Curves in spacetime violate Heisenberg’s uncertainty principle

If an object traveling through spacetime can loop back in time in a certain way, then its trajectory can allow a pair of its components to be measured with perfect accuracy, violating Heisenberg’s uncertainty principle. This new finding involves a particular trajectory called an open timelike curve (OTC), which is a special case of a closed timelike curve (CTC), a theoretical concept that has previously provoked controversy because it raises the possibility of traveling backwards in time.According to Heisenberg’s uncertainty principle, measurements of any pair of variables must have at least a minimum amount of error. The most well-known example of the pair of variables is position and momentum, but the principle applies to any two variables that have a mathematical relationship which makes them conjugate variables. The uncertainty principle is thought to be an inherent property of quantum systems due to their wave-particle duality, rather than any observational limitations. Although previous studies have found that CTC models can theoretically violate the uncertainty principle, nobody knew that this could happen for the special case of an OTC.

Now, physicists Jacques Pienaar, Tim Ralph, and Casey Myers at The University of Queensland in Australia have theoretically shown that OTCs can allow scientists to measure a pair of conjugate variables of a quantum state to an arbitrary degree of accuracy forbidden by the uncertainty principle. The finding could have implications for quantum gravity and change the way that scientists view quantum uncertainty.

“There is some speculation that the Heisenberg uncertainty principle might be different in a future theory of quantum gravity,” Pienaar told Phys.org. “However, most of these studies suggest that quantum gravity will introduce more uncertainty. Our model suggests the complete opposite: that a theory of quantum gravity might actually remove the uncertainty of quantum mechanics.”

This perfect measurement ability arises from the nature of OTC trajectories. As the physicists explain, OTCs are the simplest and most normal type of CTCs. Whereas CTCs form closed loops in time that allow systems to affect events in their own past, OTCs form open loops in time and do not allow systems to interact with previous versions of themselves. These interaction-free OTCs overcome some of the paradoxes associated with time travel, such as the grandfather paradox in which a time traveler kills their own grandfather, preventing their own existence.

Despite such paradoxes, CTCs in general are compatible with general relativity; however, they are not compatible with quantum mechanics. One way to make them compatible is to extend quantum mechanics in a way that resolves the paradoxical aspects of CTCs. An example of such an extension is the Deutsch model, which makes the mathematics of quantum mechanics nonlinear, allowing for CTCs. Previously, scientists have shown that this nonlinearity leads to some unusual properties, such as the possibility to build a super quantum computer that can quickly solve some complex problems called NP-complete problems, a task that would take trillions of years using today’s computers. …

Read the rest: http://m.phys.org/news/2013-02-spacetime-violate-heisenberg-uncertainty-principle.html

If you could travel back in time, where and when would you go? Personally, I’d go to a time traveler’s convention and meet people who had been everywhen.

Light from nothing

‘Virtual particles’ can have real physical effects.

A vacuum might seem like empty space, but scientists have discovered a new way to seemingly get something from that nothingness, such as light. And the finding could ultimately help scientists build incredibly powerful quantum computers or shed light on the earliest moments in the universe’s history.

Quantum physics explains that there are limits to how precisely one can know the properties of the most basic units of matter—for instance, one can never absolutely know a particle’s position and momentum at the same time. One bizarre consequence of this uncertainty is that a vacuum is never completely empty, but instead buzzes with so-called “virtual particles” that constantly wink into and out of existence.

These virtual particles often appear in pairs that near-instantaneously cancel themselves out. Still, before they vanish, they can have very real effects on their surroundings. For instance, photons—packets of light—can pop in and out of a vacuum. When two mirrors are placed facing each other in a vacuum, more virtual photons can exist around the outside of the mirrors than between them, generating a seemingly mysterious force that pushes the mirrors together.

