotion and memory, such as the amygdala and hypothalamus.

One of the most famous aspects of near-death hallucinations is moving through a tunnel toward a bright light. Although the specific causes of this part of near-death experiences remain unclear, tunnel vision can occur when blood and oxygen flow is depleted to the eye, as can happen with the extreme fear and oxygen loss that are both common to dying.

Altogether, scientific evidence suggests that all features of the near-death experience have some basis in normal brain function gone awry. Moreover, the very knowledge of the lore regarding near-death episodes might play a crucial role in experiencing them—a self-fulfilling prophecy. Such findings “provide scientific evidence for something that has always been in the realm of paranormality,” Mobbs says. “I personally believe that understanding the process of dying can help us come to terms with this inevitable part of life.”



What is the nature and extent of the stigma associated with problem drug users?

Written by: Timokleia Panagopoulou.

The nature and extent of stigma is associated with problem drug users and that creates implications for policy and practice.  More specifically, stigma is “a mark of disgrace associated with a particular circumstance, quality, or person” (Oxford Dictionaries, 2013). Stigma for problem drug users has been created because people believe stereotypes such as drug users  are ‘junkies’, burglars inferiors (Lloyd, 2010) and burdens (Singleton,2011; UK Drug Policy Commission [UKDPC], 2010). As a result people don’t want to live next door to a drug user and many of them are opposed to a relationship with a drug dependent. All these beliefs create discrimination for that group of people, as they may be isolated from social events as well as from all of society and as a result their drug use may have increased (Buchanan & Young, 2000).

The nature and extent of stigma on problem drug users

The stigma facing problem drug users is multi-levelled, as it has a lot of consequences. The three most serious are the personal problems they face, as well as mental and psychical problems. Also, their families face stigma.  Health professionals, as well as the media, are responsible for introducing negative stereotypes.  Finally, the whole society is responsible for the current state of stigma in society.

User’s problems

Drug users often report social exclusion from other members of society.  They accept that other people stigmatise them, and they henceforth don’t react to people in a manner typical of the rest of society.  Non-drug users view users as a lower social class of society and more than 50% in Scotland believe that they are a burden on society (Singleton, 2011).  Sometimes they feel that other people are talking about them negatively when they are not present.  It seems that they are unable to create true friendships and relationships with others for a long period because of the isolation created by stigma (Buchanan & Young, 2000). As a result of all these stereotypes, discrimination is increased and (Young, Stuber, Ahern & Galea, 2005) drug user’s self-esteem is substantially decreased (Simmonds & Coomber, 2009).

Mental and physical problems

Because of stigma, problem-drug users not only face rejection, but they also anticipate others’ rejection of them.  The result of this is chronic stress. A research, which took place in three New York city neighbourhoods between 2000 and 2001, shows that drug users are more stressed at work or at home than non-drug users, on account of such stigma (Young, Stuber, Ahern & Galea, 2005). Sometimes, this chronic stress effects parts of the brain (Ahern, Stuber & Galea, 2007), which in turn can lead to chronic health problems, in general (Young, Stuber, Ahern & Galea, 2005). This kind of problems drive drug users cannot cope without self-medication and as a result they continue to use drugs.


Family members of problem-drug users, also face stigma in their daily life.  More specifically, stereotypes and people’s reactions stigmatise also them. 29% of people in Scotland believe that heroin users suffer family difficulties (Corrigan, Miller & Watson, 2006). Family members feel shame for drug use and because of that they avoid personal relationships with people who know about the family member’s drug dependence because they believe that people will judge them in a negative way (Singleton, 2011). The consequence of that is, to remain isolated and not make new relationships.

Health Professionals

Some of health professionals also have stigmatized reactions to drug users. More specifically, the attitudes of some doctors, nurses are negative, and these individuals accept that their behaviour toward them is different than that to their other patients (Lloyd, 2010). Research from the U.S.A. points primary-care doctors and physicians, who work at hospitals viewing problem-drug users in a negative light (Lloyd, 2013). It seems that, they agree with the stereotype that problem-drug users have a poor social prognosis. Social services refer to them as junkies (Simmonds & Coomber, 2009).  These negative attitudes have an impact on treatment, as those with such attitudes are inappropriate for helping a drug user to gain the goal of recovery.


Media has a real power to create imagery that can have widespread influence. Sometimes it is pivotal in the stigmatisation of problem-drug users. However, they do not report the full extent of the issues facing problem-drug users as they represent criminality as one and the same.  Taylor (2008) suggests that the media turns these individuals into ‘outsiders’ of their society. A lot of people in a given society may not know a drug dependent, personally, but all of them have their own opinion about the dangers of use, as well as the lifestyle of users.  This is the public opinion that the media has created (Australian Injecting and Illicit Drug Users League, 2011. This is happening because people love watching this kind of programmes and as a result media may earn more money.  If someone has been identified as a drug-user, by the media, they then have great difficulty in shedding this label (Count the costs, 2011). Consequently, the level of drug use grows at 70%, because of the stigma created by media (Lloyd, 2010).


The majority of people believe that drug addicts are dangerous and unable to be reasoned with (Lloyd, 2010). In general, when people speak of drug users, they describe them as dirty, homeless and jobless. However, this is often an untrue assessment (Australian Injecting and Illicit Drug Users League, 2011). A case of society stigmatising drug users can be seen in pharmacy interactions. Some heroin users pick up their prescribed methadone from their pharmacy, where they cannot avoid the stigmatisation of both staff and other customers (Lloyd, 2010). Drug users face exclusion from the society even when they manage to overcome their addiction (Taylor, 2008). Moreover, drug addiction is one of the most serious causes for social disapproval (Room, 2005). Simmonds and Coomber (2009) support the notion that society stigmatises poor drug users more so than more affluent users. Also, especially in smaller towns, friend groups are often segregated between groups who use and groups who do not, with very little mixing (Simmonds & Coomber, 2009).

Measures to reduce the problem of stigma

Drug users don’t have any support from governments or from whole of society and as a result their treatment blocked as their access is made difficult. In order to reduce the problem of stigmatisation, governments must take measures to ensure the successful reintegration of prior drug-users into society. This will only happen when a better general knowledge of drug use, amongst national populations, reduces national fears (Singleton, 2011).

