Will the LHC Prove the Existence of Higher Dimensions?


In Brief
  • To achieve an accurate description of the universe, physical theories are increasingly invoking extra dimensions to explain the mysteries of nature.
  • The problem is—how do you prove the existence of something so elusive? New experiments with the LHC may finally prove just how many extra dimensions, if any, our universe really has.

How many dimensions are there? Is time a dimension? Or is our 3-dimensional space-time just one element—and a minor one at that—of a greater hyperdimensional universe?

It’s a question that’s been asked many, many times, and the answers can be almost as varied as there are potential extra dimensions. From Paul Ehrenfest’s exploration of 3-dimensional physics in 1917 to the M-theory of the 1990s, experts throughout the years have proposed their own answers—some more forcefully than others.

But with advances in technology, and armed with new mathematical models and theories, we might be in a unique position today to begin to understand one of the natural world’s most baffling mysteries.

Dimensions, Gravity, and Light

At the heart of almost all theories that deal with the number of dimensions are the fundamental forces of gravity and light, both of which are possibly the most observed and easily the most studied phenomena in the physical universe. Among the four fundamental forces in nature—the others being the strong and weak nuclear forces—gravity and electromagnetism (which is responsible for generating light) are the trickiest to deal with. Individually, they’ve caused grief to countless scientists and theorists; and when put together, they wreak absolute havoc.

Models generally draw from these observable features of the universe to build theories and conjectures about how things work. The simpler ones proposed that the universe was made up of three dimensions: length, width, and depth. This is especially easy to grasp since it’s how we perceive the world; it’s intuitive and entirely logical.

Illustration of gravity leaking from space-time
Illustration of gravity leaking from space-time “branes” into the hyperdimensional “bulk.”

But this neat, trinary division of the universe doesn’t exactly sum up how we experience it. To build on this, some mathematicians—notably Hermann Minkowski—combined the three spatial dimensions with a fourth, temporal dimension, to construct a space-time description of reality.

This is where things start to become knotty. There are embarrassing discrepancies and inconsistencies that just don’t seem to tally. For instance, why does gravity operate on such a massive scale—planets, stars, galaxies—whereas the other forces act upon such a tiny scale? Or, put somewhat differently, why is gravity so much weaker than the other four fundamental forces?

In an interesting essay for PBS, Paul Halpern illustrates the problem using a simple example: “Pick up a steel thumbtack with a tiny kitchen magnet, and see how its attraction overwhelms the gravitational pull of the entire earth.”

So a number of theories were evolved to attempt to compensate for these discrepancies. Building on the work of Theodor Kaluza and Oskar Klein in the 1920s, superstring theories advanced the idea that the vibrations of minuscule energy strings were responsible for all that we observe in nature; these theories only worked, however, in a universe comprising ten or more dimensions, with the extra six or so all “compactified” into a tiny space beyond the limits of ready observation.

Another approach (M-theory) subsumed this 10-dimensional universe, composed of strings and energetic membranes, within a large, potentially observable extra dimension called the “bulk.” In this notion, matter and energy and most of the fundamental forces cling timidly to the energetic space-time membranes, or “branes;” gravity, however, is something of a free agent, operating alike on the branes and within the hyperdimensional bulk. For this reasons, gravitons—the carriers of gravitational energy—can bleed off in to the bulk, diminishing the small-scale strength of gravity but still allowing it to exert undue power over large distances.

A Large Hadron Collision of Ideas

Enter the Large Hadron Collider. The machine, based in Geneva, Switzerland, just might hold the answer to the dimensional puzzle. Capable of running extremely high-energy particle collisions, experts are able to construct specialized experiments which might, in turn, yield data that point to theories that actually hold water.

Right now, scientists are looking for three specific occurrences to prove that higher dimensions exist: the presence of massive particle traces, sort of like reverberating echoes; missing energy caused by gravitons migrating to higher dimensions; and microscopic black holes.

Ongoing experiments will explore these possibilities, just as scientists are hotly pursuing an elusive theory that unifies all the laws of the universe. If the volume of discoveries in recent years is an indicator, then we just might be closer than we ever thought.

 

The real reason that nothing goes faster than the Light.


Light is faster than anything else (Credit: Amana Images Inc/Alamy Stock Photo)

It was September 2011 and physicist Antonio Ereditato had just shocked the world.

The announcement he had made promised to overturn our understanding of the Universe. If the data gathered by 160 scientists working on the OPERA project were correct, the unthinkable had been observed.

Particles – in this case, neutrinos – had travelled faster than light.

This time the scientists got it wrong

According to Einstein’s theories of relativity, this should not have been possible. And the implications for showing it had happened were vast. Many bits of physics might have to be reconsidered.

Although Ereditato said that he and his team had “high confidence” in their result, they did not claim that they knew it was completely accurate. In fact, they were asking for other scientists to help them understand what had happened.

In the end, it turned out the OPERA result was wrong. A timing problem had been caused by a poorly connected cable that should have been transmitting accurate signals from GPS satellites.

There was an unexpected delay in the signal. As a consequence, the measurements of how long the neutrinos took to travel the given distance were off by about 73 nanoseconds, making it look as though they had whizzed along more quickly than light could have done.

Despite months of careful checks prior to the experiment, and plentiful double-checking of the data afterwards, this time the scientists got it wrong. Ereditato resigned, though many pointed out that mistakes like these happen all the time in the hugely complex machinery of particle accelerators.

Why was it such a big deal to suggest – even as a possibility – that something had travelled faster than light? And are we really sure that nothing can?

Let’s take the second of those questions first. The speed of light in a vacuum is 299,792.458 km per second – just shy of a nice round 300,000km/s figure. That is pretty nippy. The Sun is 150 million km away from Earth and light takes just eight minutes and 20 seconds to travel that far.

