Einstein's Impossible Measurement...

Figure 1. Brownian motion trajectories. When examined at modest measurement rates (a), the observed positions (red dots) of particles executing Brownian motion appear to lie on the jerky trajectory illustrated in red. The black curve shows the underlying particle path. (b) Measurements at finer time scales reveal that the particle path is in fact built from short bursts of constant velocity motion.

Citation: Phys. Today 68, 1, 56 (2015); http://dx.doi.org/10.1063/PT.3.2665

It's always exciting when I recognize and actually know the authors!

Dr. Mark G. Raizen is the Sid W. Richardson Foundation Regents Chair of Physics and Professor of Physics at the University of Texas, Austin.

Dr. Tongcang Li received his PhD under Mark's guidance and is now Assistant Professor of Physics and Astronomy/Assistant Professor of Electrical and Computer Engineering at Purdue University. They were both kind enough when Dr. Li was completing his graduate degree to give Cassandra and I a tour of their lab and impressive work at UT.

Mark has pioneered, in his own words, a "general methods to control the motion of atoms and molecules. This work will be used to test very basic questions in physics, and will also find real-life applications," which is a modest understatement! First to do this was former Department of Energy Secretary and Nobel Laureate Dr. Steven Chu. The process in the Raizen Group is a vast improvement on this impressive achievement. An excerpt of the article is below; explore the article at the link for "optical tweezers": think James Clerk Maxwell's "demon" thought experiment. Keep in mind real-life applications going forward. Nicely done, gentlemen: I applaud your great research and a well-written presentation. I thank you for your permission to post this.

Particles undergoing Brownian motion move with constant velocity between Brownian kicks. Albert Einstein predicted the velocity distribution, but he wrongly thought his result would never be experimentally confirmed.

Brownian motion, the seemingly random wiggle-waggle of particles suspended in a liquid or gas, was first systematically studied by Robert Brown in 1827 and described in the Philosophical Magazine the next year (volume 4, page 161). When Brown used a microscope to look at particles from pollen grains immersed in water, he “observed many of them very evidently in motion.” It looked like the particles were alive, so vigorously did they move.

The phenomenon of Brownian motion was first explained by Albert Einstein in 1905 as a consequence of the thermal motion of surrounding fluid molecules. Einstein’s theory predicts that Brownian particles diffuse; as a consequence, their mean-square displacement 〈(Δ x)²〉 = 2 Dt in each dimension is proportional to a diffusion coefficient D and the measured time interval t. As illustrated in figure 1 a, the motion of Brownian particles looks like a jerky and unpredictable dance, and the sudden changes in direction and speed seem to indicate that velocity is not defined. Moreover, the mean velocity
〈 v〉 ≡ 〈(Δ x)²〉 ^1/2/ t = (2 D/ t) ^1/2 diverges as t approaches 0. If you think all that is strange, you are in good company: Einstein felt the same way.

Physics Today: The measurement Einstein deemed impossible
Mark G. Raizen and Tongcang Li

Related #P4TC Links:

Improved Isotope Enrichment, July 1, 2014
Einstein, Entropy and Information, March 23, 2013
Brownian Motion...Einstein "wrong..ish", May 16, 2011
Maxwell's Demon & information-to-energy, November 16, 2010
Comprehensive Control of Atomic and Molecular Motion, August 23, 2010

Improved Isotope Enrichment...

Caption: This is a still frame from an artist's animated rendering of the MAGIS Device (magnetically activated and guided isotope separation). To begin the MAGIS process, unpurified ore is vaporized and enters an optical pumping region where a one-watt laser (red beam) tuned to a specific wavelength magnetizes only the particles of the desired isotope so that they are repelled by a magnetic field. The magnetized and unmagnetized particles enter a curved tunnel lined with permanent magnets, called a wave guide. The particles must follow the curve to make it to the collector at the end, but can only do so if repelled by the magnetic field. Since only the particles of one isotope are magnetized (blue dots), only those particles make the trip and end up in the collector. The MAGIS method was developed by Mark Raizen, Tom Mazur and Bruce Klappauf. The full animation can be viewed at https://www.youtube.com/watch?v=zIRi-7AxFAM.