This phenomenon, predicted in 1948 by the Dutch physicist Hendrick Casimir and known as the Casimir effect, was first seen with mirrors held still . Researchers also predicted a dynamical Casimir effect that can result when mirrors are moved, or objects otherwise undergo change. Now quantum physicist Pasi Lähteenmäki at Aalto University in Finland and his colleagues reveal that by varying the speed at which light can travel, they can make light appear from nothing.

The speed of light in a vacuum is constant, according to Einstein’s theory of relativity, but its speed passing through any given material depends on a property of that substance known as its index of refraction. By varying a material’s index of refraction, researchers can influence the speed at which both real and virtual photons travel within it. Lähteenmäki says one can think of this system as being much like a mirror, and if its thickness changes fast enough, virtual photons reflecting off it can receive enough energy from the bounce to turn into real photons. “Imagine you stay in a very dark room and suddenly the index of refraction of light [of the room] changes,” Lähteenmäki says. “The room will start to glow.”

The researchers began with an array of 250 superconducting quantum-interference devices, or SQUIDs—circuits that are extraordinarily sensitive to magnetic fields. They inserted the array inside a refrigerator. By carefully exerting magnetic fields on this array, they could vary the speed at which microwave photons traveled through it by a few percent. The researchers then cooled this array to 50 thousandths of a degree Celsius above absolute zero. Because this environment is supercold, it should not emit any radiation, essentially behaving as a vacuum. “We were simply studying these circuits for the purpose of developing an amplifier, which we did,” says researcher Sorin Paraoanu, a theoretical physicist at Aalto University. “But then we asked ourselves—what if there is no signal to amplify? What happens if the vacuum is the signal?”

The researchers detected photons that matched predictions from the dynamical Casimir effect. For instance, such photons should display the strange property of quantum entanglement—that is, by measuring the details of one, scientists could in principle know exactly what its counterpart is like, no matter where it is in the universe, a phenomenon Einstein referred to as “spooky action at a distance.” The scientists detailed their findings online February 11 in Proceedings of the National Academy of Sciences.

“This work and a number of other recent works demonstrate that the vacuum is not empty but full of virtual photons,” says theoretical physicist Steven Girvin at Yale University, who did not take part in the Aalto study.

Another study from physicist Christopher Wilson and his colleagues recently demonstrated the dynamical Casimir effect in a system mimicking a mirror moving at nearly 5 percent of the speed of light. “It’s nice to see further confirmation of this effect and see this area of research continuing,” says Wilson, now at the University of Waterloo in Ontario, who also did not participate in the Aalto study. “Only recently has technology advanced into a new technical regime of experiments where we can start to look at very fast changes that can have dramatic effects on electromagnetic fields,” he adds.

The investigators caution that such experiments do not constitute a magical way to get more energy out of a system than what is input. For instance, it takes energy to change a material’s index of refraction.

Instead, such research could help scientists learn more about the mysteries of quantum entanglement, which lies at the heart of quantum computers—advanced machines that could in principle run more calculations in an instant than there are atoms in the universe. The entangled microwave photons the experimental array generated “can be used for a form of quantum computation known as ‘continuous variable’ quantum information processing,” Girvin says. “This is a direction which is just beginning to open up.” …

via nature.com

Physicists Create Crystals That Are Nearly Alive

The best way to understand something–such as life–is to build it yourself. That’s why, determined to understand the way groups move, a team of New York University physicists set out to create particles that could imitate the way flocks of birds, schools of fish and even colonies of bacteria organize and move together.

What they ended up with, described in Science magazine yesterday, were two-dimensional “living crystals” that form, break, explode and re-form themselves elsewhere.

The researchers developed self-propelled particles that would turn on in response to blue light. When the light is on, the randomly swimming particles collide and cluster. A chemical reaction set off by the light causes the particles to crystalize. When the light turns off, the particles stop and split apart.

The crystals have metabolism and mobility, two of the general requirements for classifying something as life, according to Paul Chaikin, one of the paper’s authors, but they lack the ability to reproduce. By one count, there are a total of seven requirements that an organism should exhibit to be considered life.

