Tag: science

New ice core data from Antarctica suggests in the past 10,000 years temperatures have often been higher than today, and that the rise in temperatures during the past 100 years is also not unprecedented.

12:37 pm

The uncertainty of science: New ice core data from Antarctica suggests that in the past 10,000 years temperatures have often been higher than today, and that the rise in temperatures during the past 100 years is also not unprecedented.

These results are actually not news. Climate scientists have known for decades that today’s climate is not unique, and that the Earth has gone through similar temperature fluctuations in the past. The results simply reconfirm this fact, and make any global warming claims to the contrary less believable.

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In a paper published today in Science, astronomers show that Type 1a supernovae, the kind used to measure the expansion rate of the universe, can be caused in more than one way, something not previously expected.

11:44 am

The uncertainty of science: In a paper published today in Science, astronomers show that Type 1a supernovae, the kind used to measure the expansion rate of the universe, can be caused in more than one way, something not previously expected.

Andy Howell, second author on the study, said: “It is a total surprise to find that thermonuclear supernovae, which all seem so similar, come from different kinds of stars. It is like discovering that some humans evolved from ape-like ancestors, and others came from giraffes. How could they look so similar if they had such different origins?” Howell is the leader of the supernova group at LCOGT, and is an adjunct faculty member in physics at UCSB.

Recently, some studies have found that Type Ia supernovae are not perfect standard candles –– their brightness depends on the type of galaxy in which they were discovered. The reason is a mystery, but the finding that some Type Ia supernovae come from different progenitors would seem to suggest that the supernova’s ultimate brightness may be affected by whether or not it comes from a nova or a white dwarf merger.

“We don’t think this calls the presence of dark energy into question,” said Dilday. “But it does show that if we want to make progress understanding it, we need to understand supernovae better.”

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Sunspots and climate

8:54 am

Scientists have found new evidence that the solar sunspot cycle has influenced the Earth’s climate in the recent past.

Sirocko and his colleagues found that between 1780 and 1963, the Rhine froze in multiple places fourteen different times. The sheer size of the river means it takes extremely cold temperatures to freeze over making freezing episodes a good proxy for very cold winters in the region, Sirocko said.

Mapping the freezing episodes against the solar activity’s 11-year cycle — a cycle of the Sun’s varying magnetic strength and thus total radiation output — Sirocko and his colleagues determined that ten of the fourteen freezes occurred during years when the Sun had minimal sunspots. Using statistical methods, the scientists calculated that there is a 99 percent chance that extremely cold Central European winters and low solar activity are inherently linked.

Also this:
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Are the glaciers in the Himalayas shrinking? A third paper published today falls between one study that said no and another that said yes.

11:17 am

The uncertainty of science: Are the glaciers in the Himalayas shrinking? A third paper published today falls between one study that said no and another that said yes.

The new estimate raises further questions about satellite and field measurements of alpine glaciers, and ”will set the cat among the pigeons,” says Graham Cogley, a remote-sensing expert at Trent University in Peterborough, Ontario. … Although the ICESat results show twice as much ice loss as the re-interpreted GRACE data, this figure is still three times lower than regional losses estimated on the basis of field studies.

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One of Curiosity’s two wind sensors has been found to be damaged and is inoperable.

6:57 pm

One of Curiosity’s two wind sensors was apparently damaged in landing and is inoperable.

The Rems team first noticed there was something wrong when readings from the side-facing boom were being returned saturated at high and low values. Further investigation suggested small wires exposed on the sensor circuits were open, probably severed. It is permanent damage. No-one can say for sure how this happened, but engineers are working on the theory that grit thrown on to the rover by the descent crane’s exhaust plume cut the small wires. The wind sensor on the forward-facing mini-boom is unaffected. With just the one sensor, it makes it difficult to fully understand wind behaviour.

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Astronomers have now confirmed 41 new exoplanets, first pinpointed by the Kepler space telescope

5:20 pm

Astronomers have now confirmed 41 new exoplanets, first pinpointed by the Kepler space telescope.

One paper, by Jiwei Xie at the University of Toronto, confirms 24 new planets in 12 systems. Another study, by Steffen and his colleagues, confirms 27 planets in 13 systems. Five of the systems, and 10 of the planets, are the same in both papers. All in all, the new research adds 20 new planetary systems to the 47 that Kepler had previously confirmed, marking a more than 40 percent increase.

Among the Kepler candidates are five Earth-sized planets in the habitable zone, according to the vidoe at the link. However, this announcement does not tell us if any of those candidates were confirmed by these two papers.

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NASA has announced its next planetary mission, a lander to Mars that will drill down thirty feet into the planet’s surface

3:36 pm

NASA has announced its next planetary mission, a lander to Mars that will drill down thirty feet into the planet’s surface.

Though exciting in its own right, this mission is far less ambitious than the two missions which competed against it, a boat that would have floated on the lakes of Titan and a probe that would have bounced repeatedly off the surface of a comet. I suspect the reason this mission was chosen is the tight budgets at NASA, combined with Curiosity’s success which makes it politically advantageous to approve another Mars mission. As the NASA press release emphasized,
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On August 13, 2012, Voyager 2 became the longest-operating spacecraft in history, finally topping Pioneer 6, which was launched on Dec. 16, 1965, and sent its last signal back on Dec. 8, 2000.