He needed to use ever-larger amounts of additional energy to make ever-smaller differences to the speed

Can any of our own creations compete in a race with light? One of the fastest human-made objects ever built, the New Horizons space probe, passed by Pluto and Charon in July 2015. It has reached a speed relative to the Earth of just over 16km/s, well below 300,000km/s.

However, we have made tiny particles travel much faster than that. In the early 1960s, William Bertozzi at the Massachusetts Institute of Technology experimented with accelerating electrons at greater and greater velocities.

Because electrons have a charge that is negative, it is possible to propel – or rather, repel – them by applying the same negative charge to a material. The more energy applied, the faster the electrons will be accelerated.

You might imagine that you just need to increase the energy applied in order to reach the required speed of 300,000km/s, but it turns out that it just is not possible for electrons to move that fast. Bertozzi’s experiments found that using more energy did not simply cause a directly proportional increase in electron speed.

As objects travel faster and faster, they get heavier and heavier

Instead, he needed to use ever-larger amounts of additional energy to make ever-smaller differences to the speed the electrons moved. They got closer and closer to the speed of light but never quite reached it.

Imagine travelling towards a door in a series of moves, in each of which you travel exactly half the distance between your current position and the door. Strictly speaking, you will never reach the door, because after every move you make you still have some distance still to travel. That is the kind of problem Bertozzi encountered with his electrons.

But light is made up of particles called photons. Why can these particles travel at the speed of light when particles like electrons cannot?

 “As objects travel faster and faster, they get heavier and heavier – the heavier they get, the harder it is to achieve acceleration, so you never get to the speed of light,” saysRoger Rassool, a physicist at the University of Melbourne, Australia.

“A photon actually has no mass,” he says. “If it had mass, it couldn’t travel at the speed of light.”

For the most part it is fair to say that light travels at 300,000km/s

Photons are pretty special. Not only do they have no mass, which gives them free reign when it comes to zipping about in vacuums like space, they do not have to speed up. The natural energy they possess, travelling as they do in waves, means that the moment they are created, they are already at top speed.

In fact, in some ways it makes more sense to think of light as energy rather than as a flow of particles, though truthfully it is – a little confusingly – both.

Still, light sometimes appears to travel more slowly than we might expect. Although internet technicians like to talk about communications travelling at “the speed of light” through optical fibres, light actually travels around 40% slower through the glass of those fibres than it would through a vacuum.

In reality, the photons are still travelling at 300,000km/s, but they are encountering a kind of interference caused by other photons being released from the glass atoms as the main light wave travels past. It is a tricky concept to get your head around, but it is worth noting.

Similarly, special experiments with individual photons have managed to slow them down by altering their shape.

 Still, for the most part it is fair to say that light travels at 300,000km/s. We really have not observed or created anything that can go quite that quickly, or indeed more quickly. There are a few special cases, mentioned below, but before those, let’s tackle that other question. Why is it so important that this speed of light rule be so strict?

Even though the distance has increased, Einstein’s theories insist that the light is still travelling at the same speed

The answer lies, as so often in physics, with a man named Albert Einstein. His theory of special relativity explores many of the consequences of these universal speed limits.

One of the important elements in the theory is the idea that the speed of light is a constant. No matter where you are or how fast you are travelling, light always travels at the same speed.

But that creates some conceptual problems.

Imagine shining light from a torch up to a mirror on the ceiling of a stationary spacecraft. The light will shine upwards, reflect off the mirror, and come down to hit the floor of the spacecraft. Let’s say the distance travelled is 10m.

Now let’s imagine that the spacecraft begins travelling at a hair-raising speed, many thousands of kilometres per second.

Time travels slower for people travelling in fast-moving vehicles

When you shine the torch again, the light will still seem to behave as before: it will shine upwards, hit the mirror, and bounce back to hit the floor. But in order to do so the light will have to travel diagonally rather than just vertically. After all, the mirror is now moving quickly along with the spacecraft.

The distance the light travels therefore increases. Let’s imagine it has increased overall by 5m. That is 15m in total, instead of 10m.

And yet, even though the distance has increased, Einstein’s theories insist that the light is still travelling at the same speed. Since speed is distance divided by time, for the speed to be the same but the distance to have increased, time must also have increased.

Yes, time itself must have got stretched. That sounds wacky, but it has been proved experimentally.

 It is a phenomenon known as time dilation. It means time travels slower for people travelling in fast-moving vehicles, relative to those who are stationary.

For example, time runs 0.007 seconds slower for astronauts on the International Space Station, which is moving at 7.66 km/s relative to Earth, compared to people on the planet.

The muons are generated with so much energy that they’re moving at velocities very near the speed of light

Things get interesting for particles, like the electrons mentioned above, that can travel close to the speed of light. For these particles, the degree of time dilation can be great.

Steven Kolthammer, an experimental physicist at the University of Oxford in the UK, points to an example involving particles called muons.

Muons are unstable: they quickly fall apart into simpler particles. So quickly, in fact, that most muons leaving the Sun should have decayed away by the time they reach the Earth. But in reality muons arrive at Earth from the Sun in great numbers. This was something scientists long found difficult to understand.

“The answer to this puzzle is that the muons are generated with so much energy that they’re moving at velocities very near the speed of light,” says Kolthammer. “So their sense of time, if you will, their internal clock, actually runs slow.”

The muons were “kept alive” longer than expected, relative to us, thanks to a real, natural bending of time.

 When objects move quickly relative to other objects, their length contracts as well. These consequences, time dilation and length contraction, are both examples of how space-time changes based on the motion of things – like you, me or a spacecraft – that have mass.