To conclude, it is true to say that stereotypes, for drug users, create a lot of difficulties in their daily lives, such as psychological problems, chronic stress and isolation for themselves as well as for their families. These stereotypes have been increased because of health professionals, media and society and as a result they implicate policy and practise. More specifically, people face them as criminals and ‘junkies’. Consequently, they suffer from discrimination as often they cannot work and they cannot vote as members of society. Moreover, drug users are responded to differently than other patients within the health care system and some of them are abused. What is more, their families have problems with their accommodation. Finally, some of them who are younger lose their rights to ask for studentships and continue their studies.

The main and the most important consequence of stigma on problem drug users is that the discrimination and the stereotypes which create more drug use.  It is for this reason that health professionals and all members of every society should understand the powerlessness of problem-drug users, and it is thus necessary that these other members assist them in establishing normalcy within their lives (Weil, 2013).


  • Ahern, J., Stuber, J., & Galea, S. (2007). Stigma, discrimination and the health of illicit drug users. Drug and Alcohol Dependence, 88, 188-196.
  • Australian Injecting and Illicit Drug Users League (2011). Why wouldn’t Discriminate against all of them? A Report on Stigma and Discrimination towards the Injecting Drug User Community. Canberra, Australia.
  • Buchanan, J., & Young, L. (2000). The war on drugs- a war on drugs users?. Drugs: education, prevention and policy, 7(4), 409-422.
  • Corrigan, P.W., Miller, F.E., & Watson, A.C. (2006). Blame, shame, and contamination: The impact of mental illness and drug dependence stigma on family members.  Journal of Family Psychology, 20(2), 239-246.
  •  Count the costs, (2011). The War on Drugs: Promoting stigma and discrimination.
  • Lloyd, C. (2010). Sinning and sinned against: the stigmatisation of problem drug users.  Kings Place. London: UK Drug Policy Commission.
  • Oxford Dictionaries, (2013). 
  • Room, R. (2005). Stigma, social inequality and alcohol and drug use. Drug and Alcohol Review,24, 143 -155.
  • Simmonds, L., & Coomber, R. (2009). Injecting drug users: A stigmatised and stigmatising population. International Journal of Drug Policy, 20, 121–130.
  • Singleton, N. (2011). Getting serious about stigma in Scotland: The problem with stigmatising drug users. London: UK Drug Policy Commission.
  • Taylor, S. (2008). Outside the outsiders: Media representations of drug use. Probation Journal 55(4), 369-387.
  • Weil, L. (2013). Drug-related evictions in public housing: congress’ addiction to a quick fix. Yale Law & Policy Review, 9(1), 161-189.
  • Young, M., Stuber, J., Ahern, J., & Galea, S. (2005). Interpersonal discrimination and the health of illicit drug users. The American Journal of Drug and Alcohol Abuse, 31, 371–391.

Bishop Berkeley

In Our Time this week (Thursday 20th March) was on the subject of George (Bishop) Berkeley. He was, of course, one of the great British empiricists of the 17th and 18th centuries – Locke and Hume being the other two giants of the era. Berkeley’s big idea was, literally, idealism, that is that the world consists of ideas formed in the mind rather than material objects. Locke felt that these ideas must be based on something rooted in reality but Berkeley’s view that this could not be proven and therefore remained a belief. He sought, through this logic, to prove – what Descartes had failed to do 100 years previously – the existence of God. Idealism far from being a dead end, however, is still very much with us (although God is invoked less than hitherto) and formed a fundamental plank of Kant’s ‘Critique of Pure Reason.’

Dr Johnson’s famous act of kicking a rock and saying, ‘I refute it thus,’ when Boswell said that it (idealism) was difficult to refute, is not really a refutation. I am with Boswell on this. Everything we experience comes to us through the brain – we cannot stand outside our nature and view the world objectively, so how can we possibly know whether our thoughts and feelings relate to a ‘Real’ world or not?

Berkeley, incidentally, visited the USA and was the inspiration for the naming of Berkeley college, now part of the University of California.

Gravitational waves in the cosmic microwave background by Sean Carroll (written before the announcement)

The BICEP2 experiment has purportedly detected signs of gravitational waves in the polarization of the cosmic microwave background radiation.

Punchline: other than finding life on other planets or directly detecting dark matter, I can’t think of any other plausible near-term astrophysical discovery more important than this one for improving our understanding of the universe. It would be the biggest thing since dark energy. (And I might owe Max Tegmark $100 — at least, if Planck confirms the result. I will joyfully pay up.) Note that the big news here isn’t that gravitational waves exist — of course they do. The big news is that we have experimental evidence of something that was happening right when our universe was being born.

Cosmic inflation is actually a pretty simple idea. Very early on–we’re not sure exactly when, but plausibly 10-35 seconds or less after the Planck time–the universe went through a phase of accelerated expansion for some reason or another. There are many models for what could have caused such a phase; sorting them out is exactly what we’re trying to do here. The basic effect of this inflationary era is to smooth things out: stuff like density perturbations, spatial curvature, and unwanted relics just get diluted away. Then at some point–again, we aren’t sure when or why–this period ends, and the energy that was driving the accelerated expansion converts into ordinary matter and radiation, and the conventional Hot Big Bang story begins.

Except that quantum mechanics says that we can’t completely smooth things out. The Heisenberg uncertainty principle tells us that there will always be an irreducible minimum amount of jiggle in any quantum system, even when it’s in its lowest-energy (“vacuum”) state. In the context of inflation, that means that quantum fields that are relatively light (low mass) will exhibit fluctuations. (Gauge fields like photons are an exception, due to symmetries that we don’t need to go into right now.)

So inflation makes certain crude predictions, which have come true: the universe is roughly homogeneous, and the curvature of space is very small. But the perturbations on top of this basic smoothness provide more specific, quantitative information, and offer more tangible hope of learning more about the inflationary era (including whether inflation happened at all).

There are two types of perturbations we expect to see, based on two kinds of light quantum fields that fluctuated during inflation: the “inflaton” field itself, and the gravitational field. We don’t know what field it is that drove inflation, so we just call it the “inflaton” and try to determine its properties from observation. It’s the inflaton that eventually converts into matter and radiation, so the inflaton fluctuations produce fluctuations in the density of the early plasma (sometimes called “scalar” fluctuations). These are what we have already seen in the Cosmic Microwave Background (CMB), the leftover radiation from the Big Bang. Maps like this one from the Planck satellite show differences in temperature from point to point in the CMB, and it’s these small difference (about one part in 105) that grow into stars, galaxies and clusters as the universe expands.

