Proposed experiment would prove that quantum jumps are not objective events

The famous physicist Niels Bohr first conceived of the notion of quantum jumps, or quantum leaps, in 1913. Bohr understood quantum jumps as objective events in which an atom emits or absorbs a photon, causing an electron to jump from one energy level – or quantum state – to another inside the atom. But a few decades later, when physicists began to understand how the act of measuring can affect the result in quantum mechanics, the assumed objectivity of quantum jumps required a second look.

Then in the early 1990s, physicists developed quantum trajectory theory, showing that quantum jumps are not caused by the emission of a photon, but by the detection of a photon. If an emitted photon is not detected, then there is no quantum jump. In other words, quantum jumps are detector-dependent, which is in marked contrast to Bohr’s objective emission events.

Despite the wide acceptance of the assertion that there can be no detector-independent quantum jumps, no experiment has ever been performed to rigorously test this claim.

Now in a new study, physicists Howard M. Wiseman at Griffith University in Queensland, Australia, and Jay M. Gambetta at the IBM T.J. Watson Research Center in Yorktown Heights, New York, have proposed experimental tests to prove that all quantum jumps must be detector-dependent. Their work is published in a recent issue of Physical Review Letters.

“Our work relates to something everyone has heard of (quantum jumps) but says that their fundamental nature has still not been established experimentally,” Wiseman told Phys.org. “By proposing actual experiments, it gives experimentalists a real motivation to try to increase their collection and detection efficiency.”

The proposed tests would rule out not just certain specific detector-independent models of quantum jumps, but all models that could conceivably describe quantum jumps as detector-independent.

(more at phys.org) 

 ”This is it—the paradigm shift,” archaeologist Chris Fisher told Ars. “Just like the advent of radiocarbon dating, LiDAR will have the same impact.”

LiDAR, or “light detection and ranging,” acts as a sort of radar with light, painting the target area with lasers and recording the time it takes to reflect back to the instruments.

An archaeologist specializing in Western Mexico, Fisher studies the way environments affect and change cultures. LiDAR has helped him repaint the picture of ancient Mexico, bringing the little-known Purepecha empire a lot more historical prominence.

(via Indiana Jones goes geek: Laser-mapping LiDAR revolutionizes archaeology) 

Black Panther Party, 1966

(Source: sluteverbabe, via monstermadeofeyes)

smooth:

RD_LA_FK_FRONT_2.jpg

FELA KUTI & AFRICA 70

(via monstermadeofeyes)

biaguedes:

MARIE SKLODOWSKA CURIE opened up the science of radioactivity. She was the discoverer of the radioactive elements polonium and radium and  the first person to win two Nobel prizes. For scientists and the public, her radium was a key to a basic change in our understanding of matter and energy. Her work not only influenced the development of fundamental science but also ushered in a new era in medical research and treatment

Trane!

Mystery Fossils Link Fungi to Ancient Mass Extinction

Of the five mass extinctions in the Earth’s past, one stands above the rest in magnitude: the Permian-Trassic extinction, known as the Great Dying. It saw the disappearance of almost 60 percent of all families, and over 80 percent of all genera — in the ocean, that added up to about 96 percent of all species. The cause of this event, 250 million years in the past, is still a matter of debate.

The most likely culprit is the prolific volcanism of the Siberian Traps — the erupted basalt still covers about 2 million square kilometers — but other events may have also played a role. Evidence for a massive destabilization of methane hydrates on the seafloor (a phenomenon described as “The Big Burp”), ocean anoxia and even contemporary asteroid impacts have all been found.

A couple of recent papers in the journal Geology have brought some new information to the discussion, and may help make the picture just a little bit clearer.

One source of significant mystery has been the nature of the organic microfossils that are common in rocks dated to the time of the extinction worldwide. The tiny fossils resemble filamentous colonies of cells, but have evaded positive identification.

Some researchers think they are the remains of fungi, while others argue that they are algae instead. There’s evidence on both sides, but the two scenarios represent very different conditions. The fungus indicates a widespread dying of woody vegetation, while algae suggest extensive swamps forming along river systems.

A paper published this month shows that the microfossils are almost identical morphologically to a group of pathogenic soil fungi that can infect trees. If its authors have identified these correctly, it fits in well with an overall picture showing loss of forests and topsoil. The demise of tree species is clear in pollen studies, and there is a lot of evidence for greatly accelerated soil erosion, including increased sediment deposition in deltas with lots of soil-derived organic debris.

Modern studies show that drought stress and UV damage, both of which could be caused by the massive releases of volcanic gases from the Siberian Traps, can make trees susceptible to fungal infection.

Connecting a fungus to a global mass extinction may seem tenuous, but the authors point out that processes down in the world of the very small are often overlooked in any extinction discussions. They summarize by saying, “There may have been a variety of other globally operating environmental stress factors, but whatever sequence of events triggered ecosystem destabilization on land, the aggressiveness of soil-borne pathogenic fungi must have been an integral factor involved in Late Permian forest decline worldwide.”

(via Wired.com)

scandyfactory:

It’s Big. It’s Heavy…It’s Wood.

(via monstermadeofeyes)

marsiouxpial:

study of insects, herman hestenburg, 1682-1726

(Source: spacehotelusa, via scientificillustration)

Well, yeah.

comicallyvintage:

Do you want to be Astronaut tough?

scienceetfiction:

Secured on a foot restraint device connected to the Canadian-built remote manipulator system arm aboard the Earth orbiting Atlantis, astronaut Jerry Ross, in Nov. 1985, participates (with astronaut Sherwood Spring, out of frame) in a STS-61B demonstration of future space station construction. 

info via NASA

(Source: mrcainessuits, via eirizu)

Why so cold? The last refuge of Antarctica’s forests

We know Antarctica as an unfathomably cold wasteland, suitable for little beyond penguins and foolhardy researchers. But it hasn’t always been like that. At times in the distant past, plate tectonics and warmer climates have combined to cover Antarctica with lush forests, dinosaurs, and even marsupials. A paper published in PNAS details the final transition from habitable continent to the inhospitable ice cap that has developed over the past 40 million years. Its results describe the ecosystems that survived in the last unglaciated corner of Antarctica before the ice sheet swept away the last remnants of terrestrial life.

(via Ars Technica)

Seeing beneath the surface at Knole

Helen Fawbert and her team at Knole have recently spent a day x-raying some of the magnificent pieces of furniture in the house…

(via Treasure Hunt)