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Posts Tagged ‘antimatter’

Costumes to make zombie Einstein proud

Wednesday, October 29th, 2014

This article appeared in symmetry on Oct. 21, 2014.

These physics-themed Halloween costume ideas are sure to entertain—and maybe even educate. Terrifying, we know. Image: Sandbox Studio, Chicago with Corinne Mucha

These physics-themed Halloween costume ideas are sure to entertain—and maybe even educate. Terrifying, we know. Image: Sandbox Studio, Chicago with Corinne Mucha


So you haven’t picked a Halloween costume, and the big night is fast approaching. If you’re looking for something a little funny, a little nerdy and sure to impress fellow physics fans, look no further. We’ve got you covered.

1. Dark energy

This is an active costume, perfect for the party-goer who plans to consume a large quantity of sugar. Suit up in all black or camouflage, then spend your evening squeezing between people and pushing them apart.

Congratulations! You’re dark energy: a mysterious force causing the accelerating expansion of the universe, intriguing in the lab and perplexing on the dance floor.

2. Cosmic inflation

Theory says that a fraction of a second after the big bang, the universe grew exponentially, expanding so that tiny fluctuations were stretched into the seeds of entire galaxies.

But good luck getting that costume through the door.

Instead, take a simple yellow life vest and draw the cosmos on it: stars, planets, asteroids, whatever you fancy. When friends pull on the emergency tab, the universe will grow.

3. Heisenberg Uncertainty Principle

Here’s a great excuse to repurpose your topical Breaking Bad costume from last year.

Walter White—aka “Heisenberg”—may have been a chemistry teacher, but the Heisenberg Uncertainty Principle is straight out of physics. Named after Werner Heisenberg, a German physicist credited with the creation of quantum mechanics, the Heisenberg Uncertainty Principle states that the more accurately you know the position of a particle, the less information you know about its momentum.

Put on Walter White’s signature hat and shades (or his yellow suit and respirator), but then add some uncertainty by pasting Riddler-esque question marks to your outfit.

4. Bad neutrino

A warning upfront: Only the ambitious and downright extroverted should attempt this costume.

Neutrinos are ghostly particles that pass through most matter undetected. In fact, trillions of neutrinos pass through your body every second without your knowledge.

But you aren’t going to go as any old neutrino. Oh no. You’re a bad neutrino—possibly the worst one in the universe—so you run into everything: lampposts, trees, haunted houses and yes, people. Don a simple white sheet and spend the evening interacting with everyone and everything.

5. Your favorite physics experiment

You physics junkies know that there are a lot of experiments with odd acronyms and names that are ripe for Halloween costumes. You can go as ATLAS (experiment at the Large Hadron Collider / character from Greek mythology), DarkSide (dark matter experiment at Gran Sasso National Laboratory / good reason to repurpose your Darth Vader costume), PICASSO (dark matter experiment at SNOLAB / creator of Cubism), MINERvA (Fermilab neutrino experiment / Roman goddess of wisdom), or the Dark Energy Survey (dark energy camera located at the Blanco Telescope in Chile / good opportunity for a pun).

Physics-loving parents can go as explorer Daniel Boone, while the kids go as neutrino experiments MicroBooNE and MiniBooNE. The kids can wear mini fur hats of their own or dress as detector tanks to be filled with candy.

6. Feynman diagram

You might know that a Feynman diagram is a drawing that uses lines and squiggles to represent a particle interaction. But have you ever noticed that they sometimes look like people? Try out this new take on the black outfit/white paint skeleton costume. Bonus points for going as a penguin diagram.

7. Antimatter

Break out the bell-bottoms and poster board. In bold letters, scrawl the words of your choosing: “I hate things!,” “Stuff is awful!,” and “Down with quarks!” will all do nicely. Protest from house to house and declare with pride that you are antimatter. It’s a fair critique: Physicists still aren’t sure why matter dominates the universe when equal amounts of matter and antimatter should have been created in the big bang.

Fortunately, you don’t have to solve this particular puzzle on your quest for candy. Just don’t high five anyone; you might annihilate.

8. Entangled particles

Einstein described quantum entanglement as “spooky action at a distance”—the perfect costume for Halloween. Entangled particles are extremely strange. Measuring one automatically determines the state of the other, instantaneously.

