There are seven basic units of measurement that we use everyday. In SI units, These are:

Standard Mass

• Length (Meter): Equal to 1,650,763.73 wavelengths in vacuum of the orange-red line of the krypton-86 spectra
• Mass (Kilogram): Cylinder of platinum-iridium alloy kept in France and a number of copies
• Time (Second): Time for 9,192,631,770 cycles of resonance vibration of the caesium-133 atom
• Temperature (Kelvin): Absolute zero is defined as 0 Kelvin and the triple point of water as 273.16 Kelvins
• Luminosity (Candela): Intensity of a light source (Frequency 5.40x10¹⁴ Hz) that gives a radiant intensity of 1/683 watts/steradian in a given direction
• Electric Current (Ampere): Current that produces a force of 2.10^-7 Newtons per meter between a pair of infinitely long parallel wires 1 meter apart in a vacuum
• Amount of Substance (Mole): Number of elementary entities of a substance equal to the number of atoms in 0.012 kg of Carbon-12

Only the standard for mass is based upon a physical standard, and not on fundamental physical constants (Gravitational constant, Planck's constant, Speed of Light in vacuum, etc.), which means that everytime one wishes to calibrate a kilogram, it has to be physically compared with the French mass, or with some mass already calibrated using that mass. Now for the first time, the kilogram may be moving toward a new definition based on a universal constant.
A paper to be released Monday proposes redefining the unit via fixing the values of one of two well-known universal constants. The choices are either, a) Avogadro's number (measures the amount of carbon-12 atoms in 0.012 kg of that element), or b) Planck's constant (used to explain the sizes of quanta, in quantum mechanics). As reported by the Wired magazine, the change would mean the kilogram would no longer be known exactly, but would instead be determined by experiments using the chosen defined constant. A definition based on Planck's constant could mean scientists would determine a certain number of photons of light of a certain frequency would correspond to a kilogram. A definition based on Avogadro's constant could mean the kilogram would be determined by a certain number of an element's atoms.
The french mass lasted for about 100 years (first standardized in 1889, kept at the International Bureau of Weights and Measures), and has been the standard for the 20th century. Soon, perhaps, we will have a standard for the 21st century (and beyond).

These great pictures are from the SOlar and Heliospheric Observatory website. This ultraviolet image of the Sun shows a very long filament slanting up roughly at a 45 degree angle across much of the Sun, underneath a long and narrow coronal hole (22 Feb. 2005). Filaments are twisting masses of cooler ("only" 10,000 - 100,000 degrees Kelvin) gas contained by magnetic fields above the Sun's surface in the midst of the much hotter (~ 1,500,000 K) corona. Filaments are called prominences if observed on the Sun's limb or edge.

Ultraviolet Image

H-Alpha Image (Courtesy: SOHO, Click images for Hi-Res)This particular filament was already there 28 days ago (one solar rotation earlier), as were the two coronal holes. While filaments are fairly common, this one is longer than most that have ever been seen. The filament is particularly well visible in this H-alpha image obtained at the Kanzelhoehe Solar Observatory.
This video shows the filament virtually unchanged for two days. One (looking closely) can detect (around 10:00 UT on Feb. 22) a small coronal mass ejection as it blasts out into space from the lighter, upper active region on the right edge of the Sun.

A team of Boston University physicists led by Assistant Professor Pritiraj Mohanty have developed a nanomechanical oscillator (essentially a small comb-like structure vibrating between two anchors). The oscillator is comprised of 50 billion atoms (0.0107 milli-meter). When it is oscillated at a frequency of 1.49 GHz (1.49 billion times per second), with an amplitude equal to the size of an atom, the oscillator displays quantum mechanical properties.
In our (classical) macroscopic world, physical constructs (space, time, weight, temperature etc.) are continous in nature. For example, when we move from point A to point B, we are traveling through all points between A and B. Similarly, when we heat a bowl of water, say from 25º to 75º, the temperature of the water rises continuously from 25º to 75º. However, the world of small (typically, less than a nanometer) is dominated by quantum mechanics, where these common-sense rules of continuous change do not apply. All physical parameters at such small scales behave quantum-mechanically, that is, the parameter values increase (or decrease) in discrete (quantum) jumps. It is as if the water temperature can only rise from 25º to 75º by steps of 1º! Fortunately, this quantum step is usually extremely small (of the order of 10^-30), and hence indetectable to the naked eye.
Einstein in his seminal paper in 1905 (on Photoelectric effect) showed that for light to behave as it does, it must come in small energy packets (later) called photons. Soon, scientists such as Heisenberg and Schroedinger developed the new physics of Quantum Mechanics, where everything comes in discrete packets of extremely small size. Under this theory, even space and time are quantized in nature, and at such small scales, particles cannot move continuously from point A to B, but must travel this distance in discrete steps/jumps.
The above phenomenon has already been observed in particles such as electrons and photons. Now the physicists have for the first time observed the above phenomenon at a (comparatively) macroscopic level. In our macroscopic world, we would expect a structure such as the above mentioned oscillator to move smoothly. Instead, it behaves in a peculiar manner: it moves in steps. It is as if instead of rolling smoothly down a hill, a ball is moving as if it is climbing down a staircase.
At the quantum level, energy comes in packets as well. Since the oscillator can only have energy values that come in integral multiples of this quantum packet (you can have 10 packets, or 11 packets, but not 10.5), it moves in steps. Thus we observe (Movie here) a jerky motion by the oscillator.