Credit: ©Marianna Grenadier, College of Natural Sciences, The University of Texas at Austin.

I don't know what's more exciting - the new discovery, or knowing one of the discoverers.

I guess it's both!

MAGIS: Magnetically-activated and guided isotope separation:

AUSTIN, Texas — Researchers at The University of Texas at Austin have devised a new method for enriching a group of the world's most expensive chemical commodities, stable isotopes, which are vital to medical imaging and nuclear power, as reported this week in the journal Nature Physics. For many isotopes, the new method is cheaper than existing methods. For others, it is more environmentally friendly.

A less expensive, domestic source of stable isotopes could ensure continuation of current applications while opening up opportunities for new medical therapies and fundamental scientific research.

Chemical elements often exist in nature as a blend of different variants called isotopes. To be useful in most applications, a single isotope has to be enriched, or separated out from the rest.

A combination of factors has created a looming shortage of some of the world's most expensive but useful stable isotopes.

Last year, the Government Accountability Office released a report warning that there may soon be a shortage of lithium-7, a critical component of many nuclear power reactors. Production of lithium-7 was banned in the U.S. because of environmental concerns, and it's unclear whether the current sources, in China and Russia, will continue meeting global demand.

Nuclear medicine in particular could benefit from the new method, the researchers say. Many stable isotopes are precursors to the short-lived radioisotopes used in medical imaging, cancer therapies and nutritional diagnostics.

The new method also has the potential to enhance our national security. The researchers used the method to enrich lithium-7, crucial to the operation of most nuclear reactors. The U.S. depends on the supply of lithium-7 from Russia and China, and a disruption could cause the shutdown of reactors. Other isotopes can be used to detect dangerous nuclear materials arriving at U.S. ports.

Raizen's co-authors on the paper are Tom Mazur, a Ph.D. student at the university; and Bruce Klappauf, a software developer at Enthought and a former senior research scientist at UT Austin.

Now, Raizen's top goal is getting this technology out of the lab and into the world. The MAGIS invention has been issued a U.S. patent, which is owned by The University of Texas at Austin, with Raizen and Klappauf as inventors.

Raizen plans to create a nonprofit foundation to license the technology.

University of Texas at Austin:
Improved method for isotope enrichment could secure a vital global commodity
Contact: Steve Franklin
sefranklin@mail.utexas.edu
512-232-3692
University of Texas at Austin

Seeding Greatness...

Credit @ link below

TECHNOLOGY REVIEW: A couple of months back, we looked at the notion of time crystals, an idea put forward by Nobel-prize winning physicist Frank Wilczek and his pal Al Shapere.

These guys examined the fundamental properties of ordinary spatial crystals and asked why similar objects couldn't exist in the dimension of time instead.

One of the basic properties of spatial crystals is that they form when a system drops to its lowest possible energy state. They are not the result of adding energy to a system, but of taking it away. All of it.

Another basic property is that when these objects reach their lowest energy configuration, their symmetry breaks down. Instead of being the same in all directions, like the laws of physics, these objects become the same in only a few directions. It is this symmetry-breaking and the periodic structure it produces that defines crystals.

Wilczek and Shapere persuasively argued that there's no reason why similar periodic structures couldn't exist in time. And they said that finding them would give physicists a new way to study the process of symmetry-breaking and the laws of physics behind it.

There was just one problem, however. These guys hadn't worked out how to build a time crystal.

That changes today with the work of Tongcang Li at the University of California, Berkeley and a few buddies who say they've worked out how to do it. These guys say they know how to create an object in its lowest energy state that shows periodic structure both in space and time--a space-time crystal.

I had the pleasure of meeting Tongcang Li just before his PhD dissertation defense under Mark Raizen. This obviously builds on his research with the Raizen Group. This is amazing!

Physics arXiv: Space-time crystals of trapped ions

New York...

I touched down last Saturday, 2 April 2011 @ JFK at 2:40 PM EST. That was the easy part...

My turtle was shipped as Priority Parcel Post; my 92 lb lab as part of my luggage. I payed as much for the turtle as I did for my luggage: $200 each.

