Misc. science facts

[twilyth]

Fructose may increase hunger more than glucose.

The type of sugar you consume may affect how quickly subsequent hunger pangs kick in, according to new research. A new study compared the effects of fructose and glucose on hunger and food responses in the brain.

24 healthy people were asked to drink a beverage sweetened with fructose one day and glucose another. Before and after each session, blood samples were taken and the participants rated their hunger level and motivation for food on a scale of 1 to 10. They also underwent brain scans while they were shown images of high-calorie foods. The men and women reported greater appetite after drinking fructose compared with glucose. Their scans also showed more activity in areas of the brain related to food cue reaction in response to the images. When offered a choice between delayed monetary rewards or immediate high-calorie food rewards, participants were more willing to choose food after ingesting fructose.The study authors say these findings suggest fructose may not produce the same feelings of fullness and satisfaction as glucose.

 

[twilyth]

A new state of matter discovered.

When an international team of physicists, chemists, and material scientists tested the phase properties of a new type of material that they had created in the lab, they discovered something they had never seen before: A substance that exhibited the properties of an insulator, superconductor, metal, and magnet all in one. They published their results in the journal Science Advances on April 17.

They did it by taking a crystalline arrangement of carbon-60 molecules — or buckyballs — and inserting, or doping, the substance with atoms of rubidium, a type of alkali metal. The scientists could then control the distance and pressure between the buckyballs by manipulating the rubidium atoms to tune the substance's phases — sort of like how you can change a solid into a liquid by dislodging the atoms from their rigid structure.

While they were tweaking the pressure between the buckyballs, the team came across a phase shift that transformed the material from an insulator into a conductor — a process called the Jahn-Teller effect that was first predicted in 1937. Appropriately, the team is calling this novel material a Jahn-Teller metal.

 

[twilyth]

At 7 orders of magnitude higher than the maximum energy of the LHC, the Oh-My-God particle has created a mystery that researchers are trying to explain.

The Particle That Broke a Cosmic Speed Limit

On the night of October 15, 1991, the “Oh-My-God” particle streaked across the Utah sky.

A cosmic ray from space, it possessed 320 exa-electron volts (EeV) of energy, millions of times more than particles attain at the Large Hadron Collider, the most powerful accelerator ever built by humans. The particle was going so fast that in a yearlong race with light, it would have lost by mere thousandths of a hair. Its energy equaled that of a bowling ball dropped on a toe. But bowling balls contain as many atoms as there are stars. “Nobody ever thought you could concentrate so much energy into a single particle before,” said David Kieda, an astrophysicist at the University of Utah.

It's a long article but well worth reading if you're interested in this sort of stuff.

 

[twilyth]

What really makes a particle accelerator useful? Trackers and calorimeters.

Much of the complexity of particle physics experiments can be boiled down to two basic types of detectors: trackers and calorimeters. They each have strengths and weaknesses, and most modern experiments use both.

The first tracker started out as an experiment to study clouds, not particles. In the early 1900s, Charles Wilson built an enclosed sphere of moist air to study cloud formation. Dust particles were known to seed cloud formation—water vapor condenses on the dust to make clouds of tiny droplets. But no matter how clean Wilson made his chamber, clouds still formed.

Moreover, they formed in streaks, especially near radioactive sources. It turned out that subatomic particles were ionizing the air, and droplets condensed along these trails like dew on a spider web.

This cloud chamber was phenomenally useful to particle physicists—finally, they could see what they were doing! It's much easier to find strange, new particles when you have photos of them acting strangely. In some cases, they were caught in the act of decaying—the kaon was discovered as a V-shaped intersection of two pion tracks, since kaons decay into pairs of pions in flight.

In addition to turning vapor into droplets, ionization trails can cause bubbles to form in a near-boiling liquid. Bubble chambers could be made much larger than cloud chambers, and they produced clear, crisp tracks in photographs. Spark chambers used electric discharges along the ionization trails to collect data digitally.

More recently, time projection chambers measure the drift time of ions between the track and a high-voltage plate for more spatial precision, and silicon detectors achieve even higher resolution by collecting ions on microscopic wires printed on silicon microchips. Today, trackers can reconstruct millions of three-dimensional images per second.

The disadvantage of tracking is that neutral particles do not produce ionization trails and hence are invisible. The kaon that decays into two pions is neutral, so you only see the pions. Neutral particles that never or rarely decay are even more of a nuisance. Fortunately, calorimeters fill in this gap, since they are sensitive to any particle that interacts with matter.

