Scientific Britain

The 5th dimensional camera is a fictional device that was...

Wed, 30 May 2012 09:23:13 +0100

The 5th dimensional camera is a fictional device that was designed for the 2010 Impact! exhibition and recently on display at the MoMA. Designed by Superflux in collaboration with EPSRC, Nesta, RCA and scientists from QIPIRC it helps to bridge the void between quantum theory at the heart of fundamental physics and public understanding. Like many concepts in physics, the notion of multiple universes, or a multiverse, is not one that the average person would find easy to comprehend, however the 5th dimensional camera has helped reveal what it might be like to view many parallel worlds at the same time using a metaphorical many lensed object. Collectively the multiverse describes everything that can and will exist, from the planets and stars we see today and all fragments of subatomic particles that temporarily spring into existence or annihilate, as well as all laws and the physical constants that bound them. There are different interpretations of the multiverse and each is fundamentally speculative attracting criticism as well as praise, but nonetheless the collection of alternative theories have ignited philosophical debate, one which we can all challenge, and perhaps a deeper understanding of the universe we inhabit beyond the limitations of scientific method. In M-theory, for example, universes are created as a result of the collisions between “branes” of higher dimensions, where gravity remains and the other forces vanish. While Hugh Everett’s “many worlds” interpretation of quantum mechanics helps to answer why scientific measurements cannot be predicted absolutely, for which there is a range of possible observations with differing probabilities and each corresponds to a different universe. Each alternative future is regarded as having a real existence, but it need not stop with the future possibilities, indeed Richard Feynman suggested the idea of multiple histories, for which any event in the present could have been the eventuality of many alternative routes. The volume of possible interpretations of the multiverse is ironic at the very least and also captivating to a audience well beyond scientific circles.

Pioneer 10 and 11 are space probes that left Earth respectively...

Mon, 07 May 2012 07:32:00 +0100

Pioneer 10 and 11 are space probes that left Earth respectively in 1972 and 1973, and that have since been steadily proceeding across the solar system and exiting our astronomical neighbourhood. Both probes sent back to Earth, year after year, endless streams of pictures and other astronomical data—until the on-board electrical generators run out of power, in 1995 for Pioneer 11 and 2003 for Pioneer 10, after an amazing 31 years of service. As the two probes approached the heliosphere, the boundary between the outer reaches of the solar wind and the interstellar medium, they unexpectedly started slowing down. A few hypotheses for this phenomenon had been put forward during the years, many involving exotic effects and new physics, but it’s only recently that a new analysis of the heaps of data accumulated over the years by the two probes shed some light on what was actually happening. It appears that the deceleration of the two spacecrafts could be likely ascribed to the on-board power sources, which produced electricity from the spontaneous radioactive decay of radioactive pellets. When the excess heat produced by the power generators was dissipated, it was mainly in the same direction of travel of the probes. The net effect of the solar pressure, pushing the probes forward, and the small but measurable photon pressure from heat dissipation, against the direction of travel, then produced the almost imperceptible deceleration of the Pioneer probes—dubbed the Pioneer Anomaly.

Pictured: the iconic Pioneer 10 plaque.

The fact that information technology is growing every year...

Fri, 04 May 2012 13:12:44 +0100

The fact that information technology is growing every year doesn’t surprise many, but perhaps the statistics attributed to this growth will. Videos are typically one of the largest in file size and in 2011 around 1 trillion videos were watched on YouTube equating to about 140 videos for every person on the planet, a statistic which gets bigger every day and in the next 24 hours we will watch another 4 billion on YouTube alone. Internet video traffic is growing at approximately 48% every year and in 2015 the gigabyte equivalent for all movies ever made will be crossing the global IP networks every 5 minutes. In addition, there are now more phone connections than people on Earth, and our reliance on the internet is deepening, so to keep up with demand server data centres are popping up faster than Moore’s law. But how sustainable is this growth? Despite the relatively high efficiency of electronic devices, information technology has the same energy and carbon impact as the airline industry. We may choose to cycle to work. We may turn the lights off around the house. We may recycle the cans and bottles that pile up. But we will still choose to search for the actor in that thing we can’t remember. The fact is searching for information has never been so convenient, and for every search there is a very real and tangible cost to the environment. Although the true statistics for energy consumption among the search giants are trade secrets so as not reveal how many servers are active, one can easily calculate the net energy cost for a typical internet search by taking a step back and looking at the big picture. If we take Google as an example, which claims to be 50% more efficient than its competitors, it is estimated that they continually require around 260 million Watts (or Joules / second) to power all their servers and computers. Since there are approximately 34,000 Google searches every second, it is easy to determine that 1 search is roughly 7.5kJ, however Google claim a figure closer to 1kJ. So how much energy is this? Around 1/10 of the energy required to boil the water for a cup of tea. This is small but certainly not negligible and if we are going to keep growing our internet usage we will need to reduce the amount of energy required for computer calculations and transferring information. The energy in computation is largely consumed in charging and discharging the capacitances of wires and there is ongoing research into alternative approaches for data manipulation that make use of a combination of optical and electrical components, which may help address the internet energy issues of the future.