“Here we show that with a simple, synthetic active system, we can reproduce some features of living systems,” lead author Jeremie Palacci told Wired. “I do not think this makes our systems alive, but it stresses the fact that the limit between the two is somewhat arbitrary.”

Palacci and Chaikin are now working on a particle that has a metabolism and can self-replicate, but lacks mobility. …

via Physicists Create Crystals That Are Nearly Alive | Popular Science.

… Scientific evidence suggests that life began on Earth approximately 3.5 billion years ago.^[6] The mechanism by which life emerged is unknown although many hypotheses have been formulated. Since then, life has evolved into a wide variety of forms, which biologists have classified into a hierarchy of taxa. Life can survive and thrive in a wide range of conditions. The meaning of life—its significance, origin, purpose, and ultimate fate—is a central concept and question in philosophy and religion. Both philosophy and religion have offered interpretations as to how life relates to existence and consciousness, and on related issues such as life stance, purpose, conception of a god or gods, a soul or an afterlife. Different cultures throughout history have had widely varying approaches to these issues.

Though the existence of life is only confirmed on Earth, many scientists believe extraterrestrial life is not only plausible, but probable. Other planets and moons in the Solar System have been examined for evidence of having once supported simple life, and projects such as SETI have attempted to detect transmissions from possible alien civilizations. According to the panspermia hypothesis, life on Earth may have originated from meteorites that spread organic molecules or simple life that first evolved elsewhere. …

Since there is no unequivocal definition of life, the current understanding is descriptive. Life is considered a characteristic of organisms that exhibit all or most of the following:^[25][27]

1. Homeostasis: Regulation of the internal environment to maintain a constant state; for example, electrolyte concentration or sweating to reduce temperature.
2. Organization: Being structurally composed of one or more cells — the basic units of life.
3. Metabolism: Transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
4. Growth: Maintenance of a higher rate of anabolism than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter.
5. Adaptation: The ability to change over time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism’s heredity, diet, and external factors.
6. Response to stimuli: A response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of multicellular organisms. A response is often expressed by motion; for example, the leaves of a plant turning toward the sun (phototropism), and chemotaxis.
7. Reproduction: The ability to produce new individual organisms, either asexually from a single parent organism, or sexually from two parent organisms.

These complex processes, called physiological functions, have underlying physical and chemical bases, as well as signaling and control mechanisms that are essential to maintaining life.

Via Wikipedia

Researchers create metamaterial that looks similar to 3D Minkowski spacetimes

—Researchers from the University of Maryland and Towson University have created a new type of metamaterial that they describe as looking similar to 3D Minkowski spacetimes. In their paper, which they’ve uploaded to the preprint server arXiv, the researchers explain how the metamaterial can be adjusted to create a demonstration of a multiverse.

Because the exact definition of a universe is difficult to pin down, it’s difficult to say whether the creation of a metamaterial that acts the same as a theoretical universe, is an actual universe if it follows the same rules. And if that metamaterial is capable of demonstrating different types of universes, with unique properties and rules that govern how things behave in them, is it a true multiverse, or simply a simulation of one?

In the case of the metamaterial made by the researchers in Maryland, the answer might lie in the eye of the beholder. They created a solution that had cobalt suspended in kerosene, than applied a magnetic field. Because cobalt is ferromagnetic, the applied field caused the cobalt to line up in columns. But not just ordinary columns, they were mathematically equivalent to a 2+1 Minkowski spacetime. Light passing through the columns has one dimension of time, while light aligned perpendicular to the columns has two dimensions of space. In this configuration, light behaves according to Einstein’s theory of relativity, which means, it might be construed to be its own unique universe, albeit, analogous to the one we perceive around us. But the researchers didn’t stop there, they found that by varying the amount of cobalt in the fluid, they were able to cause different types of columns to form, collapse, and reform, which don’t necessarily conform mathematically to the laws governing our own universe, but do for others, at least in theory.