Interestingly, the Higgs boson was discovered in two decay modes at once. One of these, Higgs to four muons, uses tracking exclusively, since the muons are all charged and deposit minimal energy in a calorimeter. The other, Higgs to two (neutral) photons, uses calorimetry exclusively.

 

[Deleted member 67555]

sub'd for good reads

 

[twilyth]

And after the cloud chamber was the bubble chamber - long thought to have been inspired by drinking beer, even if that turns out not to be true (or at least the inventor won't admit it )

A bubble chamber is a vessel filled with a superheated transparent liquid (most often liquid hydrogen) used to detect electrically charged particles moving through it. It was invented in 1952 by Donald A. Glaser,[1] for which he was awarded the 1960 Nobel Prize in Physics.[2] Supposedly, Glaser was inspired by the bubbles in a glass of beer; however, in a 2006 talk, he refuted this story, although saying that while beer was not the inspiration for the bubble chamber, he did experiments using beer to fill early prototypes.[3]

 

[twilyth]

Follow up article on particle detectors - calorimeters.

The previous article in this series introduced tracking, a technique that allows physicists to see the trajectories of individual particles. The biggest limitation of tracking is that only charged particles ionize the medium that forms clouds, bubbles, discharges or digital signals. Neutral particles are invisible to any form of tracking.

Calorimetry, which now complements tracking in most particle physics experiments, takes advantage of a curious effect that was first observed in cloud chambers in the 1930s. Occasionally, a single high-energy particle seemed to split into dozens of low-energy particles. These inexplicable events were called “bursts,” “explosions” or “die Stöße.” Physicists initially thought they could only be explained by a radical revision of the prevailing quantum theory.

As it turns out, these events are due to two well-understood processes, iterated ad nauseam. Electrons and positrons recoil from atoms of matter to produce photons, and photons in matter split to form electron-positron pairs. Each of these steps doubles the total number of particles, turning a single high-energy particle into many low-energy particles.

This cascading process is now known as a shower. The cycle of charged particles creating neutral particles and neutral particles creating charged particles can be started by either type, making it sensitive to any particle that interacts with matter, including neutral ones. Although the shower process is messy, the final particle energies should add up to the original particle's energy, providing a way to measure the energy of the initial particle—by destroying it.

Modern calorimeters initiate the shower using a heavy material and then measure the energy using ordinary light sensors. To accurately measure the energy of the final photons, this heavy material should also be transparent. Crystals are a common choice, as are lead-infused glass, liquid argon and liquid xenon.

Not all calorimeters are made in the laboratory. Neutrinos produce electrons in water or ice, which cascade into showers of electrons, positrons and photons. The IceCube experiment uses a cubic kilometer of Antarctic ice to observe neutrinos a hundred times more energetic than the beams in the Large Hadron Collider. Cosmic rays form showers in the Earth's atmosphere, producing about 4 watts of ultraviolet light and billions of particles. The Pierre Auger Observatory uses sky-facing cameras and 3000 square kilometers of ground-based detectors to capture both and has measured particles that are a million times more energetic than the LHC's beams.

 

[CAPSLOCKSTUCK]

The light powered by GRAVITY: Lamp uses energy from falling weight to illuminate homes without electricity


It works using a pulley system where a weight can be fixed at one end and as it drops the force drives a generator through a series of low torque gears.
The generator produces just under a tenth of a watt which powers an LED light on the unit itself and two smaller satellite lights that can be hung over a desk or bed.

The designers of GravityLight claim that with a 26lb (12kg) weight it is possible to provide between 25 minutes of light if installed at a height of six feet (1.8 metres).


Jim Reeves and Martin Riddiford, who are based in London, invented the device.
They point out that unlike devices that rely upon solar energy to provide power to remote communities, gravity does not disappear at night.
The device is installed to the ceiling of a room and a bag filled with around 26ft (12kg) of rocks or sand is attached to a cord that runs through the unit.
A beaded cord running through the unit allows the weight to be lifted into the air and it then falls slowly to the ground.
A system of gears and a generator inside the device convert the kinetic energy released by the bag as it falls under the influence of gravity into electricity.
Once the bag reaches the ground it can be raised back up to the ceiling to produce more power.
The energy produced can be used to power the light and other devices attached to a DC power outlet.

The generator produces just under a tenth of a watt which powers and provides between 20 to 30 minutes of light if installed at a height of over 6ft (1.8 metres).