Faces. For this episode of It’s Not My Field we...

Mon, 30 Apr 2012 13:53:00 +0100

Faces. For this episode of It’s Not My Field we interviewed Rob Jenkins, cognitive psychologist and senior lecturer at the University of Glasgow. His research focuses on face perception and social interaction. We asked him what makes us humans so much better than computers at recognising faces, how good (or bad) passport control agents are at matching pictures with faces, and why we sometimes see faces and familiar patterns where there are none.

If you are interested in doing a PhD with Rob Jenkins on the subject of 3D reconstruction of crime scenes from eye reflections then click the link above for more information.

The episode includes CC-licensed Freesound.org sound samples by users Setuniman and WaterminD.

The final chapter in the Sagan Series - Humans - looks at our...

Fri, 27 Apr 2012 09:11:26 +0100

The final chapter in the Sagan Series - Humans - looks at our impact on Earth, our domesticated lifestyle, and our willingness to explore the universe. Narrated by Carl Sagan nearly 30 years ago, both the subject and context have not changed in the present day. If anything we are receding inside the comfort of our planet a little more every day. Will mankind ever venture to the planet Mars and beyond or will we succumb to the regular and perpetual life that we have made for ourselves on Earth?

Chapter 6 of the Sagan Series highlights the end of...

Sun, 22 Apr 2012 13:39:56 +0100

Chapter 6 of the Sagan Series highlights the end of NASA’s Space Shuttle program on August 31, 2011. It is the end of an era, and the beginning of another. We have acknowledged the costs involved in sending manned missions to space, choosing instead to explore with robotics. The worldwide space budget is handsome $38 billion, but that is just small change in comparison to the trillions spent on military. It is easy to think that our priorities need straightened out and our goals set further into the cosmos. Thankfully private ventures are opening up the possibilities for space flight and in some areas taking over domestic space tasks on behalf of our governments. The future of space travel will certainly be nothing like the past.

DNA and RNA are the fundamental biological blueprints for all...

Fri, 20 Apr 2012 10:19:00 +0100

DNA and RNA are the fundamental biological blueprints for all known life of Earth, capable of storing information, evolving and helping cells to manufacture proteins. But now researchers at the MRC Laboratory of Molecular Biology, in Cambridge, have created alternative genetic polymers called xeno-nucleic acids or XNA’s by replacing the d (deoxyribose) or r (ribose) for other molecules. The XNA’s produced in the lab were shown to exhibit similar behaviour and were more stable compared with their natural counterparts. The research reported today in Science could help scientists develop new forms of synthetic life, improve medicines and advance biotechnology. It also indicates that other life forms existing elsewhere with a completely different chemistry may also be driven by evolution.

Your bathroom scale can easily tell you whether you lost those...

Mon, 16 Apr 2012 07:29:00 +0100

Your bathroom scale can easily tell you whether you lost those couple of kilograms, but will definitely not notice whether you trimmed your fingernails or had your hair cut. Not only do the relatively rudimentary mechanisms of ordinary scales limit the measurement precision, but they also make the accuracy of the order of some dozen grams—not enough to notice minute differences in weight. Measuring smaller and smaller masses, such as those of microscopic object or even molecules, require scales with fantastically high degrees and precision and accuracy that the weighing scales we are used to can’t obviously provide. By using the now seemingly ubiquitous carbon nanotubes researchers at the Catalan Institute of Nanotechnology in Spain created a scale with an accuracy of 10⁻²⁴ grams (called a yoctogram) that makes it able to potentially measure the mass of an atom down to the last proton. The nanotubes vibrate at different frequencies, depending on the mass of the particles or compounds deposited on them. By measuring these frequencies it is then possible to infer with the highest sensitivity ever achieved the mass of the tiny objects to be weighed. It is like listening to the note produced by a guitar string that vibrates when plucked, and comparing it to the different note that it produces when some object—a little ball of Play-Doh, for instance—is attached to the string. By comparing the two notes, one could know the mass of the Play-Doh sitting on the string.

Chaste et al., “A nanomechanical mass sensor with yoctogram resolution”, Nature Nanotechnology (2012)

Image: Bundles of carbon nanotubes (Wikipedia)

A building is a complicated entity. Many elementary blocks, such...