This meant they had created a metamaterial that was able to look like different universes at different moments over time. And if it looked like them, and acted like them, who’s to say that each wasn’t a unique existence of a true universe? …

via Researchers create metamaterial that looks similar to 3D Minkowski spacetimes.

Expert psychologist suggests the era of genius scientists is over

Dean Keith Simonton, a psychology professor at the University of California, has published a comment piece in the journal Nature, where he argues that it’s unlikely mankind will ever produce another Einstein, Newton, Darwin, etc. This is because, he says, we’ve already discovered all the most basic ideas that describe how the natural world works. Any new work, will involve little more than adding to our knowledge base.

Simonton’s comments are likely to draw a strong reaction, both in and out of the science world. It’s been the geniuses among us that have driven science forward for thousands of years, after all. If no more geniuses appear to offer an entirely new way of looking at things, how will the human race ever reach new heights?

Simonton has been studying geniuses and their contributions to science for more than 30 years and has even written books on them. He also writes that he hopes he is wrong in his assessment, even as he clearly doesn’t think he is. Sadly, the past several decades only offer proof. Since the time of Einstein, he says, no one has really come up with anything that would mark them as a giant in the field, to be looked up to hundreds, if not thousands of years from now. Worse perhaps, he details how the way modern science is conducted is only adding to the problem. Rather than fostering lone wolves pondering the universe in isolation, the new paradigm has researchers working together as teams, efficiently going about their way, marching towards incremental increases in knowledge. That doesn’t leave much room for true insight, which is of course, a necessary ingredient for genius level discoveries.

Simonton could be wrong of course – there might yet be some person that looks at all that has been discovered and compares it with his or her own observations, and finds that what we think we know, is completely wrong, and offers evidence of something truly groundbreaking as an alternative. The study of astrophysics, for example, appears ripe for a new approach. Scientists are becoming increasingly frustrated in trying to explain why the universe is not just expanding, but is doing so at an increasing rate. Perhaps most of the theories put forth over the past half-century or so, are completely off base. Modern science can’t even explain gravity, after all. Isn’t it possible that there is something at work that will need the intelligence, insight and courage of an Einstein to figure out? It appears we as a species are counting on it, even as we wonder if it’s even possible. …

via Expert psychologist suggests the era of genius scientists is over.

The next scientific genius may be a quantum super computer.

Miniature Star Trek-Style ‘Tractor Beam’ Created in Lab

…A group of scientists from Scotland and the Czech Republic says it’s managed to drag around teeny-tiny objects using nothing more than a beam of light.

That’s essentially how it worked when the crew of the starship Enterprise periodically unleashed its tractor beam to tug derelict vessels (and once even the captain himself, snared by an interstellar disco-light show). Unfortunately, the no-longer-science-fiction light beam is currently limited to yanking around microscopic matter. …

How’d they do it? According to Phys.org, researchers at the University of St. Andrews in Scotland and the Institute of Scientific Instruments in the Czech Republic figured out a way to reverse what’s known as the “radiation pressure” of light — that is, the actual force exerted by electromagnetic radiation on matter.

 

Shine a light source at something and the photons in the beam exert a force on the object. It’s minuscule force — if we’re talking about a flashlight pointed at a refrigerator, forget about it — but examine what’s happening at microscopic levels and you find those photons are acting on objects in quantifiable ways. In fact an MIT graduate student recently proposed using this force as a way to deflect Earth-threatening asteroids by bombing them with clouds of white paint (think “cosmic paintball gun”); because brighter colors reflect more light than darker ones, the sun’s photons can — over the course of many, many years — gradually nudge the asteroid into a non-lethal trajectory.

 

Imagine that force operating in reverse and you have a sense for how this micro-scale “tractor beam” works: A laser beamed through a lens strikes a mirror, causing it to fire back and across the oncoming beam in a vaguely X-like configuration. The photons in the reflected beam then interfere with the oncoming one, ultimately shoving the particles of matter being “tractored” backwards.