2:00 pm

On August 13, 2012, Voyager 2 became the longest-operating spacecraft in history, finally topping Pioneer 6, which was launched on Dec. 16, 1965, and sent its last signal back to Earth on Dec. 8, 2000.

And Voyager 2, along with its partner Voyager 1, are still working, and engineers hope they will still be working for another eight to twelve years, enough time for them to leave the solar system and enter interstellar space.

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Engineers at Sandia National Laboratories have developed a robot hand that costs less than $10,000.

9:48 am

Engineers at Sandia National Laboratories have developed a robot hand that costs less than $10,000 and is capable of replacing a flashlight battery.

The researchers were able to scrimp in a number of clever ways. “One was scouring the globe for the least expensive, highest-performing components like motors, gears, etcetera,” says Curt Salisbury, the project’s principal investigator. “Another was to build the entire electronics system from commodity parts, especially those found in cell phones. We also moved from metal structural elements to plastic, being careful to design the structures so plastic would provide adequate strength.”

The article focuses on the potential of using such a robot hand to defuse bombs. I see it as a first step in providing amputees a replacement hand that is fully functional. And that their goal is to bring the cost down to $1,000 is even more exciting.

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Earth spacecraft on Mars fires its laser for the first time.

2:59 pm

War of the Worlds! The Earth invading spacecraft on Mars has fired its laser for the first time!

Forgive me the hyperbole. I have this childhood vision from that moment when I first read H.G. Wells’ War of the Worlds, when the Martian tripod first rose up and fired its death ray at a crowd of curious humans. And here we are, a century after Wells penned that classic science fiction novel, and humans have put a spacecraft on Mars, Curiosity, capable of firing lasers! The laser isn’t a death ray but a scientific tool, but nonetheless the ironies remain delicious.

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The failed predictions of the last half century of scientific doomsayers.

7:39 pm

The failed predictions of the last half century of scientific doomsayers.

It is entertaining to read this long list of foolish predictions describing the certain and soon-to-arrive end of humanity. Maybe the best is the prediction of Rajendra Pachauri, head of the IPCC, who in 2007 predicted that “if there’s no action before 2012, that’s too late … This is the defining moment.”

However, it is Ridley’s concluding thoughts about climate change that are maybe the most worthwhile:

We hardly ever allow the moderate “lukewarmers” a voice: those who suspect that the net positive feedbacks from water vapor in the atmosphere are low, so that we face only 1 to 2 degrees Celsius of warming this century; that the Greenland ice sheet may melt but no faster than its current rate of less than 1 percent per century; that net increases in rainfall (and carbon dioxide concentration) may improve agricultural productivity; that ecosystems have survived sudden temperature lurches before; and that adaptation to gradual change may be both cheaper and less ecologically damaging than a rapid and brutal decision to give up fossil fuels cold turkey.

Read the whole thing. It is a truly educational experience.

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Facing tight budgets, a National Science Foundation panel has recommended the shuttering of five major ground-based telescopes.

5:46 pm

Facing tight budgets, a National Science Foundation panel has recommended the shuttering of five major ground-based telescopes.

Stay tuned for loud screams of outrage. However, some of these facilities have not been very useful for years. Consider the Robert C. Byrd Green Bank Radio Telescope. It was only rebuilt after it collapsed in 1988 because of the political clout of Senator Robert Byrd. By the time that reconstruction was finished, a process that took more than 20 years, the telescope was completely obsolete. Though it has done some good science, it is far outmatched by other radio telescope arrays.

Many of the facilities are funded merely due to bureaucratic and political inertia. For the astronomical community to be willing to recognize this is a good thing, for which they should be lauded.

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The promised land: where Curiosity is headed.

1:48 pm

The promised land: where Curiosity is headed.

This image (cut out from a mosaic) shows the view from the landing site of NASA’s Curiosity rover toward the lower reaches of Mount Sharp, where Curiosity is likely to begin its ascent through hundreds of feet (meters) of layered deposits. The lower several hundred feet (meters) show evidence of bearing hydrated minerals, based on orbiter observations. The terrain Curiosity will explore is marked by hills, buttes, mesas and canyons on the scale of one-to-three story buildings, very much like the Four Corners region of the western United States.

Click through to the image itself. Like all mountains, what appears to be a featureless mountainside from a distance instead becomes a complex and rough terrain in close-up.

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The mysterious dark streaks on Vesta

11:25 am

dark material on Vesta

In a preprint paper published today at the Los Alamos astro-ph website, scientists have taken a detailed look at the mysterious dark streaks seen by Dawn on the surface of the asteroid Vesta and have concluded that the material comes from impacts, not from volcanic activity.

The scientists also concluded that

the majority of the spectra of [dark material] are similar to carbonaceous chondrite meteorites mixed with materials indigenous to Vesta.

Carbonaceous chondrite meteorites are considered to be the most primeval material in the solar system. This means that Vesta has the potential to give scientists a convenient laboratory for studying that primeval material and the early formation of the solar system. Ideally, the best way to do this would of course be to go there.

The scientists also theorize that much of this material was brought to Vesta by a single large impact.
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