The GravityLight comes with a bag that can be filled with sand or rocks to provide the weight needed to power it

 

[twilyth]

Third article in the particle detection series, other 2 noted above.

F***ing magnets, how do they work. LOL, just kidding but the article is about magnets used in particle detectors.

http://www.symmetrymagazine.org/article/june-2015/inside-particle-detectors-magnets?email_issue=770

Broadly speaking, a modern particle physics detector has three main pieces: (1) tracking, which charts the course of charged particles by letting them pass through thin sensors, (2) calorimetry, which measures the energy of charged or neutral particles by making them splat into a wall and (3) a strong magnetic field. Unlike tracking and calorimetry, the magnet doesn't detect the particles directly—it affects them in revealing ways.

Magnetic fields curve the paths of charged particles, and the direction of curvature depends on whether the particle is positively or negatively charged. Thus, a tracking system with a magnetic field can distinguish between matter and antimatter. In addition, the deflection is larger for slow, low-momentum particles than it is for fast, high-momentum ones. Fast particles zip right through while slow ones loop around, possibly several times.

Both effects were used to discover positrons in 1932. A cloud chamber (tracking system) immersed in a strong magnetic field revealed particles that curved the wrong way to be negatively charged electrons, yet were also too fast to be positively charged protons. The experimenters concluded that they had discovered a new particle, similar to electrons, but positively charged. It turned out to be the first evidence of antimatter.

Today, most particle physics experiments feature a strong magnet. The radius of curvature of each particle's track precisely determines its momentum. In many experiments, these magnets are stronger than the ones used to conduct MRI scans in hospitals, yet are also large enough to fit a whale inside.

Most of these magnets work the same way as a hand-held electromagnet: a DC current circulates in a coiled wire to produce a magnetic field. However, particle physics magnets are often made of superconducting materials to achieve extremely high currents and field strengths. Some magnets, such as the one in the CMS experiment at the Large Hadron Collider, are cylindrical for more precision at right angles to the beamline, while others, such as the outer magnet at the ATLAS experiment, are toroidal (doughnut-shaped) for more precision close to the beamline. In some cases, an experiment without a built-in magnet can surreptitiously make use of natural magnetic fields: the Fermi-LAT satellite used the Earth's magnetic field to distinguish positrons from electrons.

Since the particle momentum that a magnetized tracking system measures is closely related to the particle energy that a calorimeter measures, the two can cross-check each other, be used in combination or reveal the particles that are invisible to tracking alone. Advances in understanding often come from different ways of measuring similar things.

 

[Frick]

Russia has used ion thrusters since the 70's, and they never failed in orbit. And here I was thinking they were just science fiction.

 

[Caring1]

The light powered by GRAVITY: Lamp uses energy from falling weight to illuminate homes without electricity

It works using a pulley system where a weight can be fixed at one end and as it drops the force drives a generator through a series of low torque gears.

Jim Reeves and Martin Riddiford, who are based in London, invented the device.

So basically they stole borrowed the concept of a cuckoo clock and inserted a tiny generator in the gears.

 

[dorsetknob]

So basically they stole the concept of a cuckoo clock and inserted a tiny generator in the gears.

Not Stole But Adapted an existing device for a new USE

Much in the same way the cuckoo clock adapted the pendulum clock to mechanize and animate its chimes

So to use your concept the Swiss stole their concept from the makers of pendulum clocks

 

[dorsetknob]

Now Your TROLLING

 

[CAPSLOCKSTUCK]

So basically they stole the concept of a cuckoo clock and inserted a tiny generator in the gears.

yep, someone reinvented the wheel...again,

lets hope it makes them a tidy sum of money and shines a light in many peoples lives.
I like it.

 

[Frick]

Now Your TROLLING

Technically (and better suiting IMO) trolls are fishers, fishing for reactions essentially.

 

[Caring1]

Now Your TROLLING

So by posting that, by definition you are a troll.
It worked, I reacted.

 

[dorsetknob]

@Caring1
ninja edit/removed his apple trolling post oh cute

Now lets resume the thread with out being sidetracked

or it will be Moderated

 

[twilyth]

The octopus only uses 2 of its 3 hearts when swimming

Octopuses crawl when they can swim because their cardiac systems don’t operate at full capacity. Although an octopus has three hearts, only two of them beat while they are swimming. This is because two of the hearts are used to pump blood to the octopuses’ gills, while the third heart is reserved for circulating blood to the organs only.

