Wednesday, November 12, 2014

Will Future Generations Prosecute Old Climate Change Deniers?

     I can imagine a future say 2070 where some efforts were made to stop climate change but it was not enough.  But the carbon industry was so strong with its large amounts of money.  Because more money could be made using fossil fuels not enough effort was put in reducing carbon dioxide emission.  Lots of renewable energy  was put into the grid.  There were large solar and wind farms.  The mid west and Texas had many wind generators and California led the nation with electricity generated by solar power.  Many people around the world had solar panels on their roofs to help in the generation of electricity.  But carbon dioxide emission was still too much and most of what the climate models predicted occurred.  The earth's temperature continues to rise.  The ice in the Arctic and Antarctic have dramatically melted as models predicted, thus a global rise in sea levels.  Lower areas along the coasts have serious flooding problems and many areas had to be abandoned.    Weather patterns have changed also.  In North America Canada's prairies are now doing what the mid west of the US used to do.   Similar efforts have been happening around the world.  Some regions are now uninhabitable and this forced the mass exodus of millions of people.  Water and food shortages have occurred in many parts of the world causing large regional wars.  The migration caused tens of millions of deaths with possibly billions on the brink of death.  Deadly diseases such as cholera  have spread  All of this could have been stopped 50  or 60 years ago but greed caused a failure to help save the lives of possibly billions of people.  This didn't need to have happened if only policy makers world wide would have listened to the scientists back then.  But climate change deniers were a powerful force and policy makers followed them instead of the science.  Thus the planet was changing in a direction that would dramatically change the future of mankind.

     In the future will they then prosecute the climate change deniers?

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Monday, November 3, 2014

Book review: Endless Universe: Beyond the Big Bang by Steinhardt and Turok

Competition to the inflationary modelNovember 3, 2014
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This review is from: Endless Universe: Beyond the Big Bang -- Rewriting Cosmic History (Paperback)
This book is about the ekpyrotic model for the evolution of our universe. It states that about every trillion years or so our universe recycles itself.As the authors say in their glossary "ekpyrosis: a collision between two branes that produces a flat, expanding universe filled with matter and radiation, with a nearly scale-invariant distribution of density inhomogeneities." It is a competing theory to the better known inflationary model of the universe. Both the authors are practicing cosmologists with Steinhardt at Princeton and Turok at the Perimeter Institute. Steinhardt made early contributions to the inflationary model in the early 1980's and is therefore well aware of the strengths and weaknesses of the inflationary model. This is a well written book and was a pleasure to read. If you are interested in cosmology this book is a must for you. The level of this book is such that any interested high school student should have no trouble reading this book.

This book is written in a casual style and mentions how the authors first got the idea for their theory while they were both attending a lecture on the overview of string theory. They both went up to the speaker after his talk and asked him questions about strings and branes. Later the authors met at a small physics conference in Finland and started to work out the details their theory. The book describes the various questions that must be overcome such as flatness and thermodynamics. In the past various cyclic models of the universe have been proposed but they were later shown to have flaws. In careful precise wording they explain how they were able to overcome all the previous questions with their new model.

As expected they describe very well the inflationary model since the book compares the two models closely. One of the main differences being that their model has small if any primordial gravitational waves which have been in the news since March 2014 because of the BICEP2 cosmic microwave radiation data which initially claimed to have observed these gravitational waves to only latter say that their results could also be explained by galactic dust. The physics community awaits further data on this subject.

Steinhardt has been a public vocal critic of inflation going so far to say that it isn't even science since one can get just about any prediction from the theory since it is so general in nature. This is also discussed in the book.

My disagreement with the theory is that it is based on string theory and brane theory. There have been no experimental tests that have every shown that string and brane theory have anything to do with reality. There are two wonderful books that show the problems with string theory. They are Lee Smolin's "The Trouble with Physics" and Peter Woits "Not Even Wrong". If anything since this book was written string theory has lost some of the luster it had back in 2007. Nevertheless I would recommend this book since it is quite educational and very well written.

Thursday, October 16, 2014

Phase Transitions in the Early Universe

     There is a really nice article in the most recent Quanta magazine on phase transitions.  A phase transition is like when liquid water becomes solid water, ice or when liquid water becomes a water vapor, steam.  This got me wondering about all the different phase transitions that occurred in the early universe.  So lets look at and count them from most recent to the farthest one in time.

Phase transition 1:  When electrons could combine with nuclei and make stable atoms.  This occurred about 380,000 years after the big bang in the inflationary model of the big bang.  This has given us the cosmic microwave background (CMB) radiation that has been in the news and I blogged about here.  This would occur at energy levels of electron volts (eV).

Phase transition 2:  When protons and neutrons had cooled down at the million electron volt (MeV) scale to form nuclei, namely the deuteron, He  and Lithium nuclei, along with high energy photons.

Phase transition 3:  When the quark-gluon plasma had cooled down to give rise to hadrons.  This would occur at the billion electron volt (GeV) range.  These hadrons would give as all the particle that we observe at large particle accelerators such as pions, kaons, but also the protons and neutrons that make up nuclei.  All of these particles except the proton are unstable and decay creating all the known leptons such as the electron muon and the three different neutrino types.

