Physics Feed

Heisenberg might have been amused.

An unintentionally funny passage from the AP story Scientists dubious of quantum computer claims:

[ D-Wave Chief Executive Herb Martin] said all the evidence the company has indicates that the device is performing quantum computations, but he acknowledged there is some uncertainty.

Here is the D-Wave press release, World’s First Commercial Quantum Computer Demonstrated.

Retrocausality & the Movies

Further to the subject of retrocausality, my dad, John Cramer, emailed to say:

My planned experiment has been concantated with a review of the upcoming movie "Deja Vu" in an article on MSNBC at


From the article:

Over the next few years, some experiments hold out a chance of finally being able to show whether or not time can move backward as well as forward. Theoretically, at least, it might be possible for the future to influence the past, said John Cramer, a physicist at the University of Washington. He and his colleagues plan to try just such an experiment next year.

Cramer acknowledged that the concept of retro-causality doesn't seem to make sense, "but I don't understand why not."

Both Greene and Cramer know the science as well as the fiction side of the time-travel issue: Greene is the author of "The Elegant Universe," a best-selling book on string theory — but he also played a cameo role in "Frequency," a time-travel movie released in 2000, and served as a scientific consultant for "Deja Vu."

"It was a kick to be in the room with [producer] Jerry Bruckheimer and [director] Tony Scott and the writers, talking about special relativity and general relativity and wormholes," he told

Cramer, meanwhile, has done research into ultra-relavistic heavy-ion physics at CERN and Brookhaven National Laboratory — but he's also written two science-fiction novels and pens a regular column for Analog magazine called "The Alternate View." If his experiments show that retro-causality is a reality — that one event can determine the outcome of another event taking place 50 microseconds earlier — it could lend support to the ultimate alternate view of quantum physics.

"It opens the door to doing all kinds of really bizarre things," he said.

Nigerian Spam about Quantum Mechanics

Someone in Nigera apparently read my most recent post, because I got a hillarious piece of Nigerian spam on the subject of quantum mechanics:

I am Civ Opopekim, the only son of the late Professor Lawrence Opopekim, of a much respected university in my country of NIGERIA, who was dedicated to the study of RETROCAUSALITY. Upon examining my father's scientific journals, I have discovered a matter of the most URGENT importance to your future (and past) well-being. As most of my father's work has not yet been published, I am counting on your discretion in this sensitive matter.

In the course of research, my father discovered the photons created in his experiments were entangled through QUANTUM MECHANICS with photons found in your locale. Further study revealed the break-through discovery of photon tilt patterns in the photons of your area based on experiments planned but yet to be performed by my father.

Alas since my father was poisoned to death with tainted YAK MILK by scientists from rival laboratories who lured him to GENEVA under the false pretense of a scientific conference, a financial situation has arisen where I can no longer assure the continuation of his research or the operation of his laboratory (it embarrasses me to admit this sad truth).

As a person of science, you are aware that even changes at the quantum level cause universes to take separate but parallel infinite paths. I fear that if I am unable to continue my father's schedule of experiments and therefore cause the photons in your immediate area to not have tilted in the way they already have, the life you have come to know and enjoy will cease to be and you will find yourself in a parallel existence unfavorable to you.

To this end, and for the sake of your past and current self as well as my father's research, I humbly ask you for the sum of US$10,000, which will allow me to keep for father's laboratory open for a time to carry out the scheduled experiments.

As an indication of your willingness, please forward to me your: full name, company, full contact address, phone, cell, fax, city, sate, zip code, occupation, SSN and all the necessary information will be sent to you on the acceptance of this arrangement.

His dad must have been a very important guy! It's not everyone who gets fed poisoned yak milk in Switzerland!

My father, John Cramer, remarks that he will know to avoid the yak milk at future physics conferences.

My Dad Is Cooler than Your Dad: "If the experiment works, a signal could be received before it's sent"

My Dad is Cooler than Your Dad

From yesterday's Seattle PI: Going for a blast into the real past: If the experiment works, a signal could be received before it's sent

If his experiment with splitting photons actually works, says University of Washington physicist John Cramer, the next step will be to test for quantum "retrocausality."

That's science talk for saying he hopes to find evidence of a photon going backward in time.

"It doesn't seem like it should work, but on the other hand, I can't see what would prevent it from working," Cramer said. "If it does work, you could receive the signal 50 microseconds before you send it."

Uh, huh ... what? Wait a minute. What is that supposed to mean?

Roughly put, Cramer is talking about the subatomic equivalent of arriving at the train station before you've left home, of winning the lottery before you've bought the ticket, of graduating from high school before you've been born -- or something like that.

Yaaay for the home team!!! (See also my previous post: Retrocausality.)

SEE ALSO Slashdot. (Daddy's been Slashdotted!)