Since their two hearts are not pumping as much blood throughout their bodies as they would normally, octopuses can become fatigued while swimming. Crawling conserves their energy while still allowing them to travel through the water.

More about octopuses:

• An octopus can squeeze into a small opening that accommodates its beak – for instance, 50 pound (22.68 kg) octopuses have been known to fit through 2 inch (5.08 cm) holes.
  
• Two-thirds of the nerves in an octopus are located in its arms, rather than its brains – this is necessary to enable a protective mechanism that prevents its eight arms from tangling or the suckers on its limbs from sticking together.
  
• Octopuses will eat their own species – giant Pacific octopuses regularly kill and consume smaller octopuses.

You can subscribe to daily wisegeek factoids here.

 

[twilyth]

The search for neutrino-less double beta decay

This is a pretty interesting article if you're interested in particle physics. There has been speculation for some time that neutrinos might be their own anti-particle, or what's called majorana fermions. We know that they change flavors on the fly as was recently proven by the OPERA experiment in Italy. There, a small number of muon neutrinos produced at CERN were detected as tau neutrinos at OPERA.

The question now will be whether or not neutrinos also act as their own anti-particle much like the positron is the anti-particle of an electron. If it turns out that it is, it could explain why matter exists and wasn't gobbled up by anti-matter in the first fractions of a second after the big bang.

In the first few instants after the big bang, perfectly equal amounts of matter and antimatter particles were produced. This was a clincher moment for our newborn universe: When a particle of matter meets its antimatter twin — which carries an identical mass but an opposite charge — both particles are annihilated, producing only pure energy. Roughly one second later, however, a large amount of matter and practically all the antimatter disappeared from the universe. That leftover matter forged galaxies, stars, planets, people — everything that we know exists.

Why did so much matter remain when antimatter all but disappeared? We don’t know. The Majorana Demonstrator has the potential to help us figure this out.

“What we really want to learn from this particular experiment is whether neutrinos are their own antiparticle. If they are their own antiparticle, then there’s a family of theories that might explain why the universe has got all this leftover matter,” Majorana Spokesperson Steve Elliott of Los Alamos National Laboratory said. “The fact that we’re here requires that all the matter that’s here didn’t interact with anti-matter and go away after the big bang. If neutrinos are their own antiparticle, there are ways to understand that.”

See first link for full article.

 

[CAPSLOCKSTUCK]

Death of a white blood cell:

Exploding cells captured on film for first time - shedding light on how our immune system works

A key component of the body’s defence against disease has been captured on film for the first time.

Researchers at La Trobe University in Melbourne, Australia, used time lapse photography to film a white blood cell as it died.

It had been thought these cells broke down in a random way when they died in the cell.
But the new research has revealed they actually die in an organised manner that may help to alert other parts of the immune system to a threat.

The study revealed molecules are ejected from the dying cell on long ‘beads’ that shoot out like a necklace and then break apart.

The researchers say the monocytes appear to die in three stages – bulging, exploding and breaking apart.

Dr Ivan Poon, a molecular biologist at La Trobe University who led the work, said they may have uncovered a key part of the immune systems defence mechanism.

WHAT ARE MONOCYTES
Monocytes are the largest of all the white blood cells in the immune system.
They are produced in the bone marrow and then migrate rapidly through the blood stream in response to infections in tissues around the body.
Once at the site of an infection, they differentiate into macrophages or dendritic cells that mounting an immune response to the pathogen.
Monocytes are also capable of killing infected cells.
If a disease or infection causes white blood cells to die, they can then warn others nearby to mount an immune response.

Dr Poon said: 'The role of white blood cells is central to our body's innate immune system and much like fighter jet pilots are ejected from their downed aeroplane, we have discovered certain molecules are pushed free from the dying cell, while others are left behind in the 'wreckage' of the cell fragments.

'It is the first time we have ever seen this take place and we now need to better understand the reasons behind this and the implications of this process of cell fragmentation.

'It could be that we've identified the mechanics of how dying white blood cells go about alerting neighbouring cells to the presence of disease or infection.

‘Alternatively we may have discovered the transportation mechanism for a virus to infect other parts of the body.’

The research, which is published in the journal Nature Communications, could now help scientists develop new ways of harnessing the power of the immune system to fight off disease.

