Exploring the last white spot on Earth

by Staff Writers
Grenoble, France (SPX) Nov 15, 2011

This image shows the heating of a catalyst sample in an "in situ" cell at actual operating conditions. The catalyst is studied using time-resolved X-ray absorption spectroscopy. At ID24, the time resolution can be as short as a few microseconds. Credit: ESRF.

Scientists will soon be exploring matter at temperatures and pressures so extreme it can only be produced for microseconds using powerful pulsed lasers. Matter in such states is present in the Earth’s liquid iron core, 2500 kilometres beneath the surface, and also in elusive "warm dense matter" inside large planets like Jupiter.

A new X-ray beamline ID24 at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France, allows a new quality of exploration of the last white spot on our globe: the centre of the Earth.

We know surprisingly little about the interior of the Earth. The pressure at the centre can be calculated accurately from the propagation of Earthquake waves, and it is about three and a half million times atmospheric pressure. The temperature at the centre of the Earth, however, is unknown, but it is thought to be roughly as hot as the surface of the sun.

ID24, which was inaugurated today, opens new fields of science, being able to observe like in a time-lapse film sequence many rapid processes, whether laser-heating of iron to 10.000 degrees, charge reactions in new batteries or catalysts cleaning pollutants.

It is the first of eight new beamlines built within the ESRF Upgrade Programme, a 180 million Euros investment over eight years to maintain the world-leading role of the ESRF. ID24 extends the existing capabilities at the ESRF in X-ray absorption spectroscopy to sample volumes twenty times smaller and time resolutions one thousand times better than in the past.

“Scientists can use several other synchrotrons notably in Japan and the U.S for fast X-ray absorption spectroscopy, but it is the microsecond time resolution for single shot acquisition (or experiments) coupled to the micron sized spot that makes ID24 unique worldwide,” says Sakura Pascarelli, beamline responsible scientist for ID24.

“The rebuilt ID24 sets the ESRF apart, and even before the first users have arrived, I am asked to share our technology.”

The Earth’s interior is literally inaccessible and today it is easier to reach Mars than to visit even the base of the Earth’s thin crust.

Scientists can however reproduce the extreme pressure and temperature of a planet’s interior in the laboratory, using diamond anvil cells to squeeze a material and once under pressure, heat it with short, intense laser pulses. However, these samples are not bigger than the size of a speck of dust and remain stable under high temperatures only for very short time, measured in microseconds.

Thanks to new technologies employed at ID24, scientists can now study what happens at extreme conditions, for example when materials undergo a fast chemical reaction or at what temperature a mineral will melt in the interior of a planet. Germanium micro strip detectors enable measurements to be made sequentially and very rapidly (a million in one second) in order not to miss any detail.

A stable, microscopic X-ray beam means they can also be made in two dimensions by scanning across a sample to obtain a map instead of a measurement only at a single point. A powerful infrared spectrometer complements the X-ray detectors for the study of chemical reactions under industrial processing conditions.

Today, geologists want to know whether a chemical reaction exists between the Earth’s mostly liquid core and the rocky mantle surrounding it.

They would like to know the melting temperature of materials other than iron that might be present in the Earth’s core in order to make better models for how the core – which produces the Earth’s magnetic field – works and to understand why the magnetic field changes over time and periodically in Earth’s history, has disappeared and reversed.

We know even less about warm dense matter believed to exist in the core of larger planets, for example Jupiter, which should be even hotter and denser. It can be produced in the laboratory using extremely powerful laser shock pulses compressing and heating a sample.

The dream of revealing the secrets of the electronic and local structure in this state of matter with X-rays is now becoming reality, as ID24 allows to look at sample volumes 10000 times smaller than those at the high power laser facilities, making these experiments possible at the synchrotron using table top lasers.

The ID24 beamline works like an active probe rather than a passive detector, firing an intense beam of X-rays at a sample. It uses a technique called X-ray absorption spectroscopy where the way how atoms of a given chemical element absorb X-rays is studied in fine detail.

From this data not only the abundance of an element can be deducted but also its chemical states and which other atoms, or elements, are in their immediate neighborhood, and how distant they are. In short, a complete picture at the atomic scale of the sample studied is obtained.

In the past weeks, ID24 has been tested with X-ray beams, and it will be open for users from across the world as of May 2012, after the ESRF winter shutdown 2011/12. The date for its inauguration was chosen to coincide with the autumn meeting of the ESRF’s Science Advisory Committee of external experts who played a key role in selecting the science case for ID24 and the other Upgrade Beamlines.

“ID24 opens unchartered territories of scientific exploration, as will the seven other beamlines of the ESRF Upgrade Programme. The economic crisis has hit our budgets hard, and it is not obvious to deliver new opportunities for research and industrial innovation under these circumstances”, says Harald Reichert, ESRF Director of Research.

“I wish to congratulate the project team for extraordinary achievements, and I look forward to seeing some extraordinary new science.”

via Exploring the last white spot on Earth.

