Good News: Harbor Porpoises’ Remarkable Return
After a 65-year absence, harbor porpoises are back in San Francisco Bay, providing scientists a unique view into their lives
by Anne Bolen
ON A BLUSTERY CALIFORNIA AUGUST DAY, researchers are studying some of San Francisco’s least-known residents from an unlikely laboratory: the Golden Gate Bridge. Below in the bay glides a parade of boats—fishing vessels, a tall ship, a slow container barge packed with colorful boxes like giant Legos.
Behind the scientists, tourists pause to snap pictures, unaware of the ongoing hunt. Through binoculars, Bill Keener suddenly spots his quarry: a harbor porpoise, its dark gray dorsal fin appearing briefly before resubmerging. Keener predicts the porpoise’s course and, just as it surfaces again, photographs the animal before it disappears. “Got it,” he declares triumphantly.
This harbor porpoise is one of more than 600 that Keener and the three other marine mammal scientists of Golden Gate Cetacean Research have recorded in the San Francisco Bay since 2008. This team, made up of Keener, Isidore Szczepaniak, Jonathan Stern and Marc Webber, is compiling the world’s first photo catalog of wild harbor porpoises…
(read more: National Wildlife)
photos: Golden Gate Cetacean Research
Lithium (from Greek: λίθος lithos, “stone”) is a chemical element with symbol Li and atomic number 3. It is a soft, silver-white metal belonging to the alkali metal group of chemical elements. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and flammable. For this reason, it is typically stored in mineral oil. When cut open, lithium exhibits a metallic luster, but contact with moist air corrodes the surface quickly to a dull silvery gray, then black tarnish. The lithium in the Gif above has been exposed for a few minutes and a black tarnish has already formed.
Fun Fact: Lithium is my favourite element. :)
The eastern emerald elysia (Elysia chlorotica) is a sea slug that steals and absorbs chloroplasts from the algae it eats, a behavior called kleptoplasty.
photograph by Patrick J. Krug
Penelope Eckert, Stanford
Andy Goldsworthy’s art
Six hundred goddamn AD
Six hundred. Goddamn AD.
This needs to be en-grained in every single living human.
What if you could fly through the universe and see dark matter? While the technology for taking such a flight remains under development, the technology for visualizing such a flight has taken a grand leap forward with the completion of the Bolshoi Cosmological Simulation.
After 6 million CPU hours, the world’s seventh fastest supercomputer output many scientific novelties including the above flight simulation. Starting from the relatively smooth dark matter distribution of the early universe discerned from the microwave background and other large sky data sets, the Bolshoi tracked the universe’s evolution to the present epoch shown above, given the standard concordance cosmology. The bright spots in the simulation above are all knots of normally invisible dark matter, many of which contain normal galaxies. Long filaments and clusters of galaxies, all gravitationally dominated by dark matter, become evident.
Statistical comparison between the Bolshoi and current real sky maps of actual galaxies show good agreement. Although the Bolshoi simulation bolsters the existence of dark matter, many questions about our universe remain, including the composition of dark matter, the nature of dark energy, and how the first generation of stars and galaxies formed.
- For more information about the Bolshoi Cosmological Simulation, click here.