So how long before we’re running around with gravity guns, Half-Life 2 style? Probably never: According to study lead Dr. Tomas Cizmar, the light particles still transfer energy to the object — scale up the laser’s power, in other words, and you’ve just turned your innocuous ultra-cool tractor beam into an ultra-fiery death ray. …

via Miniature Star Trek-Style ‘Tractor Beam’ Created in Lab | TIME.com.

Hearing Test – high frequency sounds measure hearing loss

We got a lot of positive feedback on our “Can You Hear Like a Teenager? ” article, and it inspired us to take it just a little bit further.

Here is a list of tones that go from 8Hz all the way up to 22,000Hz. It’s fairly common for people who are over 25 years of age to not be able to hear above 15kHz, so this will help you find out where your high frequency hearing cuts off.

Musicians have a much higher risk of hearing loss that most people do, and many of us don’t really wear proper hearing protection. Even just listening to an iPod for an extended period of time can permanently damage your hearing. We also gradually lose our high-frequency hearing as we age.

Take our unscientific hearing test: listen to each of these tones and let us know where your hearing cuts out:

8 kHz10 kHz 12 kHz 14 kHz 15 kHz 16 kHz

17 kHz18 kHz 19 kHz 20 kHz 21 kHz 22 kHz

Listen here: Hearing Test – high frequency sounds measure hearing loss.

I’m using iPhone earbuds and 12 kHz is loud, but I can barely hear 14 kHz. Everything above that is just the initial click… possibly a pressure, but no sound. Can anyone else using iPhone earbuds hear these higher sounds?

Apple says they have a Frequency Response of 20 Hz to  20KHz, so I think they are playing the sounds. I probably just have to admit my hearing loss. I did clear up that the constant ringing in my ears is about 14 KHz.

Woah, when I played 8 KHz the ringing in my ears seemed to stop for a few seconds….Cool.  More experimenting to do on this… I should sweep the entire spectrum slowly and see what happens.

Do cell phones cause cancer?

Do cell phones cause cancer?  There was a big study of cell phones that found no cancer (brain, nerve, salivary and leukemia anyway):

… the Journal of the National Cancer Institute published the results of a massive study in Denmark that followed the cancer histories of 420,000 cell phone users over 13 years.

http://jnci.oxfordjournals.org/content/93/3/203.abstract?ijkey=fe4d6f43f440f51426ab0fba45f17afc8d353c06&keytype2=tf_ipsecsha

The study’s main interest was to search for increased incidences of brain or nervous system cancers, salivary gland cancer, and leukemia. The study concluded:

Risk for these cancers … did not vary by duration of cellular telephone use, time since first subscription, age at first subscription, or type of cellular telephone (analogue or digital). Analysis of brain and nervous system tumors showed no statistically significant [standardized incidence ratios] for any subtype or anatomic location. The results of this investigation … do not support the hypothesis of an association between use of these telephones and tumors of the brain or salivary gland, leukemia, or other cancers.

The lack of any connection is not surprising, given that no plausible hypothesis exists for how a cell phone could cause tissue damage. RF below the visible spectrum, which includes the frequencies used by cell phones and all radio devices, is not ionizing radiation and so has no potential to damage living cells or break any chemical bonds. Microwave ovens, which operate just above cell phones on the frequency scale, work by oscillating such an extremely powerful field back and forth, causing the water molecules to rub against each other and create heat by friction. Cell phone signals are three orders of magnitude weaker, too weak to move the water molecules, and do not oscillate to cause friction. Scratch the heat hypothesis, scratch the ionizing radiation hypothesis, and there are no plausible alternatives. Of course it’s not possible to prove that there is no potential for harm, but all sources of harm known or theorized to date are clearly excluded. … http://skeptoid.com/episodes/4117

One doctor says we haven’t studied breast cancer effects of cell phones yet:

Is there a link between breast cancer and cell phones? Some doctors say they’re seeing evidence of breast cancer that could be connected to where some women  keep their mobile phone–in their bras. Tiffany Franz got breast cancer at just 21-years-old. She had no genetic predispositions or other risk factors–except where she kept her cell phone.