Then, of course, there are quantum fluctuations in the gravitational field: gravitational waves, or “gravitons” if you prefer speaking quantum-mechanically (sometimes called “tensor” fluctuations in contrast with “scalar” density fluctuations). It was in the early 80′s, soon after inflation itself came along, that several groups pointed out this prediction: Rubakov, Sazhin, and Veryaskin; Fabbri and Pollock; and Abbott and Wise. Just as an electromagnetic wave is an oscillation in the electric and magnetic fields that propagates at the speed of light, a gravitational wave is an oscillation in the gravitational field that propagates at the speed of light. We can detect electromagnetic waves because they would cause a charged particle to jiggle up and down; we could (in principle, though not yet in practice) detect gravitational waves because they alternately stretch things apart and then compress them together as they pass.

Gravitational waves from inflation are interesting for a couple of reasons. First, we know they should be there; gravitation certainly exists, and it’s a massless field. Second, there is a way to disentangle the gravitational waves from the density fluctuations, using the polarization of the CMB. This was noted in a flurry of papers from 1996 by different subsets of Seljak, Zaldarriaga, Kamionkowski, Kosowsky, and Stebbins: 1, 2, 3, 4, 5. Finally, how strong the gravitational waves are at different wavelengths reveals a great deal about the details of inflation — including one magic number, the energy density of the universe during the inflationary era.

Any kind of electromagnetic radiation, such as the microwaves we observe in the CMB, has a polarization. An electromagnetic wave is just a propagating ripple in the electric and magnetic fields, and we (somewhat arbitrarily) define the direction of polarization to be the direction in which the electric field is oscillating up and down. Of course when we observe many photons, the polarizations of each photon will often be pointing in random directions, giving a net effect that adds up nearly to zero. That’s the case in an ordinary incandescent bulb, and it’s almost the case for the CMB. But not quite. There is a tiny amount of residual polarization in the CMB, first discovered by the DASI telescope. (I helped organize the talk at the Cosmo-02 where the discovery of CMB polarization was announced. It was the Ph.D. thesis project for John Kovac, who is now on the faculty at Harvard and the PI on BICEP. I can brag that he took my cosmology class back in grad school.)

But there’s polarization, and there’s polarization. Even without any gravitational waves, the CMB would still be polarized, just due to the distortions brought about by ordinary density perturbations. That’s what DASI discovered. Happily, we can distinguish density-induced polarization (“scalar modes”) from gravitational-wave-induced polarization (“tensor modes”) by the shape of the polarization pattern on the sky.

A map of CMB polarization takes the form of little line segments on the sky — the direction of the net oscillation in the electric field. If you just have polarization at one point, that’s all the information available; but if you have a map of polarization over some area, you can decompose it into what are called E-modes and B-modes. (See this nice article from Sky & Telescope.) The difference is that B-modes have a net twist to them as you travel around in a circle. That sounds a little loosey-goosey, but there is a careful mathematical way of distinguishing between the two kinds.

Very roughly: density (scalar, inflaton) perturbations produce only E-mode polarization, whereas gravitational wave (tensor) perturbations produce B-mode polarization as well as E-modes. [Update: Thanks to asad and Daniel in comments for a correction here.] That’s why looking for the B-modes is such a big deal.

It’s also hard, for a number of reasons. When we said “very roughly,” we meant it — there are various effects other than gravity waves that can create B-modes, typically by taking some E-modes and messing with them. One such effect is gravitational lensing — the deflection of light by matter in between us and the CMB. Indeed, B-modes from lensing have already been detected twice, by the South Pole Telescope and by the PolarBEAR experiment.

But now the rumor is that the BICEP2 experiment has found a signature of honest-to-goodness B-modes from primordial gravitational waves. I won’t speculate about the details like the amplitude or the statistical significance, since we’ll find that out soon enough.

Let’s instead think just a little bit about what it would mean. Both density perturbations and gravitational-wave perturbations arise from quantum fluctuations generated during inflation, and the amount of perturbation depends on the energy scale E at which inflation happens, defined as the energy density to the 1/4 power. (I’m presuming here that inflation is the right story, but of course we don’t know that for sure.) But there’s a difference: for density perturbations, what actually fluctuates is some hypothetical inflaton field ϕ. That’s related to the energy density, but it’s not exactly the same thing; the actual density comes from the potential energy, V(ϕ). So measuring the density fluctuations (which we’ve done) doesn’t tell us the energy scale of inflation directly; it’s modulated by the unknown function V(ϕ). The flatter the potential, the larger the density perturbations. We can make educated guesses, which tend to put the energy scale E at around 1016 GeV (where a GeV is a billion electron volts, about the mass of the proton). That’s pretty darn close to the Planck scale of 1018 GeV, and basically equal to the scale of hypothetical grand unification, so you see why any empirical information we can get about physics at those scales is extremely interesting indeed.

Gravitational-wave perturbations are different. They are not modulated by some unknown potential; they are produced by inflation, and we observe them directly. In straightforward models of inflation, the amplitude of the gravitational waves is directly proportional to the inflationary energy scale. If this rumored measurement (and the inflationary interpretation) are correct, we would have data about a physical process just a bit below the Planck scale. Currently, our empirical knowledge of the early universe only stretches to about one second after the Big Bang, courtesy of primordial nucleosynthesis. Here we’re talking about pushing that to less than 10-35 seconds.

Now to get a bit quantitative. We can approximately describe a set of cosmological perturbations by two numbers: the overall amplitude A, and the “spectral index” or “tilt” n that tells you how the perturbations change from large wavelengths to shorter wavelengths. For the density perturbations, we have a fairly good handle on what these numbers are; the amplitude is about 10-5, and the spectral index is about 0.96. For historical reasons, density perturbations that are the same on all wavelengths are said to have nS = 1, while gravitational perturbations that are the same on all wavelengths are said to have nT = 0, where S is for “scalar” and T is for “tensor.” (I think it’s conceivable that the data are still compatible with nS = 1 rather than 0.96, but you really have to bend over backwards.) Finally, we often compare the gravitational-wave perturbations to the density perturbations by giving the ratio r = AT/AS of amplitudes (tensor divided by scalar).