There are galaxies in the Universe moving away from one another at a velocity greater than the speed of light

Crucially, as Einstein said, light does not get affected in the same way – because it has no mass. That is why it is so important that all of these principles go hand-in-hand. If things could travel faster than light, they would disobey these fundamental laws that describe how the Universe works.

That sums up the key principles. At this point, we can consider a few exceptions and caveats.

For one thing, while nothing has ever been observed travelling faster than light, that does not mean it is not theoretically possible to break this speed limit in very special circumstances.

Take, for instance, the expansion of the Universe itself. There are galaxies in the Universe moving away from one another at a velocity greater than the speed of light.

There is yet another possible way in which faster-than-light travel is technically possible

Another interesting situation concerns particles that seem to be expressing the same properties at the same time, no matter how far apart they are.

This is called “quantum entanglement”. In essence, a photon will flip back and forth between two possible states at random – but the flips will exactly mirror the flipping of another photon somewhere else, if the two are entangled.

Two scientists each studying their own photon will therefore get the same results at the same time, faster than the speed of light.

However, in both these examples it is crucial to note that no information is travelling faster than the speed of light between two entities. We can calculate the Universe’s expansion, but we cannot observe any faster-than-light objects in it: they have disappeared from view.

 As for the two scientists with their photons, while they might achieve the same result simultaneously, they could not confirm the fact with each other any more quickly than light could travel between them.

“This gets us out of any problems, because if you are able to send signals faster than light you can construct bizarre paradoxes, under which information can somehow go backwards in time,” says Kolthammer.

What if instead you actively distorted space-time in a controlled way?

There is yet another possible way in which faster-than-light travel is technically possible: rifts in space-time itself that allow a voyager to escape the rules of normal travel.

Gerald Cleaver at Baylor University in Texas has considered the possibility that we might one day build a faster-than-light spacecraft. One of the ways to do this might be to travel through a wormhole. These are loops in space-time, perfectly consistent with Einstein’s theories, which could allow an astronaut to hop from one bit of the Universe to another via an anomaly in space-time, a sort of cosmic shortcut.

The object travelling through the wormhole would not exceed the speed of light, but it could theoretically reach a certain destination faster than light could if it took a “normal” route.

But wormholes might not be available for space travel. What if instead you actively distorted space-time in a controlled way, to travel faster than 300,000km/s relative to someone else?

 Cleaver has investigated an idea known as an “Alcubierre drive”, proposed by theoretical physicist Miguel Alcubierre in 1994. Essentially, it describes a situation in which space-time is squashed in front of a spacecraft, pulling it forward, while space-time behind the craft is expanded, creating a pushing effect.

“But then,” says Cleaver, “there’s the issues of how to do that, and how much energy it’s going to take.”

Faster-than-light travel remains a fantasy at the moment

In 2008, he and graduate student Richard Obousy calculated some of the energies involved.

“We worked out that, if you assume a ship that’s about 10m x 10m x 10m – you’re talking 1,000 cubic metres – that the amount of energy it would take to start the process would need to be on the order of the entire mass of Jupiter.”

After that, the energy would have to continue being provided constantly in order to ensure the process did not fail. No-one knows how that would ever be possible, or what the technology to do it would look like.

“I don’t want to be misquoted centuries from now for predicting it would never come about,” says Cleaver, “but right now I don’t see solutions.”

Faster-than-light travel, then, remains a fantasy at the moment.

But while that may sound disappointing, light is anything but. In fact, for most of this article we have been thinking in terms of visible light. But really light is much, much more than that.

 Everything from radio waves to microwaves to visible light, ultraviolet radiation, X-rays and the gamma rays emitted by decaying atoms – all of these fantastic rays are made of the same stuff: photons.

The difference is the energy, and therefore their wavelength. Collectively these rays make up the electromagnetic spectrum. The fact that radio waves, for instance, travel at the speed of light is enormously useful for communications.

Space-time is malleable and that allows for everyone to experience the same laws of physics

In his research, Kolthammer builds circuitry that uses photons to send signals from one part of the circuit to another, so he is well placed to comment on the usefulness of light’s awesome speed.

“The idea that we’ve built the infrastructure of the internet for example and even before that, radio, based on light, certainly has to do with the ease with which we can transmit it,” he points out.

He adds that light acts as a communicating force for the Universe. When electrons in a mobile phone mast jiggle, photons fly out and make other electrons in your mobile phone jiggle too. It is this process that lets you make a phone call.

The jiggling of electrons in the Sun also emits photons – at fantastic rates – which, of course, produces the light that nourishes life on Earth.

Light is the Universe’s broadcast. That speed – 299,792.458 km/s – remains reassuringly constant. Meanwhile, space-time is malleable and that allows for everyone to experience the same laws of physics no matter their position or motion.

Can Light and Sound Get You High?


 Makers of a new type of headphones claim to trigger your pleasure in your brain. Can technology be like a drug?

