MIT Scientists Pinpoint Location Of Memory; ‘Create’ And Manipulate Memory At Will!!

It’s a dangerous game – playing around with memories – but someone’s got to do it. MIT researchers have just found out where memories are stored – in individual neurons. Not only that, by selectively activating and deactivating certain neurons or group of neurons, the MIT team could either fire or erase certain memories. “Eternal Sunshine of the Spotless Mind” fans might have known this coming for a long time, but this is the first time this kind of manipulation is being made possible.
The team experimented on mice. They drilled a small hole through the skull and then aimed their lasers at very specific areas in the brain. So that the neurons responded to light signals, the researchers used optogenetically modified neurons. This allowed the scientists to play around with thoughts using electric signals as well as laser light.
The hippocampus of a mouse (Courtesy: MIT, Nikon Small World Gallery)

Manipulating Memory

One of the demonstrations involved creating a feeling of fear in the mice. The scientists triggered off a very specific area of the hippocampus of the brain using electric signals. This created a fear memory! The team then fired off lasers in order to activate this memory centre and immediately found that the mouse had gone into a “defensive, immobile crouch”, paralysed by fear. However, we still don’t know what the exact memory was; we just know its nature.
Just to ram home the point: scientists can pinpoint certain regions of the brain and create memories of very specific emotions. They can then ‘replay’ these memories, forcing the individual to react to these memories. Till now, the emotions need to be very simple! Remember that these memories can be very false! However, we still cannot manufacture specific detailed filled memories.

Questions…

Though these experiments have been done only on mice, human brains are not too different, except that it is a lot more complicated. Scientists think that these can be replicated in humans, but no human subjects have been used for experiment, and none will be used in the near future.
This answers the old question of what memories are in the brain. They are not merely concepts – they are physical objects, represented by individual neurons. The next question to be answered is this: how are memories formed? Also, why do we remember a scene like we do, rather than in greater detail? Also, how are memories encoded? Is it possible to create a computer program to bestow a certain set of memories to an individual? The MIT team may be close to answering that.
Memories are more mundane than one might have thought, proves the MIT team. Remember that!
More info: http://www.mit.edu/newsoffice/2012/conjuring-memories-artificially-0322.html

Communicating With Neutrinos

Not happy with the mobile phone network? Neutrinos are the way to go! A group of American scientists have achieved the transfer of information using a beam of neutrinos. The process is highly inefficient at the moment, though, with a transfer speed of merely 1 bit/s and the test being over very short distances.

The Minerva Detector at Fermilab

The experiment is ongoing at the NuMI facility at Fermilab. This facility produces some of the most energetic neutrino beams. This teams up with the Minerva detector kept 1km away from the source! The current experiment was performed on this setup

But why neutrino communication?

Neutrinos are very weakly interacting particles in nature. They have often been describes as ‘ghostly’, owing to the difficulty in detecting them. They are uncharged and thus do not interact with the electromagnetic field. Having no mass means that gravity is out of the question, although, even with a small mass, it wouldn’t have played a role.

Neutrinos can pass through hundreds of lightyears of solid lead! It’s not surprising that they should be able to tunnel through the Earth itself. It is due to this unwillingness to interact that neutrinos can be made into effective communication devices. There would be very little disturbance that would pour into the signal.

The problem is this: Neutrinos being very difficult to detect, are also extremely difficult to control. They cannot be collimated (i.e. made parallel) as easily as lightwaves. Similarly, we need a large flux of neutrinos from the source and a very good detector at the receiving end. The detector is not portable. In fact, neutrino detectors are HUGE! (Pic above)

“Neutrinos” using neutrinos

The idea is to modulate the neutrino beam so that a proper piece of information is transmitted. What is the first message to be tranferred? Simple: “Neutrinos”. The modulation bitrate was 0.1 bit/s, which is WAY slower than today’s communication devices. However, the information was transmitted over a few kilometers and the error was less than 1%.

Much work needs to be done! But, Wolfgang Pauli, the father of the neutrino, would be proud.