Here are the best constraints as of Sunday March 16, 2014, from the Planck satellite. Horizontal axis is the tilt of the density perturbations, vertical axis is the ratio of gravitational-wave to density fluctuations. (Note that Planck hasn’t yet released polarization data, but even just the temperature fluctuations provide some constraints on the gravitational-wave amplitude.) The half-ellipse blobs at the bottom are the regions allowed by the data, and the various dots and lines are the predictions of different inflationary models.

So you see that pre-BICEP, we’re quite comfortable with density perturbations that have a spectral index nS = 0.96 or so, and no tensor fluctuations at all (r = 0). From what I’m told, the only way BICEP should be able to get a really solid detection (five sigma) is if r is about 0.2. Which seems to be in a bit of tension with the limits plotted here (although admittedly they are only two-sigma error contours). But we don’t know yet, and there is a bit of room for slop; maybe the central value found by BICEP is around 0.2, but it’s consistent with 0.1, which would be perfectly fine.

What does it all mean? Most importantly, a gravitational-wave signal that big is … really big. It corresponds to an energy scale during inflation that is pretty darn high. It’s actually not so easy (although certainly possible) to come up with models that have such prominent gravitational waves. This goes back to something called the Lyth bound, after its discoverer David Lyth. The issue is that there is an interplay between the size of the density perturbations, the size of the gravitational-wave perturbations, and the total amount by which the inflaton field rolls during inflation. Very roughly, the amount of field rolling (in units of the Planck scale) is ten times the square root of r. So if r > 0.01, the inflaton ϕ rolled by more than the Planck scale during inflation. That’s not impossible — it’s just provocative. In string theory, for example, most candidates for the inflaton are periodic, with a period of about the Planck scale. [Update: at least, that’s been the conventional wisdom in certain quarters. See comment by Eva below.] So large r is hard to get. And r=0.2 is large indeed.

There are loopholes, of course. An intriguing one is axion monodromy inflation, which has been investigated by Eva Silverstein, Alexander Westphal, and Liam McAllister. Instead of having just one periodic field, they imagine multi-dimensional field spaces; then the inflaton can essentially wind around one direction several times before reaching the bottom of its potential, allowing for quite large effective field values.

More importantly than the prospects for any given model, however, this is great news for inflation itself. While it’s the starting point for much contemporary cosmological theorizing about the early universe, honest physicists are quick to admit that inflation has its conceptual problems. The prediction of gravitational waves is one of the strongest empirical handles we have on whether inflation actually happened, so if this result is announced like the rumors say (and it holds up) it will dramatically effect how we think about the earliest moments in the history of our universe. And if we succeed in measuring not only the amplitude of the gravitational waves but also their spectral index nT, there is a “consistency relation” that holds in simple models of inflation: r = -8nT. If that turns out to hold, it will be very hard indeed to deny that inflation happened. (Sadly, there are all sorts of non-simple models of inflation in which the consistency relation is violated, so if it doesn’t turn out to hold, we won’t really know one way or the other.)

There is always the possibility that a result is announced but it doesn’t hold up, of course. These are really hard measurements, with many ways to go wrong, even for experimenters as undoubtedly careful as the BICEP folks are. When the announcement is made, look not only for the claimed statistical significance, but also (as Eiichiro Komatsu has emphasized) for its robustness — does it show up in multiple frequencies (of radiation), as well as at multiple scales on the sky? Happily there are many competing experiments that will move very quickly to tell us whether this is on the right track. Science!

Christian Beginnings: from Nazareth to Nicaea by Geza Vermes

I have finally finished reading Geza Vermes’ last book – ‘Christian Beginnings, from Nazareth to Nicaea.’

It comprises a thorough piece of scholarship and a logical process of reasoning to reach his conclusions. He is clear about the reliability of the evidence and puts forward alternative explanations where appropriate. One thing he deals with is the virgin birth issue and how it came to be mainstream Christian doctrine when the source (Isaiah) clearly uses the term, ‘Almah,’ meaning young woman (neanis in the Greek) and never ‘Betulah,’ – virgin or parthenos. It is a mistranslation in the Septuagint that Origen (one of the founding fathers of Christianity) insisted was correct (even though as a scholar he would have known otherwise). Origen claimed in his defence that ‘Almah’ had indeed been used in the Jewish Bible (Deuteronomy) to indicate a virgin. However, no known text of Deuteronomy has ever been found to substantiate this. The word actually used is ‘Na’arah,’ which also means young girl rather than ‘Virgin.’ We can only speculate as to his motivation.

Vermes builds up a picture step by step of how each generation of Christian thinkers added their interpretation to the Jesus story. Paul, followed by whoever wrote the Johannine gospel began the ‘Son of God,’ story as literal, which is absent in the authentic parts of the synoptics and Acts. Right up the Council of Nicaea most Christians placed Jesus and the Holy Spirit below God in the divine hierarchy in an attempt to retain some semblance of monotheism. Arianism, which averred that Jesus was neither consubstantial nor coeval with God, was routed at Nicaea by Alexander, Bishop of Alexandria and his successor, Athanasias. Why? Because they enlisted the support of Constantine, who had grown tired of all the doctrinal bickering and imposed their view as the correct and orthodox version throughout the Empire and condemned all others, including Arianism, as heresy. I paint a very complex picture simply but Vermes is scrupulous in his forensic examination of the available evidence.

Before embarking on this quest he reprises his work on Jewish religious beliefs in the inter-testament period, from which the Jewish holy man, Jesus, emerged. He traces the history of charismatic individuals in Jewish history and puts Jesus firmly in this tradition.

Altogether, the book is a thoroughly well-researched and beautifully written testimony to a great and much missed scholar and I cannot recommend it highly enough.

Incidentally, the subject of a recent ‘In Our Time,’ – my favourite programme on any broadcast medium – was the Holy Trinity: how it came about; what it means; and why it persists. It is well worth catching on podcast.

Review of ‘The Better Angels of Our Nature,’ by Steven Pinker

Let me begin by saying that for any quibbles I might have (and there are a few) this is one of the most interesting and uplifting books I have read for many years. The title is a quote from Lincoln. It is long (841 pp in paperback) but much of that can be laid at the door of Pinker’s thorough and scholarly approach. Almost all of his assertions, with a few notable exceptions, are supported by detailed research from a wide range of fields: psychology (Pinker’s area of expertise); anthropology; history; philosophy; politics; neuroscience; evolutionary biology; and economics among others. I should also say that, despite its didactic approach, it is never an effort to read, which is largely thanks to the author’s easy demotic style and liberal use of illuminating examples.

