Excerpts from science, technology, environment and health reports from around the web.

How harmful is crack cocaine?

Hollywood seldom depicts junkies in suits and ties. But in recent weeks several public figures have admitted taking hard drugs while working in high-powered jobs. Toronto’s serially scandalous mayor, Rob Ford, has admitted that he smoked crack cocaine two years ago, while in office. Trey Radel, a Florida congressman, is under pressure to resign after being convicted of possessing powder cocaine. In Britain Paul Flowers, a former chairman of the Co-op bank (and a Methodist preacher to boot) was arrested after a newspaper filmed him apparently buying methamphetamine and other drugs.

If people can take hard drugs and still go on running a national bank or Canada’s biggest city, how dangerous can such substances be?

Fossil yields oldest known human DNA

Researchers have successfully sequenced the oldest known human DNA, and it points to unexpected relationships between hominid populations scattered across the length of Eurasia.

The genetic material came from a 400,000-year-old femur of Homo heidelbergensis, an early hominid considered to be the ancestor of both Neanderthals and modern humans. The achievement pushes back the age of the oldest hominid DNA sequencing by 200,000 years.

First example of tool use in reptiles

As predators go, there are lots of reasons to respect alligators and crocodiles. They hide patiently for hours, then launch a sudden attack with the strongest bite on the planet. Now, add cleverness to the list. In what appears to be the first example of tool use among reptiles, researchers have discovered that both animals use twigs and sticks to attract nest-building birds.

Remnants suggest Comet ISON still going

Comet ISON entered the annals of astronomical history on the night of 28 November, when it flew past the Sun and, latest updates suggest, emerged in tatters on the other side after many skywatchers had given it up as dead.

Still, the most recent images hint that most of ISON's nucleus disintegrated as the comet approached the Sun, leaving only a slim chance there will be anything left to see with the naked eye over the Northern Hemisphere in coming weeks.

CERN, eat your heart out?

Newly released research in Nature Communications from the Univ. of Alberta (U of A) has identified the existence of a giant cosmic accelerator above the Earth.

By analyzing data from NASA’s Van Allen probes, U of A physicist Ian Mann, together with his colleagues at NASA and other institutes, have been able to measure and identify the “smoking gun” of a planetary scale process that accelerates particles to speeds close to the speed of light within the Van Allen radiation belt.

Bitcoin Survival Guide: Everything you need to know about the future of money

The price of a bitcoin topped $900 last week, an enormous surge in value that arrived amidst Congressional hearings where top U.S. financial regulators took a surprisingly rosy view of digital currency. Just 10 months ago, a bitcoin sold for a measly $13.

The spike was big news across the globe, from Washington to Tokyo to China, and it left many asking themselves: “What the hell is a bitcoin?” It’s a good question — not only for those with little understanding of the modern financial system and how it intersects with modern technology, but also for those steeped in the new internet-driven economy that has so quickly remade our world over the last 20 years.

Physics solves centuries-old mystery of red paint darkening

Any regular museumgoer will recognize the darkened, muted color of red vermillion pigment that immediately signals that a painting is centuries old. But the reasons for this darkening are a mystery that dates back at least 1,200 years. Now scientists have used x-ray analysis of pigments in a medieval Spanish mural to study the degradation and have proposed a new explanation that had not been considered before.