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Q+ Hangout Lorenzo Maccone

Here are the details of the next Q+ Hangout.

Speaker: Lorenzo Maccone (Universita’ di Pavia)
Date/time: Tuesday 9th June 2015, 2pm BST
Title: Quantum Time

Abstract:
We give a consistent quantum description of time, based on Page and Wootters’ conditional probabilities mechanism, that overcomes the criticisms that were raised against similar previous proposals. In particular we show how the model allows to reproduce the correct statistics of sequential measurements performed on a system at different times.

This is joint work with Vittorio Giovannetti and Seth Lloyd and
is based on arXiv:1504.04215.

To watch the talk live, visit the event page at the appointed hour.

To keep up to date on the latest news about Q+ hangouts you can follow us on:

or visit our website at http://qplus.burgarth.de

On Outreach and Education for the Foundations of Physics

On Saturday 25th April, I took part in a discussion panel sponsored by FQXi at the “New Directions in the Foundations of Physics” conference in Washington DC.  My co-panellists were Sabine Hossenfelder and Dagomir Kaszlikowski.  Sabine has already posted her comments on her blog, and I largely agree with what she had to say.  However, since I wrote out my comments before the discussion, I might as well post them here, as it is just a cut-and-paste job for me.

The discussion was very interesting, and it evoked more passion from the audience than I thought it would.  Given the limited time, I did not give the best responses to all of the comments from the audience, so I have added a few thoughts on the discussion, particularly the points raised by Mile Gu and David Wallace.

Without further ado, here is my intro.

How do we convey foundational physics concepts to non-physics audiences?  It is obviously hard to do so in a way that is both accurate and accessible.  As this conference shows, it is difficult to do so even amongst ourselves.  However, this is not the main problem we should worry about.  To explain why, requires a diversion on the broader aims of outreach.

I think outreach has three main goals: INSPIRATION, EDUCATION, and ACTIVATION.

Inspiration is making physics seem cool and interesting, so that, for example, a high school student might decide to study physics at university.

Education is the obvious, we want people to understand more physics after the outreach than they did before.

Activation is perhaps less obvious, but it means that we want people to actually DO something after the outreach.  This might be voting for a politician who supports evidence based policy and science funding, or it might mean persuading people not to employ the services of a new age “quantum healer” who claims to resolve health issues holistically using quantum entanglement.

To my knowledge, there is very little research into the effectiveness of outreach for these various goals.  That’s worrying because it feels good to win an FQXi essay (as well as being good for the bank account), to get immediate feedback on a blog post, to give a public lecture to a large audience, and, despite the fact that I have no personal experience of this, I imagine it feels good to have a bestselling popular science book or appear on TV in flashy a documentary.  In absence of hard data on how best to spend our limited time and resources, we will continue to do the things that feel good, regardless of whether they are the most effective.

Nonetheless, I think it is fair to say that the likes of Neil de Grasse Tyson and Brian Cox are doing a pretty good job on the inspiration front, so the rest of us should not devote too much time towards that.  Regarding education, there is now voluminous evidence from Phs Ed research on what are the best methods of teaching physics to high school students and lower level undergraduates.  This research is still ignored by the vast majority of institutions, and given that we know that these methods work, I think we would be better off putting our efforts into implementing research validataed cirricula in schools and universities rather than trying to do it with outreach, the effectiveness of which is largely unknown.  Incidentally, one of the things we do know about good physics pedagogy is that it is largely uncorrelated from the personality of the instructor, which leads me to be suspicious of the personality-driven nature of much scientific outreach.

That leaves activation, and I think we could be doing a much better job here.  Not everyone is going to take action in the name of science, but that does not matter, so long as those who do it do so loudly.  We are past the age of mass media, so we need no longer always cater only to the GENERAL public, instead going for smaller niche audiences who are currently underserved.  In particular, I am thinking of the science fanboys and girls, such as the community of skeptics who like to debunk pseudo-science.  They may be a relatively small community, but they are also the ones most likely to act in the name of science.  Most of them can give you a coherent acount of evolution and why it is true, but ask them about quantum theory and you’ll likely get some vague mumblings about waves, particles and the uncertainty principle.  They’d like to understand things more deeply, but we haven’t given them the tools to do so.  I think this is because we have been far too focussed on making our popular accounts accessible to everyone, e.g. publishers always advise against
including any equations in pop physics books.  This advice is appropriate for the mass audience, but not if we are targeting niche audiences, who are probably bored of hearing the same vague and inaccurate descriptions in fifty different popsci books.