“It just so happened her tumors were exactly where her cell phone had been against her skin her bare skin for about six years,” Traci Frantz, Tiffany’s mom, told KTVU in Oakland.

Tiffany had to have her left breast removed. Donna Jayes also got breast cancer. While she was a bit older, her late 30′s, she also had no genetic risk factors. The connection is where the tumors developed. Her doctor says they formed just under the skin, exactly matching her cell phone, and just under the surface of her skin.

She says she kept her phone in her shirt for ten years. She later had a mastectomy. Breast surgeon Lisa Bailey told KTVU phone-related breast cancer may be common. Saying it mayb be the heat of the battery of the radio frequency of the radiation that makes keeping a phone directly on the skin risky.

“These young breast in the early evolution are more sensitive to changes that might lead to cancer,” Bailey said.

Nevertheless, bras are now be marketed for the express purpose of carrying cell phones, with little pockets built-in to hold cell phones. Other breast cancer specialist are now speaking out as well. Dr. John West says men who keep their phones in their shirt pockets are also at risk. The wireless industry, meanwhile, denies any problem, citing a lack of scientific evidence that cellphones cause breast cancer. Those concerned doctors though say it’s because not enough studies have been completed.

“There’s no evidence, but that’s because we haven’t studied it,” Bailey said. “Until further data either supports it or disproves it, I would keep cell phones away from the body, in particular the breasts,” adds Dr. June Chen, a Breast Cancer Radiologist.

http://wtvr.com/2012/11/19/doctors-women-who-store-phone-in-bras-at-risk-for-breast-cancer/

Our skulls are thick enough, perhaps, to protect our brains from the very weak microwave radiation cell phones emit.

The wireless companies are denying any link between their products and an increase in cancer. They may have a point. Many people, men and women, keep cell phones in their pants pockets. No links to cancer in the hip bones or genital cancers are attributed to cell phones, so why breast tissue? Maybe breast tissue is more sensitive to changes than the tissue in our thighs and backsides. … WHO classifies cell phones as potentially carcinogenic. The IARC lists it as a class 2B. This means that the phones might cause cancer but there is no concrete evidence to show that this is true. More research is needed to make a hard fast link between the two.

Maybe it is just a coincidence, but what if they are right? Could keeping a cell phone in your bra give you breast cancer? As a breast cancer patient still going through treatment, I would not want to risk it.

http://news.yahoo.com/breast-cancer-risk-increases-women-put-cell-phones-164800999.html

Then again, one guy says there is no safe amount and he should know since he worked on microwave weapons for British military intelligence. Barrie Trower says microwaves replaced radio waves because they penetrate houses … and people. He claims there are thousands of papers including a T-mobile funded study that shows that low level microwaves cause cancer and other injury. It starts as immune system suppression, then brain symptoms such as depression and loss of sleep, followed by lymphoblastic leukemia if you are unlucky.

Trower adds that sickness due to exposure to microwave radiation was first seen and reported back in 1932, when it was identified as ’microwave or radio wave sickness.’ Among the symptoms of such sickness, experts have found severe tiredness, fatigue, fitful sleep, headaches, intolerability and high susceptibility to infection. The symptoms, he says, are a consequence of the athermal effects of the radiation; that is, the effects the radiation has without emitting or exposing the victims to any kind of noticeable heat waves.

In his document prepared for the Kind of Botswana, Trower cites the example of the US Embassy in Moscow, which was irradiated with low level microwave energy during the Cold War. The consequences of this radiation, says Trower, were multiple cancers, leukaemias and other illnessess that appeared among Embassy workers and their relatives.

