Cosmology meets Philanthropy — guest post by Jess Riedel

My colleague Jess Riedel recently attended a conference  exploring the connection between these seemingly disparate subjects, which led him to compose the following essay.–CHB
Impact_event

People sometimes ask me what how my research will help society.  This question is familiar to physicists, especially those of us whose research is connected to every-day life only… shall we say…tenuously.  And of course, this is a fair question from the layman; tax dollars support most of our work.
I generally take the attitude of former Fermilab director Robert R. Wilson.  During his testimony before the Joint Committee on Atomic Energy in the US Congress, he was asked how discoveries from the proposed accelerator would contribute to national security during a time of intense Cold War competition with the USSR.  He famously replied “this new knowledge has all to do with honor and country but it has nothing to do directly with defending our country except to help make it worth defending.”
Still, it turns out there are philosophers of practical ethics who think a few of the academic questions physicists study could have tremendous moral implications, and in fact might drive key decisions we all make each day. Oxford philosopher Nick Bostrom has in particular written about the idea of “astronomical waste“.  As is well known to physicists, the universe has a finite, ever-dwindling supply of negentropy, i.e. the difference between our current low-entropy state and the bleak maximal entropy state that lies in our far future.  And just about everything we might value is ultimately powered by it.  As we speak (or blog), the stupendously vast majority of negentropy usage is directed toward rather uninspiring ends, like illuminating distant planets no one will ever see.
These resources can probably be put to better use.  Bostrom points out that, assuming we don’t destroy ourselves, our descendants likely will one day spread through the universe.  Delaying our colonization of the Virgo Supercluster by one second forgoes about 10^{16} human life-years. Each year, on average, an entire galaxywith its billions of starsis slipping outside of our cosmological event horizon, forever separating it from Earth-originating life.  Maybe we should get on with it?
But the careful reader will note that not everyone believes the supply of negentropy is well understood or even necessarily fixed, especially given the open questions in general relativity, cosmology, quantum mechanics, and (recently) black holes.  Changes in our understanding of these and other issues could have deep implications for the future.  And, as we shall see, for what we do tomorrow.
On the other side of the pond, two young investment analysts at Bridgewater Associates got interested in giving some of their new disposable income to charity. Naturally, they wanted to get something for their investment, and so they went looking for information about what charity would get them the most bang for their buck.   But it turned out that not too many people in the philanthropic world seemed to have many good answer.  A casual observer would even be forgiven for thinking that nobody really cared about what was actually getting done with the quarter trillion donated annually to charity.  And this is no small matter; as measured by just about any metric you choose—lives saved, seals unclubbed, children dewormed—charities vary by many orders of magnitude in efficiency.
This prompted them to start GiveWell, now considered by many esteemed commentators to be the premier charity evaluator.  One such commentator is Princeton philosopher Peter Singer, who proposed the famous thought experiment of the drowning child.  Singer is also actively involved with a larger movement that these days goes by the name “Effective Altruism”.  It’s founding question: If one wants to accomplish the most good in the world, what, precisely, should one be doing?  
You won’t be surprised that there is a fair amount of disagreement on the answer.  But what might surprise you is how disagreement about the fundamental normative questions involved (regardless of the empirical uncertainties) leads to dramatically different recommendations for action.    
A first key topic is animals.  Should our concern about human suffering be traded off against animal suffering? Perhaps weighted by neural mass?  Are we responsible for just the animals we farm, or the untold number suffering in the wild?  Given Nature’s fearsome indifference, is the average animal life even worth living?  Counterintuitive results abound, like the argument that we should eat more meat because animal farming actually displaces much more wild animal suffering than it creates.
Putting animals aside, we will still need to balance “suffering averted”  with “flourishing created”.  How many malaria deaths will we allow to preserve a Rembrandt?  Very, very bad futures controlled by totalitarian regimes are conceivable; should we play it safe and blow up the sun?
But the accounting for future people leads to some of the most arresting ideas.  Should we care about people any less just because they will live in the far future?  If their existence is contingent on our action, is it bad for them to not exist?  Here, we stumble on deep issues in population ethics.  Legendary Oxford philosopher Derek Parfit formulated the argument of the ”repugnant conclusion”.  It casts doubt on the idea that a billion rich, wealthy people living sustainably for millennia on Earth would be as ideal as you might initially think. 
(Incidentally, the aim of such arguments is not to convince you of some axiomatic position that you find implausible on its face, e.g. “We should maximize the number of people who are born”.  Rather, the idea is to show you that your own already-existing beliefs about the badness of letting people needlessly suffer will probably compel you to act differently, if only you reflect carefully on it.)
The most extreme end of this reasoning brings us back to Bostrom, who points out that we find ourselves at a pivotal time in history. Excepting the last century, humans have existed for a million years without the ability to cause our own extinction.  In probably a few hundred years—or undoubtedly in a few thousand—we will have the ability to create sustainable settlements on other worlds, greatly decreasing the chance that a calamity could wipe us out. In this cosmologically narrow time window we could conceivably extinguish our potentially intergalactic civilization through nuclear holocaust or other new technologies.  Even tiny, well-understood risks like asteroid and comet strikes (probability of extinction event: ~10^{-7} per century) become seriously compelling when the value of the future is brought to bear. Indeed, between 10^{35} and 10^{58} future human lives hang in the balance, so it’s worth thinking hard about.
So why are you on Facebook when you could be working on Wall Street and donating all your salary to avert disaster? Convincingly dodging this argument is harder than you might guess.  And there are quite a number of smart people who bite the bullet.
 