Read More:

Can This Light Make You High? (BBC)
“Meditation is a skill that not everyone can achieve – the ability to block out the world around you and relax, letting everything go. The makers of the Lucia No.3 light say it acts like something of a fast-track for people wanting to reach that kind of state.”
Effect of a 10-day trigeminal nerve stimulation (TNS) protocol for treating major depressive disorder (NIH)
“Considering both the burden determined by major depressive disorder (MDD) itself and the high refractoriness and recurrence index, alternative strategies, such as trigeminal nerve stimulation (TNS), are the cutting edge instruments to optimize clinical response and to avoid treatment discontinuation and relapse of symptoms. Trigeminal nerve stimulation is an incipient simple, low-cost interventional strategy based on the application of an electric current over a branch of the trigeminal nerve with further propagation of the stimuli towards brain areas related to mood symptoms.”
Correlation between GABA receptor density and vagus nerve stimulation in individuals with drug-resistant partial epilepsy (Epilepsy Research)
“Vagus nerve stimulation (VNS) is an important option for the treatment of drug-resistant epilepsy. Through delivery of a battery-supplied intermittent current, VNS protects against seizure development in a manner that correlates experimentally with electrophysiological modifications. However, the mechanism by which VNS inhibits seizures in humans remains unclear.”
I Don’t Need Drugs, I’m High on Light, Baby (Vice)
“Last Sunday, instead of getting drunk and fat on beer and roast dinner at the local pub, I headed off to Islington to trip balls in the back room of the Candid Arts Centre. However, there were no drugs involved. Instead, I tweaked my third eye using stroboscopic light stimulation, which sent me on a visionary journey into the cosmic mind-hole.”

Hospital Room Lighting May Worsen Your Mood and Pain.


Story at-a-glance

  • Hospital patients are exposed to insufficient levels of light, disrupting both their circadian rhythms and sleep cycles
  • Light-deprived patients had fragmented and low levels of sleep, and those with the lowest exposures to light during the day reported more depressed mood and fatigue
  • Inadequate bright-light exposure has a far-reaching impact on your most critical bodily functions, including your ability to heal
  • Exposure to night-time light may also hinder the production of the hormone melatonin, which is very important for immune health
  • If you or a loved one is confined to a hospital room, move to areas with brighter natural light as much as possible, or bring in some full-spectrum light bulbs, and wear an eye mask at night to block night-time artificial light exposures

Hopefully you have never spent much time in a hospital, but if you have you likely experienced frequent disruptions to your sleep.

Aside from the beeping machines and nightly checks from hospital staff, your room was probably dimly lit with artificial light both day and night — a major impediment to proper sleep and well-being.

As a new study in the Journal of Advanced Nursing1 revealed, the lighting in many hospital rooms may be so bad that it actually worsens patients’ sleep, mood and pain levels.

Hospital-Room Lighting May Lead to Disrupted Sleep Cycles, Increased Pain and Fatigue

The study found that, on average, hospital patients in the study were exposed to about 105 lux (a measure of light emission) daily. This is a very low level of light; for comparison, an office would generally provide about 500 lux and being outdoors on a sunny day could provide 100,000 lux.2

The rooms were so dimly lit that many hospital patients had trouble sleeping. Your body requires a minimum of 1,500 lux for 15 minutes a day just to maintain a normal sleep-wake cycle, but ideally it should be closer to 4,000 for healthful sleep.3

Not surprisingly, the researchers found that the patients’ sleep time was “fragmented and low,” with most averaging just four hours of sleep a night.

Those with the lowest exposures to light during the day also reported more depressed mood and fatigue than those exposed to more light. The researchers noted:4 “Low light exposure significantly predicted fatigue and total mood disturbance.”

Why You Need Exposure to Bright Light During the Day

When full-spectrum light enters your eyes, it not only goes to your visual centers enabling you to see, it also goes to your brain’s hypothalamus where it affects your entire body.

Your hypothalamus controls body temperature, hunger and thirst, water balance and blood pressure. Additionally, it controls your body’s master gland, the pituitary, which secretes many essential hormones, including those that influence your mood.

Exposure to full-spectrum lighting is actually one effective therapy used for treating depression, infection, and much more – so it’s not surprising that hospital patients deprived of such exposures had poorer moods and fatigue.

Studies have also shown that poor lighting in the workplace triggers headaches, stress, fatigue and strained watery eyes, not to mention inferior work production.

Conversely, companies that have switched to full-spectrum lights report improved employee morale, greater productivity, reduced errors and decreased absenteeism. Some experts even believe that “malillumination” is to light what malnutrition is to food.

In a hospital setting, this has serious ramifications, as patients are already under profound stress due to illness and may be further stressed by a lack of natural bright light.

Your ‘body clock’ is also housed in tiny centers located in your hypothalamus, controlling your body’s circadian rhythm. This light-sensitive rhythm is dependent on Mother Nature, with its natural cycles of light and darkness, to function optimally.

Consequently, anything that disrupts these rhythms, like inadequate sunlight exposure to your body (including your eyes), has a far-reaching impact on your body’s ability to function and, certainly, also on its ability to heal.

Nighttime Light Exposure is Also Detrimental

While the featured study didn’t focus specifically on hospital patients’ nighttime light exposures, they’re likely to be significant. Most hospital room doors remain ajar all night, allowing artificial light from the hall to flood the room. There are also lights on medical equipment and monitors, and if your room is not private you may also be exposed to light from a roommates’ television or bathroom trips.

This is important because just as your body requires bright-light exposure during the day, it requires pitch-blackness at night to function optimally – which is all the more critical in the case of a hospital stay when bodily self-healing is most needed.

When you turn on a light at night, you immediately send your brain misinformation about the light-dark cycle. The only thing your brain interprets light to be is day. Believing daytime has arrived, your biological clock instructs your pineal gland to immediately cease its production of the hormone melatonin – a significant blow to your health, especially if you’re ill, as melatonin produces a number of health benefits in terms of your immune system. It’s a powerful antioxidant and free radical scavenger that helps combat inflammation.

In fact, melatonin is so integral to your immune system that a lack of it causes your thymus gland, a critically important part of your immune system, to atrophy.5 In addition, melatonin helps you fall asleep and bestows a feeling of overall comfort and well being, and it has proven to have an impressive array of anti-cancer benefits.6 So unnaturally suppressing this essential hormone is the last thing that a recovering hospital patient needs.

