Data versus theory: the map is not the territory

[A]s an increasing body of research is suggesting, it may be that the climate is responding to higher concentrations of carbon dioxide in ways that had not been properly understood before. This possibility, if true, could have profound significance both for climate science and for environmental and social policy.

via Climate science: A sensitive matter | The Economist.

In Science, when theory meets observation, observation wins. No matter how elegant the theory, no matter how famous and intelligent the scientists who created the theory, if the theory’s predictions do not match up with observations, it is all just pretty math. Climate Science is having to come to grips with the fact that despite the sophistication of the computer models, despite the logical soundness of the underlying assumptions, the predicted warming is not being seen in the observed temperature measurements, both in the lower atmosphere and in all but the very top layer of the ocean. Real scientists will say “hey, there is more work to be done, clearly we do not yet understand the Earth’s climate well enough to predict its behavior.”

I’m a lukewarmer. I think it is clear the Earth has been warming for more than a century now, and I have no doubt that increasing CO2 levels play a part in that warming. But. There is so much we do not yet understand about the climate and the energy flows and feedback mechanisms in it. For example, cloud cover can have a significant effect on the energy flow in the lower atmosphere–white, fluffy clouds reflect solar energy back into space before it can strike the surface, be reradiated as infrared energy, and thereby trapped due to the greenhouse effect. But who has any detailed understanding about the effect of increasing CO2 and temperature on cloud cover? Without that understanding, climate models must guess at cloud cover changes. What are the effects of increasing thunderstorm activity over the oceans? Those huge heat engines transport lots of energy from the surface up to the stratosphere where it is radiated into space, bypassing the greenhouse driven delays in the lower atmosphere. In short, there are lots of questions which remain unanswered by current climate science. The answer to those questions, of which I have mentioned just two, has a great effect in the amount of negative feedback in the Earth’s climate. Without a model that accurately reflects all the important effects, we should take model results with a grain of salt. All models are wrong, but some models are useful.

So, what to do? First, we need to know more, to understand the behavior of the Earth’s climate in greater detail. More research is clearly necessary. Second, we shouldn’t be spending those resources on various social engineering schemes before the behavior of the climate itself is understood well enough to make predictions that are validated by observation. We may have a warming problem, but we may not, and until we have a deeper understanding, it is hubris to imagine we can ‘fix’ a problem which we do not understand and which may not even exist. And perhaps most importantly, climate science must be kept separate from political and social agendas. Science is never ‘settled’; Science is a process, and there is no area of scientific knowledge that is beyond questioning.


Drug dogs, cell towers, and the expectation of privacy

Attorneys representing the U.S. Department of Justice are expected to defend warrantless use of stingray devices, which trick mobile devices into connecting to them by impersonating legitimate cell towers. Prosecutors yesterday filed court documents saying stingrays were used in investigations in Arizona and Wisconsin going back to 2008.

via FBI prepares to defend ‘Stingray’ cell phone tracking | Politics and Law – CNET News.

The Supremes just decided Florida v. Jardines, a case in which the question was if a drug-sniffing dog invaded the constitutional rights of a suspect when it alerted to the scent of drugs outside the suspect’s home. The police used the dog’s reaction to obtain a search warrant, and did find drugs. In a 5-4 decision, the Court held such a ‘search’ by the dog to be unconstitutional. But was it a victory for privacy rights? The Court’s view is that the officers’ venturing onto private property with the dog was the problematical aspect. This decision will have no effect upon a drug dog ‘search’ if the home or apartment is close enough to public property–a sidewalk, for example–for the dog to do his thing.

Well, the electronic analog of this case is coming to the lower Courts now. Your cellphone listens to the cell towers in range, decides which signal is the best, and negotiates which tower it uses. For years, the FBI has used Stingray, a box that emulates a cellphone tower, to track a subject’s cellphone and to record the numbers calling and called by that cellphone. It is also possible to record conversations using this technique. Apparently, the FBI (and local law enforcement) have been quiet about the full power of this technology and the extent of its use when obtaining warrants.

So what is the relationship between drug sniffing dogs and cellphone sniffing electronics? In both cases, specialized equipment can reveal information not readily apparent to humans. I don’t know about you, but I have a reasonable expectation of privacy about what goes on in my private residence and what my cellphone reveals about my friends and my location. If we accept that, and I think the Courts will as well, what is the difference? Here’s a big one. Stingray can be used while located on public property (e.g., public roads, public right of way, und so weiter). Fido might need to get close to your home, but Stingray works as long as its signal can win the tower selection algorithm. Fido and Stingray both pull information from the air, but Stingray has a more sensitive nose that needn’t be located on private property.

Prediction: the Supremes are going to see cases involving Stingray, and they are will need to define privacy rights in a world where we carry devices that can be snooped from public areas. They’d better start thinking about this.

CongressHub: accountable, public collaboration for Congress.

Our laws start as bills in Congress. The Library of Congress has a good resource, THOMAS, enabling citizens to search the text of Congressional bills. But THOMAS could be radically improved if Congressional bills were stored there in a GitHub-like fashion. The complete textual history of a bill, from its introduction and all subsequent modifications, should be recorded. Every change to the text should have the name of the Member who approved the change and the name of the staff member who entered the change into the record. The full textual history of every bill should be completely visible to the public. Only bills whose introductory text to final version can be completely traced, with names and dates, should be eligible to become law.

