Sunday, March 22, 2015

The Perceptions Project

On Friday, March 13, 2015, I attended a conference down at the Ronald Reagan Building and International Trade Center in Washington, DC.  The conference was part of the Perceptions Project sponsored by the AAAS.  It is part an effort to build a better bond between scientific and religious communities.

Perceptions: Science & Religious Communities

Science and religion issues are often fought at the extremes.  A goal of conference is to improve communication so that more moderate voices in religious community, who also accept science, can make it clear to other religious people, specifically in the evangelical community, that it is not an either-or situation.  The conference was focused on the issues of origins,  more specifically human origins and issues of global warming/climate change.

I ran into Eugenie Scott of NCSE shortly before the conference opening.  We have met a couple of times before.

A also ran into a few people whose name I knew, but whom I had never met.  I was even surprised by a few who were familiar with this blog.

Ronald Numbers (Wikipedia), author of the book, The Creationists (Wikipedia) which is a history of the creationist movement mostly since the publication of Darwin's Theory of Evolution.  Dr. Numbers autographed my copy of his book. 

Hugh Ross of Reasons To Believe.  I have followed some of the work by RTB and have written some on it before, having attended one of their local seminars.  I used to follow some RTB podcasts, but they changed their feed a couple of years ago and I failed to follow-up.

I met the current president of the Biologos organization, which was originally started by Francis Collins of NIH (Wikipedia).  They are a group of Christians who take the extra step of accepting the scientific evidence for human evolution.  I don't know that much about this organization, but I plan to do a little more research and might start linking to some of their resources when I want to address the biological evolution aspects in a Christian-friendly way.

I also had an enjoyable conversation with a member of a local Dominican School (I think he was a student, but he could have been an instructor) who talked about the history of their Order in science.  We also discussed some Fundamentalist groups in Catholicism (Wikipedia: Dominican Order, Albertus Magnus).

The primary emphasis of the conference was that science does not necessarily have to be the enemy of religious belief. 

I've got over six pages of notes from the conference, and may write more about it in the future.

Monday, March 9, 2015

Relativity Denial: Career cost?

Yet another comment whose response became too long for the Blogger comment system.
From the comment stream of Pseudo-Astro: Black Holes and Other Relativity Denial:
Ignoring GR/black hole theory does not harm future scientists and their studies of the stars.

That is unless you can name me one example in which someone studied the stars, and their ignoring of GR/black holes has adversely affected their career?

Seems to me their acceptance resembles the concept of God in seminary. Believe in them or you shall not pass! LOL!

-Jeffrey Wolynski
The importance of General Relativity in stellar evolution depends on the nature of the studies.  Studies of stellar formation, which occupy the lower density regime of the stellar lifetime, might not have problems ignoring relativity.  However, relativity impacts so many additional aspects of atomic physics (atomic absorption and emission in moving flows, etc), that someone who actively ignored the effects would have too many ideas that would just fail under rigorous testing.  Before long, such researchers would get no funding because too many of their ideas would fail to match observations or experiments.  A number of the real incompetents will claim that they're geniuses being victimized by conspiracies, etc. (Neurologica: Lessons from Dunning-Krueger).  

At higher density regimes, such as high-mass stars, relativistic effects become important for structural changes due to gravity, and energy production mechanisms, such as pair plasmas.  If the researcher wants to claim something other than relativity, they had better be working from an idea that can pass the basic tests where relativity has done well.
As for someone who 'ignoring GR/black holes adversely affected their career.'

Adversely affected defined how?   I know loads of former grad students who washed out for various reasons.  Now days, the real relativity denier rarely makes it to grad school because their relativity denial causes them to flunk other things in doing physics.  Instrument precision is now sufficiently high that relativity can impact a number leading-edge laboratory applications (see ArsTechnica: Einstein’s time dilation apparent when obeying the speed limit).

Then there's active, working applications such as the GPS system (links)...

Anyone who denies some component of well-established science limits their own career options.  Their chance of useful discoveries is lower, so granting agencies, etc. are less willing to invest in them. 

For the most part, very few of these cranks ever actually become physicists or astronomers, though a large number manage to become engineers.  I do know of a few support scientists who advocate various crank ideas, but they're kept on because in some sub-field of their actual employment, they are competent.  There are a few I suspect were forced to retire because their crank ideas began to have negative impacts on their professional responsibilities.  Engineers engaged in relativity denial are probably competent to do run-of-the-mill engineering, but they won't be qualified for engineering applications requiring high-precision positional or timing information.  The engineers in the GPS program who doubted relativity effects in the early days of the program (see Scott Rebuttal. I. GPS & Relativity and related links from the earlier post) are probably long gone.

If the account manager in a business doesn't believe in sound accounting principles (also backed by mathematics), do you keep them on the job?

Historically, there are a number of researchers who developed problems with relativity later in their career which had some negative impacts.  Arthur Eddington (1882-1944) believed General Relativity, but didn't believe black holes could form (Wikipedia: Arthur Eddington).  Later in his career, Eddington got involved in some progressively stranger, and sillier, scientific ideas (see Bethe's Spoof).  Then there was Herbert Dingle (1890-1978) (Wikipedia) who claimed to demonstrate a logical contradiction from the 'twin paradox' (MathPages: Dingle and the Twins) but this happened after his retirement.

Relativity is no longer a question of belief, like a fairy tale or religion, any more than the theory of gravity or atoms, or electrons or thermodynamics.  It is a matter that you can make numerical predictions that we can compare to observations and measurements and a great majority of them match to high precision.

While relativity denial might have been justified 50-100 years ago, relativity is now so integrated into techniques and technologies that denying its validity, especially in the realms where it is routinely used, is equivalent to denying the reality of atoms.