A British-led team of astronomers have discovered the first galaxy completely devoid of stars. The galaxy (which is a large mass, about 50 million light years away) can only be detected using a radio telescope. First captured by the University of Manchester’s Lovell Telescope in Cheshire, the discovery was also confirmed by the Arecibo telescope in Puerto Rico.

Dark Galaxy, Invisible (Courtesy: PhysOrg)The galaxy (named VIRGOHI21) is mostly composed of hydrogen, and is about a hundred million times the mass of the Sun, lying in the Virgo cluster. Such galaxies have been predicted before (and might outnumber the visible galaxies by 100 to 1), but this is the first time anyone has 'seen' one.
It is theorized that since galaxies rotate at a fairly fast pace (our own Milky Way complete one rotation in about 250 million years), dark matter is necessary to ensure that the galaxies do not tear themselves apart. Detecting such dark matter hitherto has been elusive. The techniques that led to the discovery of this dark galaxy can undoubtedly be used to detect other dark matter clumps in our own galaxy, and beyond.

Australian scientists have shown (published in Proceedings of the National Academy of Sciences) that drywood termites (Cryptotermes domesticus) listen to their wood, before eating it. The termites also listen to the sound they produce while chewing, which helps them detect other species of termites, and help control the development of immature workers into sexually-active breeders. According to the researchers (CSIRO, University of New South Wales), this might lead to better ways of protecting wood from termite damage.

Termites! (Courtesy: NewScientist)The termites detect sound through their legs and antennae. They choose smaller wood blocks when in a new environment, and avoid larger blocks that are being fed upon by termites from other species. Over time, they get more confident and start feeding on the large blocks as well.
It is still to be seen if termites from other continents make similar sound, or if termites from different continents hear each others' sound as threats. It might be possible to stop termites from doing damage to a house by piping vibrations from another species through the wood framework. This will make the house termite-free, without having to use pesticides! Hopefully, the termites do not have a very discerning 'ear' :-)

Billed as the most important Coptic discovery found since the Nag Hammadi scripts found in 1945, (Polish) Egyptologists have uncovered a set of three ancient (6th Century AD) Coptic manuscripts in a tomb in Luxor, Egypt.

Nag-Hammadi manuscripts (Courtesy: Gnosis Archive)Copts were the ancient peoples of Egypt. The manuscripts were hidden in a Middle Kingdom (2000 to 1800 BC) tomb, perhaps kept there by the (Coptic) Christians who were being persecuted at the time by the Romans.
Egypt's Supreme Council of Antiquities head Dr. Zahi Hawas said one of the manuscripts is 22.5 centimeters by 17 centimeters (nine by seven inches) and three centimeters thick. The second has 50 pages and a cover made of skin with ornaments, while the third (which also has 50 pages) is in a poorer state.
The experts will try to decipher the manuscripts, which should shed some interesting light on early Christianity. The Naga Hammadi manuscripts contain a large number of primary Gnostic scriptures; texts once thought to have been entirely destroyed during the early Christian struggle to define "orthodoxy" -- scriptures such as the Gospel of Thomas, the Gospel of Philip, and the Gospel of Truth. Perhaps some such interesting documents will be deciphered from this batch, which will open up some new chapter in history.

Human beings are often touted as at the pinnacle of evolution. Even if this may or may not be true, one thing is certain; different parts of the body evolve at different pace. For example, one can reasonably conjecture that our brains are at the peak of the evolutionary line. Such a claim would not be made about our teeth :-). Compared to most mammals, human teeth are highly crooked, and disordered (NewScientist). Now scientists have come up with a reason for this: Cooking!

Human TeethAccording to anthropologist Peter Lucas of George Washington University, the evolutionary pressures are different for the front and the back teeth. This, and due to the lack of space inside a human jaw, the teeth are always competing with each other, often resulting in malocclusion. Teeth can be missing, broken, growing on top of each other, wisdom teeth often do not have space to come out! Other mammals do not face this problem. Other primates often have hollywood teeth.
The human front teeth are used to chop food into small pieces. The back teeth (molars and premolars) grind down harder pieces. According to Peter Lucas, cooking has allowed humans to pre-soften the food. We do not require a lot of teeth to cut food into smaller pieces, so the human front jaw has become smaller. But we still need molars to grind the harder pieces, and our jaw is not large enough to hold them all. The "Rise of The Molars" pushes the other teeth, thereby causing the disfigurement, and the pain in the neck that are the wisdom teeth.