So, turning back to the question of how we should convey foundationsal physics concepts to non-physics audiences, it is almost impossible to do so accurately for the mass audience, and it is probably best to go for inspiration in that case.  However, we can, and should, target more accurate explanations, with more math and more subtle details, to those smaller communities who are already passionate about physics, and who are more likely to act on the knowledge when they have it.

Following these remarks, there are two points from the discussion that I want to address.  Firstly, Mile Gu raised the point that we want to direct outreach to the broadest audience possible, as we need popular support to change government policies on science funding, or at least to keep it at a reasonable level.  To this, I responded that only a tiny minority of people are going to change their vote based on science policy, compared to the big issues like the economy, education, and healthcare, so we are better off focussing on that minority.  I know think that this is wrong.  If there is a general consensus within society then this can influence the policy of all major political parties, regardless of whether it is a vote-changing issue.  An example of this is the issue of gay marriage.  Very few people in the UK would have changed their vote based on this issue alone, but because there was a general feeling in the population that allowing people to marry whoever they choose is a good thing, there was a political consensus that pushed the issue forward.  Similarly, if there were known to be a general consensus in the population that science funding for basic research without ties to immediate applications is a good idea, then there would be political consensus on that too.  For this, I think we need to go beyond inspiring the general public into thinking that science is cool, by also emphasizing that the process of science and technology development as a whole does not work without the freedom to think freely, without knowing in advance what, if any, applications there may be.  We also need to emphasize that science is not just a machine for generating economic growth, but also a key part of human culture, comparable to the arts and humanities, all of which we should fund for their own sake because they enrich the human experience.

Secondly, David Wallace cautioned against my advice to verify the effectiveness of outreach via empirical research, suggesting that to emphasize research too much might make us too bogged down to actually do much outreach.  Instead, he suggested a “let a thousand flowers bloom” approach.  Let people go ahead and do the outreach they want to do, and presumably there will be enough different approaches that we’ll eventually have the desired effect.

I think I answered this badly on the day, effectively conceding David’s point.  However, David’s approach is only valid if we think there is not such a thing as bad outreach, i.e. activities that actually harm the goals we are trying to achieve.  This is especially true if there are not selection mechanisms in place that automatically weed out the bad outreach in favour of the good.

There is a compelling analogy here with physics education.  Professors have been left to their own devices to teach in whatever way they want for decades, and they almost universally choose methods that are pedagogically sub optimal, such as just lecturing from the front for an hour.  These methods can actually harm people’s perception of physics, reinforcing the idea that the subject is too hard for them.  Personally, I think it would be better if all the future medical doctors undergoing their required physics courses came out with a positive impression of the subject, and a good understanding of it, rather than regarding it as an alien subject that is irrelevant for their careers.  It is only through rigorous research that we have developed better pedagogy that is gradually being accepted in physics departments, although we still have a long way to go.

My position on outreach is that, although we shouldn’t encumber every attempt at outreach with a rigorous research investigation, if we think there are widely employed methodologies that are actually harmful to the aims of outreach then we should verify this empirically, try to figure out what works better, and encourage change.

If there are harmful aspects in current outreach, I suspect they are mostly in things like TV documentaries and popular science books, which are driven by popularity and sales.  A literary agent giving advice on how to write a popular science book is not giving advice on how to best convey the science, but rather on how to best sell it to a publisher, who is in turn concerned with how many people will buy the book.  So the usual advice to avoid any equations and to emphasize personal stories over the science, might not be good advice for communicating the science, even if they increase popularity and sales.