Phase transition 4:  This is when possibly the inflaton field undergoes a phase transition to create free quarks and gluons.  Maybe leptons were also created at this time, I just don't know  Also it is possible at this time that whatever particle(s) that makes up dark matter were also created at this time.

Phase transition 5:  When the inflaton field was created.

Phase transition 6:  When the universe was created.

     Was there a phase transition that created spacetime?  Were space and time created at the same time or separately?

    The big question is what kind of observable signal might we observe from phase transitions 2-6?
What could we observe that could help us understand transitions 2-6?  I have some ideas but I'm not sure of them.

Wednesday, September 24, 2014

BICEP2 + Planck + Foreground = Good Physics

     The Planck CMB polarization paper came out this week and its results were not good news for the BICEP2 team as shown herehere, and here. I'd commented on the BICEP2 result earlier here, Basically saying that this is how science gets done.  Now we have the future to look forward to and more results coming in at other frequencies and maybe better energy resolution so hopefully in the future we will know about primordial gravitational waves.  Again may you live in interesting times!

     What only gets briefly mentioned is that what we do have is really good data on galactic dust and the galactic magnetic field.  So people who study that should be very happy.  Again what is one research groups hindrance is another groups prize.  This happened else where in physics.  At the LHC looking for the Higgs boson its signal sits on top of a large background.  Understanding this background is important so that you can be confident in your Higgs signal.  Understanding this background means understanding the physics that gives rise to this background and here understanding and computing QCD processes becomes important.  Hence you have large groups that look at all the QCD processes that can contribute to this background and then calculate their cross sections and then see how these match the background.  So here you get more understanding and conformation of the Standard Model in trying to understand the background underneath your Nobel prize winning discovery of the Higgs boson.

    In my own research years ago in looking at the excitation of giant resonances in nuclei excited with inelastic proton scattering, the resonances sat on top of a background.  One minimized this background as much as possible but it was still there and didn't go away.  That was because as we learned that background was there because there was real physics going on that caused this background.  The background was a real signal and not instumental problems.  The background as we determined was caused by quasifree scattering of the incident protons from nuclei in the targets.  The target nucleus being a collection of nucleons acted like a collection of nucleons sort of like a collection of pool balls racked up and we were hitting these pool balls and sometimes we were exciting the nucleons  in that manner instead of other nuclear processes.  This area of study led to other experiments studying this quasifree scattering.  So looking for one signal our background signal became interesting in itself.

     Funny how science moves ahead.

Tuesday, September 9, 2014

The Question of What is Now?

     One of the cool things about physics is that every now and then a question comes up and it makes you go "what a fascinating topics for physics to look into and I'm surprised I've not heard more about it".  One of those moments happened earlier this year when in the March 2014 issue of Physics Today there was a commentary by N. David Mermin entitled "What I Think About Now".  It is a fascinating article and when I read it I wonder about that I know I've thought about my moments of Now but never really thought about what the physics meaning of Now means.  I'm capitalizing Now in the ways Mermin does to point out the Now that is being discussed.  Now being your personal conscious feeling about your Now.   Physics treats  objects as just things that don't perceive a Now.  Objects are a rock or baseball or a proton..  Physics tries to understand what these objects are made of and the forces that they interact with and the understanding of these forces.  The objects perception of Now then gets into the area of consciousness and self awareness.     In Mermin's article he mentioned about Einstein's feeling of the Now which is the following:

Einstein said that the problem of the Now worried him seriously. He explained that the experience of the Now means something special for man, something essentially different from the past and the future, but that this important difference does not and cannot occur within physics. That this experience cannot be grasped by science seemed to him a matter of painful but inevitable resignation. 2

This would seem to say that Einstein thinks physics cannot describe the Now as experienced by the individual.. The personal, conscience, self awareness of  Now..  It reads to me that Einstein didn't think that consciousness could be understood by science. Interesting.  The idea of the Now in physics is fascinating.  In the September issue of Physics Today there are third letters about Mermin's  Now commentary they are here, here, and here.  The last letter has a reference to an arxiv paper about the physics of the Now.  Finally there is a reply by Mermin to these letters.  

     There seems to be two Nows.  One the physics Now of a point in spacetime described by its coordinates i and the worldline that the objects experiences in spacetime as described by the laws of physics.  Very impersonal and sounds like the stuff that physicists do. The other is the personal, psychological, conscience Now that physicists are beginning to seriously study as mentioned in an earlier post entitled Quantum Consciousness.  

    The personal Now has to do with self awareness.  Self awareness is an emergent process of your consciousness.  It is something your consciousness develops with time./Somehow and sometime, which is not understood, your brain and body become conscious but not self aware.You then do not know the concept of Now until you are self aware.  Because Now is a subjective experience of your  self aware consciousness.  Now becomes the present state in spacetime of your self aware consciousness.  You as a person.don't know of Now until that self awareness turns on in your consciousnesses.  Then you have a feeling of time.  That the world is changing and that you perceive that change and that is what we call rime or the flow of rime.  So your subjective idea of Now starts when you become self aware.  This is probably obvious to everyone..   