The basic thesis of the book is that human-caused violence has diminished, is diminishing and, all things being equal, will continue to diminish. Whether one measures the amount of violence in society as incidents proportional to the population or by the likelihood of individuals becoming victims of violence the story is the same. Pre-state violence was endemic, whereas today the line bumps along the bottom of the graph, hardly registering when placed in a historical context. Some modes of violence are easier to measure than others but nonetheless his reach is wide and includes: wars of all kinds; murder; rape; personal attacks; gratuitous cruelty; human sacrifice; infanticide; gynecide; genocide; torture; animal cruelty; cruel and violent entertainments; slavery; domestic violence; violence carried out by the state; ideological violence; cruel punishments; and so on. Some of these, obviously, involve larger numbers than others (the category contributing the highest numbers of deaths is ideology – either religious or political) but all are meticulously researched.

Intuitively one thinks of the 20th century as a counter to Pinker’s argument of decline but even here, he argues, that proportionately the trend is still downwards, albeit with a few bumps along the way. This despite Mao (40m deaths), Stalin (20m), WW2 (55m), WW1 (15m, including the deaths from Spanish ‘flu), Pol Pot, the Spanish Civil War and any number of loony dictators and repressive regimes. The two world wars were, in his view, outliers and not sufficient to refute the conclusion of declining violence. He ranks causes against death tolls using 20th century equivalent populations. Without listing the entire table, these are the first five in order: An Lushan revolt (8th century); Mongol conquests (15th); Mid-east slave trade (7th-19th); the fall of the Ming Dynasty (17th); and the fall of Rome (3rd-5th). He also addresses the reasons why people intuitively believe the opposite is occurring – nobody sold newspapers by saying things are getting better – ‘if it bleeds, it leads.’

Much of the first part of the book is taken up with the history of violence and its causes. Man, he avers, is an intelligent ape who will do whatever is in his best interests. He employs game theory and a myriad of psychological experiments to prove his point. One of the most well-known is the Milgram experiment where participants were instructed to deliver electric shocks to their fellow participants in the next room if they failed to answer a question correctly. The shocks were not, of course, real, and the people answering the questions were, unbeknown to those delivering the shocks, complicit in the experiment. Those carrying out the experiment were surprised when 65% of participants continued to ratchet up the voltage at the behest of the man with the clipboard until the screams from next door turned to silence and the dial had reached the ‘Certain death,’ zone. Authority, it turns out, is a key cause of violence. But, paradoxically, it also turns out to be an inhibitor in that it prevents private wars because it has a monopoly of arms and, through the rule of law, it helps prevent blood feuds from spinning out of control. This is a constant theme throughout the book – the very things that cause violence also assist its decline. This applies to our mental make-up, evolutionary and social pressures, economic and political developments, technology, advances in communications, and so on.

Game theorists have used the Prisoner’s Dilemma for many years to explain human motivation in this area. If two prisoners are placed in separate rooms and questioned about a particular crime they are alleged to have committed between them and given the following choices: a) Say ‘He did it,’ b) Stay silent. If prisoner number 1 chooses a) and Prisoner 2 chooses a) they both get five years. If prisoner 1 chooses a) and prisoner 2 opts for b), 1 goes free and 2 gets 10 years, if they both choose b) they both go free. What is the optimum strategy in a one-off scenario like this? Always choose a) or ‘Defect’ in the jargon and this is, in fact, what happens. However, something changes if the exercise is not a one-off but a series. In that case the best strategy is called ‘Tit-for-tat,’ in other words, one only defects after the other person has defected. In the main, people will choose the  most advantageous strategy for their needs. Moral justification comes after the event.

Each mode of violence is examined in forensic detail for its causes and all are perfectly logical given the context of the time. He looks at wars: tribal; inter-tribal; civil wars; inter-state wars and so on. There are three main causes: greed (I want that land or those resources); fear (I shall attack that tribe/country before it attacks me); honour (that nation, race, religion etc has insulted me and I must be avenged). Some violence was officially sanctioned, such as the torturing and killing of heretics, others permitted at various times in our history (rape; the murder of adulteresses; female genital mutilation; duelling; the beating of wives, children and slaves; slavery itself; persecution of homosexuals; the execution of criminals etc) and some positively encouraged as heroic – these include ideological wars and genocides (crusades; jihads; pogroms; the religious wars in Europe; the forcible spread of communism and Nazism etc) and most inter-state conflicts.

What, then has changed if violence has so dramatically diminished? He examines and rejects any biological changes to humanity over such a short timescale, although he later claims that IQ scores have improved considerably over the 100 years or so since its inception. It is simply that the rules of the game have changed across most of the world, meaning that violence is no longer the optimum option in most cases. The book traces these changes through what he describes as six trends: the Pacification Process, when man became a settled farmer and stock-rearer, rather than a hunter-gatherer; the Civilizing Process, which created the nation states and strong central governments; the Humanitarian Revolution that grew out of the Age of Reason and the Enlightenment in Europe during the 17th and 18th centuries; the Long Peace following WW2; the New Peace since the end of the Cold War; and the Rights Revolution that has taken place since the Universal Declaration of Human Rights in 1948. Each of these, he concludes, has been responsible for the decline in violence and he demonstrates this by pointing out that wherever in the world these trends are absent violence is the most prevalent, namely: some post-colonial countries, mainly in Africa; totalitarian states (North Korea and Burma until recently); theocracies (many Muslim states) and those with weak or corrupt governments (Yemen, Somalia).

The underlying factors driving of these trends include: technology and the exchange of ideas; strong central government (Hobbes’ Leviathan); trade and communication; free markets; social and economic liberalism; democracy; feminisation; and respected institutions. In other words, the largest contributor to the fall in violence is the ‘Open Society,’ and these liberal, capitalist democracies are exactly where one finds the lowest levels of violence in the world today. He also addresses times when violence rose in these societies, such as during the 1960s and 1970s in the USA and Europe. Of course, not all countries can be lumped together. Why, for example, does the USA endure a consistently higher rate of violence than say, Sweden or Japan? Again, the book addresses these subtleties with convincing aplomb.