I think the focus on popularity leads to many popsci tropes, which might turn out to be actively harmful.  For example, there is the focus on stories of “great men struggling with grand ideas”, which may accidentally reinforce the impression that science is too hard for most people and so they should not engage with it, and discourage under-represented minorities from entering the subject.  Similarly, there is an excessive focus on speculative wild-sounding ideas, as opposed to the basics, which may inadvertently give the impression that “anything goes” in physics, and make people question why they should believe scientists over and above politicians and/or their local preacher.

One experiment I would suggest to address this would be to give a bunch of people a popular science book containing a lot of speculative ideas, and a couple of weeks after finishing the book ask them to classify how speculative the various ideas presented in the book are.  A good choice would be Max Tegmark’s “Mathematical Universe” because he goes to great pains at the beginning to classify how speculative his various multiverses are, even including a table.  My hypothesis is that most readers won’t remember how speculative the ideas are, and that ideas from standard model cosmology would be conflated with those of various multiverses in terms of the degree to which they are established.  I expect people will mostly recall the ideas that sound cool, rather than those that are most supported by evidence.  I also suspect that it won’t matter how careful the author is to distinguish speculation from established science, which could be checked by comparing results from Tegmark’s book with any randomly chosen Michio Kaku book.

If my hypothesis is confirmed, then perhaps we could persuade authors to hold back on the speculation a bit, in favour of established science, particularly in a society where the general level of science literacy is quite low.  If they do include speculation, perhaps it would be better to do so with a more skeptical treatment, including a detailed criticism of the ideas.  Perhaps a book written by a small group of experts with conflicting opinions on the speculative ideas is a better way to do this than the traditional single-author popsci books.  Whatever you think about this, these are ideas that we could clearly benefit from investigating empirically.

Lubos Motl is right

Armchair physicist and anti-quantum zealot Matt Leifer

Armchair physicist and anti-quantum zealot Matt Leifer

In recent years noted string theorist and blogger Lubos Motl has increasingly turned his attention to the foundations of quantum theory.  Those of us who study quantum foundations for a living have tended to find his commentary mildly annoying, as he consistently calls those of us who disagree with his views “anti-quantum zealots”, crackpots, and worse.

I have recently come to the realization that Lubos’ views on this subject are completely correct.  Specifically, I now believe the following:

  • The Copenhagen founders of quantum theory—Bohr, Heisenberg, Pauli, Born et. al.—had things essentially right.  They were only missing the details of decoherence theory in order to properly understand the classical limit.
  • The decoherent histories formalism as proposed by Gell-Mann and Hartle, gives a completely consistent account of these minor details and is the correct way to understand physical properties and probabilities in quantum theory.
  • People who work on high energy physics, and especially string theory, are the ultimate arbiters of truth about the nature of quantum theory.  Only they have the background needed to make meaningful statements on the subject.  This is especially true of theorists who are or ever have been employed at Harvard.  Any idea that has not been discussed by these physicists is probably wrong.  No insight is to be gained by actually studying the foundations of quantum theory for several years, rather than working on proper fundamental physics.
  • And finally, in the face of any other views on quantum theory, the correct response is always, “It’s quantum stupid!”

Having adopted this new credo, I now realize that my previous view that quantum theory should be founded on a realist ontology that gives a clear picture of what is going on in reality independently of the observer was wrong-headed.  Lubos’ blog posts on the subject make a compelling argument that my view was guided more by religious zealotry and communist ideology than by empirical data and rational argument.  It therefore seems appropriate that I should enter into a period of repentance by adopting a garb of sackcloth and ashes for a while before emerging cleansed of my previous religious views.

Given the impracticality of wearing sackcloth and ashes in modern life, I have instead decided to wear a t-shirt that identifies me as the anti-quantum zealot that I am.  You can see a picture of me wearing this t-shirt at the top of this post.  Before embarking on a career in string theory, or more likely quitting academia to become an accountant because I do not have the intelligence to understand real physics, I still have several engagements where I shall have to speak about my previous bigoted research.  I therefore promise that I will wear my anti-quantum zealot t-shirt at all such speaking engagements for the next year.