My favorite blog post on this subject is from Correntewire: Science for Republicans! which first quotes from the article on my dad and then quotes John McCain' electoral regrets:

“We departed rather tragically from our conservative principles,” McCain lamented recently, offering his take on why the GOP fell from power in Congress. He urged a return to what he called the foundation of the Republican Party — restrained spending, smaller government, lower taxes, a strong national defense and family values.

Sorry guys, not this time out. This is just a physics experiment.

My dad, also a publshed novelist,  explains the excitement of experimental phsyics:

Even if this does fail miserably, providing no insights, Cramer said the experience could still be valuable. As the author of two science-fiction novels, "Twistor" and "Einstein's Bridge," and as a columnist for the sci-fi magazine Analog, the UW physicist enjoys sharing his speculations about the nature of reality with the public.

"I want people to know what it's like to do science, what makes it so exciting," he said. "If this experiment fails in reality, maybe I'll write a book in which it works."

Physicists John Cramer, left, and Warren Nagourney work in the lab. Nagourney says he has

(Also, I've added a Restrocausality photoset to my Flickr account!)


Nscover The cover article of the September 30th issue of New Scientist features a Gedankenexperiment that my father, John Cramer, proposed in a talk he gave at an AAAS meeting in San Diego last June.

The article begins:

Ever wish you could reach back in time and change the past? Maybe you'd like to take back an unfortunate voicemail message, or rephrase what you just said to your boss. Or perhaps you've even dreamed of tweaking the outcome of yesterday's lottery to make yourself the winner.

Common sense tells us that influencing the past is impossible - what's done is done, right? Even if it were possible, think of the mind-bending paradoxes it would create. While tinkering with the past, you might change the circumstances by which your parents met, derailing the key event that led to your birth.

Such are the perils of retrocausality, the idea that the present can affect the past, and the future can affect the present. Strange as it sounds, retrocausality is perfectly permissible within the known laws of nature. It has been debated for decades, mostly in the realm of philosophy and quantum physics. Trouble is, nobody has done the experiment to show it happens in the real world, so the door remains wide open for a demonstration.

My father says:

As implied in the article, I have recruited an atomic physics experimentalist (Warren Nagourney) and we have decided to do at least the first stage of the experiment. I now have a LiIO3 non-linear crystal on order that will be needed to do this. We will begin the experiment in a couple of months when the argon-ion laser owned by the UW Atomic Physics group becomes available (sometime around December to February).

Here are the last few slides from his Power Point presentation. They outline the experiment. (Click on them to see bigger versions.)

JGC1.jpg JGC2.jpg JGC3.jpg JGC4.jpg JGC5.jpg

Nuclear Materials at the Bulgarian Border: A Puzzle

(Click on the graphic below to see a pdf version you can zoom in on.)


At the Counterterrorism Blog, in a post entitled, Iran caught red handed in smuggling nuclear material, Olivier Guitta remarks on an intriguing news story alleging that Bulgaria had detained, at the Romanian border checkpoint at the Russebridge over the Danube, a truck containing materials that could be used to build a dirty bomb. Agence France-Presse first reported it. There's also a Sofia News Agency version, and a longer Daily Mail (UK) version. Each has a detail or two that the others don't, but this excerpt from the Dail Mail will give you the general idea:

Border guards seized a British lorry on its way to make a delivery to the Iranian military - after discovering it was packed with radioactive material that could be used to build a dirty bomb.

The lorry set off from Kent on its way to Tehran but was stopped by officials at a checkpoint on Bulgaria's northernborder with Romania after a scanner indicated radiation levels 200 times above normal.

The lorry was impounded and the Bulgarian Nuclear Regulatory Agency (NPA) was called out.

On board they found ten lead-lined boxes addressed to the Iranian Ministry of Defence. Inside each box was a soil-testing device, containing highly dangerous quantities of radioactive caesium 137 and americium-beryllium.

The soil testers had been sent to Iran by a British firm with the apparent export approval of the Department of Trade and Industry.

Last night, the head of the Bulgarian NRA, Nikolai Todorov, said he was shocked that devices containing so much nuclear material could be sold so easily.

He said: "The devices are highly radioactive - if you had another 90 of them you would be able to make an effective dirty bomb."

And a spokesman for the Bulgarian customs office, said: "The documentation listed the shipment as destined for the Ministry of Transport in Tehran, although the final delivery address was the Iranian Ministry of Defence.

"According to the documentation they are hand-held soil-testing devices which were sent from a firm in the United Kingdom."

The shipping company involved is Orient Transport Services of Sevenoaks, Kent, apparently located in one of the most affluent towns in Southeast England. According to their website, they ship to Iraq, Iran, Turkey, Syria, Jordan, Bulgaria, Romania, Yugoslavia, Serbia, Croatia, Slovenia, Hungary, Slovakia, Czech Republic, Poland, Belarus, Russia.

