Tuesday, February 24, 2015

Seeing Our Way to Invisibility

The Federation did not use cloaking devices, and
the Treaty of Algernon prevented them from
developing them. However, sometimes you have to
use what you have, so Enterprise did make use of a
stolen cloaking device to escape some Romulans in
The Next Generation series.
Gene Roddenberry believed in the idea of heroes and fair play. That’s why the Federation didn’t have cloaking devices. He stated in several interviews that, “heroes don’t sneak around.”

That’s why the Romulans and the Klingons had cloaking devices for their ships, but the Federation didn’t (with very rare exceptions). It's one of the few toys that came from the series that wasn’t a Federation invention or used by them. But it was awfully cool.

You hit a button and your ship disappears for everyone looking at it. The idea wasn’t original to Star Trek, J.R.R. Tolkein had it in the Lord Of The Rings, and it was a part of many folktales hundreds of years before he gave it to Frodo. Harry Potter’s cloak is probably a direct result of Frodo’s, although the movie Predator gave it a more scientific, not magical, feel that is more reminiscent of Star Trek.

The cloaking devices in the early Star Trek episodes were not perfect, you couldn’t fire weapons while cloaked and some tracking sensors could still find you. These are some of the same problems we're having with cloaking devices today.

Oh yes, we have cloaking devices.

The Klingon bird-of-prey projected it’s invisibility through its deflector shields; we don’t have anything that cool yet, but we can make things disappear under the right conditions. However, making a ship disappear to all wavelengths of electromagnetic radiation using something projected from the ship itself is beyond us as of yet. Let’s see what we can do.

The electromagnetic spectrum is all around us, we
see with only a very small part of it. The longer the
wavelength, the lower the energy, so gamma rays are
very powerful, and radio waves can’t hurt you unless
we’re talking about your ears.
First of all, how do we sense things that are in front of us, or even a little to the side of us? Our eyes use visible light, just a small portion of the entire electromagnetic spectrum. Visible light waves from the sun or some other source strike the object; some are absorbed and some bounce off. A few of the bounced rays make it to our retina. They are the ones we decode into a shape. The object might absorb all light but red, so only the red waves bounce off and make it to our eye. We see the object as red.

But there are so many more types of waves than just visible light. Infrared waves are longer and lower energy than visible light. Heat sources give off infrared waves, so this is how you can find people in the dark with night vision goggles. Radio waves are even lower energy, while microwaves for radar are in between infrared and radio.

Higher energy waves are on the other side of the visible spectrum; things like ultraviolet, X-rays, and Hulk-producing gamma rays. All the different types of waveforms can be detected by some kind of detector or another. They all give clues to the fact that something is out there. Star Trek cloaking devices masked all of them eventually, but we’ve only gotten to the point of hiding from a few wavelengths at a time.

As with most scientific or technological advances, first we have many of ways to try it, and we finally settle on what works best. Remember VHS vs. Betamax? As our knowledge increases, we will hone in on one or two ways to make these cloaks work, but for now, there’s a bunch.

This is not to say that we haven’t been hiding things in plain sight for a long time. Camouflage is an ancient practice, something we stole from nature. Active camouflage is a little more tech-y and recent. This technique allows the camouflage to change as the background changes.

The Adaptiv technology uses hexagonal panels on the
sides and turret of tanks to project an incorrect heat
signature. To an infrared scope, they can look like a
station wagon or truck.  This is one type of active
One type of active camouflage is a way to project the background onto a screen or cover over the object. They have even gone so far as to make cloaks that capture background on tiny cameras in the back and project that image from pixels on the opposite side.

However, when the object moves, there is a blur as the cameras catches up to the new background. Plus, like with your TV, it only works very well when you are directly in front of it. Nobody wants to be the guy watching the Super Bowl from the uncomfortable chair that’s at a 45˚ angle to the TV screen.

There is also holographic camouflage, so that as you move past the object, the background appears to move with you. Better, but still not great. And these examples are for just visible light; nothing about a hologram projected on a sheet is going to hide your heat signal from a guy with infrared night specs. The new Adaptiv system allows tanks to project a different heat signature than they normally would (see picture above).