At this point, I would like to urge my colleagues who have also been denounced by Lubos’, and those who hold similar views but have so far flown under Lubos’ radar, to reconsider their views and join me in repentance.  If each of us wears an anti-quantum zealot t-shirt publicly then we may be able to prevent others from following us down the path of ideologically motivated nonsense.

Fortunately, I have made it easy for you to purchase your own anti-quantum zealot apparel and merchandise, from the Spreadshirt shop at this link.  It is available in any colour, so long as it is communist red.  I receive a commission of 2CAD for every purchase from this shop (the rest goes to Spreadshirt, so complain to them about their overpriced t-shirts rather than me).  I would dearly love to keep that commission money because I will be short of income for a while as I retrain as a string theorist or accountant.  However, that would greatly complicate my tax situation, so I have decided to donate it to a charity that will protect future generations of physicists from adopting anti-quantum ideas.  For this purpose, my commission will be donated to the Next Einstein Initiative of the African Institute for Mathematical Sciences (AIMS), which seeks to establish centres of excellence in mathematical science across Africa.  AIMS does cover fundamental physics, but I note with approval that they do not currently have programmes in quantum foundations, so they will not be teaching wrong-headed ideas to the next generation of African physicists.

You might be tempted to consider your purchase of anti-quantum zealot merchandise as a charitable contribution, but if you really want to support AIMS you should forget about the t-shirt and just donate all of the money your would have spent to them directly.  Anti-quantum zealot merchandise is only intended for those who want to seriously repent for their anti-quantum beliefs.

In order to encourage donations, either through merchandise purchases or direct contributions to AIMS, I will be offering a special prize to whoever makes the largest donation in response to this post by the end of this month (April).  You simply have to let me know how much you have donated, either by email, or by leaving a comment if you want to boast about how generous you are (I will be asking the winner to verify their donation by sending copies of their receipts).

What is this special prize you ask?  Well, it is a collection of schwag that I stole from my absolute favourite academic publisher—Elsevier—at the recent APS March meeting.

Elsevier schwag

Elsevier schwag

As you can see, it consists of two pens advertising the exciting new journal “Reviews in Physics”, which I assume will soon surpass Reviews in Modern Physics as the premier physics review journal.  I believe this because of the extremely rigorous editorial oversight that Elsevier applies to all of its journals.

In addition to this, you get a luggage tag advertising Elsevier’s offerings in Optics, which is filled with some mysterious blue liquid, because everything is better with blue stuff in it.  If your luggage accidentally ends up at the Elsevier offices because the baggage handlers read the side of the label displayed in the photo rather than the address written on the back, I am assured that Elsevier will apply their open access policy to your bags and charge you $80 for their return.

Q+ Hangout: Howard Wiseman

Here are the details of the next Q+ hangout.

Date/time: Wed. 26th Nov. 2014 10pm GMT/UTC

Speaker: Howard Wiseman (Griffith University)

Title: After 50 years, Bell’s Theorem Still Reverberates

Abstract:
Fifty years ago this month, Belfast-born physicist John Bell submitted for publication a paper [1] which has been described as “the most profound discovery in science” [2]. However, its significance is still much disputed by physicists and philosophers [3, 4].
I will explain what is so puzzling about the types of correlations Bell introduced, by a specific example based on [5]. (For those well-versed in Bell inequalities this may still be of pedagogical interest.)
But what exactly do these Bell-type correlations violate? Bell’s original answer [1] was the joint assumptions of determinism and locality. His later answer [6] was the single assumption of local causality (which, confusingly, he sometimes also called locality). Different ‘camps’ of physicists – operationalists and realists respectively – prefer the different versions of Bell’s theorem.

Which of Bell’s notions, locality or local causality, expresses the causal structure of Einstein’s theory of relativity? I will argue for the answer: neither [3,4]. Both notions require an additional causal assumption, and the one required for local causality is a stronger one. I will discuss how the different assumptions fit with the ideologies of the two camps, and how they can best be reconciled.