High-Def Video Captures A Comet As It Plunges Into The Sun

NASA’s SOHO telescope has just captured the last few moments of a comet as it smashed into the Sun. The Comet SWAN, presently officially known as C/2012 E2 (SWAN), can be clearly seen plunging into the Sun. SOHO’s LASCO C2 and C3 camera took the photos, which were then stitched up to form a High-Definition video.

The point to note is that SWAN did not actually crash into the Sun. There was no contact – it vaporized much before that. The nearest distance calculated turns out to be 350,000 km away from the Solar surface, but probably, the comet was gone much before that.

Here is a stunning photo snapped by the LASCO C2 camera, which clearly shows the SWAN comet before its demise.

Comet Swan can be clearly seen on the bottom left quarter (Courtesy: NASA, SOHO)

SWAN was a bright comet. Comet scientists were quite enthusiastic about it. Its doom was predicted by many and so SOHO knew exactly what to look for – and found it. Take a look at this spectacular video, all in 1080p goodness!

Please note that the ensuing solar flare seen in the video occurring diametrically opposite to the SWAN comet’s trajectory is just a coincidence. The two events occur hours apart and the solar flare is completely uncorrelated to the cometary demise. No comet is big enough to cause that big a disturbance on the Sun’s surface.

Enjoy the carnage.

Scientists Unleash “Designer Electrons”; Synthesize Graphene Atom-By Atom

Stanford University researchers have come up with ‘designer electrons’  – electrons whose properties can be controlled and fine-tuned. Leading the research is Hari Manoharan, associate professor at the Stanford Physics department. He reports that his group has created graphene-like electrons and then tweaked them!

The honeycomb potential

Why is this important? Let Prof. Manoharan answer that question:

The behavior of electrons in materials is at the heart of essentially all of today’s technologies. We’re now able to tune the fundamental properties of electrons so they behave in ways rarely seen in ordinary materials.

Working with individual molecules

So, this is what they did. They placed carbon monoxide molecules on an atomically smooth copper substrate using a Scanning Tunneling Microscope (STM), which then created the potential mimicking that of the carbon atoms in graphene, forcing the electrons to behave like those of graphene. The peculiarity of graphene electrons is that, within graphene, they act as if they have no mass. They thus move at the maximum speed possible within the substrate. Manoharan calls this ‘molecular graphene’, built from scratch atom-by-atom.

Making electrons go crazy – at will

Manoharan’s group could then tweak the potential properties by changing the positions of the Carbon Monoxide molecules and then the electrons suddenly gained mass! More than that, they could make the electrons behave as if they were in an electric or magnetic field. Says Manoharan:

One of the wildest things we did was to make the electrons think they are in a huge magnetic field when, in fact, no real field had been applied

The team is now looking to synthesize more semiconductor substances and also replicate certain properties of graphene. The team promises that more ‘Dirac materials’ are on the way! We live in exciting times.

The work is featured in Nature and it appeared yesterday. Here is the link: http://www.nature.com/nature/journal/v483/n7389/full/nature10941.html

More info from Stanford news: http://news.stanford.edu/news/2012/march/molecules-designer-electrons-031412.html

Also, do watch the video below, where the group explains their work. You do NOT want to miss this.

Not-So-Fast: Neutrinos Travel At Speed of Light, Says Icarus Experiment at Gran Sasso

Neutrinos seem to be travelling at speed of light once more! A different experimental group – the Icarus group, tried out the same experiment as the OPERA group in the same lab, but using different equipment and found that the speed of the neutrinos was very much compatible with the speed of light within experimental error bounds! The Icarus group have found that neutrinos travel at the speed of light, not faster. The OPERA result, already fraught by reports of device malfunctions, has received another jolt.

The Icarus Experiment

The experimental findings of the Icarus group, also based in Gran Sasso just like OPERA, and also receiving neutrinos from the same CERN source, were published in a paper which is available online here.

The T600 detector

A second opinion

The Icarus group intends on studying the different properties of neutrinos and also aspects of any proton decay. They use a Liquid Argon Detector – the T600 – which uses 600 tonnes of liquid nitrogen to detect the presence of neutrinos and also measure their direction and momentum. They have been tweaking their experiment so as to be able to re-check OPERA’s claim.

