Dark matter is believed to exist in the form of tiny particles that do not interact with light. Because they don’t emit or reflect electromagnetic radiation the way atomic, or baryonic, matter does, these dark matter particles haven’t been directly observed. However, scientists have long theorized their existence based on their gravitational effects on visible matter throughout the universe.

“The evidence for dark matter is now overwhelming, and the required amount of dark matter is becoming precisely known," says Howard Baer, Professor of Physics at Florida State University.

“For example, the gravitational effect of dark matter makes galaxies spin faster than one would otherwise expect,” Baer said.

Discovered by Sir John Herschel in 1834, NGC 3603 is known to harbour a blue supergiant star called Sher 25, believed to be on the verge of exploding as a supernova. It is often known as the Milky Way counterpart of the predecessor of the now-famous supernova SN 1987A in the Large Magellanic Cloud.

It is located in the Carina spiral arm of the Milky Way, about 20,000 light-years from the Solar System.

The swirling nebula of NGC 3603 contains around 400,000 solar masses of gas. Lurking within this vast cloud are a few Bok globules, named after Bart Bok who first observed them in the 1940s.

Bok globules are dark clouds of dense dust and gas with masses of about ten to fifty times that of the Sun.

Lower muscle mass and an increase in body fat are common consequences of growing older.

While exercise is a proven way to prevent the loss of muscle mass, a new study led by McMaster researcher Dr. Mark Tarnopolsky shows that taking a combination of creatine monohydrate (CrM) and conjugated linoleic acid (CLA) in addition to resistance exercise training provides even greater benefits.

The study involved 19 men and 20 women who were 65 years or older and took part in a six-month program of regular resistance exercise training.

We all know about the advanced machines of the ancient Greeks, like the water pumps and the steam engines devised by their greatest minds, but what is less known is how those with little theoretical background were still able to make well-calibrated devices with alarming precision.

Recent analysis of technical treatises and literary sources dating back to the fifth century B.C. reveals that technology flourished among practitioners with limited theoretical knowledge.

“Craftsmen had their own kind of knowledge that didn’t have to be based on theory,” explains Mark Schiefsky, professor of the classics in Harvard’s Faculty of Arts and Sciences.

If space travelers ever visit Saturn's largest moon, they will find a tropical world where temperatures plunge to minus 274 degrees Fahrenheit, methane rains from the sky and dunes of ice or tar cover the planet's most arid regions. These conditions reflect a cold mirror image of Earth's tropical climate, according to scientists at the University of Chicago.

"You have all these things that are analogous to Earth.

Scientists have made an important advance in understanding the genetic processes that give flowers, leaves and plants their bright colours. The knowledge could lead to a range of benefits, including better understanding of the cancer-fighting properties of plant pigments and new, natural food colourings. The research is highlighted in the new issue of Business from the Biotechnology and Biological Sciences Research Council (BBSRC).

The scientists, at the John Innes Centre and Institute of Food Research in Norwich, have pinpointed a key group of enzymes involved in the production of plant pigments. The pigments, called anthocyanins, are what give some plants the vivid colours that they use to attract insects and foraging animals.