The book is at its weakest when it strays from the evidence or where evidence is less easy to unearth, and he descends into opinion. For example, under the sub-heading ‘Reason’ he suggests that we have become more intelligent over time (as measured by IQ scores) and therefore more rational. Rationality, he claims, is one of the drivers of diminishing violence, although he doesn’t prove this in my view. Further, he states that the more intelligent presidents of the USA have been the least violent, citing Kennedy and Carter on the one hand and Nixon, Reagan and George W. Bush on the other. This seems to me to be driven by anti-Republican Party prejudice. Kennedy, of course, took the USA into Vietnam and it was Nixon who ended its involvement. The worst violence took place under Johnson, whom he fails even to mention. Reagan it was who, with Gorbachev, as he says earlier in the book, almost single-handedly extricated the world from the Cold War, thus creating the New Peace. Nor does he satisfactorily prove that the presidents he approves of had higher IQs than the others. Finally, IQ is a poor indicator of general intelligence anyway, according to much recent research.

One thing surprised me is that for all his assertions that religion, as ideology, has been one of the major sources of violence in human history (he is himself a Jewish atheist) he defends much religious thinking as also helping to promote peace. He seems to distinguish between purblind and arrogant fundamentalism and more mainstream religious thought and practice. I once attended a lecture by Melvyn Bragg (who might be described as Anglican agnostic) on the King James Bible and he vehemently asserted that Dawkins was wrong to condemn all religion. Christianity, he said, had been responsible for formulating some primitive rules of war during the Dark Ages, where previously there had been none, and that the Enlightenment had grown out of the Reformation. Pinker seems to endorse this view of history.

He has clearly demonstrated, in my view, conclusive proof that violence has fallen dramatically over the course of human history, and most steeply most recently. He admits, however, that this conjunction of propitious causes might easily be reversed given a change in circumstances but he somehow doubts it. After all, we love certainty, which fuels ideologies, and we are still highly tribal, which could easily lead us back to inter-state wars and civil conflicts but his view is that however bumpy the road we are unlikely to return to a state of nature where, ‘The life of man is solitary, poor, nasty, brutish and short.’

Steven Pinker is a Harvard Professor in the Department of Psychology at Harvard University

Review of ‘The Invention of the Jewish People,’ by Shlomo Sand

‘The Invention of the Jewish People,’ is a provocative title and deliberately designed, I think, to shock. It is even more of a shock to discover that the author is a Jewish academic based at the University of Tel Aviv. Sand has written an iconoclastic yet scholarly book that will severely test many preconceptions. I imagine that he is not universally popular either with the Israeli political elite, his fellow academics or with most of the Jewish Diaspora, for whom Israel constitutes a secondary and spiritual home. Sand, it should be stated, is a member of the faculty of contemporary, rather than Jewish, history. The reason why the university has two history faculties will become evident.

The book comprises the Introduction and five chapters, each of which is divided into a number of sub-headings. Although the author is a serious and scrupulous academic, it is an easy and fascinating read. I am not qualified to judge the accuracy of his assertions but it is certainly a brave thing to have written and, not being an expert on Jewish history, I found it a tremendous learning experience.

Following the Introduction in which he relates a thought-provoking anecdote that illustrates his motivation for writing the book, each Chapter is devoted to a specific theme in the development of the mythology of Jewish (and in particular, Jewish Israeli) culture. He weaves an intriguing tale of myth-making and self-deception that was inevitable once Zionism became the prevailing orthodoxy of the Jewish intellectual elite sometime towards the end of the nineteenth century.

The concept of the Jewish ‘Nation,’ is central to the Zionist project. Had there been no coherent set of identifiable racial, historical and cultural traits common to all Jews Zionism would, at best, have played a marginal role in the political life of the Jewish people. A parallel might be the British National Party’s claim in the UK to represent the descendants of those indigenous folk who followed the retreating glaciers into our islands. The reasons why Zionism became the driving force behind the creation and maintenance of the State of Israel is the primary theme of the book.

Chapter one deals with the rise of the nation state showing that it was a recent phenomenon which began in Western Europe sometime in the eighteenth century. This challenges Zionism’s contention that the Jews constitute a coherent, homgeneous and definable nation wherever in the world they happen to find themselves. Nation, according to Sand, is not synonymous with state, class, religion or anything else that defines a particular people. A nation can only arise when a substantial slice of the population derives a benefit from and, therefore, holds a stake in its future development. This could not have happened before the Enlightenment and the consequent democratization of the state’s social institutions. There are certain necessary conditions for a nation-state to exist: universal education; civil equality for all its members; a unifying cultural-linguistic continuum; sovereignty of its citizens; common territory; and economic aggregation within its boundaries. Under this definition, therefore, ‘Jewishness,’ whatever else it might be, cannot constitute a nation. He is careful, however, to distinguish between ‘Nationalism,’ and ‘Nation’ allowing that the former preceded the latter but is not synonymous with it. He also accepts that ‘Nation’ is an imprecise term and not all of the necessary conditions are applied equally or universally.

The foundation of the Jewish identity lies in its scriptures – the belief that the Jews are God’s chosen people and that there has been a continuing history from the earliest times of the Patriarchs to the present day. It is the Torah, the writings of the Prophets and the rest of the books of the Old Testament that binds the people together in a shared cultural and historical inheritance. In the second chapter Sand terms this ‘Mythistory,’ and demonstrates how the bulk of the Old Testament was compiled from a number of oral folk tales and ritualistic myths no earlier than the time of the Babylonian exile during the 6th century BC. In this he differs from Finkelstein and Silberman in ‘The Bible Unearthed’ (a review of which can be found under History, December 6th 2007) who suggested that much of it was written during the reign of King Josiah in Judah prior to the captivity. They agree, however, in many respects, such as the lack of independent evidence to support the existence of the Patriarchs, or the bondage and subsequent exodus, or the conquest of Canaan by Joshua, or the United Kingdom of David and Solomon etc. Also, that monotheism, the defining characteristic of Judaism, was a relative latecomer, not finally becoming established until sometime after the return of the captives from exile in Babylon. Sand further states that equating the Old Testament with the literal truth was not necessary for most Jews and only became important as Zionism began its inexorable rise during the latter part of the nineteenth century.