If a Loved One is In the Hospital, Let the Daylight Shine In

The best way to get exposure to healthy full-spectrum light is to do it the way nature intended, by going out in the sun with your bare skin – and ‘bare’ eyes — exposed on a regular basis. If you or a loved one is confined to a hospital room, however, the next best option is to move to areas with brighter natural light as much as possible, or alternatively bring in some full-spectrum light bulbs.

At night, the opposite holds true. You should turn off lights as much as possible, keep the door closed and close the blinds on the window. Wearing an eye mask is another simple trick that can help to keep unwanted light exposures to a minimum if you’re spending the night in a hospital. Taken together, these are simple ways to boost mood and improve sleep and fatigue levels among hospitalized patients.

The Other Major Risk of Spending Time in a Hospital

No matter how important it is, poor lighting may be the least of your worries if you find yourself hospitalized, as once you’re hospitalized you’re immediately at risk for medical errors, which is actually a leading cause of death in the US. According to the most recent research7 into the cost of medical mistakes in terms of lives lost, 210,000 Americans are killed by preventable hospital errors each year.

When deaths related to diagnostic errors, errors of omission, and failure to follow guidelines are included, the number skyrockets to an estimated 440,000 preventable hospital deaths each year!

One of the best safeguards is to have someone there with you. Dr. Andrew Saul has written an entire book on the issue of safeguarding your health while hospitalized. Frequently, you’re going to be relatively debilitated, especially post-op when you’re under the influence of anesthesia, and you won’t have the opportunity to see clearly the types of processes that are going on.

For every medication given in the hospital, ask, “What is this medication? What is it for? What’s the dose?” Take notes. Ask questions. Building a relationship with the nurses can go a long way. Also, when they realize they’re going to be questioned, they’re more likely to go through that extra step of due diligence to make sure they’re getting it right—that’s human nature. Of course, knowing how to prevent disease so you can avoid hospitals in the first place is clearly your best bet. One of the best strategies on that end is to optimize your diet. You can get up to speed on that by reviewing my comprehensive Nutrition Plan.

It’s Important for Virtually Everyone to Optimize Light Exposure: 5 Top Tips

Getting back to the issue of lighting, this isn’t only an issue for hospital patients. Virtually everyone requires exposure to bright light during the day and darkness at night for optimal health. Toward that end, here are my top tips to optimize your light exposure on a daily (and nightly) basis:

1.    Get some sun in the morning, if possible. Your circadian system needs bright light to reset itself. Ten to 15 minutes of morning sunlight will send a strong message to your internal clock that day has arrived, making it less likely to be confused by weaker light signals during the night. More sunlight exposure is required as you age.

2.    Make sure you get BRIGHT sun exposure regularly. Remember, your pineal gland produces melatonin roughly in approximation to the contrast of bright sun exposure in the day and complete darkness at night. If you work indoors, make a point to get outdoors during your breaks.

3.    Avoid watching TV or using your computer in the evening, at least an hour or so before going to bed.These devices emit blue light, which tricks your brain into thinking it’s still daytime. Normally your brain starts secreting melatonin between 9 and 10 pm, and these devices emit light that may stifle that process.

4.    Sleep in complete darkness, or as close to it as possible. Even the slightest bit of light in your bedroom can disrupt your biological clock and your pineal gland’s melatonin production. This means that even the tiny glow from your clock radio could be interfering with your sleep, so cover your alarm clock up at night or get rid of it altogether. You may want to cover your windows with drapes or blackout shades, or wear an eye mask while you sleep.

5.    Install a low-wattage yellow, orange or red light bulb if you need a source of light for navigation at night.Light in these bandwidths does not shut down melatonin production in the way that white and blue bandwidth light does. Salt lamps are handy for this purpose.

 

 

 

 

Accidental discovery dramatically improves electrical conductivity.


Quite by accident, Washington State University researchers have achieved a 400-fold increase in the electrical conductivity of a crystal simply by exposing it to light. The effect, which lasted for days after the light was turned off, could dramatically improve the performance of devices like computer chips.

Strontium Titanate

WSU doctoral student Marianne Tarun chanced upon the discovery when she noticed that the conductivity of some strontium titanate shot up after it was left out one day. At first, she and her fellow researchers thought the sample was contaminated, but a series of experiments showed the effect was from light.

“It came by accident,” said Tarun. “It’s not something we expected. That makes it very exciting to share.”

The phenomenon they witnessed—”persistent photoconductivity“—is a far cry from superconductivity, the complete lack of  pursued by other physicists, usually using temperatures near absolute zero. But the fact that they’ve achieved this at room temperature makes the phenomenon more immediately practical.

And while other researchers have created persistent photoconductivity in other materials, this is the most dramatic display of the phenomenon.

The research, which was funded by the National Science Foundation, appears this month in the journal Physical Review Letters.

“The discovery of this effect at  opens up new possibilities for practical devices,” said Matthew McCluskey, co-author of the paper and chair of WSU’s physics department. “In standard computer memory, information is stored on the surface of a computer chip or hard drive. A device using persistent photoconductivity, however, could store information throughout the entire volume of a crystal.”

This approach, called holographic memory, “could lead to huge increases in information capacity,” McCluskey said.

Strontium titanate and other oxides, which contain oxygen and two or more other elements, often display a dizzying variety of electronic phenomena, from the high resistance used for insulation to superconductivity’s lack of resistance.

“These diverse properties provide a fascinating playground for scientists but applications so far have been limited,” said McCluskey.

McCluskey, Tarun and physicist Farida Selim, now at Bowling Green State University, exposed a sample of  to light for 10 minutes. Its improved conductivity lasted for days. They theorize that the light frees electrons in the material, letting it carry more current.

