A group of Finnish mathematics researchers, teachers and students write an upper secondary mathematics textbook in a booksprint. The event started on Friday 28th September at 9:00 (GMT+3) and the book will be (hopefully) ready on Sunday evening. The book is written in Finnish.
Category Archives: STEM
New Comet Discovered—May Become “One of Brightest in History”
The comet is already remarkably bright, given how far it is from the sun, astronomer Raminder Singh Samra said. What’s more, 2012 S1 seems to be following the path of the Great Comet of 1680, considered one of the most spectacular ever seen from Earth.
“If it lives up to expectations, this comet may be one of the brightest in history,” said Samra, of the H.R. MacMillan Space Centre in Vancouver, Canada.
via New Comet Discovered—May Become “One of Brightest in History”.
Because 2012 S1 appears to be fairly large—possibly approaching two miles (three kilometers) wide—and will fly very close to the sun, astronomers have calculated that the comet may shine brighter, though not bigger, than the full moon in the evening sky.
Air Force sets first post in ambitious Space Fence project
The Space Fence will use multiple S-band ground-based radars — the exact number will depend on operational performance and design considerations — that will permit detection, tracking and accurate measurement of orbiting space objects. The idea is that the Space Fence is going to be the most precise radar in the space situational surveillance network and the S-band capability will provide the highest accuracy in detecting even the smallest space objects, the Air Force stated. The Fence will have greater sensitivity, allowing it to detect, track and measure an object the size of a softball orbiting more than 1,200 miles in space. Because it is an uncued tracking system, it will provide evidence of satellite break-ups, collisions or unexpected maneuvers of satellites, the Air Force said.
via Layer 8: Air Force sets first post in ambitious Space Fence project.
Quantum cryptography: yesterday, today, and tomorrow
Imagine you have a product of two prime numbers, say, 221. Now, we set that number to be an endpoint—for the purposes of our game, there are no higher integers. If we multiply two numbers together and get a number larger than 221, it wraps around, so 15 times 15 results in 225-221 = 4. If we multiply two by itself, we only get four, which doesn’t wrap, and we can do that 7 times before it wraps. But 28 results in 35. Got that? Great.
via Quantum cryptography: yesterday, today, and tomorrow | Ars Technica.
Let’s consider a consequence of using phase to calculate prime factors: 221 has prime factors 17 and 13, and factors 1 and 221. We can eliminate the latter in the classical part of our algorithm. But, what about two and 111? “Wait,” you say. “That is not a factor. The product is 222.” Nevertheless, we need to think about it, because quantum algorithms are probabilistic. 17 and 13 have the highest probabilities, but two and 111 only have a phase error of 0.5 percent. The probability of Shor’s algorithm returning the incorrect result is rather high. Unfortunately, a near miss (though easy to spot, since it is very quick to calculate that 2×111=222 not 221). This is likely not very useful in terms of decrypting a message, so we need to do something to increase the chance of getting the correct answer.
Australian researchers create world’s first working quantum bit
This enabled them to form a quantum bit or “qubit”, the basic unit of data for quantum computers, which promise to solve complex problems “that are currently impossible on even the world’s largest supercomputers,” according to team leader Dr Andrea Morello.
The paper’s lead author, UNSW PhD student Jarryd Pla, said researchers had been able to “isolate, measure and control an electron belonging to a single atom, all using a device that was made in a very similar way to everyday silicon computer chips.”
Tandem satellites probe the Moon’s interior
GRAIL’s two probes, named Ebb and Flow by schoolchildren in a NASA competition, were launched in September 2011 (see ‘Twins to Probe Moon’s Heart’). The first probe began orbiting the Moon on 31 December 2011, with the second joining the next day. By March, they had begun detailed mapping. The two spacecraft exchange radio signals, recording fluctuations in their relative positions that are then used to reveal tiny accelerations and decelerations caused by variations in the Moon’s gravitational field. The average altitude of the primary mission was 55 kilometres — much lower than the orbit used by the Gravity Recovery and Climate Experiment (GRACE), a similar gravity-mapping mission for Earth that has to fly higher to avoid atmospheric friction. Occasionally, the GRAIL operations team brought the craft lower than 20 kilometres to further improve the resolution of the data. “Nothing beats flying low,” says Zuber.
via Tandem satellites probe the Moon’s interior : Nature News & Comment.
Russia reveals shiny state secret: It’s awash in diamonds
They claim the Popigai site is unique in the world, thus making Russia the monopoly proprietor of a resource that’s likely to become increasingly important in high-precision scientific and industrial processes
via Russia reveals shiny state secret: It’s awash in diamonds – CSMonitor.com.
Russian scientists say the news is likely to change the shape of global diamond markets, although the main customers for the super-hard gems will probably be big corporations and scientific institutes.
Moving plane exchanges quantum keys with Earth
Quantum key distribution (QKD) uses photons polarised in two different ways to encode the 0s and 1s of an encryption key. The laws of quantum mechanics ensure the transmission is secure, as any attempt to intercept the key disturbs the polarisation – a tip-off to the receiver that the key has been seen and should be discarded.
via Moving plane exchanges quantum keys with Earth – tech – 16 September 2012 – New Scientist.
The researchers kept the laser on track using moving mirrors both in the aircraft and on the ground. Performing the experiment shortly after sunset avoided interference from sunlight. The transmission lasted for 10 minutes, amounting to a key long enough to encrypt 10 kilobytes of data. The team presented the work at the QCrypt conference in Singapore on 12 September.
Atomic bond types discernible in single-molecule images
The new work opens up the prospect of studying imperfections in the “wonder material” graphene or plotting where electrons go during chemical reactions.
The images are published in Science.
via BBC News – Atomic bond types discernible in single-molecule images.
They are carried out at a scale so small that room temperature induces wigglings of the AFM’s constituent molecules that would blur the images, so the apparatus is kept at a cool -268C.
While some improvements have been made since that first image of pentacene, lead author of the Science study, Leo Gross, told BBC News that the new work was mostly down to a choice of subject.
Ancient Egyptian faience may be key to printing 3D ceramics
Working under a grant from the Arts and Humanities Research Council (AHRC), Hoskins and Research Fellow David Huson have been developing a 3D ceramic printing process that can build very finely detailed, complex structures to industrial specifications and standards. The process works by depositing a layer of wet ceramic material layer by layer. As each layer is printed, the printer table drops, a layer of powder is deposited to support the object, and the process repeats.
via Ancient Egyptian faience may be key to printing 3D ceramics.
It isn’t actually a ceramic, but rather a paste made of quartz or sand, calcite lime and a mixture of alkalis. Because of this, it can be applied directly to wet clay. When the pottery is fired, the paste turns into a brilliant blue-green glaze reminiscent of lapis lazuli, which the Egyptians used faience as a substitute for.