Well to be honest, huge is not the first word that springs into mind when you say one millimeter (that’s 0.0393700787 inches for you metrically challenged), but when it comes to atoms it’s a behemoth. The usual diameter of an atom is of the order of one Angstrom, which is 0.00000000001 meters, so we’re talking about an atom approximately seven orders of magnitudes bigger!

One of the first theories put forth to explain the behavior of atoms, was the so-called Bohr model, named after one of the greatest physicists ever to live, the Danish Niels Bohr. The basic premise of the model was that electrons orbit around a core of protons and neutrons, much like the moon orbits the earth. He used classical physics to calculate several properties of atoms based on this model, but it was ultimately wrong and the correct theory of atoms was found with quantum mechanics (which he had a big hand in founding). You can check out this explanation of it (also linked in the press-release), it looks kind of childish with the cartoons and everything, but it actually does a pretty good job of explaining it in a simple way.

The story does not end there though! As it often happens, once you scale things up from the very tiny, to the somewhat large, things stop exhibiting the weird effects of quantum mechanics, and start behaving more like classical systems we know and love from our every day life. This holds true for atoms as well, so atoms that are at a sufficiently large scale actually DO behave like the Bohr model predicts!

The scientists over at Rice University managed to make one of these very large Bohr atoms and observe it’s circular path around the nucleus. Like i said before, the size of the atom was close to one millimeter, a far cry from the one angstrom they usually are. The large size was achieved using lasers to excite the atom and electric fields to manipulate it into the configuration they wanted.

You can check out their press-release here, it’s quite short actually and to the point, and also discusses in a little more detail how they actually managed to make the potassium atoms so large, so i recommend reading it.

As a followup to my last post about Bells inequality, i figured i’d give you a quick link to an article written about a very recent test of it, confirming that indeed, quantum mechanics does not obey the Bell inequality. The next two paragraphs will quickly sum up my last article in case you didn’t read it. Those who did can feel free to skip it.

In “real life” we are used to be able to precisely predict the outcome of results. Say you throw a baseball to your friend, if you were to measure it’s direction and velocity, you could accurately predict exactly where it will land and when, plus how much energy it has etc, this is what is called “deterministic”, since we can accurately determine outcomes. On the quantum scale however,q things are quite different and outcomes of measurements can not be perfectly predicted, in fact different outcomes will be measured with a certain probability, and you have no way of predicting exactly what you’ll get.

Many people did not like this at all, such as Einstein, who proposed that quantum mechanics was simply an incomplete theory, and if only we had the full picture, quantum mechanics would be deterministic as well. In order for this to be true, quantum mechanics would have to fulfill the so-called Bell inquality, and in short, it does not (you can read the older article for a more in-depth view of it, this is just a quick sum-up for those that didn’t feel like reading the whole article).

Like i explained in the article, there have been numerous experimental tests of the Bell inequality at the quantum level, and they agree, it is indeed broken. I figured you might be interested in reading about the largest test of the Bell inequality so far, which spanned two laboratories across two different towns! They had it at this distance so they could make sure that there was no way that the two particles could have exchanged any information before they were measured, and once again, it has been confirmed that quantum mechanics are weird.

As this is not a press-release like most their news, but an actual article written by PhysOrg, i will simply point you towards it rather then recite it here.

Since i just finished a course in Quantum Information, which studies quantum cryptography, quantum computers and other such things, i thought i might write a few articles about these things as they are interesting, highly useful and seem to have captured the interest of the general public fairly well. I hope i can manage to explain this in a way that a lay-person could read this and get the gist of it, if i fail for some reason, feel free to leave a comment and i’ll try to elaborate on points i was unclear on.

To start with, i wanted to do a short article on something called Bells inequality, which shows us that the fact that outcomes of measurements in quantum systems occur with a certain probability (as opposed to being able to precisely predict the outcome of an experiment in classical physics) can not be explained away by simply saying that the theory of quantum mechanics is incomplete and if only we knew about those factors we have not found yet, we could perfectly predict everything.

To begin with, i’ll have to introduce one of the weirdest results of quantum mechanics, quantum entanglement. It more or less means that it is possible to have two quantum systems (for example single photons (particles of light) or single atoms), that are somehow connected (entangled) with each-other, so there is no way to describe one particle without including the other. So for example lets say we have two atoms that have their spin entangled. A simplified way of imagining what the spin of an atom is, is that it’s the equivalent of the earth rotating about it’s axis. The two possible spins that the atom can have is spin-up, or spin-down, and using the analogy from before about the earths rotation, you can imagine spin-up being a clockwise rotation and spin-down being a counter-clockwise rotation. So what does it mean that they are entangled? Well it means that if you were to take atom #1 and measure it’s spin along the x-axis and get some result, then you know for certain, that atom #2 has the exact opposite spin. So say #1 measures spin-up, then you know that #2 has spin-down. This holds true even if the two particles are at the opposite ends of the galaxy!