Seeing light in a new light.


Scientists create never-before-seen form of matter

Harvard and MIT scientists are challenging the conventional wisdom about light, and they didn’t need to go to a galaxy far, far away to do it.

Working with colleagues at the Harvard-MIT Center for Ultracold Atoms, a group led by Harvard Professor of Physics Mikhail Lukin and MIT Professor of Physics Vladan Vuletic have managed to coax photons into binding together to form molecules – a state of matter that, until recently, had been purely theoretical. The work is described in a September 25 paper inNature.

The discovery, Lukin said, runs contrary to decades of accepted wisdom about the nature of light. Photons have long been described as massless particles which don’t interact with each other – shine two laser beams at each other, he said, and they simply pass through one another.

“Photonic molecules,” however, behave less like traditional lasers and more like something you might find in science fiction – the light saber.

“Most of the properties of light we know about originate from the fact that photons are massless, and that they do not interact with each other,” Lukin said. “What we have done is create a special type of medium in which photons interact with each other so strongly that they begin to act as though they have mass, and they bind together to form molecules. This type of photonic bound state has been discussed theoretically for quite a while, but until now it hadn’t been observed.

“It’s not an in-apt analogy to compare this to light sabers,” Lukin added. “When these photons interact with each other, they’re pushing against and deflect each other. The physics of what’s happening in these molecules is similar to what we see in the movies.”

To get the normally-massless photons to bind to each other, Lukin and colleagues, including Harvard post-doctoral fellow Ofer Fisterberg, former Harvard doctoral student Alexey Gorshkov and MIT graduate students Thibault Peyronel and Qiu Liang couldn’t rely on something like the Force – they instead turned to a set of more extreme conditions.

Researchers began by pumped rubidium atoms into a vacuum chamber, then used lasers to cool the cloud of atoms to just a few degrees above absolute zero. Using extremely weak laser pulses, they then fired single photons into the cloud of atoms.

As the photons enter the cloud of cold atoms, Lukin said, its energy excites atoms along its path, causing the photon to slow dramatically. As the photon moves through the cloud, that energy is handed off from atom to atom, and eventually exits the cloud with the photon.

“When the photon exits the medium, its identity is preserved,” Lukin said. “It’s the same effect we see with refraction of light in a water glass. The light enters the water, it hands off part of its energy to the medium, and inside it exists as light and matter coupled together, but when it exits, it’s still light. The process that takes place is the same it’s just a bit more extreme – the light is slowed considerably, and a lot more energy is given away than during refraction.”

When Lukin and colleagues fired two photons into the cloud, they were surprised to see them exit together, as a single molecule.

The reason they form the never-before-seen molecules?

An effect called a Rydberg blockade, Lukin said, which states that when an atom is excited, nearby atoms cannot be excited to the same degree. In practice, the effect means that as two photons enter the atomic cloud, the first excites an atom, but must move forward before the second photon can excite nearby atoms.

The result, he said, is that the two photons push and pull each other through the cloud as their energy is handed off from one atom to the next.

“It’s a photonic interaction that’s mediated by the atomic interaction,” Lukin said. “That makes these two photons behave like a molecule, and when they exit the medium they’re much more likely to do so together than as single photons.”

While the effect is unusual, it does have some practical applications as well.

“We do this for fun, and because we’re pushing the frontiers of science,” Lukin said. “But it feeds into the bigger picture of what we’re doing because photons remain the best possible means to carry quantum information. The handicap, though, has been that photons don’t interact with each other.”

To build a quantum computer, he explained, researchers need to build a system that can preserve quantum information, and process it using quantum logic operations. The challenge, however, is that quantum logic requires interactions between individual quanta so that quantum systems can be switched to perform information processing.

“What we demonstrate with this process allows us to do that,” Lukin said. “Before we make a useful, practical quantum switch or photonic logic gate we have to improve the performance, so it’s still at the proof-of-concept level, but this is an important step. The physical principles we’ve established here are important.”

The system could even be useful in classical computing, Lukin said, considering the power-dissipation challenges chip-makers now face. A number of companies – including IBM – have worked to develop systems that rely on optical routers that convert light signals into electrical signals, but those systems face their own hurdles.

Lukin also suggested that the system might one day even be used to create complex three-dimensional structures – such as crystals – wholly out of light.

“What it will be useful for we don’t know yet, but it’s a new state of matter, so we are hopeful that new applications may emerge as we continue to investigate these photonic molecules’ properties,” he said.

Scientists create never-before-seen form of matter.


Harvard and MIT scientists are challenging the conventional wisdom about light, and they didn’t need to go to a galaxy far, far away to do it.

Working with colleagues at the Harvard-MIT Center for Ultracold Atoms, a group led by Harvard Professor of Physics Mikhail Lukin and MIT Professor of Physics Vladan Vuletic have managed to coax photons into binding together to form molecules – a state of matter that, until recently, had been purely theoretical. The work is described in a September 25 paper in Nature.

The discovery, Lukin said, runs contrary to decades of accepted wisdom about the nature of light. Photons have long been described as massless particles which don’t interact with each other – shine two laser beams at each other, he said, and they simply pass through one another.

“Photonic molecules,” however, behave less like traditional lasers and more like something you might find in science fiction – the light saber.

“Most of the properties of light we know about originate from the fact that photons are massless, and that they do not interact with each other,” Lukin said. “What we have done is create a special type of medium in which photons interact with each other so strongly that they begin to act as though they have mass, and they bind together to form molecules. This type of photonic bound state has been discussed theoretically for quite a while, but until now it hadn’t been observed.