The next two chapters deal with two of the components in the Zionists’ view of Jewish history; namely that all of the Jews of the Diaspora are descendents of those forced from their Palestinian homeland; and that proselytizing has never been a tradition within Judaism. The main concentrations of Jews for most of the Medieval and early modern periods were North Africa and Spain (Sephardim), Central and Eastern Europe (Ashkenazim) and the Arabian Peninsula (Hamyarite). He traces a detailed voyage of the spread of Judaism, beginning with the end of the Jewish revolt in 70 AD right through to the 20th century. From this he concludes that most of the agrarian peasantry were not exiled from Judaea and largely stayed put, contrary to Jewish tradition, and that the Diaspora, such as it was, comprised mainly the political and religious elites. Furthermore, there is ample documentary evidence to support widespread proselytizing. He also appeals to our common sense by carrying out some simple calculations suggesting that if all the Jews in the world were descendents of Judean exiles they would have been the most fecund people ever to have inhabited the earth – the numbers simply do not add up. The advance in our understanding of genetics confirms that those regarding themselves as Jews do not possess a distinctive inheritance but conform to the generality of the populations wherever they have dwelt. In other words, again contrary to the Jewish tradition of racial and religious purity, there has been much inter-marriage between Jews and gentiles.

The final chapter brings us up to date with the creation and continued survival of the modern state of Israel. It becomes clear why the Zionist project had to succeed. One particular irony is that many educated Ashkenazi Jews were early admirers of Hitler’s Aryan race policies. This helped to justify their own concept of a Jewish people that was racially, culturally and religiously pure. The continued persecution throughout the nineteenth and early 20th centuries of the Jewish people, particularly in Eastern and Central Europe, resulted in huge movements of populations and mass migrations, much of it to the USA. This upheaval began the process of the longing for a homeland (and where better than the spiritual and ancestral lands of the Old Testament) and the wish became father to the thought. This thought would have remained a mere wish without the active compliance of the Western powers, especially the USA. The reason for this support for an independent Jewish state in Mandatory Palestine was a simple desire to halt the flow of Jewish immigrants without the unpleasantness of appearing to return them to the brutal life from which they were fleeing. Sands states that the modern state of Israel is a political contradiction. It claims to be a Jewish state and also a democracy. It cannot be a democracy, he suggests, unless all its citizens enjoy equal rights which Israeli Arabs manifestly and legally do not, even though they have the vote. I found his take on post-1967 Israeli policy interesting. Even if it were possible, the government would not wish to incorporate the occupied territories into the state of Israel because Jews would then be outnumbered by Arabs and it would either have to give up any pretence to democracy or cease to be a Jewish state. Occupation suits it just fine.

So, why two history faculties at Tel Aviv University? Because it allows bona fide ‘Jewish’ historians to base their research firmly on the scriptures without interference from inconvenient contradictory evidence from more mainstream academics. Sand and his colleagues are looked down upon by members of the Jewish History faculty because they clearly have no deep knowledge or understanding of the Old Testament on which any accurate assessment of Jewish history must be based. And it is Jewish history that is taught in Jewish Israeli schools and thus is the Zionist mythology perpetuated.

I have merely been able to scratch the surface here but for anybody interested in how we got to where we are in the Middle East this book provides an indispensible source.

Review of ‘Predictioneer’ by Bruce Bueno de Mesquita

This is one of the most interesting books I have read for a long time. The impetus to read it came from a recent ‘Start the Week’ broadcast on Radio 4, chaired by Andrew Marr. As I tuned in Marr was interviewing the author.

The basic premise of the book is that we humans are all more or less alike in that our behaviours are governed by what we perceive to be our self-interest. So much, so obvious, but he has taken this mundane observation to a rarefied level of rationality and analysis. Using game theory he has developed a highly sophisticated modelling tool that narrows the probabilities in any given scenario to a verifiable (and therefore usable) prediction.

The book can be divided into three fairly equal sections. The Introduction and the first three chapters deal with human behaviour and its rationale, followed by an exposition of game theory. The two game theory chapters depict various scenarios, some of which are real case studies with which the author has been engaged, to demonstrate that our behaviours are largely predictable. A well known example he uses is the Prisoner’s Dilemma, where two prisoners are placed in separate rooms for interview. If they co-operate and say nothing they will both get a light sentence; if one defects and the other co-operates, the defector will get out immediately and the other will get life. If both defect they will each get a medium sentence. The winning strategy in a one-off situation is, ‘Always defect,’ and this is what the police rely on to break down criminals’ stories.

He draws some interesting parallels in this part of the book between, for instance, Mother Teresa and Adolf Hitler to demonstrate that we will all pursue our own interests in a logical and predictable fashion. The key is to understand what those interests comprise. More conflict could be avoided, he asserts, if only we took the time  and effort to better understand what our adversaries’ real interests are instead of focusing our attention so much on our own  objectives.

The second part of the book describes his methodology using real examples, either from the historical records or from case studies that he has worked on. With most of the latter, of course, his predictions are more or less right, including the scary geo-political issue of North Korean aggression. Kim Jong Il (and his father before him) he says, is not an irrational lunatic who cannot be reasoned with; it is just that we have not fully understood his motivations. He is driven, according to de Mesquita, by his desire to retain power, so understanding the power relationships both inside and outside the country is critical to successful diplomacy.

He does, in the interests of modesty, quote one example where he was spectacularly wrong but most of his illustrations are offered as proofs for the success of his method, as one would expect. The secrets of his success are accurate and comprehensive data-gathering coupled with the precision of his model, which he has developed over many years (the current version is the third in the series).

The final few chapters are in many ways the most interesting. He begins by taking some scenarios from the past and running them through his model to ascertain what actions would have been required, and by whom, to have averted the actual historical events. The four he selects are: Sparta’s fall; why Columbus worked for Spain; how we could have avoided WW1; and ditto for WW2. This is a terrific history lesson using an approach rarely employed by historians, who are, by and large, more interested in what actually happened than what might have been.

Finally, he sets a challenge by predicting the outcomes of current situations pre-occupying the world and, although his view of human nature is somewhat cynical, he is rather more optimistic about the endgame. The unfolding events and the conclusions predicted by his methods are: Al Qaeda and the Taliban in Afghanistan and Pakistan; Iran/Iraq and a possible partnership; the rise and fall of the Roman Catholic Church; and global agreements on climate change. All but the third present current serious challenges for the world. The fortunes of the Catholic Church do not quite fit the pattern but it is offered, I imagine, as a sort of long-term example demonstrating a thousand year time frame of events governed by decisions taken in the High Middle Ages.

He goes into fairly painstaking detail with each so that his methods, analysis and reasoning become crystal clear. This is far from being a dry academic treatise, however. On the contrary, it is a surprisingly easy read and I find his prose style both lucid and refreshingly free from the prolix that often spoils American popular science writing.