Wed, 11 Apr 2012 07:01:34 +0100

A building is a complicated entity. Many elementary blocks, such as bricks and concrete pillars, are put together and made to interact in simple ways to produce the final structure. If interacting in varied manners, however, objects apparently as basic as bricks, concrete and mortar can produce interesting collective behaviours. The workings of the resulting systems, of which ant colonies and city traffic are excellent examples, often cannot be traced back to their constituents but arise instead from the complex interactions between them. Researchers at MIT’s Computer Science and Artificial Intelligence Laboratory Objects have been building tiny cubes—some 10 millimeters wide—with magnets on their faces that can be switched on and off by a rudimentary microprocessor contained within the cube itself. Each cube, rather unintelligent in itself and of limited capabilities, can be programmed to interact with many other such cubes by means of its magnets, following complex sets of rules. This kind of technology, which combines modular robotics, nanotechnology and computer science, is also known as claytronics and was pioneered by a collaboration between Carnegie Mellon and Intel. Building smaller and smaller smart cubes and designing more efficient algorithms may one day lead to self-assembling macroscopic objects—like a sand castle that puts itself together on account of whatever rules have been programmed in each of its grains of sand.

The infinity puzzle. In this episode we interview Frank Close,...

Mon, 09 Apr 2012 07:01:00 +0100

The infinity puzzle. In this episode we interview Frank Close, professor of physics at the University of Oxford and author of the book The Infinity Puzzle. We discussed with him the public perception of modern physics, who should be awarded Nobel prizes and what sort of scientific questions are the right ones.
Visit our SoundCloud page to download the episode.

“The people who have missed out on Nobel prizes but were very near to getting one, they are known in the field but they are not known to the general public. […] The stories of the winners are very well-known, and I am sure that there are stories that are not told by many people who are in the running who do not get one and keep the secret to themselves.”

We thank Frank Close and the School of Physics and Astronomy of the University of Glasgow.
This episode includes a CC-licensed Freesound.org sound sample by user Setuniman.

Cryptography is the science of secure communications in the...

Fri, 06 Apr 2012 09:02:29 +0100

Cryptography is the science of secure communications in the presence of unwanted eavesdroppers. Historically it started with just a pencil and paper where letters or groups of letters would be substituted for others based on system that only the communicators knew. Simple mechanical devices like the syctale (a wooden rod with a particular shape and diameter) were used by the Spartan army on which to wrap messages around in order to decipher the content. As technology advanced further and computers we developed more elaborate techniques and methods for encryption and decryption were devised with ever increasing complexity. Until fairly recently, all useful encryption algorithms had relied on using a cryptographic key that was the same for both the sender and receiver in order to decipher the content of their communications. One major issue with this is that the key must somehow be kept secret. This is problematic when often the key is itself required to be communicated over large distances publicly before it can be used. However in 1976, a fundamentally different approach was proposed by Whitfield Diffie and Martin Hellman, in a paper titled “New Developments in Cryptography”, which largely changed the way encryption was performed ever since. Asymmetric key encryption uses a pair of keys, one private that only you know and one public that anyone can know, and both of which are mathematically related, allowing you to decrypt the encryption performed by the person you are trying to communicate with in private. This video above goes a long way at making sense of how the private and public key is determined in cryptography.

“A Reassuring Fable” is the third chapter in the...

Wed, 04 Apr 2012 09:01:54 +0100

“A Reassuring Fable” is the third chapter in the Sagan Series on the subject of human existence on Earth and the lives we all lead. Narrated by Carl Sagan alongside evocative cinematography, he touches upon the role of faith and of science in human experience, and so eloquently argues that we put aside our prejudice and differences for a worthy cosmic goal.

If you were to fly north from Europe towards the Arctic, you...

Mon, 02 Apr 2012 07:00:00 +0100

If you were to fly north from Europe towards the Arctic, you wouldn’t be able to follow a perfectly straight line. As the airplane (relatively slowly) moves north, the entire Earth rotates under the airplane. The resulting flight path is then slightly curved—to the right in the northern hemisphere, to the left in the southern one. Naturally, the plane is not actually moving off its course: it’s just that, when observed in a rotating frame of reference (such as the Earth’s), its net trajectory looks like as a curve. This apparent deflection, known as the Coriolis effect, affects airplanes as well as the large-scale dynamics of oceanic currents and the atmosphere. The Coriolis effect due to Earth’s rotation affects microscopic objects too. The atoms used in atom interferometry—a technique that allows to measure accelerations with extreme precision—are affected by a tiny Coriolis force that reduces the accuracy of the measurements performed, by introducing an effect that can’t be easily accounted for. It’s for this reason that physicists at the University of California at Berkeley recently developed an experimental method to reduce the effect of the Coriolis effect in their atom interferometers, which dramatically increased the precision of their measurements.

Lan et al., “Influence of the Coriolis Force in Atom Interferometry”, Physical Review Letters 108 (2012)

Image: Low pressure system over Iceland (Wikipedia)

Looking at the universe with human eyes is not always the best...