I had to first go get my luggage to the rental car place via the Air Train, then go get my turtle and lab: two neurotic pets that did not like the plane ride or the monorail at all...trust, me: the turtle (as turtles go) wasn't herself; the dog got car sick -- probably an extension of the plane trip -- on the way upstate.

Map Quest or Google Maps cannot tell me it's 1.5 - 2 hours from JFK...given traffic, juggling luggage, pets and my own naivete, I got where I was going by 10:15 PM.

Thank God for the GPS on my phone -- brought to us all courtesy of "The Photoelectric Effect" and a bit of quantum mechanics (of course, I had to say that...).

*****

I was deeply moved by the affection extended to me by the staff and students at Manor High School:

- I received a drawing by a student of a Mustang (the car, and so happens the school mascot). It could have been a magazine cover. I plan to have it framed and placed in my office.

- I took photos of all the students in my 1st - 7th period classes, that will go into an electronic frame: I plan to look at them daily.

- My martial arts students put on a party for me in which they made an "Oreo cake": essentially, they stacked oreos in the shape of a cake, and brought Doritos and popcorn.

- My 2nd and 4th period physics classes each had a party with food - 4th with pizza they'd ordered. I was probably 5 lbs heavier by the day's end.

- Since my last Friday was April 1st, I was accused by some as playing a cruel "April Fool's" joke.

It was not, and I apologize to those whom this move was upsetting.

Again, I'm touched that I'd affected so many young lives and made friends with so many talented teachers. It's nice to know that one's life has significance in other's lives as well. It is what makes us altogether human and adds value to our brief existence...

*****

Centura...CMP...Endura...EPI...FEP...Producer...

My reintroduction to semiconductors as an operations manager: I admit to the dilemma reported in "The E-Myth": my love of being the "technician." That's when you like being the "fix it" person; the guy/gal that turns the screw; designs the experiment & analyzes the data. I have to let go and empower others to do the same.

Once I can let go, I feel I can do so much more. I, like a lot of physics graduates, romanticize Einstein as the wild-haired loner genius: the Munich patent office -- though he thought it defeating -- allowed him to ponder the universe deeply. In the pre-relativity world, life probably moved at a much slower pace.

My thanks to my lovely wife, family, friends and New Light Church for believing in me.

My thanks to my students for allowing me to impact their lives positively for a short time.

My thanks to Mark and Alicia Raizen for inspiring someone selling security services -- my own "patent office" experience -- to have the courage to pursue once again a career in science. I am in debt for their friendship.

Lastly, my thanks for having been blessed to have parents that saw beyond their circumstances in east Winston-Salem, NC to inspire my sister and I to build lives of purpose and significance:

                Robert H. Goodwin       Mildred D. Goodwin
Sunrise:    June 19, 1925     (1)      September 15, 1925
Sunset:     August 26, 1999 (2)      May 7, 2009 (3)

1. My father and sister were both born on Juneteenth, celebrated in Texas as the day the former slaves learned of their emancipation.

2. My layoff from high tech occurred August 26, 2003: 4 years to the day after my father's death.

3. My mother expired two days before Mother's Day, and a day before the recent Star Trek reboot, at the time a sad coincidence that Mr. Spock lost his mother (I'm sure by the third movie, she and the rest of the original plot line will be back...)

Comprehensive Control of Atomic and Molecular Motion

"The Raizen Group has developed new methods of cooling and trapping that are applicable to any atom in the periodic table as well as many molecules. The starting point for our work is the supersonic molecular beam which is an standard tool in Physical Chemistry. The supersonic beam serves as a universal platform for cold but fast atoms and molecules that are seeded or entrained into the supersonic flow. We proposed that a series of pulsed magnetic field coils could stop and trap any paramagnetic species. This 'atomic coilgun' was inspired by the coilgun which is used to launch large projectiles."

Photo by Adam Libson

Dr. Mark Raizen is particularly proud of the construction, that by shear coincidence "looks" like UT's familiar symbol!

Center for Nonlinear Dynamics: Raizen Group Research areas