Of course, OPERA itself has been in a soup with its own problems. We reported the initially reported error of an optical fibre delay here and then followed up with yet another error that might have influenced the speed. With so much at stake, the littlest things might compromise the findings of the biggest experimental groups.

Icarus says that there are more tests to come – as many as four more experiments intend to verify OPERA. The entire physics community is expecting negative results, akin to Icarus’, but to be sure of such a thing would be prejudice.

The Woolly Mammoth To Return From The Dead, Guarantee Korean and Russian Scientists

The magnificent beasts shall once more roam this planet. This may be an overstatement, but South Korean and Russian scientists intend to research a proper cloning technique to recreate the wooly mammoth by trying and gestating the fertilized egg in the womb of an Indian elephant mother. The fertilization, after the required genetic modification, will be done in the lab.

Coming back from the dead?

Several very neatly preserved remains of mammoths, from more than 10,000 years ago, were found under the Siberian permafrost. The first step is to extract the DNA. With the DNA, the scientists are trying to recreate blood protein. If all goes well, the next step will be to create the nuclei of mammoth cells, which will contain the required genetic material. This will then be implanted in the cell of an Indian elephant. Since the two species are genetically very similar, this is the best bet! The gestation period will be 22 months. Research for this entire process should be complete by the next 5 years.

Cloning…

Cloning has been a long-time obsession for many geneticists. It’s a great way to showcase the giant leaps in genetics that have happened in the last 50 or so years. After the sheep Dolly, the world’s first cloned mammal and Snuppy, the first cloned dog, followed by numerous other clones like a cat and a coyote, this is the natural big leap! Even Chinese scientists are interested in this project.

There have always been raised eyebrows and pessimistic  opinions about being able to ‘tinker with the very essence of life itself’. Brushing all those silly opinions aside, let us just marvel at the very prospect of a giant mammoth being resurrected.

Happy Pi Day, Everyone!

At the very outset, let’s get one thing straight – ‘Pi’ is not the same as ‘Pie’. Pi is an irrational number; ‘Pie’ is a food item, horribly less important than Pi and much less faithful to a circle as well. Pi –the constant ratio between the circumference and the diameter of a circle – is always 3.14… and a few more digits. Actually, a lot more digits!

Geeky, geekier…

Now, glance at today’s date – 14th March. Write it as the Americans do – month first and then day – and you get 3.14! Ah ha, Pi!

Some people choose to take this one step further. Let’s look at a few more digits of Pi – 3.14159… Some people celebrate 1:59 AM and 1:59 PM on 14th March as “Pi Minutes”. How about continuing the trend? Sure, 3.1415926, occurring at 1:59:26 AM and 1:59:26 PM, are celebrated as “Pi Seconds”.

These are delicacies on this one day. Pi pies.

If you think all of this is extremely loony, you’d be right. However, it’s more than just fun and games. Pi day is also meant to promote math and show that it is a lot of fun. Pi day founder, Larry Shaw, a physicist at the Exploratorium, participates actively in the Pi Day celebrations by hosting a number of activities in the Exploratorium. Here’s this year’s list: http://www.exploratorium.edu/pi/pi_schedule.html

Plus, check out the homepage for pi: http://www.exploratorium.edu/pi/

… And a very happy birthday

In addition to all this fun, let us not forget that the great Albert Einstein was born on 14th March. So, it’s a double whammy and all Pi day celebrations spend some time wishing the Grand Old Man of Physics a Happy Birthday.

Wishing you a very happy Pi day!

Giant Radio Telescope: South Africa Wins Bid To Host The Square Kilometer Array

South Africa have won the bid for hosting the Square Kilometer Array, beating rival bidders Australia by a narrow margin. The bid was settled today by a scientific panel. However, the exact location of the telescope, especially the central square, has not been decided.