It is a page-turner and curiously uplifting, despite the author’s rather jaundiced view of our motives – base and singularly lacking in altruism, in his opinion. The good news, according to de Mesquita, is that we are neither doomed to destroy ourselves in a nuclear conflagration nor will we wipe ourselves from the planet by turning the earth into an uninhabitable greenhouse.

Review of ‘The Universe Next Door,’ by Marcus Chown

The Universe Next Door, published in 2002, is much more interesting for my money than his more recent book on quantum theory. The title is part of a quote from e.e. cummings.

It comprises three parts divided into a total of 12 chapters, the three parts are headed:

1)      The Nature of Reality;

2)      The Nature of the Universe; and

3)      Life and the Universe.

I am not sure that this sub-division achieves very much more than the chapter headings alone.

Chown’s purpose is to widen our imagination by showing us some fairly recent speculative hypothesising by various eminent theoretical physicists. Some of these conjectures are more grounded than others but the basic pattern is the same: state some facts; ask some questions; express complete puzzlement; come to the rescue with suggested meanings from a scientist or two; scatter around words such as, ‘Astonishing’ ‘Amazing’ ‘Remarkable’ or even ‘Astounding;’ move on to the next topic.

Some of the chapters deal with fairly well-worn ideas such as ‘Many worlds’ ‘Panspermia’ and ‘the Multi-verse’ but there were others that I had not previously encountered including the possibility of the arrow of time running backwards, mirror particles (not to be confused with anti-matter) and interstellar dust comprising bacteria (a variation of panspermia).

The last example emerges from the puzzle that stars should be brighter than they appear but they have been dimmed, apparently, by clouds of dust each particle of which has been calculated to be the precise size of a single bacterium. From this the late Fred Hoyle and Chandra Wickramasinghe (two eminent cosmologists) speculate that passing comets pick up some of these possible bacteria and release them as the comet nears the sun. The solar wind then scatters them to all corners of the universe and some, inevitably, will fall on to planets. We know how hardy bacteria can be, surviving extremes of heat and cold, just waiting for favourable conditions before bursting into life and dividing. This is how life might have arrived on earth in its formative stages just waiting for it to cool sufficiently for liquid water to provide ideal living conditions. If true, life is probably common in the cosmos but intelligent life rare as it would not have had sufficient time to develop much beyond where we are now. The evidence is interesting without being compelling. The trouble with this conjecture is: where did the cosmic bacteria come from in the first place? Hoyle and Wickramasinghe are silent.

‘Many worlds’ is based on the peculiarities of the wave function in quantum mechanics. It states, briefly, that all possible realities exist as parallel worlds but we can only experience the one that we are in. The ‘Multiverse’ is a logical extension of string theory whereby there are an infinite number of universes created from the vacuum, each with its own unique set of physical laws. It follows that perhaps this is the only one so far created that is suitable for life.

I must say that I rather enjoyed the book. There is more depth I felt than the one I recently reviewed by the same author. In the end though it depends for its impact on the Erich von Daniken approach in the 1970s – ‘We can’t explain x, so it must have been caused by y.’ I suppose much religious faith is based on such speculations – ‘Where did the world come from? No idea, so it must have been created by… (substitute whichever is your chosen creation myth.) Books like this rely for their success on our craving for concrete answers, our apparent need for certainty. The human mind, like nature, abhors a vacuum.

Review of Quantum Theory Cannot Hurt You by Marcus Chown

Strictly speaking this book should be entitled, ‘Physics Cannot Hurt You,’ as the second half of it is devoted to what Chown calls ‘Big things.’ The quantum world, of course, deals with very small things. The title gives it away as a light-hearted quick run round the current state of theoretical physics. This sort of jocular science writing for the masses, as it were, has become fashionable of late but I found the humour here laboured and many of the metaphors unoriginal. On the other side of the equation, however, the book undoubtedly works as vehicle for explaining difficult concepts lucidly and simply for us non-physicists. The depth of his scholarship and the love he has for his subject are also evident throughout. I particularly liked his sparing use of footnotes as a way of giving us the real science without spoiling the narrative.

The book is divided into two parts – Part 1: Small Things and Part 2: Big Things (of course) with a vain attempt at the end to reconcile the two. His approach is to amaze us with the sheer improbability of the world we live in and to demonstrate just how counter-intuitive both quantum theory and General Relativity are. The Foreword begins with a bulleted list of unlikely things that, of course, turn out to be true. The first one, for example, states that every breath one takes contains at least one atom that was breathed out by Marilyn Monroe. There is much more of this sort of stuff in the book.

Each chapter is devoted to one physical characteristic beginning with a quote and an italicised introduction. The story begins with the discovery of the atom and what this meant for the then current state of scientific knowledge. He tries to illustrate the properties of the atom with various metaphors. For example, he quotes Tom Stoppard’s famous analogy suggesting that if the nucleus of a Hydrogen atom were the size of a fist then the whole thing would be equivalent to the interior of St Paul’s and its single electron would flutter about the cathedral like a tiny moth.

We are taken on a historical journey as one improbable atomic fact after another is discovered: wave/particle duality; uncertainty; the collapse of the wave function; non-locality; alpha decay; vacuum fluctuation; and how such an apparently diverse world can be constructed from identical building blocks. He admits where he is over-simplifying and lets us know that picturing the true nature of the atom is beyond our imagination.

Part two follows a similar pattern and is substantially devoted to Einstein’s two theories of relativity. The entire book is a mere 158 pp (excluding the glossary) so confining it to the subject of its title would make it a very slender volume indeed. Also, Chown is a cosmologist by profession and this is his bread and butter, so I expect that this part of the book did not take him very long to write. The final chapter deals with some post-Einsteinian discoveries such as Big Bang (the idea had been around for a while but it was only confirmed as a theory in the early 1960s), the existence of Dark Matter and the recent revelation that the universe is not only expanding but also accelerating driven by the mysterious Dark Energy (of which we know almost nothing). The final paragraph expresses the hope that one day (soon?) we will be able to reconcile quantum theory with General Relativity.

I would certainly recommend the book for newcomers to the subject or for those, like me, who are not specialists but would like to keep up with the present state of knowledge (it was first published in 2006). It is an easy read and a lengthy train journey or two should get it finished.

Marcus Chown is a science writer and the cosmology advisor for New Scientist