Find someone you are extremely in tune with and dress in opposite colors, like black and white. When no one is observing you, you can relax. But when interacting with people, be sure to coordinate movements. They spin to the left, you spin to the right. They wave with the right hand? You wave with the left. You get the drill.

You can also just wrap yourselves together in a net. No one said quantum entanglement has to be hard.

9. Holographic you(niverse)

The universe may be like a hologram, according to a theory currently being tested at Fermilab’s Holometer experiment. If so, information about spacetime is chunked into 2-D bits that only appear three-dimensional from our perspective.

Help others imagine this bizarre concept by printing out a photo of yourself and taping it to your front. You’ll still technically be 3-D, but that two-dimensional picture of your face will still start some interesting discussions. Perhaps best not to wear this if you have a busy schedule or no desire to discuss the nature of time and space while eating a Snickers.

10. Your favorite particle

There are many ways to dress up as a fundamental particle. Bring a lamp along to trick-or-treat to go as the photon, carrier of light. Hand out cookies to go as the Higgs boson, giver of mass. Spend the evening attaching things to people to go as a gluon.

To branch out beyond the Standard Model of particle physics, go as a supersymmetric particle, or sparticle: Wear a gladiator costume and shout, “I am Sparticle!” whenever someone asks about your costume.

Or grab a partner to become a meson, a particle made of a quark and antiquark. Mesons are typically unstable, so whenever you unlink arms, be sure to decay in a shower of electrons and neutrinos—or candy corn.

Lauren Biron


Anti-beam me up, Scotty!

Tuesday, January 28th, 2014

While the CERN accelerator complex was being revamped in 2013, the ASACUSA experiment took time to carefully review the data taken in 2012 at the Antiproton Decelerator (AD) facility. This painstaking work paid off and they just announced in Nature having produced the first ever beam of antihydrogen atoms.

In laboratory experiments like the ones conducted at CERN, matter and antimatter are always created in equal amounts. The Big Bang theory predicts that the same quantities of matter and antimatter were also created at the origin of the Universe. However, nowadays, one sees absolutely no trace of this “primordial” antimatter. So what happened to all the antimatter that once was in the Universe?

To answer this question, CERN has a full antimatter program underway at the AD to check if antimatter has the same properties as matter. One of the best ways to do so is to compare antihydrogen atoms with hydrogen atoms. This is the simplest of all atoms, having only one electron orbiting around one single proton.

Antihydrogen atoms are replica of hydrogen atoms but with an anti-electron – called positron – and an antiproton replacing the electron and proton of regular atoms.

All matter emits light when excited just as a piece of metal shines when heated up. The light emitted gives a unique signature for each atom. For example, hydrogen emits and absorbs light of specific frequency when an electron jumps from one energy level to another. It also has a “hyperfine structure” corresponding to magnetic interactions between the nucleus and the electron.

The ASACUSA experiment aims to check the hyperfine structure of antihydrogen. This can be done by observing which frequencies antihydrogen atoms absorb.

asacusa-realThe ASACUSA experiment at CERN (Image: Yasunori Yamakazi )

So here is what ASACUSA did: they produced antihydrogen atoms by first decelerating and cooling antiprotons down to very low temperature. Then they mixed antiprotons with positrons and combined them in a strong non-uniform magnetic field. These strong magnetic fields are necessary to keep antiprotons and positrons from touching any matter. That would cause their immediate annihilation and prevent the formation of antihydrogen atoms.

The next problem was to move the antihydrogen atoms away from this field to be able to study their hyperfine structure. Otherwise, the strong non-uniform magnetic field would mask the tiny effects generated by the magnetic interaction between the antiproton and the positron responsible for the hyperfine structure.

But atoms are neutral and cannot be controlled by electric fields. However, antihydrogen atoms are like tiny magnets. So by using non-uniform magnetic fields, the scientists were able to manipulate these tiny magnets and create a beam of antihydrogen atoms. It was directed towards a small detector located after a microwave cavity and a sextupole magnet.

The sextupole magnet focuses or defocuses antihydrogen atoms on the detector depending on the direction of the antihydrogen tiny magnets.