Why the laity hope Einstein was wrong.

Although reputable news sources pointed out that most scientists think some more mundane explanation will be found for the too-early arrival of CERN-generated neutrinos in Gran Sasso, recently confirmed by a second round of experiments with much briefer pulse durations to exclude the most likely sources of systematic error, the take-home message for most non-scientists seems to have been “Einstein was wrong.  Things can go faster than light.”  Scientists trying to explain their skepticism often end up sounding closed-minded and arrogant.  People say, “Why don’t you take evidence of faster-than-light travel at face value, rather than saying it must be wrong because it disagrees with Einstein.”  The macho desire not to be bound by an arbitrary speed limit doubtless also helps explain why warp drives are such a staple of  science fiction.  At a recent dinner party, as my wife silently reminded me that a lecture on time dilation and Fitzgerald contraction would be inappropriate, the best I could come up with was an analogy to another branch of physics where where lay peoples’ intuition accords better with that of specialists:  I told them, without giving them any reason to believe me, that Einstein showed that faster-than-light travel would be about as far-reaching and disruptive in its consequences as an engine that required no fuel.
That was too crude an analogy. Certainly a fuelless engine, if it could be built, would be more disruptive in its practical consequences, whereas faster-than-light neutrinos could be accommodated, without creating any paradoxes of time travel, if there were a preferred reference frame within which neutrinos traveling through rock could go faster than light, while other particles, including neutrinos traveling though empty space, would behave in the usual Lorentz-invariant fashion supported by innumerable experiments and astronomical observations.
But it is wrong to blame mere populist distrust of authority for this disconnect between lay and expert opinion. Rather the fault lies with a failure of science education, leaving the public with a good intuition for Galilean relativity, but little understanding of how it has been superseded by special relativity.  So maybe, after dinner is over and my audience is no longer captive, I should retell the old story of cosmic ray-generated muons, who see the onrushing earth as having an atmosphere only a few feet thick, while terrestrial observers see the muons’ lifetime as having been extended manyfold by time dilation.
It is this difference in appreciation of special relativity that accounts for the fact that for most  people, faster-than-light travel seems far more plausible than time travel, whereas for experts, time travel, via closed timelike curves of general relativistic origin, is more plausible than faster-than-light travel in flat spacetime.

Entangled LIGO


The quest to observe gravitational waves has been underway for several years now, but as yet there has been no signal. To try to detect gravitational waves, the LIGO collaboration basically uses huge kilometer-scale Michaelson-type interferometers, one of which is seen in the aerial photo to the left. When a gravitational wave from, say, a supernova or in-spiraling pair of black holes arrives at the detector, the wave stretches and shrinks spacetime in the transverse directions, moving the test masses at the ends of the interferometer arms and hence changing the path length of the interferometer, creating a potentially observable signal.
The problem is, the sensitivity requirements are extreme. So extreme in fact, that within a certain frequency band the limiting noise comes from vacuum fluctuations of the electromagnetic field. Improving the signal-to-noise ratio can be achieved by a “classical” strategy of increasing the circulating light power, but this strategy is limited by the thermal response of the optics and can’t be used to further increase sensitivity.
But as we all know, the quantum giveth and the quantum taketh away. Or alternatively, we can fight quantum with quantum! The idea goes back to a seminal paper by Carl Caves, who showed that using squeezed states of light could reduce the uncertainty in an interferometer.
What’s amazing is that in a new paper, the LIGO collaboration has actually succeeded for the first time in using squeezed light to increase the sensitivity of one of its gravity wave detectors. Here’s a plot of the noise at each frequency in the detector.The red line shows the reduced noise when squeezed light is used. To get this to work, the squeezed quadrature must be in phase with the amplitude (readout) quadrature of the observatory output light, and this results in path entanglement between the photons in the two beams in the arms of the interferometer. The fluctuations in the photon counts can only be explained by stronger-than-classical correlation among the photons.
It looks like quantum entanglement might play a very important role in the eventual detection of gravitational waves. Tremendously exciting stuff.

Geocentrism Revival

Robert Sungenis is an idiot.Seriously?

A few conservative Roman Catholics are pointing to a dozen Bible verses and the church’s original teachings as proof that Earth is the center of the universe, the view that was at the heart of the church’s clash with Galileo Galilei four centuries ago.