Tuesday, March 3, 2015

Relativity Denial: Messin' with c

Relativity, now passing its first century, continues to be one of the bugaboos of pseudo-scientists.  In spite of repeated attempts to prove it logically inconsistent, etc. occasionally by professional scientists about 50 years ago, it continues to be one of the best tested physical theories we have. 

Still, modern-day relativity deniers keep picking up on reports of laboratory experiments which reportedly 'alter' the speed of light.  Perhaps they think that such reports indicate relativity is showing a few cracks of impending failure?  This thinking is sometimes encouraged by sensationalistic science reporting.

Few, okay, probably NONE, of the anti-relativity cranks I've encountered recognize that the results of these experiments are actually predicted due to some rather counter-intuitive effects of the wave nature of light.  Such effects are perfectly consistent with relativity and do not signal a 'problem' with the theory.

I was recently directed by a commenter (comment to be released when I complete responses to it) arguing against relativity to a paper published under Science Express:
"Spatially structured photons that travel in free space slower than the speed of light." Science, 347(6224):857–860, 2015. doi: 10.1126/science.aaa3035.
I guess they were promoting the paper as evidence that the theory of relativity is about to fall.

So I read the paper and was not surprised to find that the authors had found another technique for reducing the speed of photons (yes, it has been done before), consistent with propagating them at the group velocity.  This method works perfectly within the known relationships of wave phase and group velocities for the same old value of the speed of light, c.  Some of this is even described in the introduction to the paper.

Waves can be described by three different speeds, the wave velocity, c, the phase velocity v_p, and the group velocity, v_g.  These three parameters are related by

v_g * v_p = c^2

which is one of the equations in the second paragraph of the paper.  These distinctions are commonly important at microwave frequencies for waveguides.  Note that if v_g goes less than c, v_p will always be greater than c and vice versa.

As the authors of the paper note, they have significantly reduced the GROUP velocity in empty space of a wave packet by a technique that has not been used before, which works for propagating the photons across free space.  The wave velocity, c, as well as other aspects of relativity, is not impacted.  There is no violation of established physics here, in spite of some rather odd wording.

There were a number of statements in the paper alluding to the fundamental nature of the speed of light:
"That the speed of light in free space is constant is a cornerstone of modern physics. ''
"The speed of light in free space propagation is a fundamental quantity. It holds a pivotal role in the foundations of relativity and field theory, as well as in technological applications such as time-of-flight measurements."
But I saw nothing in the paper indicating the results had any actual implications for relativity, a point which the authors clarify:
``Our measurement of group velocity is strictly a measurement of the difference in propagation speed between a reference photon and a spatially structured photon. No direct measurement of the speed of light is made. Within this manuscript, the velocity we measure is strictly the group velocity of the photons"
``Beyond light, the effect observed will have applications to any wave theory, including sound waves.''
Notice that the authors do clarify that this result is important for the wave nature of light, but make no mention for any possible impact on relativity.

Thanks to Dr. Padgett for helpful feedback clarifying the results of this work.

Why do Anti-Relativity Cranks Gravitate to these Stories?

Like most science fiction fans, myself growing up on the original Star Trek (wikipedia), I've always been fond of the idea of Faster-than-Light travel.  Numerous researchers have explored possibilities for object moving faster than light.  I was a big fan of tachyons (wikipedia) when I first read about them in high school and subsequently wrote a review of the physics literature (as it existed up to the late 1970s) as an undergraduate writing project.  I do hope that we will one day find a way to get around the limitation for interstellar travel, but I do recognize that the theory that makes it possible will be an EXTENSION of the existing theory of relativity, much like General Relativity is an extension of Newtonian gravity.

While this may be the motivation of a number of anti-relativity cranks, there are also a number who are opposed to relativity for social, political, or religious reasons.

Perhaps it feeds on the word games which are common in pseudo-science circles.  The popular statement used in the scientific community is that nothing can exceed the speed of light.  Therefore any report of light traveling slower than the maximum speed means that the statement is not strictly true, and therefore must allow all manner of other possibilities.  It's a cute word game, used commonly in politics, religion, and comedy. 

Creationists love to pull these kinds of rabbits out of their hats in debates with evolutionists, as evidence that some important physical law may not be so certain.  Catching an opponent by surprise can win points in debate class, but in science, the details and the math matter. 

Reality does not play word games.

And why they are Wrong...

In many popularizations, we like to say that the speed-of-light is the limiting speed in our universe.  We call it the 'speed of light' because it was the earliest measurement we had of something traveling at this ultimate speed. 

But it may more correctly be defined by some principle more fundamental, and light just happens to max-out at that speed.  Light travels at this speed because the photon is mass-less and the translational symmetry of position and time (no preferred location or time) creates a relationship between rest mass, energy and momentum of particles (a consequence of Noether's Theorem (wikipedia).  A zero rest-mass particle will always travel at the speed of light.

It has been known since the early days of relativity that the Lorentz transformations can be derived WITHOUT the assumption of constancy of the speed of light in all reference frames.  The basic assumptions of uniformity in how we measure time and spatial positions in reference frames (basically saying that any clocks and measuring sticks I can use on Earth will behave exactly the same on a spacecraft traveling at high speed relative to Earth) permit TWO different solutions for transformations between moving reference frames.

One solution is the Galilean transformations. 

The other transformation solution defines an invariant velocity.  These transformations become the Lorentz transformations if the invariant velocity is equal to what we call the 'speed of light'.

Light, under optimum conditions, travels at this cosmic speed limit.  There's nothing wrong with it traveling slower.

Additional Resources: 

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