Now if you think this is weird, don’t feel stupid, great minds were (and are) boggled by this as well, and in fact Einstein was sure that this could not be true. He argued that if you have two systems, A and B, that are completely separated by space, then the measurement of A must not modify the description of B. But when doing the math in quantum mechanics, this is exactly what you get! So Einstein maintained that the theory of quantum mechanics was incomplete, and that if you DID have the complete theory then the results of a measurement of a quantum system would not depend on probabilities, but you should be able to completely predict your results (like you can in classical everyday physics).

Phew! Ok that was a lot of backstory and explaining in order to get to what i really wanted to talk about, Bells inequality. So on one hand we have a theory giving us some very unintuitive answers, and on the other we have Einstein saying that this is only because the theory is incomplete, and if we had the full picture then all the weird things in quantum mechanics would make sense to us. But how can we test which one is true? This is where Bells inequality comes into play!

What it basically states, is that if you have three coins, and throw them all into the air at once, then you are 100% sure that at least two of them will be identical (heads/heads or tails/tails). So of P(1,2) is the probability of coin 1 and coin 2 being the same, then

P(1,2)+P(2,3)+P(1,3) >= 1

So the sum of all the probabilities should be equal to or more than 1 (100% probability). Seems pretty straight forward and obvious yes? Obviously 3 coins will have a 100% certainty to have 2 outcomes be the same, at least in the classical world we live in, and that’s where the catch is. If Einstein was to be right, and quantum mechanics was indeed deterministic like the classical world we know (that is to say, the current model of quantum mechanics is wrong), then this inequality HAS to be fulfilled for quantum mechanics.

So lets see what happens in the quantum picture. We’ll return to our entangled atoms from before, where Alice has one of them, and Bob has the other. The coins in this picture, are the spins of the atoms along different axis, so for example the spin along the x-axis can be either up or down, and each one has a 50% probability of being measured (remember that they can only do one measurement on each atom). So lets say that Alice measures the spin in the x-direction, and gets spin-up, she calls Bob and tells him the good news, so now Bob KNOWS that if he measures in the x-direction as well, he’ll get spin-down with 100% certainty (because they are entangled). So what happens now if Bob measures the spin along the y-axis? What is the probability of him getting the same result as he would have got along the x-axis (the equivalent of getting heads/heads, tails/tails)? Well without going into the math of quantum mechanics, i can tell you that it is 1/4. So looking back at the equation from Bells inequality, P(1,2)=1/4, and in fact P(2,3) and P(1,3) is also 1/4 (it doesn’t matter which axis you measure, it’s always the same math), so you see that

P(1,2)+P(2,3)+P(1,3)=3/4

which is obviously less then 1, and Bells inequality is therefore NOT fulfilled, and Einsteins explanation was wrong. This is also heavily backed by experiments done to test the Bells inequality, so it would seem that the current theory of quantum mechanics lives to see another day!

Now if you think about it, it’s not really that surprising that these things are completely counter-intuitive. After all, we humans never experience any quantum mechanical effects (they can only be observed at extremely small levels, like single atoms or single photons), so our brains have simply not evolved to be able to comprehend these things intuitively.

Lastly! Phil Plait over at the Bad Astronomy blog actually did a similar article a few weeks ago, where he discusses quantum cryptography (which also heavily depends on entanglement), i might write an article on that as well, assuming people didn’t fall sleep over this one and are interested in hearing more, but until then, you can check out his article.

As i’m sure you all know by now the Large Hadron Collider (LHC) is about to arrive in all it’s glory (and if you don’t, i refer you to an excellent video-explanation of it mentioned in a previous post). Set to kick off in July, the scientists are in full crunch mode to get all bells and whistles ready for the demolition of the world as we know it by creating a black-hole.

One of the major experiments in the LHC, is the so called ALICE experiment (A Large Ion Collider Experiment), which will, as the name suggests, study the collision of large ions, such as two lead ions colliding head on. In order to get data from these massively energetic collisions, they need some kind of measurement device to see how the particles coming out of it are flying around, and the Time Projection Chamber (TPC) is the main particle tracking device in ALICE.