Fri, 30 Mar 2012 07:00:05 +0100

Looking at the universe with human eyes is not always the best way to unveil its secrets and its beauty. Many pictures of remote astronomical objects we’ve grown so fond of use in fact false colours, as they were originally taken with cameras sensitive to different regions of the electromagnetic spectrum than those our eyes can see. Photographs of galaxies and nebulae are often used to study their full spectral emissions—well beyond the visible spectrum—, which provide useful information about the elements that make up these celestial bodies otherwise entirely out of our reach, and also about their temperature, density and many other features.

Each region of the spectrum, corresponding to a different energy of the electromagnetic radiation that we can detect with our instruments, carries interesting information. Looking at radiation at 511 keV, which corresponds to the energy discharge produced by an electron meeting a positron (its antimatter twin) and annihilating each other, we get a very unusual picture of our galaxy. The image above shows what the universe would look like if all we could see were the gamma rays produced by an electron meeting a positron. The centre of our galaxy, in the middle of the image, appears to be a place of frequent matter-antimatter annihilations. The reason of this intense activity is still uncertain. Among the hypoteses considered by this extensive review available on the arXiv are the activity in the immediate surroundings of the black hole at the centre of the Milky Way and exotic dark-matter interactions.

MIT researchers have developed a camera that can see around...

Wed, 28 Mar 2012 10:40:00 +0100

MIT researchers have developed a camera that can see around corners to view objects, that would otherwise be hidden from sight, by using ultra short bursts of light. To do this Ramesh Raska and his colleagues adopted the basic principle of a periscope, but instead of mirrors they use walls or floors or doors etc. Light that is emitted in femtosecond (10^-15 of a second) long pulses scatters and reflects off the wall, entering unseen places, like for example a room with an articulated wooden doll, where once again a fraction of the light will reflect off the object, travel back along a similar path and reach a camera that can take pictures every 2 trillionths of a second. Knowing the time of arrival of the detected photons enables 3D reconstruction of the hidden object as shown in the video above.

Quantum information. For this episode of It’s Not My Field...

Mon, 26 Mar 2012 08:20:00 +0100

Quantum information. For this episode of It’s Not My Field we interviewed Anton Zeilinger, professor of physics at the University of Vienna, director of the Viennese section of Institute for Quantum Optics and Quantum Information IQOQI at the Austrian Academy of Sciences, and one of the pioneers in the field of quantum information. We talked with him about quantum information and why it matters, how it could provide a general and fascinating description of reality, whether we will ever build a quantum computer, and how a scientist can consistently produce good scientific output.

Visit our SoundCloud page to download the episode.

We thank Anton Zeilinger and the University of Vienna.
This episode includes CC-licensed Freesound.org sound samples by users WaterminD, genghis attenborough and ERH.

“Life looks for life” is the second chapter of the...

Fri, 23 Mar 2012 09:09:00 +0000

“Life looks for life” is the second chapter of the Sagan Series collection, by Reid Gower. As with all the videos in this collection the narration comes from the legendary Carl Sagan, who finds a poetic perspective in all scientific frontiers and our place on Earth. The very existence of life is probably the most fascinating subject to consider when we look out to space and observe the vast potential of opportunities for other life forms, intelligent, curious, advanced or otherwise.

An amusing, yet accurate description of gravitational effects...

Wed, 21 Mar 2012 08:00:00 +0000

An amusing, yet accurate description of gravitational effects near a black hole.

This video was taken from http://www.youtube.com/user/vsauce/

The words of Carl Sagan really are timeless. This is the first...

Mon, 19 Mar 2012 20:51:00 +0000

The words of Carl Sagan really are timeless. This is the first in a collection of tribute videos dedicated to his scientific work as a cosmologist, astronomer, astrophysicist, and science communicator. Alongside inspirational narration from his 1980 TV series Cosmos: A Personal Voyage we are provided with impressive cinematography and a powerful soundtrack. Enjoy!

This video was taken from The Sagan Series, a project by Reid Gower.

This image released by NASA yesterday shows the entire night sky...

Sat, 17 Mar 2012 09:00:00 +0000

This image released by NASA yesterday shows the entire night sky as seen by the Wide-field Infrared Survey Explorer (WISE) mission. Across the centre we observe our galaxy, the Milky Way, as seen from our location in universe. Our solar system is located about two thirds from the centre of our galaxy, and due to Earths inclination, the southern hemisphere points towards the galactic nucleus, where we see a noticeable increase in stars in the middle of the image, while the northern hemisphere points outwards (the left and right edges). Though it may not be obvious, there are over 560 million individual objects in this image and would need a 15TB hard drive to store the 2.7 million images required to make it. The image took approximately 2 years to collate and over 100 papers have been published from the WISE mission results so far.

Click here to see the full size image from NASA.