SciTechDaily;

UCLA chemists have discovered a major flaw in a fundamental rule of organic chemistry that has held for 100 years. They say it’s time to rewrite the textbooks.

Organic molecules, which are primarily made of carbon, have specific shapes and arrangements of atoms. Molecules called olefins contain double bonds, or alkenes, between two carbon atoms. Typically, these atoms and their attached groups lie in the same 3D plane, and deviations from this structure are rare.

The rule being questioned, known as Bredt’s rule, was established in 1924. It asserts that molecules cannot have a double bond at the “bridgehead” position—the junction of a bridged bicyclic molecule—because this position would distort the geometry of the double bond. Bredt’s rule has constrained the design of synthetic molecules by preventing chemists from creating certain structures. Since olefins play a critical role in pharmaceutical research, Bredt’s rule has limited the types of molecules that scientists could envision, potentially holding back innovations in drug discovery.

h/t

Everything is Amazing:

This is one of the great underlying wonders of practical modern archaeology: how fantastically incomplete it is, and how much has still to be discovered.

Easter Island findings change everything we know about the Earth’s mantle.

Geoffrey Kabat;

In 2003, UCLA epidemiologist James Enstrom and I published a study of environmental tobacco smoke (ETS)—also called “secondhand smoke” or “passive smoking”—in the British Medical Journal (BMJ). Using data from the American Cancer Society’s prospective study of 1 million adults, we concluded that ETS exposure was not associated with increased mortality.

Since that conclusion flew in the face of the conventional wisdom that had long driven state and local bans on smoking in public places, our study understandably sparked a controversy in the public health community. But the intensity of the attack on us in the pages of a medical journal—by critics who were certain that our study had to be wrong but typically failed to provide specific evidence of fatal errors—vividly illustrates what can happen when policy preferences that have taken on the status of doctrine override rational scientific debate.

A recent study by American Cancer Society (ACS) researchers underscores that point by showing that, contrary to what our critics asserted, the cancer risk posed by ETS is likely negligible. The authors present that striking result without remarking on it, which may reflect their reluctance to revisit a debate that anti-smoking activists and public health officials wrongly view as long settled.

Because there’s no grift in “likely negligible”.