The ASACUSA setup. From left to right: the magnets (grey) used to produce antihydrogen atoms, the microwave cavity (green) to induce hyperfine transitions, the sextupole magnet (red and grey) and the antihydrogen detector (gold). Credit: Stefan Meyer Institute.

The detector reveals the number of antihydrogen atoms passing through the device after they go through a microwave cavity. It was turned off in 2012 but will be on in the future.  The antihydrogen atoms will only absorb microwave photons having exactly the energy corresponding to its hyperfine transitions. This process will alter the trajectory of antihydrogen atom in the sextupole magnet, and eventually the number of antihydrogen atoms reaching the detector will be reduced.

By counting how many antihydrogen atoms reach the target when the microwave cavity is tuned to specific frequencies, the scientists will determine the frequencies of the hyperfine structure.

ASACUSA now has the proof that 80 antihydrogen atoms made it to their detector. The next step is to see if fewer are observed when the microwave cavity is turned on at the right frequency.

And then we will know if antihydrogen is the exact mirror image of hydrogen. This may reveal if antimatter differs from matter and explain why it has all vanished.

Pauline Gagnon

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Weighing Antimatter

Thursday, July 28th, 2011

How much does antimatter weigh?

It is a great question and to be honest physicists don’t know. In fact, it is a great question precisely because we don’t know. To clarify: I am talking about “weight,” not “mass.” I wrote a few words at the bottom of this post about the difference between the two. For now I will just say that mass is what makes pushing or pulling something in a new direction harder; weight is that pull, by a planet’s gravity, on things that have mass. In the Universe, there are some kinds of matter that do not have mass, like photons (packets of light), and thus are also weightless. Other kinds of matter, like protons & electrons, do have mass and consequentially weigh something.

Figure 1: CERN’s Atomic Spectroscopy And Collisions Using Slow Antiprotons (ASACUSA) Experiment. (Photo: CERN)

Okay, so here is where things get interesting. Back in the 1920’s a guy named Paul Dirac discovered the theory of antimatter.  The theory not only predicted that each piece of matter has an “antimatter partner” but also that the two partners have the same mass. This morning, the ASACUSA Experiment (Fig. 1) at CERN announced that the anti-proton has the same mass as its partner, the proton. Well, at least up to experiment’s capabilities of resolving the two. Anyone keeping track of CERN’s anti-matter physics program, or has watched the first 15 minutes of “Demons & Angles,” might know that the lab has been making significant progress trapping and collecting anti-hydrogen. While the amount being produced at CERN may not be enough to make a small city-state disappear, it is close to the amount needed to determine the weight of anti-hydrogen. This is good news for physicists at Fermilab who are working on the Antimatter Gravity Experiment (AGE), the goal of which is to measure anti-hydrogen’s weight. Interesting, no?

Figure 2: A hydrogen atom consists of an electron and a proton orbiting around one another, and are kept together because of their mutual electric attraction. Similarly, an anti-hydrogen atom consists of a positron (anti-electron) and an anti-proton. (Image: Wikipedia)

Now for the exciting part. Our theories, e.g. the time-tested Standard Model of Physics, only say that matter-antimatter partners should have the same mass. There is NO reason whatsoever, other than helping one sleep at night, that the partners should have the same weight. Since weight is innately related to gravity, any measurement of an individual anti-particle’s weight is inherently a measurement of gravity at the quantum scale. Additionally, any description of the behavior of antimatter acting under gravity is at the very least a stepping stone to Quantum Gravity. Quantum Gravity, by the way, is the theory of gravity at the microscopic scale; it does not really exist, yet; and is preventing physicists from constructing a full description (theory) of our universe. Determining that the proton and anti-proton have the same mass makes it easier to spot any differences in their weight. On top of that, if there is a difference in the weight of hydrogen & anti-hydrogen, then it might also explain why there is so much more matter in the universe than antimatter.

If you are not excited by now, I give up. 🙂 Note: A big thanks to @symmetrymag for bringing this news to my attention.

