People sometimes think the space between stars is 'empty' but that's not the case. That area is filled with patches of low-density gas and when a relatively dense clump of gas gets near a star, the resulting flow produces a drag force on any orbiting dust particles. The force only affects the smallest particles -- those about one micrometer across, or about the size of particles in smoke.
This explains the otherwise difficult to understand shapes of those dust-filled disks, according to a team led by John Debes at NASA's Goddard Space Flight Center in Greenbelt, Md.
Fish and some amphibians possess a unique sensory capability that allows them to 'feel' objects around them without physical contact and see in the dark.
Colloquially this is called a 'sixth sense' but scientifically it is called a lateral-line system.
A team in the physics department of the Technische Universitaet Muenchen say they are able to explore the fundamental basis for this sensory system. The goal of that would not be to solve M. Night Shyamalan movies faster but rather, through biomimetic engineering, better equip robots to orient themselves in their environments.
A new study in the Journal of Child Psychology and Psychiatry says nearly 15 percent of preschoolers have high levels of depression and anxiety.
Their investigation also said depressed pre-schoolers were more likely to have mothers with a history of depression. So is that actual depression or learned social behavior that seems like depression?
Being a kid is not easy, of course, despite what parents think. But is finding pre-school depression in high numbers due to better diagnosis or, in the cases of rampant ADD prescriptions in the 1990s, a new field looking for patients? If it's better diagnosis, finding it earlier may be a help.
Researchers writing in, ironically, the journal Addiction have associated abstaining from alcohol with an increased risk of depression.
Doesn't make sense, right? Excessive alcohol consumption has been linked to poor physical and mental health but they cite evidence saying that levels of alcohol consumption that are too low may also be associated with poor mental health possibly - obviously, abstainers may have other issues or even be reformed heavy drinkers.
In 1935 one of the founders of modern genetics, J. B. S. Haldane, studied men in London with the blood disease hemophilia and estimated that there would be a one in 50,000 incidence of mutations causing hemophilia in the gene affected – the equivalent of a mutation rate of perhaps one in 25 million nucleotides across the genome.
Others have measured rates at a few further specific genes or compared DNA from humans and chimpanzees to produce general estimates of the mutation rate expressed more directly in nucleotides of DNA.
16 scientists report today the first direct measurement of the general rate of genetic mutation at individual DNA letters in humans and show that those early estimates were spot on.
A team of researchers say long held beliefs about how stars are formed have been just a myth, and they say this astronomy myth got busted using a set of galaxies found with CSIRO's Parkes radio telescope.
When interstellar gas collapses to form stars, the stars range from massive to minute. Since the 1950s many astronomers have believed that in a family of new-born stars the ratio of massive stars to lighter ones was always about the same — for every star 20 times more massive than the Sun or larger, you'd get 500 stars the mass of the Sun or less.