An artist's impression of the Square Kilometer Array

The Giant

The SKA is a mammoth project, having 3,000 dishes, each having a diameter of 15 meters. It will cover a very large frequency range. Owing to its huge area – the name square kilometer refers merely to the total added area of the dishes, not of the area coverage on the ground – the collecting area will be very large. This will enable it to be extremely sensitive to any radio sources in the Universe. The downside of this extreme ability is that it will also pick up a lot of Radio Frequency Interference (RFI) from ground based radio sources. This means that the location of the telescope will have to be in a very arid place, nearly devoid of any human settlement, and definitely devoid of any strong usage of radio technology.

We reported about SKA and the location problem here: http://techie-buzz.com/science/ska-location-problem.html

The construction of the SKA is due to start in 2016 and it is expected to be completed in 2019. The telescope should see first light some time in 2020.

Not yet over

Even though the scientific committee has voted for South Africa, the win is so narrow and the contention so strong, that other countries like China, Italy, the Netherlands and the United Kingdom might vote either way and swing it.

A final decision is awaited on 4th April, during a board meeting in Amsterdam.

Observed: Atomic Movements Inside Molecule For The First Time Ever!!

Ultra-fast movements of atoms within a molecule have been observed for the first time ever, courtesy scientists led by Prof. Louis Di Mauro, a professor of physics at Ohio State University. The principle is simple: Shining light onto a molecule will excite the electrons of the atoms in the molecule. These electrons can then be the probe for the atomic movements within the molecule. The team used oxygen and nitrogen molecules, the simplest diatomic molecules you can get.

Procedure:

The team shone light on the molecules, which knocked out a single electron from one of the two atoms. This electron can then be reabsorbed into the molecule, but when that happens, it will interact with both the atoms. This interaction can be used to track back the potential between the atoms. Thus, we can probe the potential landscape within the molecule, using the interaction information of the electrons.

To probe the movement of the electrons, the team used an ultrafast laser, with a pulse width of 50 femtoseconds. That a millionths of a billions of a second!! Light travels just 300 nanometers in that time! 

The technology required to image complicated molecules like protein is still far away.

Atomic interactions inside molecules may augur in great fortunes in the soon-to-come future. 

First Spectrum Of Anti-Hydrogen Atom Observed By CERN

The first spectrum of anti-hydrogen has just been obtained by CERN’s ALPHA team and studies are on-going to find differences between its spectrum and that of ordinary hydrogen. Hanging in the balance are answers to crucial questions on the nature of anti-matter and why matter supersedes anti-matter in the visible Universe.

Trapping anti-hydrogen (Courtesy: ALPHA, CERN)

Mysteries of the Universe

The fundamental mystery is this: why is there more matter than anti-matter in the Universe, even though all equations of physics predict that the two are exactly the same. If we lived in a Universe made up of anti-matter particles, we wouldn’t know the difference. Or would we? A hypothesis, involving two discrete symmetries of nature – Charge (you reverse the charge on a particle), denoted by C and Parity (you take the mirror image of a particle), denoted by P – taken together and called CP symmetry, could be broken giving rise to more matter particles than anti-matter particles. However, this still doesn’t violate another symmetry called CPT symmetry, in which Charge and Parity are joined by Time reversal symmetry.

The object of study is this: There is an anti-proton about which a positron (anti-electron) orbits. As is well known, such a system will have energy levels like those of the hydrogen atom, composed of a proton orbited by an electron. The question is how similar are the two systems. How much is CP symmetry violated? What about CPT symmetry?

How is the study done?

The study, published in Nature, describes the very first attempts at studying resonances in this bound system. They attempted to flip the magnetic moment of the atoms using a microwave laser radiation. This is basically flipping the poles of a tiny atomic magnet. Now, the trapping of the anti-atoms, perfected by the same team at ALPHA, CERN, depends on the magnetic moment. If that is flipped, the anti-atoms leave the trap, escape and get annihilated. This happens at a particular energy. If the laser is tuned to this energy, most of the laser energy will be absorbed. This signifies a resonance.

This is just the first among, surely, several tests that will be performed on anti-hydrogen, now that it can be produced and trapped easily.