If in fact the radioactive soil-testing devices traveled all the way from Kent, they were a little less than half way on their 3,000 mile journey to Tehran when they were impounded by the Bulgarians, and would have already passed through Belgium, Germany, Austria, Hungary, and Romania before being stopped after crossing into Bulgaria.

The news articles imply that the radioactive materials were apprehended in the same truck they left Kent in. But an examination of the Orient Transport Services site has maps of countries where they deliver suggesting regular delivery routes, and the Map Key mentions an "Istanbul control centre" suggesting a transportation network rather than just individual trucks that make really long drives. Also, the truck stopped in Bulgaria had Turkish plates; the location where it was stopped is a little over 150 miles from the Turkish border. So it seems to me unlikely that the truck itself came all the way from Kent. News reports have not yet identified the UK company alleged to have sent the equipment.

So how much mischief could have been caused with the kind of stuff that was in the truck? Some. Apparently, these devices in their native state pose little danger of radiation exposure and breaking them down for parts is a lot of trouble for not very much radioactive material. Nonetheless, there is a perceived problem with the theft of portable radioactive gages, and some consideration has been given to what could be done with them. Here is a discussion of safety issues involving similar equipment left lying around in California: Radioactive material not life threatening: Soil density gauge stolen, then recovered in Chualar.

A scientific instrument the size of an ice chest that contains low-grade radioactive material touched off a nuclear alert Sunday when it was found abandoned outside a neighborhood grocery store in Chualar.

The device, a soil density gauge, had been stolen from a vehicle belonging to Salinas-based Kleinfelder Inc. on Saturday, the Monterey County Sheriff's Office said. The machine is used to measure soil density and helps contractors determine whether soil will support various structures.

. . . The machine was returned to Kleinfelder personnel, who assured the public safety workers that although the device does contain radioactive material there was no threat to anyone who came in contact with it.

In general it seems that while someone could use the contents of that truck as ingredients of something that might be called a "dirty bomb," it would be a rather disappointing one, not up to the standards of the popular imagination.

So what's going on here? Are Iranians with overactive imaginations ordering soil testing equipment in hopes of blowing stuff up and making a radioactive mess? Are Bulgarian customs officials with overactive imaginations detaining perfectly legal shipments of soil testing equipment which otherwise would have been shipped to someone at the Iranian Ministry of Defense who urgently needed some soil tested? Was the equipment really going to end up in Iran? If so, why was it traveling by ground when it was still about 1,500 miles from its destination? Or was it going to one of the other places OTS ships? Whatever the answers to these questions are, what this situation isn't is an open and shut case of the Iranian military ordering up fissionable materials from a source in the UK, which is what it appeared to be at first blush. It seems to me that someone somewhere in this supply chain is being conned. I'm just not sure who.

Superconducting Magnet Quench

These are pictures from the STAR detector at the RHIC facility at Brookhaven that my father, John G. Cramer, brought to lunch today.  He was running on the machine at Brookhaven as part of the STAR Collaboration.  The first two are from a "normal" collision of two gold nuclei, producing several thousand particles in the center of the detector.  The next four show the results of a superconducting magnet quench that happened at noon on March 25, 2006.

The quench dumped all the protons they were planning to use for the next four hours of collisions, which hit the accelerator walls and produced a flash of radiation picked up the the STAR detector. I'm told the accelerator recovered after a couple of days.

Here is the sequence of pix with his captions. Click on them to see bigger images:


1.  Central collision of two gold nuclei with collision energy 25,610 GeV as recorded by the STAR detector at RHIC in August, 2000. (End View)

And the second one . . .


2.  Central collision of two gold nuclei with collision energy 25,610 GeV as recorded by the STAR detector at RHIC in August, 2000. (Side View)


3.  Catastrophic superconducting magnet quench;  all stored proton beam dumped abruptly when magnetic field went to zero, as recorded in STAR detector (End View)


4.  Catastrophic superconducting magnet quench;  all stored proton beam dumped abruptly when magnetic field went to zero, as recorded in STAR detector (Side View)


5.  Next view of catastrophic superconducting magnet quench;  all stored proton beam dumped abruptly when magnetic field went to zero, as recorded in STAR detector (Side View)


6.  Next view of catastrophic superconducting magnet quench;  all stored proton beam dumped abruptly when magnetic field went to zero, as recorded in STAR detector (End View)

And here we are right after we came back from lunch.

Kathryn Cramer & John G. Cramer

See also these sites: MRI Scanner Superconducting Magnet Quench, a diagram with a video, & Superconducting Magnet Issues (CERN).