Regarding exposure to people and especially children to low levels of Wi Fi radiation, Trower said: “That’s wrong”, as he asserted there are no safe levels of exposure to that kind of radiation. According to his research and the International Commission for Non-Ionizing Radiation Protection Guidelines, children, the elderly and people with poor health are the most likely to have less tolerance to Wi Fi radiation, that is why he considers it inadmissible to promote the installation of Wi Fi technology in highly populated areas or places like schools, where children spend a great deal of time.

http://mother-earth-journal.com/2012/07/16/wifi-radiation-as-dangerous-as-microwave-weapons-warns-physicist/

Barrie Trower, a British physicist who carried out research for the Royal Navy and military intelligence into the effects of microwave radiation, has come out of retirement to exhort bodies such as Health Canada to heed his life’s work.

http://www.thestar.com/news/gta/article/853091–u-k-expert-warns-against-wi-fi

Others disagree with Trower:

The claim by Trower that Wi-Fi can cause DNA damage is based on a study that was later withdrawn because of scientific fraud. No properly conducted scientific studies have ever demonstrated DNA damage or any other serious effect from microwaves within existing safety standards. Virtually all of the public health authorities of the industrialized world including the World Health Organization, and Health Canada have reviewed the scientific literature and concluded that there is no credible evidence that Wi-Fi, cell phones, etc. cause health effects.

However, looking at the link the head of the ethics committee that found the data was fabricated was a lawyer for the telecom industry. Either the data was falsified, or good scientists were discredited and fired due to industry pressure.

Rüdiger says he initially agreed to withdraw both papers based on the ethics committee’s findings. But several days later, he discovered that the chair of the ethics committee was a lawyer who had worked for a telecom company. He also says that Kratochvil denies any wrongdoing.

http://www.emfandhealth.com/sciencerudigerfraud.pdf

Are people getting worked up about nothing? Trower says every single phone call is recorded and logged by governments. They don’t want to lose this ability or the location technology that allows them to track everyone with a cell phone. Then there is the fact that this is a three trillion dollar per year industry giving the financial incentive to hide negative health effects.

So, I’d like to read some of these thousands of papers of which Trower speaks. Are they available?

Star Wars ‘hyperdrive’ space flight explored by physicists

… if it were possible, the reality of interstellar travel would be a lot less spectacular, according to a group of student physicists.

The ”hyperdrive” featured in Star Wars enables Han Solo’s Millennium Falcon spaceship to take short cuts between stars through a higher dimension of space.

Racing through hyperspace at near light speed, the ship’s crew sees the stars appear to radiate out from a central point and stretch past them.

But in reality, the view through the Millennium Falcon’s cockpit window would probably consist of a fuzzy luminous fog surrounding a bright central disc.

There would be no sign of stars because the wavelength of their light would be shortened to the invisible X-ray range, say the team of four young scientists from the University of Leicester.

This is due to the Doppler effect – the same effect that causes a police car siren to increase in pitch as it approaches.

The luminous disc would be due to Cosmic Microwave Background (CMB) radiation being shifted into the visible part of the light spectrum.

The CMB is radiation left behind by the Big Bang that gave birth to the universe.

As a result of the Doppler shift the spaceship would be bombarded by intense X-rays, exerting a pressure strong enough to slow it down. The ship’s engines would need extra power to overcome this pressure, the calculations suggest.

One of the students, Riley Connors, 21, from Milton Keynes, said: ”If the Millennium Falcon existed and really could travel that fast, sunglasses would certainly be advisable. On top of this, the ship would need something to protect the crew from harmful X-ray radiation.”

The findings appear in the University of Leicester’s Journal of Physics Special Topics. …

via Star Wars ‘hyperdrive’ space flight explored by physicists – Telegraph.

A rock is a clock: Physicist uses matter to tell time

Ever since he was a kid growing up in Germany, Holger Müller has been asking himself a fundamental question: What is time?

That question has now led Müller, today an assistant professor of physics at the University of California, Berkeley, to a fundamentally new way of measuring time.

Taking advantage of the fact that, in nature, matter can be both a particle and a wave, he has discovered a way to tell time by counting the oscillations of a matter wave. A matter wave’s frequency is 10 billion times higher than that of visible light.