The chamber is filled with a gas that gets ionized (loses an electron) when the particles pass through it, leaving a trail behind that the detectors can measure. These detectors however, need to be very finely calibrated to get the best measurements possible, and that is what the scientists are working on now. Using a finely tuned laser to ionize the gas and shining it on mirrors very carefully placed throughout the chamber, they effectively simulate a particle trail, allowing for the first measurements on the finished system to be made. The results from these measurements are then used to finely calibrate the equipment, to have it all in tip-top shape for the big day. To quote Børge Svane Nielsen, the leader of the Danish research group from the Niels Bohr Institute:

We were very happy, when we managed to measure the first traces. It’s an important step and it shows that the detector system is working.

Original article here (sorry, only in Danish), courtesy of the Niels Bohr Institute (University of Copenhagen).

Hey guys, you may remember a few days ago i posted about a story that researchers from Cornell were venturing into a new way of creating X-Rays called Energy Recovery Linac (ERL), which should result in much more powerful x-rays.

Well i was slightly skeptical to the claim that things being examined using the ERL, did not have to be in crystalline form, so i decided to talk to a professor at my school that teaches the x-ray physics course and he did indeed confirm that this could well be the case if they were able to focus a strong beam on a single structure (like a protein for example). This is something that will definitely please many in the field when/if the ERL comes, because today when you intend to look at the structure of a protein you must first make it into a crystalline material before it can be probed using the x-ray. That is to say you need to have a lot of proteins arranged in a static symmetric way, which can be quite a hassle.

Also something he pointed out to me as he read the article, that i hadn’t really noticed was that the projected cost of building an ERL is not that high compared to Synchrotrons (which is the source most commonly used to create high powered x-ray beams). The ERL is projected to cost around 300-400 million$, which seems to be about the same they are projecting the new Synchrotron MAX-IV is going to cost (source). However if you compare it to another exciting project that also aims at creating very high powered x-ray beams, the free electron x-ray laser (FEL), their cost is a projected one billion euro, or about 1.5 billion US dollars. Although, i do think that the free electron one will create much better x-rays (i couldn’t find any hard numbers for the ERL to compare to the FEL), the ERL does seem to perform much better then a normal synchrotron, at what appears to be practically the same price.

On a more personal note, i may not be able to write terribly frequently in the coming week, i have an exam coming up, my last one ever in fact, so i’ll have to study pretty hard to try and pass it. Quantum Information certainly is not easy stuff (Quantum computers/encryption/etc), but if i manage to get a decent handle on it and pass the exam, i might just write a short roundup about it, it’s quite fascinating really.

According to a press release from the National Science Foundation (NSF), Cornell researchers are working on completing a device called an Energy Recovery Linac, or ERL, that promises to provide a much brighter source of X-Rays then are known today.

Today, X-Rays in physics research are mainly created using so called Synchrotrons, where electrons are accelerated around in a circle, and eventually undulated left and right using strong bar-magnets to produce x-rays (accelerating electrons produce light). The beam size of these synchrotrons are however limited, and that is where the Cornell team comes in. As far as i cant tell, it is more or less the same principle, they will also send the electrons through a circle and undulate it with strong bar-magnets to produce the x-rays, but the big difference is that in synchrotrons the same electrons are accelerated through the chamber again and again, but the ERL will only send them around once before slowing them down again and sending out a new batch of electrons. This process is suppose to make it possible to make much smaller beams, all the way down to the micron regime.

Now to me, the most exciting thing about this press-release is that they say that using this new better x-ray source, there is the potential of looking at much smaller things, that do not have to be in a crystalline form. Basically, today, everything we want to determine the structure of (at such small levels) needs to be in a crystal, that is to say, the molecules are arranged in an organized repeating pattern, which obviously strongly limits what things we can look at. In addition to that, they also compare the data that the new source can get, to the difference between a photograph and a video (the photograph being current technology). I must admit that i am not entirely sure of the physics that are involved in these ultra bright x-rays, but seeing as how the NSF and Cornell are releasing this, I’ll take their word for it..

I can highly recommend actually reading their press-release, it’s not as dry and boring as press-releases tend to be, and they also discuss possible uses for it (although it all seems a bit sensational to me). Also, there is a video there (access it here) with an interview with one of the scientists involved in the project.

Not a whole lot to say about this video, it’s just incredibly cool. It shows in an animated/CGI way how magnetic field lines act (for example on the sun). It’s not your normal boring/dry NASA material, it’s incredibly cool and mesmerizing.

This youtube video is a quick 1.5 minute clip from the movie, check out the full movie (~5min) here. The movie was made by NASA’s Space Sciences Laboratory, and they provide the commentary as well.