Tuesday, September 2, 2014

Quantum Weirdness

     What do I mean by quantum weirdness?  Its the observation of things that cannot be explained with the classical laws of physics and need to be explained or are the results of quantum mechanics that seem odd, strange or just plain weird.  Maybe quantum bizarre would be better word.  What effects or thing do I mean that are quantum weird?  Here are some examples:

Schrodinger's cat  This is the most famous cat in physics.  Also apparently Schrodinger owned a cat when he thought of his thought experiment in 1935 I think.  This is the paradox that can arise when one applies quantum mechanics to macroscopic sized objects in which we can not observe.  The paradox is that the state that describes the cat quantum mechanically has to have the cat both alive and dead at the same time.  This is because Schrodinger equation is linear so the most general solution is a linear combination of all the solutions.  This is also known as superposition.  It leads to a just weird situation.

Image without detecting light  Another article on the same experiment is here.  This is a recent experiment using entangled photons.  Entanglement can led to many weird quantum effect.  Basically using entangled photons physicists were able to make a photograph of an object where the entangled photons never were involved in the illumination or reflection from the object whose picture was taken.  The photons didn't see the object or have  anything to do with the object yet they could be used to make a picture.  Of course the picture was of a cat.  This is just plain weird.  Einstein called entanglement "spooky".

Quantum computing  Where in a qubit does the calculation take place in a quantum computer?  This has to do with superposition.

The uncertainty_principle can lead to many odd effects.

Wave particle just plain weird.  How a particle can both be a wave and a particle.

     You can probably think of other weird quantum effects, or in quantum mechanics things are different.  This quantum weird is something that all students of physics talk about partially because it is just plain weird.  Some people learn about quantum weirdness in reading about science in newspapers or other popular media.  Recently a meeting was held to help educate science journalists about quantum mechanics and some of its weirdness.  One of my favorite blogs Backreaction has a post about this meeting because blog author helped organize the meeting.

     One of the problems with quantum mechanics is that physicists don't really understand what quantum mechanics is trying to tell us.  Quantum mechanics has many interpretations.  The equations of quantum mechanics are well known its just what do they mean?  Some blog discussions about this are very illuminating on this subject.  One is in the blog quantum frontiers posted here.  This is written by John Preskill a physics prof at Caltech.  Another is posted by Sean Carroll here.entitled "The Most Embarrassing Graph in Modern Physics".  The graph mentioned is about a poll taken at a meeting showing that physicists can't agree on which interpretation of quantum mechanics is correct.  As is usual the comment sections of the posts are very educational..  I have also talked about the problems with quantum mechanics here.  This is one of my earlier posts and might be poorly written.

Tuesday, August 26, 2014

Quantum Consciuosness

     No this isn't a post about new age type stuff.  Its about recent posts and a meeting about the interface of the quantum world and the classical world and scientists talking about consciousness.

     In a previous post I talked about a meeting on the foundations of quantum mechanics and its relationship to the classical world.  One of the people in the discussion was Scott Aaronson a computer science professor at MIT who spoke about quantum computers and consciousness. .   On his blog Shtetl_Optimized he has posted his talk at this meeting.  It is fascinating to read about his thoughts on computers and consciousness.  He gives his definitions of consciousness in regard to the arrow of time.  It is a good read.  Another MIT professor has also been working on consciousness and that is the physics professor Max Tegmark.  He discussed his work on consciousness in his book "Our Mathematical  Universe" which you can learn more about by going to his homepage which I gave a link to. It is a fun and enjoyable book to read.  For a more technical article on Tegmark's work you can go here.  What he proposes is that consciousness is a state of matter 

     What I find refreshing is that these are two younger professors talking about consciousness.  To be sure they are both tenured professors so they are more free to discuss consciousness.  The reason I mention this is that in the past seriously talking about consciousness by a faculty member was sort of off limits due to the problems that such talk was thought to verge on the area of crackpottery.  Consciousness was studied by older retired professors and was not considered a serious subject in a physics department, I'm guessing the same is true for all sciences.  Lee Smolin in one of his books, either "The Trouble with Physics" or "Time Reborn" talks about he will not discuss consciousness except with one elderly gentleman he has respect for.  It was not a subject to openly discuss.  In the past few years it seems like more physicists and some computer scientists are talking about consciousness and in Tegmark's case it appears to be part of his research agenda.

     Consciousness is considered to be one of the hard problems in science.  Its nice to see younger faculty discussing and working on this question. It is an area that more  scientists should seriously study  Its fun to learn about consciousness. Or our conscious likes to study consciousness.

After writing this last night I came across this article on computing and consciousness from a theoretical physics student Shaun Maguire at Caltech in the blog Quantum Frontiers.  Its another interesting article and discusses some of Aaronson work on computers and hard problems along with consciousness.  Quantum Frontier is a blog of Caltech's Institute for Quantum Information and Matter and usually has interesting articles many of which are written by students.

Added 9-2-14  I came across another post by Scott Aaorson en "Quantum Information and the Brain".  It is interesting