Molecular biologists have captured the death of a white blood cell on film for the first time. As the cell collapses it spits out long beads studded with molecules, as shown in the image above, before finally breaking apart. It is thought this forms a key part of the body's immune response alerting surrounding cells to an infection

The study shows the monocytes going through three stages of cell death, the first of which is bulging, as can be seen in the cell shown on the bottom left in the image above

Next the cell explodes (seen above) spewing out long beads of molecules up to eight times longer than itself

Finally the cell breaks apart, after the beads extend outwards and then break into shorter segments. Above the long beads can be seen extending out of the cell shortly before they begin to break apart

 

[Steevo]

https://en.wikipedia.org/?title=NERVA

 

[CAPSLOCKSTUCK]

@Steevo ^.....Epic !

 

[twilyth]

• the complexity of detecting particles

Note - if you want to find this link after June25th, click on the archive link and then the correct date.

The wonderful thing about triggers

Somehow, you have to get those marvelous tracks to film.
Imagine you're a particle physicist in 1932. You have a cloud chamber that can show you the tracks of particles, and you have a camera to capture those tracks for later analysis. How do you set up an apparatus to take pictures whenever tracks appear?

At first, you might just try to be quick with your finger, but since the tracks disappear in a quarter of a second, you'd end up with a lot of near misses. You might give up and snap pictures randomly, since you'll be lucky some fraction of the time. Naturally, this wasteful process doesn't work if the type of event you're looking for is rare. You could also leave the shutter open and expose the film to anything that appears over a long interval. All events would overlap in the same picture, making it harder to interpret.

Now suppose you have another piece of equipment: a Geiger counter. This device emits an electric signal every time a charged particle passes through it. Two physicists, Blackett and Occhialini, surrounded their cloud chamber with Geiger counters and used the electric signals to trigger the cloud chamber and take pictures. This kind of apparatus is crucial to detectors today.

Experiments such as CMS only record one in a million LHC collisions — the rest are lost to further analysis. Collisions that break up protons but do not create new particles are 10 billion times more common than collisions that produce Higgs bosons, so modern triggers must be extremely selective.

Blackett and Occhialini's original trigger system relied on two Geiger counters: one above and one below the cloud chamber. Each Geiger counter was noisy and therefore prone to taking bad pictures, but both counters were unlikely to accidentally trigger at the same time. The two electronic signals were passed through a circuit that registered only if both counters triggered.

Today, triggers combine millions of data channels in complex ways, but the main idea is the same. Events should be selected only if signals in adjacent detectors line up. The desired geometric patterns are encoded into microchips for fast, coarse decisions and then are computed in detail using a farm of computers that make slower decisions downstream.

The modern trigger filter resembles a pipeline: Microchips make tens of millions of decisions per second and then pass on hundreds of thousands of candidates per second to the computing farm. By comparison, Google's computing farm handles 40,000 search queries per second.

—Jim Pivarski

 

[twilyth]

Black holes might really be fuzzballs.

This is a pretty theoretical article and a bit long but it does a decent job of explaining the firewall paradox and some related concepts.

The firewall paradox called attention to the possibility of structure at the event horizon — an irony not lost on string theorists like Warner. “We’ve been screaming that for about ten years now,” he said. He insists that the central firewall argument is fundamentally Mathur’s argument with a few extra flourishes: A firewall is essentially a hot fuzzball. “We’re not giving up on equivalence, we’re saying there is no singularity and no horizon. It just caps off into some fuzz,” he said. “The firewall is simply the fact that this stuff can be hot. I’m curious to see where the firewall story goes, because my view is it’s hot fuzzballs, and that’s the end of it.”

 

[twilyth]

LHC may be the most powerful accelerator in the world, but a lot of the research being done involves neutrinos

Fermilab’s flagship accelerator sets world record
Most powerful high-energy particle beam for a neutrino experiment ever generated

Fermilab's Main Injector accelerator, one of the most powerful particle accelerators in the world, has just achieved a world record for high-energy beams for neutrino experiments. Photo: Fermilab
A key element in a particle-accelerator-based neutrino experiment is the power of the beam that gives birth to neutrinos: The more particles you can pack into that beam, the better your chance to see neutrinos interact in your detector. Today scientists announced that Fermilab has set a world record for the most powerful high-energy particle beam for neutrino experiments.

Scientists, engineers and technicians at the U.S. Department of Energy’s Fermi National Accelerator Laboratory have achieved for high-energy neutrino experiments a world record: a sustained 521-kilowatt beam generated by the Main Injector particle accelerator. More than 1,000 physicists from around the world will use this high-intensity beam to more closely study neutrinos and fleeting particles called muons, both fundamental building blocks of our universe.

More at link.