Thanks to Zac for tipping me and letting me know about this! Originally saw this at Gizmodo.

Aside from being the plotline in bad Val Kilmer movies, cold-fusion is the subject of heated debate in scientific circles. It was first in 1989 that two researchers announced at a press-conference that they had observed excess heat in a very simple experiment at room temperature (hence the “cold”, fusion is normally achieved at high temperatures). They proposed that this excess heat was because of nuclear fusion. This obviously turned the world upside down, because cold fusion would mean almost free and clean energy for all (again, much like the Val Kilmer movie). It didn’t really work out though, as you may have noticed when you fill up your car, the world is not full of free and clean energy, almost 20 years after it’s announcement.

There were several problems that lead to severe skepticism over cold fusion, like the failure of consistently reproducing the results (not for the lack of trying), the lack of nuclear products (you would expect this from a fusion process) and the fact that there is no theory today that could explain how cold fusion could occur (although it’s obviously possible that we just haven’t made that theory yet). You can check out the wikipedia article on cold fusion for more detail on both the history and the skepticism (and supposed findings).

Fast-forward to today, and there are yet again news reports circulating about researchers having achieved cold-fusion. This time it is from the University of Osaka, in Japan, a fairly reputable University, putting some weight behind the claims. Although there is no mention of measurements of nuclear products that were always missing in the past, they do claim to have a completely reproducible system, with scientists at the scene saying that the data they saw being produced live, was giving the same result as the data they had shown in their previously published article (J. High Temp. Soc. Jpn, Feb. and March issues, 2008).

Everyone of course is hoping for the best, cold-fusion would be a great thing of course, but given the dirty past it has, i’m afraid we’ll need a lot more then a flashy press-conference to lay off the skepticism.

This isn’t exactly breaking science news, but it is still a pretty cool demonstration of electrostatic force.

I saw this news over at Popular Mechanics, and according to them the inventors of this lovely device are a non-profit group called SRI. They will be unveiling this new design of a wall-climbing robot shortly, but until then you’ll have to watch the video from the original story.

What’s happening here is basically the same as when you rub a balloon against your hair and it sticks to the wall. There is a buildup of electric charge on the balloon as a result of rubbing it on your hair, and because of this it is able to stick to most wall surfaces. The vehicle does the same thing, creating an electric charge on a large surface of the car (probably on the belt it uses to move), causing a strong enough attraction to the wall to overcome gravity.

If i had to guess, I’d say that the car was built much like a Van der Graaf generator, which is basically a machine made for creating a huge amount of electrostatic charge (you might recognize it if you see one, it’s basically a pole with a big metal sphere on top, it’ll emit sparks if you get too close). Van der Graaf generators are fairly simple contraptions, consisting of a conveyor belt that literally transfers electrons from small needles at the bottom, to the sphere on top (check out HowStuffWorks.com’s guide to Van Der Graaf generators if you want to know more). My guess is that the belt that is moving the machine, works in much the same way, collecting electrons onto the belt and using them to “stick” to the wall. I’m sure there is more to it, and there’s a pretty good chance that i’m just talking out of my ass, but hey, it’s fun to guess. If you think you know how it works, leave comments! I’d love to hear your ideas.

Now i’m not one to love all things labeled “nano”, but being a HUGE soccer (football!) fan, i can’t resist this piece of news.

The national institute of standards and technology (NIST) is now giving the public a chance to watch the second annual nano-soccer cup, where competitors from various research institutes will compete with tiny robots to complete various tasks. The nano-bots will be controlled via remote-control and react to changes in magnetic field, or through electric signals sent through the microchip arena (which is about the size of a single rice). The robots will compete in events such as the two millimeter dash, the slalom (dodging between obstacles to make it to the goal), ball handling skills, which involves moving balls into a goal. Much hope is tied to nanobots being a big thing in the medical field in the future, performing microsurgery and such, plus of course, they will play an intricate part in the BORG plan to assimilate all races (as long as 7of9 is there, i welcome my borg overlords).

It should be said though, that it would appear that they have slapped the nano-label on these things as a way to cash in on the nano-hype, as the actualy bots are several micrometer long (one micrometer is 1.000 nano-meters). They claim that because the robots actually weigh nano-GRAMS they can rightfully call it a nanobot competition, but to me it just seems that people are eager to call anything nano as it’s a pop-thing these days. You can see a nano-bot with a micrometer scale next to it in our image above (courtesy of NIST)

Be that as it may! It’s still darn impressive and i can highly recommend checking out their website. There they actually have pictures of the soccer ball to be used, the actual field and even sweet pictures last years nanobots that competed for nano-soccer glory.