Help

# Matter

warning: Creating default object from empty value in /var/www/vhosts/sayforward.com/subdomains/recorder/httpdocs/modules/taxonomy/taxonomy.pages.inc on line 33.

## Synthetic particles that flock like birds

A flock of starlings is called a murmuration.

Scientists have built a self-organizing system of synthetic particles that assemble into clusters in a way that mimics the complicated organization of flocks of birds or colonies of bacteria. The particles form a “living crystal” that moves, swirls, and adjusts to heal cracks.

Self-assembly is a common way to build materials. Often, individual building blocks stick together due to inherent attractions, like bases of DNA bonding to form a nanotube, proteins gathering to form a helical virus coat, or nanospheres gathering to form a photonic crystal.

But what draws flocks of starlings, schools of fish, or rafts of ants together? Flocking or schooling can be a social behavior. However, the similarities among these phenomena, regardless of the creatures involved, led NYU's Jérémie Palacci and his colleagues to wonder if an underlying physical principle could also govern the organization process.

## Powerful stellar outbursts could be sign of dual-core stars

The star V838 Monocerotis erupted catastrophically in 2002, growing from obscurity to become one of the brightest known stars in the Milky Way. As the comic strip above shows, it shed a lot of mass during the process. A new model may explain how this happened, if the star was actually part of a binary.

NASA/ESA/The Hubble Heritage Team (STScI/AURA)

Stars are plasma, gas ionized as the result of extreme internal temperatures. A solitary star will be mostly spherical under the force of its own gravity. However, when stars are in close binaries, their mutual attraction distorts their shapes. The extreme version of this is the common envelope stage, wherein the stars' outer regions merge to make a single, huge double star. According to theory, that is. While nobody seriously doubts this model, all the observational evidence for common envelope binaries is indirect.

A new Science paper proposes that a class of violent astronomical events that we've observed may be due to common envelope stars, providing more direct evidence for their existence. These cataclysms are known as "red transient outbursts," and in brightness terms, they're somewhere between novas (flares of nuclear activity at the surfaces of white dwarfs) and supernovas, the violent deaths of stars. N. Ivanova, S. Justham, J. L. Avendado Nandez, and J. C. Lombardi Jr. identified a possible physical model for these outbursts, based on the recombination of electrons and ions in the plasma when the stars' envelopes merge.

The most famous red transient outburst came from the star euphoniously known as V838 Monocerotis. Before 2002, nobody had noticed the star at all, but for a brief period of time, it expanded hugely, flared brightly, and shed an impressive amount of gas and dust into surrounding space. The Hubble Space Telescope (HST) tracked the outburst over the intervening years, but despite the regular check-ins, there is no widely accepted explanation for it.

## How Thorium can save the world: Salim Zwein at TEDxBeirut 2012

How Thorium can save the world: Salim Zwein at TEDxBeirut 2012

Staunch environmentalist, Salim Zwein informs us on Thorium; a cheap, efficient, clean and abundant energy source with the capacity to replace Uranium as a nuclear fuel, and turn the nuclear industry into a safe, environmental alternative. szwein@gmail.com F: Salim Zwein T: @SalimZwein S: salimzwein AboutTEDx In the spirit of ideas worth spreading, TEDx is a program of local, self-organized events that bring people together to share a TED-like experience. At a TEDx event, TEDTalks video and live speakers combine to spark deep discussion and connection in a small group. These local, self-organized events are branded TEDx, where x = independently organized TED event. The TED Conference provides general guidance for the TEDx program, but individual TEDx events are self-organized.* (*Subject to certain rules and regulations).
From:
TEDxTalks
Views:
9

11
ratings
Time:
13:04
More in
Nonprofits & Activism

## Gold rush

I witnessed gold bar production at Austria's Oegussa company and it was impressive to hold something of so much value.

## The Graphene Age isn't (quite) here yet

Enlarge / Scanning electron micrograph of graphene, showing the hexagonal structure of the single layer of carbon atoms.

Graphene—a two-dimensional sheet of carbon one atom thick—is exciting stuff. Combining good electrical properties, flexibility, mechanical strength, and other advantages, graphene can seem like a miracle material, especially when potential applications are listed. Talk of graphene-based protective coatings, flexible transparent electronics, super powerful capacitors, and so forth may seem like something from a Neal Stephenson science fiction novel, but they've all been seriously considered.

The material's potential is so high that its discovery merited the 2010 Nobel Prize in physics, awarded to Andre Geim and Konstantin Novoselov. Certainly my fellow Ars Technica writers and I have spilled a lot of digital ink on the subject.

However, with so much excitement, you would be forgiven for wondering if at least some of it is hype. (After all, graphene has been around for a number of years, but we don't have our transparent computers yet.) For this reason, Nobel Laureate Konstantin Novoselov and colleagues have written a critical, yet optimistic, assessment of the state of graphene research and production.

## ian willms – fort chipewyan

This SlideShowPro photo gallery requires the Flash Player plugin and a web browser with JavaScript enabled.

Hover over the image for navigation and full screen controls

EPF 2012 Finalist

Ian Willms

Fort Chipewyan

play this essay

If anyone would listen, the First Nations peoples in Fort Chipewyan, Canada, would tell them about an ongoing ‘slow motion cultural genocide’. The isolated indigenous reserves of Northern Alberta are watching their land become unlivable as their communities are slowly poisoned by the world’s largest and most environmentally destructive oil extraction project.

