The 2018 Nobel Prize In Physics...

October 2, 2018
The big day has arrived, and the Nobel committee has now announced the recipients of the 2018 Nobel Prize in Physics. And as I predicted, this year they have gone with a technological development rather than work in pure science. However the research that resulted in this year's prize is still pretty amazing.

I must also start with a disclaimer here that this research is well outside my own specialist field of theoretical and mathematical physics / astrophysics / particle physics. As such I can only give a very rough overview of the work that the three recipients have done in the field of laser physics. (And I should also add here that I am going to focus solely on the research here, and avoid some of the unfortunate side issues and politics that seem to have arisen in some of the reporting on the selection and awarding of this year's prize)

There are actually two separate but closely related topics in laser physics that have been recognized this year. The first of these is the development of the optical tweezers by Arthur Ashkin. Most people are familiar with the use of tweezers in everyday usage. They allow us to grab and manipulate tiny objects that would be otherwise to small to work with. However at some small scale, it is no longer possible to use a physical object such as tweezers. In particular it would be impossible to manipulate single molecules or atoms using a tool comprised of billions of atoms and molecules. Therefore a new technology was needed.

The new technology that Ashkin and others developed was the optical tweezers or laser tweezers. By using multiple laser beams, scientists were able to trap atoms and molecules in between two or more streams of photons. By adjusting the laser emitters, these atoms can be moved around and manipulated. When other technologies such as scanning electron microscopes are added to the setup, scientists are able to create quite intricate and complicated patterns of atoms and molecules, as well as perform experiments that would have been impossible just a few decades ago. By the late 1980s the method had been developed to the point where scientists could manipulate living viruses and bacteria without harming them, simply by using precise laser beams. And so the optical tweezers are certainly a major scientific advance not only in physics but also in chemistry and biology, and are certainly worthy of a share of the Nobel Prize.

Meanwhile, the other half of the Nobel Prize this year was given to Gerard Mourou and Donna Strickland for their work in developing high intensity, ultra-fast pulsed lasers. A traditional laser takes a certain amount of time to "turn on", as it requires first pumping atoms into excited states before the laser can begin triggering their decay, which then creates the characteristic monochromatic beam of light. This startup time makes it impossible for a traditional laser to create short bursts,  or pulses of light.

The methods developed by Mourou and his graduate student, Strickland, are quite technical and too complicated to give a proper description of here. However they used a novel new technique to speed up the switching of the laser, which created not only a very fast startup and cool down but also a very high intensity beam. The method is known as chirped chirped pulse amplification, and essentially involves first creating a long, low intensity laser pulse using traditional methods. Once the pulse has been generated, they compress it in such a way that the start of the pulse is slightly slowed and the back of the pulse is slightly accelerated, resulting in the production of a much short pulse that also has a higher intensity due to the all of the original laser energy being compressed into a much smaller region. This method allowed them to generate very short, rapid pulses of high intensity laser energy that could be used for a number of practical applications. The most significant of these for the general public has been the development of laser eye surgery, which is now commonly used to correct vision defects in patients. This technique has been so powerful that even thirty three years after they first published their results, scientists are still exploring all of the potential applications for such amplified laser pulses.

And so that is my brief summary of the two fascinating pieces of laser physics research that earned this year's Nobel Prize. They are very different techniques with very different applications, but they are both major advances in the science and technology of laser beams, and have both had a significant impact not only one the scientific world but on society in general.

So congratulations to the three recipients of this year's prize, and may they and their students continue this amazing research that has so changed our understanding of light and lasers!
 

Nobel Predictions

October 2, 2018
Yes folks, its that time of year again. This week the Nobel committees will be announcing the 2018 winners of the most prestigious prize in science, and that means it is time to once again make a few predictions.

As usual I will begin with some comments on which theories and potential candidates will not be receiving a prize this year.

Every year when I make my predictions, I have readers from outside of the scientific community complain that I "forgot" to list certain people. I won't name the ...
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The Planet Pluto

September 11, 2018
Just when you thought you knew the solar system...

Some long term readers may recall a heated debate twelve years ago over the nature of Pluto. When it was first discovered over a century ago, astronomers named it and labelled it the ninth planet. Generations of students learned the names of the planets, and wrote endless reports about the ninth planet. A few years ago the New Horizons probe sent back detailed images of its surface, taken from orbit during a flyby as the probe left the solar s...
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Random Updates

September 7, 2018
Now that everyone is settling back in to their school and work schedules, I thought it was time to give a few updates on my life and websites and whatever else comes to mind.

First off is a blatant money grab :)

For a few years I have been accepting donations of bitcoins or litecoins to help offset the costs of maintaining my various websites, and I appreciate the response that I have received. It is certainly not required and I do not expect people to donate. I will always keep my website free...
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Back To School

September 4, 2018

Some loyal readers will recognize this entry as a repeat from the last four years. Each year it gets a good response, and kudos from my readers, and so as before I must appease my loyal followers...

To all the students starting University, enjoy this time of your life. Long ago when I started, a prof told me that this is the start of your real education. Now you get to choose your own courses and your own field of study. It is entirely up to you to decide what to do with this chance.

I know fro...


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Free Software

September 4, 2018
With the arrival of September, students around the world will be returning to classes this week. And for those who are starting out at college or university, one of the most important considerations is how to live on a budget. These are the years when one has little or no income, but must bear the expenses of living independently for the first time. While giving advice on living on a budget is far too expansive to cover in this blog, I can tackle one small aspect of student life by providing ...
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The Opposition of Mars

July 27, 2018
For those who are interested in astronomy, tonight Mars will make its closest approach to Earth in fifteen years. That means that it will be both large - though still only viewable in detail through binoculars or a telescope - and very bright. 

As most people already know, both the Earth and Mars orbit the sun, in neighbouring orbits. Usually they are at different points in their respective orbits, and so Mars appears small and distant. Roughly every two years, the two planets pass close toget...
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Neutrinos By The Sea

July 19, 2018
Neutrinos are popular right now. 

Last week the IceCube neutrino observatory announced the discovery of the origin of many high energy cosmic rays as being a massive black hole and active galaxy, using the flux of neutrinos that it produced as a pointer to their source. The observations were then confirmed by a variety of observatories working in radio waves, visible light, and gamma-rays, but the original signal was through neutrinos.

Today we have the announcement that the University of Victo...
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The Origin of Cosmic Rays

July 13, 2018
After weeks of speculation, today the IceCube neutrino observatory has revealed their big news. After more than a century of debate about the origin of high energy cosmic rays, the IceCube team together with astronomers around the world have managed to pinpoint the source of at least some high energy cosmic rays as being a very active and violent distant galaxy known as a blazar. (For those interested in the technical details, the two research papers can be found here and here)

Cosmic rays wer...
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Sterile Neutrinos

July 10, 2018
There has been a lot of discussion lately of the possible existence of sterile neutrinos in the Universe, due in large part to a few papers in the recent weeks making claims of possible signs of detection in one of the bigger neutrino observatories. And although these results are preliminary, with the formal announcements coming later this week, and may show no clear sign of anything other than a statistical fluctuation, the theory of sterile neutrinos is still quite interesting to the theore...
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About Me


Dr. Chris Bird I am a theoretical physicist & mathematician, with training in electronics, programming, robotics, and a number of other related fields.

   


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