“It’s not an in-apt analogy to compare this to light sabers,” Lukin added. “When these photons interact with each other, they’re pushing against and deflect each other. The physics of what’s happening in these molecules is similar to what we see in the movies.”

To get the normally-massless photons to bind to each other, Lukin and colleagues, including Harvard post-doctoral fellow Ofer Fisterberg, former Harvard doctoral student Alexey Gorshkov and MIT graduate students Thibault Peyronel and Qiu Liang couldn’t rely on something like the Force – they instead turned to a set of more extreme conditions.

Researchers began by pumped rubidium atoms into a vacuum chamber, then used lasers to cool the cloud of atoms to just a few degrees above absolute zero. Using extremely weak laser pulses, they then fired single photons into the cloud of atoms.

As the photons enter the cloud of cold atoms, Lukin said, its energy excites atoms along its path, causing the photon to slow dramatically. As the photon moves through the cloud, that energy is handed off from atom to atom, and eventually exits the cloud with the photon.

“When the photon exits the medium, its identity is preserved,” Lukin said. “It’s the same effect we see with refraction of light in a water glass. The light enters the water, it hands off part of its energy to the medium, and inside it exists as light and matter coupled together, but when it exits, it’s still light. The process that takes place is the same it’s just a bit more extreme – the light is slowed considerably, and a lot more energy is given away than during refraction.”

When Lukin and colleagues fired two photons into the cloud, they were surprised to see them exit together, as a single molecule.

The reason they form the never-before-seen molecules?

An effect called a Rydberg blockade, Lukin said, which states that when an atom is excited, nearby atoms cannot be excited to the same degree. In practice, the effect means that as two photons enter the atomic cloud, the first excites an atom, but must move forward before the second photon can excite nearby atoms.

The result, he said, is that the two photons push and pull each other through the cloud as their energy is handed off from one atom to the next.

“It’s a photonic interaction that’s mediated by the atomic interaction,” Lukin said. “That makes these two photons behave like a molecule, and when they exit the medium they’re much more likely to do so together than as single photons.”

While the effect is unusual, it does have some practical applications as well.

“We do this for fun, and because we’re pushing the frontiers of science,” Lukin said. “But it feeds into the bigger picture of what we’re doing because photons remain the best possible means to carry quantum information. The handicap, though, has been that photons don’t interact with each other.”

To build a quantum computer, he explained, researchers need to build a system that can preserve quantum information, and process it using quantum logic operations. The challenge, however, is that quantum logic requires interactions between individual quanta so that quantum systems can be switched to perform information processing.

“What we demonstrate with this process allows us to do that,” Lukin said. “Before we make a useful, practical quantum switch or photonic logic gate we have to improve the performance, so it’s still at the proof-of-concept level, but this is an important step. The physical principles we’ve established here are important.”

The system could even be useful in classical computing, Lukin said, considering the power-dissipation challenges chip-makers now face. A number of companies – including IBM – have worked to develop systems that rely on optical routers that convert light signals into electrical signals, but those systems face their own hurdles.

Lukin also suggested that the system might one day even be used to create complex three-dimensional structures – such as crystals – wholly out of light.

“What it will be useful for we don’t know yet, but it’s a new state of matter, so we are hopeful that new applications may emerge as we continue to investigate these photonic molecules’ properties,” he said.

 

 Source:  Nature 

Nanotechnology May Lead To The End Of Laundry Forever.


A few months ago, I reported on the futuristic possibility of robots learning how to do laundry. Alas, technology marches on, and it may well be that laundry robots are already obsolete. Several different companies using nanotechnology are working on products that may well spell the end of the need to do laundry – forever.

 

Take, for example, Schoeller textile’s Nanosphere technology. This is a finishing technology utilizing polymer nanospheres which take their cues from the way leaves let water run right off of them. Schoeller has partnered with several different companies to use their finishing technology on their clothing. Perhaps one of the most notable companies they’ve partnered with is iRepel, which makes chef shirts and aprons, and whose products are featured on ThinkGeek.

Check out a video of the iRepel chef shirt in action below:

Another interesting bit of research was recently published describing cotton shirts that are treated with Titanium Oxide particles. When exposed to light in the visible spectrum, the fabric turns out to be self-cleaning. Robert Gonzales has a nice writeup of the technology in io9.

Simply put, Long and Wu’s fabric is more versatile. For decades, TiO2 was only known to exhibit photocatalytic properties in the presence of ultraviolet light. But recently, it was shown that spiking TiO2 with nitrogen ions gives it photocatalytic capabilities in UV light and visible light. By coating their fabric with nano particles made from this new N-TiO2, the researchers have created a fabric that self-cleans in the presence of a very broad spectrum of light. What’s more, they found that further dispersing additional silver iodide nanoparticles in the fabric accelerated the N-TiO2‘s stain-fighting properties.

Neat as that particular fabric sounds, however, I think I might hold off on buying a shirt made from it until we’re sure that Titanium Oxide doesn’t cause brain damage. If it’s safe, however, that’s a pretty amazing thing – just lay your shirts out in the sun and they clean themselves.

Perhaps one of the most amazing upcoming nanotech coatings, however, is Ross Nanotechnology’s Neverwet. Neverwet is a superhydrophobic coating that can be used on a variety of surfaces, including use as a spray coating for clothing, the way you might use a typical waterproofing spray. Check out this video from LancasterOnline showing the coating applied to a pair of shoes – chocolate syrup literally runs right off of them.

With more and more companies using nanotechnology create clothing and other materials that are resistant to water and staining, it may not be too long before we never have to do the laundry again – because our clothes are always clean. Imagine the time, money, energy and money that would save.  Especially imagine the benefits for people living in developing countries where all the laundry is done by hand. Not only does the lack of laundry mean cleaner water, it means that people can be spared hours of tedious, backbreaking labor.