Sunlight is the best disinfectant

Congress should not be some insular club whose Members work in closed rooms or who outsource the text of bills to lobbyists. All changes to bills should be a matter of public record, searchable, and attributable to Members and their staff. Citizens should be able to see the progress and process of our Representatives, and access to the full textual history of a bill will enable better feedback from the public to their Representatives. We shouldn’t expect any less from our Representatives in this computer age.

How MOOCs Could Meet the Challenge of Providing a Global Education | MIT Technology Review

Many are now already looking to the next phases of these online courses in the developing world, a future that may look more like a blending of online and traditional college work than one existing entirely on the Internet.

via How MOOCs Could Meet the Challenge of Providing a Global Education | MIT Technology Review.

I have been waiting for this for 15 years. To my mind, being able to watch–and rewatch as needed–lectures by the best lecturers in their fields is a game-changer for higher ed (and as Khan Academy is proving, primary/secondary ed too). The real challenge now is how to do student interactions with subject matter experts. The whole subject of credentials will be very interesting for traditional higher ed in the brave new world.

Planck telescope peers into the primordial Universe : Nature News & Comment

Planck’s results strongly support the idea that in the 10-32 seconds or so after the Big Bang, the Universe expanded at a staggering rate — a process dubbed inflation.

via Planck telescope peers into the primordial Universe : Nature News & Comment.

Planck telescope peers into the primordial Universe : Nature News & Comment

Big news! Several papers out from the Planck satellite results. The satellite has produced the best, most precise, most detailed look at the Cosmic Microwave Background radiation. The CMB is the glow left behind by the Big Bang when the universe cooled enough to become transparent and photons began traveling freely through space. As space itself has expanded, the wavelength of the CMB photons have increased, leading to the current blackbody temperature of around 2.725K.

Quick takes: at small angles, the CMB is very uniform and consistent with out current understanding (Big Bang, Inflation, a lot of Dark Energy, and Dark Matter). No challenges to Inflation at small to medium angles. The universe is slightly older than we thought, but just slightly. The large angle non-uniformities seen by WMAP, Planck’s older brother, are also seen by Planck. Half the sky is slightly hotter than the other half. The Axis of Evil (an alignment of a significant CMB temperature minimum, a large void of radio galaxies, and an alignment and handedness of galaxy spins) is confirmed. This is a very interesting phenomenon that is not predicted by the Standard Model and the Big Bang.

More later when I have some time to digest the new results.

Many-Worlds and locality

Commenter Amanurea pointed out that the Many-Worlds Interpretation of quantum mechanics doesn’t require spooky at action at a distance even with locality. I didn’t realize MWI could be a local theory and yet produce violations of Bell’s Inequality as Nature seems to do. I’ve been thinking about this for a bit, and I think I understand it now. A local MWI is such a delightful thing I thought I’d write up a post about my new understanding. Brickbats and corrections welcomed.

The Many Worlds Interpretation views Objective Reality as a many branched tree in which each possible quantum event occurs! Instead of having a wavefunction collapse, quantum decoherence provides the appearance of a wavefunction collapse, but no collapse actually occurs. In MWI, the full wavefunction of the universe exists and continues to evolve in a unitary fashion. Any (quantum) measuring device becomes entangled in many different ways with the (quantum) environment of the system being measured, and therefore can no longer measure any interference or superposition of states in the system under measurement. When the measuring device is entangled with the environment in a very large number of ways, it is extremely probable that any measurement will return only a single value, and even though the other states exist in the many-branched tree, these other states cannot be measured from the point of view of the environment entangled with the measuring device. We say the universe ‘splits’ into N branches when we have N possible values of the measured quantum state, in effect giving rise to N ‘copies’ of the entire universe. Each ‘copy’ will contain one distinct state of the (former) superposition of states. Further, in each ‘copy’, for all other systems entangled with the measured state, only those states that are consistent with the measured value of the state will appear. This may be a little non-intuitive, so a classical example might help!

Suppose we have two coins, a gold coin and a silver coin. We put the coins into two different envelopes, and mix the envelopes up. The coins in the envelopes are thus ‘classically entangled’ in the sense that if we open one envelope, we instantly know what opening the other envelope will reveal, regardless of the distance between the two envelopes. No superluminal communication was necessary so the coin in the second envelope would be the correlated color. Our understanding of this is intuitive.

