A block glacier is an ice stream with scree (a large amount of small rocks of assorted sizes). For example, similar glaciers (22,000 years ago) have been instrumental in the creation of the Long Island (my home!) on the Eastern sea-shore of continental USA. Now scientists may have found evidence of such (old) glacial activity on Mars. Images taken by the High Resolution Stereo Camera (HRSC) on board ESA's Mars Express spacecraft, shows flow features most likely formed by 'block' glaciers.

Glacial Imprint on Mars (Courtesy: Mars Express)This unusual 'hourglass'-shaped structure (9 and 17 kilometer wide craters) is located in Promethei Terra at the eastern rim of the Hellas Basin (which contains the lowest point on Martian surface), at about latitude 38º South and longitude 104º East.
Features include:
a) Along the crater walls, numerous concentric rings called 'end' moraines (similar to moraines on Earth, which are depositions of rocks as the glacier retreats; similar effects formed the rocky shores of Long Island),
b) Presence of 'middle' moraines, which are parallel stripe-like structures displaying the direction of the glacial flow,
c) Cracks when the glacier is moving over a steep terrain, similar to those found on Earth-glaciers,
d) Elongated grooves/ridges similar to drumlins (structures formed beneath ice by glacial flow resulting in compression and accumulation of abraded material) on Earth.
The density of meteor impacts within the craters is quite low. The statistical analysis of these craters shows that part of the surface with its present-day glacial characteristics was formed only a few million years ago. This is extremely young! This means that Mars must have had a thicker atmosphere a few million years ago (since glaciers will not easily form under thin atmospheres), and much of the glacial ice might be now trapped under a layer of dust, thus both protecting it from evaporation, and hiding it from the on-board instruments on the Mars Express.
If the above conjecture is true, this would mean that Martian climate underwent a dramatic change in the last few million years. It could be because of a polar axis shift, or some other process we know nothing about today.

In the March issue of the Journal of the Minerals, Kenneth S. Vecchio of University of San Diego, California has described a new metallic laminate (composed of layers of one of more kind of metals) which has certain unique properties. The metal is made of alternating layers of Aluminum and Titanium alloy foils, compressed and heated in an inexpensive energy-conserving process. It can serve as armor, and also as a replacement for beryllium, a strong but toxic metal commonly used in demanding aerospace applications.

Good results with ballistics tests (Courtesy: University of San Diego)The new material we developed is environmentally safe, and while its stiffness equals that of steel, it’s only half as dense. It has a hard ceramic-like intermetallic layer of Titanium Aluminide, and a pliable layer of residual Titanium alloy. The layers can be stacked like 1-millimeter-thick pages of a book, and even contoured into desired shapes prior to heating. This gives the metal excellent armor properties: a heavy Tungsten alloy bullet fired into a three-quarters-inch (2 cm) thick sample at a velocity of about 2,000 mph (900 m/s) penetrated only half the thickness of the test sample!
Interestingly, the laminate architecture was chosen to mimic the internal structure of the tough shell of the red abalone! This is another example of science getting inspired by what is already available in Nature. Researchers are currently studying structural and functional designs of everything from mollusk shells and bird bills to sea urchin spines and other biocomposites in the development of new smart materials and devices.
According to Professor Vechhio, it might be possible to include electrical pathways within the laminate, and thus create piezoelectric sensors within the metal. This will be immensely useful, for example in case of a body armor, as the sensors can provide real-time data about the status of the soldier and the armor to the commanders in the field. These materials can also deform when electricity is applied, and this might have applications in robotics to create artificial muscles :).

Dark Energy is a (still) hypothetical form of energy that is supposed to permeate all space. It is almost like a sea of radiation, over which all normal matter (things that make us, stars and galaxies), normal energy (e.g. photons/light) and dark matter (termed such since it does not emit any light and thus cannot be detected) are like small islands. At large scales (larger than galaxies), according to General Relativity, dark energy acts as a force opposite to gravity, which causes the universe to expand at an ever-accelerating rate. Scientists had previously found evidence of dark energy billions of light years away, but a new computer model (coupled with observations from the Hubble Telescope) has found evidence of dark energy right in our own Milky Way galaxy :-).

Simulation: Red galaxies in a sea of dark energy (Courtesy: McMaster University)University of Washington professor Fabio Governato designed a computer model in 1997 that simulated the evolution of the universe from the big bang until the present. However, his model was unable to simulate the behavior of the galaxies in the local neighborhood of our Milky Way. By comparing his work to the recent observations by the Hubble telescope, he was able to add dark energy to his model, and voila! it was a perfect match!
This work suggests that there is dark energy in our Milky Way, and it is critically important in the life of a galaxy like ours. Slowly, but surely, the pieces of the cosmic puzzle are falling into place.

Tang-e Bolaghi (Fars Province, Iran) is situated some 4 kilometers from Pasargadae, the first capital of the Achaemenids (about 550-330 B.C.) and the residence of Cyrus the Great (the first ruler of the Achaemenids). Pasargadae was added to the UNESCO World Heritage List last July; its palaces, gardens, and the mausoleum of Cyrus are outstanding examples of the first phase of royal Achaemenid art and architecture and exceptional testimonies of Persian civilization.