[1]  J. S. Bell, “On the Einstein-Podolsky-Rosen paradox”, Physics 1, 195-200 (1964).
[2]  H. P. Stapp, “Are superluminal connections necessary?”, Nuovo Cim. 40B, 191 (1977).
[3]  H. M. Wiseman, “The two Bell’s theorems of John Bell”, J. Phys. A 47, 424001 (2014) (Invited Review for Special Issue, 50 years of Bell’s theorem)
[4]  H. M. Wiseman, “Bell’s theorem still reverberates”, Nature 510, 467-9 (2014).
[5] P. K. Aravind, “Bell’s theorem without inequalities and only two distant observers”,  Found. Phys. Lett. 15, 397 (2002).
[6]  J. S. Bell, “The Theory of Local Beables”, Epistemological Lett. 9, 11-24 (1976).

To watch the talk live, visit the event page at the appointed hour.

To keep up to date on the latest news about Q+ hangouts, you can follow us on:

or visit our website.

Q+ Hangout: Marco Piani

Here are the details of the next Q+ hangout:

Date: Monday 27th October 2pm GMT/UTC

Spekaer: Marco Piani (University of Strathclyde)

Title: Usefulness of entanglement and steering in the discrimination of physical processes

Abstract: Not all entangled states are created equal: they are all special, but some are more special than others. In particular, this is true in an operational characterization of quantum correlations based on their usefulness in the discrimination of physical processes. We will discuss how every entangled state of a probe-ancilla composite system is useful as a resource for the problem of minimum-error channel discrimination. We will then focus on the subset of entangled states that exhibit steering. The latter is the entanglement-based quantum effect that embodies the “spooky action at a distance” disliked by Einstein and scrutinized by Einstein, Podolsky, and Rosen. We prove that, for any fixed steerable state, there are instances of a generalization of the channel discrimination problem, which we dub quantum subchannel discrimination, where such a state allows a correct discrimination with strictly higher probability than in absence of entanglement, even when measurements are restricted to local measurements aided by one-way communication. On the other hand, unsteerable states are useless under such a restriction, even when entangled. We also prove that the above steering advantage can be exactly quantified in terms of the steering robustness, which is a natural measure of the steerability exhibited by the state.
This talk is based on joint work with J. Watrous, arXiv:1406.0530.

To watch live, visit the hangout page at the appointed hour.

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Q+ Hangout: Daniel Gottesman

Here are the details of the next Q+ hangout. To watch live, visit this link at the appointed hour.

Date/time: Tue. May 20th 2014 2pm BST/UTC+1

Speaker: Daniel Gottesman (Perimeter Institute)

Title: Fault-tolerant quantum computation with constant overhead

Abstract: The threshold theorem for fault tolerance tells us that it is possible to build arbitrarily large reliable quantum computers provided the error rate per physical gate or time step is below some threshold value. Most research on the threshold theorem so far has gone into optimizing the tolerable error rate under various assumptions, with other considerations being secondary. However, for the foreseeable future, the number of qubits may be an even greater restriction than error rates. The overhead, the ratio of physical qubits to logical qubits, determines how expensive (in qubits) a fault-tolerant computation is. Earlier results on fault tolerance used a large overhead which grows even larger (albeit slowly) with the size of the computation. I show that it is possible in principle to do fault-tolerant quantum computation with the overhead constant in the size of the computation, and with a low constant at that. The result depends on recent progress on quantum low-density parity check codes.

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Q+ hangout: Chris Richardson

Here are the details of the next Q+ hangout.

Date/time: 22nd April 2014 2pm BST/UTC+1

Speaker: Chris Richardson (University of Liege)

Title: On the Uncertainty of the Ordering of Nonlocal Wavefunction Collapse when Relativity is Considered

Abstract: The temporal measurement order and therefore the originator of the instantaneous collapse of the wavefunction of a spatiality entangled particle pair can change depending on the reference frame of an observer. This can lead to a paradox in which its seems that both measurements collapsed the wavefunction before the other. We resolve this paradox by demonstrating how attempting to determine the order of measurement of the entangled pair introduces uncertainty which makes the measurement order impossible to know.

To watch the talk live, go to the event page at the appointed hour.

To keep up to date on the latest news about Q+ hangouts you can follow us on:

or visit our website.