It is mostly straightforward to use the coin analogy to consider a system of two entangled photons with correlated polarized states of VERTICAL and HORIZONTAL. Unlike the coin in the envelope, each photon is a superposition of the two polarized states, and we can’t be sure which state we’ll get until we actually measure the polarization. In MWI, when we measure photon 1, the universe ‘splits’ into two universes, one with photon 1 VERTICAL and one with photon 1 HORIZONTAL. The properties of quantum entanglement of the two photons insures that in VERTICAL photon 1’s universe, only HORIZONTAL photon 2 is present. Therefore, photon 2 is no longer a superposition of states, and when we measure photon 2, we must get HORIZONTAL as the result. There is no other possible outcome in VERTICAL photon 1’s universe! You see no superluminal communication is takes place (the world is local). The correlated values always come out correctly when we measure both photons, regardless of which photon is measured first or how far apart they are when the measurement takes place. It is interesting that the universe no longer has a ‘split’ when photon 2 is measured, because no quantum decoherence is necessary to produce a single polarization value. This is what prevents Bell’s Inequality from being valid, and hence a violation of that inequality no longer requires a non-local universe.

Whew! It may not be the best analogy, but it is where I am in understanding how MWI does not require non-local interactions, even if Bell’s Inequality does not hold.

Life’s mysteries

Life's mysteries



From XKCD.

Yes, it is a Standard Model Higgs with spin 0.

Well, spin 2 (with positive parity) is now strongly disfavored, as a result of new results from the ATLAS and CMS experiments at the Large Hadron Collider.  CMS has disfavored it at the 98.5-99.9% confidence level (the number depending on assumptions about whether the particle is produced in collisions of gluons or in collisions of a quark and anti-quark) using their data from the particle’s decays to two lepton/anti-lepton pairs.  ATLAS has disfavored it at the 95%-99% confidence level (similarly depending on assumptions) using their data from  decays of the new particle to a lepton, anti-lepton, neutrino and anti-neutrino.  Meanwhile, there is no reason for a spin-2 particle (especially with negative parity) to have the relative decay probabilities that are observed in the data, so the fact that all these probabilities are similar to those of a simple Higgs particle disfavors spin 2 and favors spin 0.  And there’s simply no theory of a spin-2 particle (with either parity) that doesn’t have other observable particles rather nearby in mass.    No one of these arguments is definitive, but in combination they are pretty convincing.

via The Spin of the Higgs-Like Particle.

I’m a little late in getting to this, but results presented at the Moriond conference earlier in March are consistent with a spin 0 Standard Model scalar boson, or in other words, a Standard Model Higgs, and not some exotic new particle with spin 2 or other non-Higgs-like property. So, confirmation is coming in, and while we still can’t be sure if the Higgs is the simplest Standard Model Higgs predicted, the new LHC discovery is the Higgs to high probability. Break out the Nobel Prizes for the theoreticians behind this–Higgs, François Englert, and, because Nobels in the sciences are customarily limited to three names, one of Dick Hagen, Gerrry Guralnik, and Tom Kibble. Sadly, Robert Brout died in 2011 and the Nobel is not awarded posthumously, or he would most likely have been the third theoretician.

We don’t yet know if the Higgs is a simple SM Higgs, or if some surprises await, but a Higgs of some kind it is.

Solar Wind Heating Source Discovered

Ion cyclotron waves are made of protons that circle in wavelike-rhythms around the sun’s magnetic field.  According to a theory developed by Phil Isenberg (University of New Hampshire) and expanded by Vitaly Galinsky and Valentin Shevchenko (UC San Diego), ion cyclotron waves emanate from the sun; coursing through the solar wind, they heat the gas to millions of degrees and accelerate its flow to millions of miles per hour. Kasper’s findings confirm that ion cyclotron waves are indeed active, at least in the vicinity of Earth where the Wind probe operates.

via Solar Wind Energy Source Discovered – NASA Science.

Great news! The mechanism for heating the solar wind to millions of degrees while the photosphere remains around 6000 degrees has been unclear for decades. And the discovery has caught the attention of researchers attempting to build fusion power plants on Earth. The Sun’s ability to heat heavy ions might provide some clues on how to deal with contamination that cools the plasma inside a fusion reactor.

Life in a meteorite: Claims by N. C. Wickramasinghe of diatoms in a meteorite are almost certainly wrong.

In the end, the idea of life in space is a scientific one, and must be solved with scientific processes. Careful scientific processes. After all, this is one of the biggest and most fundamental questions we have. Flamboyant articles with grand conclusions based on questionably-conducted research and incomplete reporting are not the right way to go about this.

via Life in a meteorite: Claims by N. C. Wickramasinghe of diatoms in a meteorite are almost certainly wrong.

I disagree with Phil Plait on a few things, but here I think he is exactly right. Evidence of extraterrestrial life would be a super extraordinary claim, and super extraordinary claims require super extraordinary evidence. And the Wickramasinghe paper isn’t even close.

Wickramasinghe was a student and collaborator of Fred Hoyle, the famous and eccentric British cosmologist. Hoyle had some clever and interesting at the time ideas such as continuous creation, and his work on stellar nucleosynthesis was brilliant. Wickramasinghe worked with Hoyle on the idea of panspermia–life is common in the Universe and life on Earth originated due to extraterrestrial contamination. Hoyle and Wickramasinghe also believed the evolution of life on Earth is influenced by a continual bombardment of viruses from comets and the like. A discovery of diatoms in a meteorite would move those ideas from fringe to hot topic status. One can see why Wickramasinghe would be eager to find fossils in meteorites. All the more reason to maintain a skeptical, show me the evidence attitude. Plait lays out the skeptic’s case quite well.