US Northern Lights Show Anticipation Mounting

By Kristina Pydynowski, Senior Meteorologist

Nov 6, 2011; 10:54 AM ET

Photo by Randy Halverson in Cross Plains, Wis.

Anticipation is mounting that soon the world will be treated to an incredible light show with a sunspot bubbling with activity.

Spaceweather.com reports that the unusually large sunspot unleashed at least five M-class solar flares since Saturday and has a "delta-class magnetic field that harbors energy for X-class flares."

Solar flares are ranked by NOAA’s Space Weather Prediction Center (SWPC) based on their x-ray energy output. M-class solar flares are the second strongest with X-class flares sitting at the top of the list.

The sunspot sparking an X-class solar flare, however, would not necessarily translate to enhanced northern lights (called southern lights in the Southern Hemisphere).

A coronal mass ejection, or CME (a cloud of charged particles), must follow the solar flare in order for the Earth to witness a magnificent light show with communication disruptions also a possibility.

Joe Kunches from SWPC told AccuWeather.com that in some cases a CME is never produced.

Even if a CME occurs, it may not head to Earth, as was the case last Thursday. With the sunspot situated on the sun’s outer edge (from Earth’s viewing point), the CME that was unleashed took aim on Mercury and Venus instead.

The Earth has a better chance at feeling the effects of a CME through midweek as the sunspot rotates with the sun and faces toward Earth.

The sunspot, labeled 1339, can be seen at the top of this image (courtesy of NASA's Solar and Heliospheric Observatory) with its size relative to Earth and Jupiter shown in the lower right hand corner. The sunspot was positioned close to the sun's left edge on Friday.


If the sunspot erupts and an Earth-bound CME is produced, Kunches reports that it could reach the planet in as little as 18 hours, or as long as three or four days.

The strength of the eruption determines the speed of the CME, which NOAA can calculate based on observational tools currently in place.

From these calculations, NOAA can then estimate when the CME will reach Earth. The accuracy of such predictions, according to Kunches, has improved to within five hours of its actual arrival.

AccuWeather.com Astronomy Blogger Mark Paquette will continue to provide updates on any eruptions.

In the event a CME is expected to reach Earth, be sure to check your local AccuWeather.com forecast to find out if rain, snow or clouds will obscure your view of what promises to be a magnificent light show.

via US Northern Lights Show Anticipation Mounting.

Experts use magnetic scanner to see videos ‘playing’ inside people’s brains

So our minds CAN be read: Magnetic scanner produces these actual images from inside people’s brains

Process reproduces visual images from analysis of blood flow to brain

Experts believe it could be used in future to analyse dreams and memories

By CHRIS PARSONS and ROB WAUGH

Last updated at 9:44 AM on 28th October 2011

Scientists have created a revolutionary brain imaging process which allows them to ‘see’ moving images inside people’s minds. As the test subjects think of a video, the researchers ‘see’ it on screen.

It’s the most astonishing demonstration of ‘mind reading’ technology ever demonstrated.

The academics from the University of California, Berkeley, managed to decipher brain activity by measuring blood flow through the brain’s visual cortex, and used this information to construct images of what they were ‘thinking’. 

Reproduction: An image, left, of Steve Martin in Pink Panther 2 is amazingly recreated through analysis of blood flow into the brain’s visual cortex to produce the representation on the right

They then converted this information into visual patterns after feeding it through a computer, in a process which scientists say ‘opens a window into the movie of our minds’.

As yet, the technology can only recognise and reconstruct movie clips shown to the test subjects before they braved the scanner.

However, the breakthrough paves the way for reproducing the movies inside our heads that no one else sees, such as dreams and memories, according to researchers.

Professor Jack Gallant, a UC Berkeley neuroscientist, said: ‘This is a major leap toward reconstructing internal imagery.’

[…]

Test subjects watched two separate sets of Hollywood movie trailers, while an MRI scanner was used to measure blood flow through the visual cortex, the part of the brain that processes visual information.

On the computer, the brain was divided into small, three-dimensional cubes – a computer-imaging term known as volumetric pixels, or ‘voxels.’

Shinji Nishimoto, one of the scientists involved in the procedure, said: ‘We built a model for each voxel that describes how shape and motion information in the movie is mapped into brain activity.’

The brain activity recorded while subjects viewed clips was fed into a computer program that learned, second by second, to associate visual patterns in a particular film with the corresponding brain activity.

The computer was then ‘fed’ information so that it could construct its own ‘versions’ of the trailers the subjects were watching – without using the original material. This was done by feeding 18 million seconds of random YouTube videos into the computer program.

The computer then cross-refefenced the two sets of data – and the subjects were shown an entirely new set of film trailers.

The 100 YouTube clips that the computer program decided were most similar to the trailer the subject was watching were merged, creating a blurry, but recognisable image of what was ‘happening’ inside their minds.

[You’ve got to see the rest of the images to believe them…]

via Mind’s eye: Experts use magnetic scanner to see videos ‘playing’ inside people’s brains | Mail Online.