This is one of those things that seems kind of neat at first – hey look, no stains! But when you think about it, the ramifications for day to day life are pretty extraordinary. I’m excited to see where this technology goes.

Also, I look forward to never having to do laundry again. I’m also glad that robots won’t be doing the laundry, either. That’s just one less reason for them to want to rise up and overthrow their human masters.

Source: http://wakeup-world.com

Did Asteroid Impacts Spark Life’s “Left-Handed” Molecules?


asteroid-impacts-spark-left-handed-molecules_1

The mysterious bias of life on Earth toward molecules that skew one way and not the other could be due to how light shines in star- and planet-forming clouds, researchers say

If correct, researchers’ findings suggest the molecules of life on Earth may initially have come from elsewhere in the cosmos.

The organic molecules that form the basis of life on Earth are often chiral, meaning they come in two forms that are mirror images, much as right and left hands appear identical but are reversed versions of each other.

Strangely, the amino acids that make up proteins on Earth are virtually all “left-handed,” even though it should be as easy to make the right-handed kind. Solving the mystery of why life came to prefer one kind of handedness over the other could shed light on the origins of life, scientists say. [7 Theories on the Origin of Life]

One possible cause for this bias might be the light shining on these molecules in space. One can think of all light waves as corkscrews that twist either one way or the other, a property known as circular polarization. Light circularly polarized one way can preferentially destroy molecules with one kind of handedness, while light circularly polarized the other way might suppress the other handedness.

To see how much light is circularly polarized in outer space, astronomers used a telescope at the South African Astronomical Observatory to detect how light is polarized over a wide field of view across the sky encompassing about a quarter diameter of the moon.

The scientists focused on the Cat’s Paw Nebula about 5,500 light-years from Earth in the constellation Scorpius. The nebula is one of the most active star-forming regions known in the Milky Way.

The researchers discovered that as much as 22 percent of light from the nebula was circularly polarized. This is the greatest degree of circular polarization yet seen in a star-forming region, and suggests circular polarization may be a universal feature of star- and planet-forming regions.

“Our findings show circular polarization is common in space,” study lead author Jungmi Kwon, an astronomer at the National Astronomical Observatory of Japan, told SPACE.com.

Computer simulations the astronomers developed suggest this large amount of circular polarization is due to grains of dust around stars. Magnetic fields in the nebula align these dust grains, and light that scatters off these aligned grains end up circularly polarized — dust on one side of the magnetic field gives light scattering off it one kind of circular polarization, while grains on the other side have the opposite effect.

“Until now, the origin of circular polarization was unclear and circular polarization was basically considered a rare feature,” Kwon said.

Chemical reactions inside nebulas can manufacture amino acids. These molecules end up possessing a certain handedness depending on the light shining on them. The researchers suggest left-handed amino acids may then have rained down on Earth bypiggybacking on space rocks, resulting in one handedness dominating the other.

“Left-handed amino acids produced by circular polarization in space can be delivered by meteorites,” Kwon said.

Source: Scientific American

 

LED streetlamp aims to improve public’s view of stars.


_67230974_stars _67244302_led2

Researchers believe they have come up with a new type of LED-powered streetlamp that could radically reduce light pollution.

Current designs “leak” large amounts of light in unwanted directions, obscuring views of the stars, wasting energy and making it harder for drivers to see.

The team, based in Mexico and Japan, said they believed their solution was the “best ever reported”.

However, they have yet to turn their theory into a working prototype.

The study – carried out by scientists in Mexico and Taiwan – appears in the open-access journal Optics Express.

LED lens

According to the researchers, conventional street lamps – which use high-pressure sodium or mercury vapour – scatter up to 20% of their energy horizontally or vertically because it is difficult to control their beams.

It is easier to direct light from LEDs because it is being emitted from a smaller area.

So, while manufacturers controlled the direction of the light rays from older lamps using a reflector typically made out of polished aluminium, they can now take advantage of lenses to be more precise.

The researchers say the best LED (light-emitting diode) streetlamps on the market direct about 10% of their energy horizontally or vertically.

But they claim their own invention could further reduce the amount to just 2%.

Their proposed lamp uses three features to ensure the vast majority of its light is limited to a pre-determined rectangular shape covering the road:

The researchers suggest that the set-up would also save on electricity costs since it should require between 10 and 50% less power to illuminate a section of road than current LED streetlamps.

They added that they were now working to build a prototype and hoped to have it completed by October.

LED revolution

London-based light design firm Speirs and Major unveiled anLED-based streetlamp design of its own last year.

The firm’s associate director, Andrew Howis, said the latest study was just one of several efforts under way aimed at tackling the problem of stray light.

“As a result of LEDs it is now possible to place light exactly where it is needed and to greatly reduce spill light and energy wastage,” he said.

“This new research is an example of the innovation in LED optics – of which there are many – which uses a fairly sophisticated optical system to produce an optimised distribution for street lighting.

“It sounds like an advance on what is already available, but of itself is not revolutionary. The change from conventional light sources to LED is the revolution.”

The Campaign to Protect Rural England (CPRE) also gave the new work a qualified welcome.

The lobby group carries out an annual star count to publicise the problem of light pollution which it says disrupts wildlife and people’s sleep.

It noted that the new technology would only be of use if councils were willing to invest in it.

“From 1993 to 2000, light pollution in England increased by 26%, which shows the huge amount of energy and money wasted,” said campaigner Emma Marrington.

“It should be seen as an investment for local authorities to install more efficient street lighting, which will save money and energy waste in the long-term.

“Design is great but councils have to follow through with investment.”

Source:BBC