The Alberta Oil Sands are the second largest oil reserves on Earth next to Saudi Arabia and are worth an estimated \$1 trillion to Canada’s GDP over the next decade. This oil extraction involves an energy-intensive process of strip-mining and chemical upgrading. The liquid waste from Oil Sands production ends up in man-made tar lakes that are large enough to be visible from space. The Oil Sands have a larger carbon footprint than any other commercial oil product on Earth.

As the world entered the era of Peak Oil in 2003, Canada saw a dramatic boom in Oil Sands production. Since then, contaminated water systems, deformed fish, oil spills and alarmingly high rates of aggressive and fatal cancers have become part of life for the indigenous peoples of Northern Alberta. Industrial activity has all but wiped out the traditional economies of First Nations communities in the area. An important part of my work is to communicate how these problems now prevent people from sustaining themselves off of the land that has nurtured their lives for generations.

This work speaks to the disturbing truth that has been lost in a climate of misinformation. As part of their ‘Ethical Oil’ campaign, the Canadian Association of Petroleum Producers (CAPP) diligently publicizes industry-funded research and statistics that downplay or negate the environmental and health impacts of Oil Sands production. Meanwhile, First Nations peoples continue to lose their land, culture and lives. The Canadian government and the CAPP have made an individual and collective life expendable in the name of energy security and economic progress.

Bio

Born in 1985, in Kitchener, Canada, Ian Willms is an independent documentary photographer and a founding member of the Boreal Collective.

His curious and socially conscious nature has driven Ian to explore the fringes of our society, photographing abandoned environments and the people who inhabit them. From the depressed, post-apocalyptic suburbs of Detroit to the poisoned shorelines of Fort Chipewyan, Ian’s work is deeply rooted in the discussion of consumption, classism and social and political power struggles.

Ian’s work has been exhibited in North America and Europe, including solo exhibitions at Pikto Gallery and Gallery 44 Centre For Contemporary Photography and group exhibitions at O’Born Contemporary and Bau-Xi Photo. His work has also been supported and honoured by the Magnum Expression Photography Award, the National Press Photographers Association Best of Photojournalism competition, the Magenta Foundation and the Ontario Arts Council.

## Q: Is it possible for an artificial black hole to be created, or something that has the same effects? If so, how small could it be made?

Physicist: Not with any current, or remotely feasible technology.  The method in use by the universe today; get several Suns worth of mass into a big pile and wait, is a pretty effective way to create black holes.

In theory, all you need to do to create an artificial black hole (a “black faux”?) is to get a large amount of energy and matter into a very small volume.  The easiest method would probably be to use some kind of massive, super-duper-accelerators.  The problem is that black holes are dense, and the smaller and less massive they are the denser they need to be.

A black hole with the mass of the Earth would be so small you could lose it pretty easy.  Except for all the gravity.

But there are limits to how dense matter can get on its own.  The density of an atomic nucleus, where essentially all of the matter of an atom is concentrated, is about the highest density attainable by matter: about 1018 kg/m3, or about a thousand, million, million times denser than water.  This density is also the approximate density of neutron stars (which are basically giant atomic nuclei).

When a star runs out of fuel and collapses, this is the densest that it can get.  If a star has less than about 3 times as much mass as our Sun, then when it gets to this density it stops, and then hangs out forever.  If a star has more than 3 solar masses, then as it collapses, on it’s way to neutron-star-density, it becomes a black hole (a black hole with more mass needs less density).

The long-winded point is; in order to create a black hole smaller than 3 Suns (which would be what you’re looking for it you want to keep it around), it’s not a question of crushing stuff.  Instead you’d need to use energy, and the easiest way to get a bunch of energy into one place is to use kinetic energy.

There’s some disagreement about the minimum size that a black hole can be.  Without resorting to fairly exotic, “lot’s of extra dimensions” physics, the minimum size should be somewhere around $2\times 10^{-21}$ grams.  That seems small, but it’s very difficult (probably impossible) to get even that much mass/energy into a small enough region.  A black hole with this mass would be about 10-47 m across, which is way, way, way smaller than a single electron (about 10-15 m).  But unfortunately, a particle can’t be expected to concentrate energy in a region smaller than the particle itself.  So using whatever “ammo” you can get into a particle accelerator, you find that the energy requirements are a little steeper.

To merely say that you’d need to accelerate particles to nearly the speed of light doesn’t convey the stupefying magnitude of the amount of energy you’d need to get a collision capable of creating a black hole.  A pair of protons would need to have a “gamma” (a useful way to talk about ludicrously large speeds) of about 1040, or a pair of lead nuclei would need to have a gamma of about 1037, when they collide in order for a black hole to form.  This corresponds to the total energy of all the mass in a small mountain range.  For comparison, a nuclear weapon only releases the energy of several grams of matter.

CERN, or any other accelerator ever likely to be created, falls short in the sense that a salted slug in the ironman falls short.

There’s nothing else in the universe the behaves like a black hole.  They are deeply weird in a lot of ways.  But, a couple of the properties normally restricted to black holes can be simulated with other things.  There are “artificial black holes” created in laboratories to study Hawking radiation, but you’d never recognize them.  The experimental set up involves tubes of water, or laser beams, and lots of computers.  No gravity, no weird timespace stuff, nothin’.  If you were in the lab, you’d never know that black holes were being studied.

## Gergely Szatmari

This is an image from Gergely Szatmari's Meadowlands - not necessarily a particularly new subject matter, but the photographer found quite a few great shots. Also make sure to check out American Idler.