“A rock is a clock, so to speak,” Müller said.

In a paper appearing in the Jan. 11 issue of Science, Müller and his UC Berkeley colleagues describe how to tell time using only the matter wave of a cesium atom. He refers to his method as a Compton clock because it is based on the so-called Compton frequency of a matter wave.

“When I was very young and reading science books, I always wondered why there was so little explanation of what time is,” said Müller, who is also a guest scientist at Lawrence Berkeley National Laboratory. “Since then, I’ve often asked myself, ‘What is the simplest thing that can measure time, the simplest system that feels the passage of time?’ Now we have an upper limit: one single massive particle is enough.”

While Müller’s Compton clock is still 100 million times less precise than today’s best atomic clocks, which employ aluminum ions, improvements in the technique could boost its precision to that of atomic clocks, including the cesium clocks now used to define the second, he said.

“This is a beautiful experiment and cleverly designed, but it is going to be controversial and hotly debated,” said John Close, a quantum physicist at The Australian National University in Canberra. “The question is, ‘Is the Compton frequency of atoms a clock or not a clock?’ Holger’s point is now made. It is a clock. I’ve made one, it works.”

Müller welcomes debate, since his experiment deals with a basic concept of quantum mechanics — the wave-particle duality of matter — that has befuddled students for nearly 90 years.

“We are talking about some really fundamental ideas,” Close said. “The discussion will create a deeper understanding of quantum physics.”

Müller can also turn the technique around to use time to measure mass. The reference mass today is a platinum-iridium cylinder defined as weighing one kilogram and kept under lock and key in a vault in France, with precise copies sparingly dispersed around the world. Using Müller’s matter wave technique provides a new way for researchers to build their own kilogram reference.

De Broglie’s “crazy” idea

The idea that matter can be viewed as a wave was the subject of the 1924 Ph.D. thesis by Louis de Broglie, who took Albert Einstein’s idea that mass and energy are equivalent (E=mc2) and combined it with Ernst Planck’s idea that every energy is associated with a frequency. De Broglie’s idea that matter can act as a wave was honored with the Nobel Prize in Physics in 1929.

Using matter as a clock, however, seemed far-fetched because the frequency of the wave, called the Compton, or de Broglie, frequency, might be unobservable. And even if it could be seen, the oscillations would be too fast to measure.

Müller, however, found a way two years ago to use matter waves to confirm Einstein’s gravitational redshift — that is, that time slows down in a gravitational field. To do this, he built an atom interferometer that treats atoms as waves and measures their interference.

“At that time, I thought that this very, very specialized application of matter waves as clocks was it,” Müller said. “When you make a grandfather clock, there is a pendulum and a clockwork that counts the pendulum oscillations. So you need something that swings and a clockwork to make a clock. There was no way to make a clockwork for matter waves, because their oscillation frequency is 10 billion times higher than even the oscillations of visible light.”

One morning last year, however, he realized that he might be able to combine two well-known techniques to create such a clockwork and explicitly demonstrate that the Compton frequency of a single particle is, in fact, useful as a reference for a clock. In relativity, time slows down for moving objects, so that a twin who flies off to a distant star and returns will be younger than the twin who stayed behind. This is the so-called twin paradox.

Similarly, a cesium atom that moves away and then returns is younger than one that stands still. As a result, the moving cesium matter wave will have oscillated fewer times. The difference frequency, which would be around 100,000 fewer oscillations per second out of 10 million billion billion oscillations (3 x 1025 for a cesium atom), might be measurable.

In the lab, Müller showed that he could measure this difference by allowing the matter waves of the fixed and moving cesium atoms to interfere in an atom interferometer. The motion was caused by bouncing photons from a laser off the cesium atoms. Using an optical frequency comb, he synchronized the laser beam in the interferometer with the difference frequency between the matter waves so that all frequencies were referenced solely to the matter wave itself.

via A rock is a clock: Physicist uses matter to tell time.