A Few Words on Mass vs. Weight


Physically, “inertia” is the natural resistance to a change in movement; a measurement of inertia is called “mass.” One way to think about mass is if you & I were running down a football pitch, side-by-side, and you tried pushing me over. Mass is that bit of resistance you feel when you try pushing me over. If I were twice as tall, it would be harder to push me over. If I were half as tall, it would be easier to push me over. Next time you are playing football, like right after you read this Quantum Diaries post, try it out. “Weight” is that specific, attractive pull (force) a planet has on an object. The big difference is that mass is universal property of an object whereas weight can vary. A single electron will always have the same mass but a human will weigh less and less the further away he/she is from the Earth. Since this rock I like to call home is approximately a sphere, the gravitational pull it has at its surface is approximately constant. Consequentially, the difference between 1 lb (a unit of force) and 1 kg (a unit of mass) is a numerical constant. I hope this helped.


Happy Colliding.

– richard (@bravelittlemuon)


Researchers at the ALPHA experiment at CERN made major news today with the announcement that they’ve trapped antimatter atoms for 1,000 seconds. That’s more than 16 minutes and 5,000 times longer than their last published record of two tenths of a second.

The ALPHA magnet being wound at Brookhaven

The new feat will allow scientists to study the properties of antimatter in detail, which could help them understand why the universe is made only of matter even though the Big Bang should have created equal amounts of matter and antimatter.

These studies have been made possible, in part, by a bottle-like, anti matter-catching device called a minimum magnetic field trap. At the heart of the trap is an octupole (eight-magnetic-pole) magnet that was fabricated at Brookhaven Lab in 2006.

Several special features of the coil design and a unique machine used to wind it contributed to the suc­cess of this magnet. For exam­ple, the magnet generates a very pure octupole field, which keeps the antimatter away from the walls of the trap, preventing them from annihilating.

Antiprotons and positrons are brought into the ALPHA trap from opposite ends and held there by electric and magnetic fields. Brought together, they form antiatoms neutral in charge but with a magnetic moment. If their energy is low enough they can be held by the octupole and mirror fields of the Minimum Magnetic Field Trap.

To figure out how many antiprotons were in the trap, the scientists “quench,”  or abruptly switch off the superconducting magnet, releasing the antimatter. The anti-atom’s subsequent annihilation into particles called pions is recorded by a three-layer silicon vertex detector similar to those used in high-energy experiments like Fermilab’s Tevatron and the Large Hadron Collider.

But the pions must travel through the magnets of the trap before reaching the silicon. To prevent the particles from scattering multiple times during their journey to the detector, Brookhaven physicists and engineers had to figure out how limit the amount of material used in the magnet. A specially developed 3D winding machine allowed the researchers to build the magnet directly onto the outside of the ALPHA vacuum chamber. The result is a magnet that looks far different from the bulky, steel-surrounded instrumentation in most particle colliders. In fact, only the superconducting cables are metal.

–Kendra Snyder, BNL Media & Communications


“This is terrible,” I muttered over breakfast. “I haven’t posted anything on the blog in two weeks. All of my posts are supposed to have something to do with particle physics, but I must say that the particle physics I have done in the past two weeks has been either been politics that I wouldn’t want to dump on my readers, or totally boring. Or both. My post about trying to keep track of datasets was boring enough.”

My wife peered over the edge of the section with the comics. “Your statement is predicated on the idea that you actually have readers,” she said. “Have you been reading Dilbert this week? He built a particle accelerator. You could write about that.”

True enough — take a look over here. (Scott Adams owes me for directing millions of readers to his site.) Dilbert has built a particle accelerator in his basement, and has used it to create an antimatter Dilbert. The comic strip isn’t totally off base; Dilbert realizes that if his antimatter partner comes into contact with matter, he will disappear in a puff of energy. How anti-Dilbert solves the problem isn’t so scientific, but, hey, it’s the comics. (Suffice it to say that anti-Dilbert doesn’t survive the week at the office, and not just because of the pointy-haired boss.)

Richard Feynman, one of the iconic physicists of the second half of the 20th century, had an interesting anecdote about the idea of meeting an intelligent alien made out of antimatter; you can read a version of it here. We expect to be creating quite a lot of antimatter at the LHC…but an anti-Dilbert would be unexpected. But boy, if we could make an anti-pointy haired boss to annihilate with certain university administrators….