I can confidently speak for all of the quantum pontiffs when I say that we reject the geocentric view of the universe. I never thought I would have to boldly stand up for these beliefs, yet here I am.

… Those promoting geocentrism argue that heliocentrism, or the centuries-old consensus among scientists that Earth revolves around the sun, is a conspiracy to squelch the church’s influence.

This sentence nearly made my head explode.
First of all, heliocentrism is of course not agreed upon as scientific fact. As readers of this blog surely know, General Relativity teaches us that there are an infinite number of valid coordinate systems in which one can describe the universe, and we needn’t choose the one with the sun or earth at the origin to get the physics right (though one or the other might be more convenient for a specific calculation.) 
Second, you’ve gotta love the form of argument which I affectionately call “argument by conspiracy theory”, in which any evidence against your position is waved away as the work of a secret organization with interests aligned against you. Oh, what’s that? You don’t have any evidence for the existence of this secret society? Well, that simply proves how cunning they are and merely strengthens the argument by conspiracy theory!

“Heliocentrism becomes dangerous if it is being propped up as the true system when, in fact, it is a false system,” said Robert Sungenis, leader of a budding movement to get scientists to reconsider. “False information leads to false ideas, and false ideas lead to illicit and immoral actions — thus the state of the world today.… Prior to Galileo, the church was in full command of the world, and governments and academia were subservient to her.”

So in case you were wondering: yes, this guy is serious. In fact, he is also happy to charge you $50 to attend his conference, or sell you one of several books on the topic, as well as some snazzy merchandise like coffee mugs and t-shirts that say “Galileo was wrong” on the front. (Hint: they don’t say “Einstein was right” on the back.)
To Mr. Sungenis and his acolytes: I implore you. Please just stop. It’s embarrassing for both of us. And if you’re worried about your bottom line, then consider going into climate change denial instead, which I hear is quite lucrative.

Don't Forget To Look Up Tonight!

Perseids meteor shower peaking Thursday night through Friday morning.

“For my part I know nothing with any certainty, but the sight of the stars makes me dream.” – Vincent van Gogh

Many Paths Interpretation of Scientific Careers

Items sharing a similar topic, meandered onto in the depths of a major outpouring of procrastination…
The path less traveled by Andrea Schweitzer (via @mattleifer) on a different way to have a career as a scientist. And for a description of one of the most successful scientists from quantum computing, an interview with Ignacio Cirac (sent to me by Daniel.) Somedays, however, one might wonder about all the time professors spend working and contemplate the idea of death by tenure track. Or if you care a lot about the notion of tenure versus non-tenure AND you don’t mind reading redstate.org, you can amuse yourself reading Glorious Leader Gap: More Evidence Our Pretentious President Was Never a Law School Professor. Equally depressing, but perhaps in a different form, is the state of the astronomy job market. For better options, you might try computer science (unless of course you’re going to start screaming about DEH TOOK OUR JRBS OVER CCCCs, in which case, go ahead rant, but please include at least one link to statistics in your rant.)

Glorious Dawn Record

I get a lot of press releases forward to me which usually get forwarded directly into my gmail archive. But this one I’m happy to pass along: Third Man Records is releasing A Glorious Dawn. You know the Carl Sagan remix (w/ guest appearance of the Hawkmeister) that I’ve been looping over and over again while I work:

Third Man Records is over the moon to announce the 7-inch release of “A Glorious Dawn” on November 9th.

The release is timed to coincide with the 75th anniversary of Sagan’s birth. Also happening that day is a reception in United States’ Congress with speeches by senators, NASA officials and assorted scientists, all hosted by the Planetary Society, which was co-founded by Sagan.
Third Man Records, in conjunction with United Record Pressing, fabricated a special “Cosmos Colored Vinyl” of which 150 copies will be available…50 randomly inserted into mail orders for “A Glorious Dawn” and the remainder to be made available at the Third Man Records Nashville store front at noon on November 9th.
The one-sided single features a very special etching on the flipside. Reproduced from the original artwork, the etching copies the etching included with the Voyager Golden Record, set off into space in 1977 as the most elaborate message-in-a-bottle idea ever imagined. With its inclusion of Blind Willie Johnson’s “Dark Was The Night” it goes without saying that the Voyager Golden Record is one of Third Man’s favorite releases of all-time..

I fell asleep last night listening to an episode of Cosmos. Maybe that explains da alienz in my dreamz?

Apple Pie From Scratch

Via physicsandcake, on some days I wish I was as dorky and as elegant as Carl Sagan:

Look again at that dot. That’s here. That’s home. That’s us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every “superstar,” every “supreme leader,” every saint and sinner in the history of our species lived there-on a mote of dust suspended in a sunbeam.
The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds.
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe:, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves.
The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand.
It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we’ve ever known