Village Walls, Tang-e Bolaghi (Courtesy: IranMania)Sadly, some 129 ancient sites in Tang-e Bolaghi will be flooded by the waters of the Sivand Dam by March 2006. A team of Iranian and foreign (Italian, Polish, Japanese, French, German, and Australian) archaeologists were rushed in to save and document the sites. Earlier this month, they found a huge Achaemenid era jug (weighing 50 kilograms!), and also identified some architecture of the homes of the ordinary people during that period.
During the excavations, archaeologists discovered a yard with three rooms around it, which was the style of architecture of ordinary people’s houses in the Achaemenid era. According to the director of the team, Alireza Asgari, the house has a central yard surrounded by several rooms 4 and 5 square meters in area, constructed with cobblestones as well as cut stones. Tang-e Bolaghi is located near the imperial route during this era, and thus might provide a lot of information about the lifestyles during those times.
Tang-e Bolaghi also contains sites from the Neolithic and Paleolithic periods, the middle and late Elamite era (2700-645 B.C.), and the Sassanid era (224-651 C.E.). Archaeologists had also identified 80 sites in the region from the Epipaleolithic period (20,000-10,000 B.C.), including 13 caves and four rock shelters. According to experts, only a small part of the area can be studied before it is devoured by the dam, and at least four years is needed to save the artifacts and gather information at the ancient site. But if the dam is in business by 2006, many sites will be submerged before they are even properly studied :-(:-(.

A prime number is an integer (> 1) that is divisible by 1 and itself (for example, 2, 3, 5, 7, 11, 13, 17, 19, 23, and so on). Mathematicians have tried in vain to find any order in the distribution of the prime numbers, and the prime sequence remains the most interesting sequence of numbers. Prime numbers can be computed easily (for example, by using the Sieve of Eratosthenes). There are an infinite number of prime numbers, and it is always an interesting project to find the largest known prime. An interesting subset of the prime numbers is the set of the so-called Mersenne Primes, named after the 17th century Frenchman, Marin Mersenne.

Marin Mersenne (1588-1648)Mersenne primes are of the form M_p = 2^p-1, where p is also prime. The first eight such primes are 3, 7, 31, 127, 8191, 131071, 524287, and 2147483647. Last month, using the Great Internet Mersenne Prime Search (GIMPS), Dr. Martin Nowak discovered the largest known prime, which is also a Mersenne prime. The prime number is 2^25,964,951-1, and has 7,816,230 digits (Click here for the full number!). It took more than 50 days of calculations on Dr. Nowak's 2.4 GHz Pentium 4 computer. The discovery is the eighth record prime for the GIMPS project.
As computing power increases, more and more such primes will be found :-).

Modern day chips are marvels of miniaturization. The size of a typical component (say, a transistor) in a top-of-the-line Pentium-4 processor is about 0.13 micron (1 micron = millionth of a meter). In comparison, a human hair is about 60-90 microns wide! As demands on processor speed and data bandwidth are rising, the push for miniaturization is increasing. However, quantum physics imposes a barrier at about 0.01 micron, below which quantum effects become more dominant (this would cause random changes in data bits inside the processor, for example), and must be taken into consideration. Now researchers at University of Delaware could break down the brick wall of miniaturization and revolutionize modern electronics through the formation and control of wires made of molecules.

Nano-wire (Courtesy: Technischen Universität München)A typical transistor inside a microprocessor is a fraction of a micron in size. But even then, it is made up of thousands of silicon and other atoms. Many research groups all over the world have been pursuing alternate avenues by which to make smaller electronic devices. One of the approach is to create molecular-sized devices, by lining up molecules in a string. Such wires can have novel properties, and can be used to replace components in a processor. Such nano-wired processors would consume less energy, would be much faster (1000 GHz or more) than modern processors, and have more functionalities.
Such next generation of molecular processors would be the pinnacle in miniaturization. The second half of the 20th century was the era of micro-electronics. The first half of the 21st might just be the era of nano-electronics.

Microwires were invented in the old Soviet Union for military applications. These wires are three to five times thinner than a human hair, and have a metal body (1-20 micrometer) and a glass coating (about 5-20 micrometer). The wires are flexible, and can be bent into any shape desired. The metal body conducts electricity, while the glass coating acts as a insulator. Recently, a lot of research has been focussed on microwires, especially on its ability to carry and possibly store data as well! A research team at the University of the Basque Country has launched a project that uses microwires as a system for storing information. The microwires become possible substitutes for the CD-ROM.

Microwire (Courtesy: University of the Basque Country)The researchers exploit a property found in cylindrical, bamboo-like structures like microwires: they become magnetised when subjected to a magnetic field. The two orientations of the magnetisation (north and south poles) can be interpreted as the 1 and the 0 of a digital system. This is similar to how hard-drives store data. A piece of microwire 10 cm long, can then store about 10 million bits (10 Mbits) of data. The wire can then be (possibly) wound in a spool/platter of some kind, which would be able to store giga-bytes of information!
Some practical problems remain. Noise is a big factor during the reading of data. Also, heat and/or light can destroy the data stored. However, researchers are confident they can overcome these problems, and develop a system that could, in principle, exceed the capacity of a modern CD-ROM.