A metamaterial is any solid that derives its properties
from its structure, not its composition. It is how they are
made in 3-D, together with what they are made of, that
allows them to cancel out waves or bend them. On the
right is a significant feature of some metamaterials, a
negative refractive index. Regular materials can reflect
a beam more than 90˚ to the face of the object,
metamaterials can, and this is how they can bend the light
around objects.
Now we have moved on to true cloaking, which is more passive than active camouflage. The methods with which we are currently hiding objects are mostly defined by which wavelengths of radiation we want to hide them from. The first real cloak of invisibility was demonstrated in 2006, and hid a small object or part of an object from some microwave wavelengths. Other cloaks hide things only from radio waves.

Many of the newer techniques bend light around the object, sort of like a stone in a stream. The water comes back together on the other side and moves on as if the object weren’t there. Same with light rays that bounce off the background. Using proper technology, they can be made to travel around the object being cloaked and travel to your eye as if it wasn’t even there.

The mantle cloak technique uses a very thin layer of
metamaterial to bend light rays or cancel them out. Harry
Potter might have been hidden better, but I like our chances
with science better than magi
True cloaking makes use of either traditional or some complex surfaces called metamaterials (or superlenses made of metamaterials). See the picture above to learn a little about metamaterials but I suggest that quite a bit of reading is necessary to make you feel like you understand them at all. I’m not to that point yet.

The metamaterials offer several different ways to hide something, like plasmonic cloaking, where the light scattered by an object is detected by the cloak. The clock then emits a canceling wave at precisely the same length but 180˚ out of phase. The two waves cancel each other out and it is as if no light was bounced toward your eye or your detector. Other metamaterials don’t cancel the signal, but truly bend it around the object as described above.

A mantle cloak is thinner, using a metamaterial screen just a few millimeters thick to produce the antiphase radiation that cancels out whatever strikes it. This was demonstrated in 2013 by Andrea Alu from the University of Texas, just as the plasmonic cloak was a few years previous. The advantage is that the thinner the cloak or mantle, the broader the range of wavelengths that it could cancel out.

The Rochester cloak uses the mirrors of different focus
lengths to bend visible light rays. Check out this website to
make one yourself. While cloaks in the visible range are the
biggest show, the military or security will be interested in
cloaks of broad wavelengths, not just visible light.
Several groups have demonstrated the use of a  traditional lens, sometimes called a Rochester Cloak because they were developed at the University of Rochester in New York. All you need is two sets of lenses with two different focal lengths (a and b); use "a" then "b" to bend the light around, then "b" and "a" to bend it back. This isn’t really dynamic cloaking because it's stationary. Whatever is behind that lens at that moment will disappear. We need to be able to have either huge sets of lenses or make the air act like a lens so that something large and moving could be cloaked.

A big problem that we must overcome to mimic Star Trek cloaking is that fictional ships can scan and see what is out there via emission of their own probes or detectors, we can't do that yet. With current technologies, the object is covered or masked, so it can’t emit anything or see anything around it. Most current cloaks work by absorbing or channeling EM waves, so if the cloaked object emits anything, it can be detected.

As Frodo could see through the weave of his cloak, we need to be able to look out from a cloaked object and see what we want, or even send out some energy to detect things that might be out there. There is limited advantage to a cloaked ship that is ostensibly blind itself. However, 2012 experiments did develop a plasmonic cloak that detected light, so over a very narrow range it was an invisible device that could see.

Another low-tech cloak is using mirrors, but again, you
have to be positioned exactly right for them to give you
the right image. Plus, this is just for visible light, a true Star
Trek cloak would mask all wavelengths of
electromagnetic radiation.
Another problem with cloaked materials was described in a 2013 paper. Despite being “invisible” to some EM wavelengths, the cloaks may increase the scatter in the other wavelengths by the cloaked object so that the total scatter is greater than that of the uncloaked object alone.

In addition, the cloaks themselves usually scatter light, so even though the object being cloaked is hidden, the cloak itself might be detected! The authors suggest that there could be a passive solution using superconductors, or that mixed metamaterials could scatter the waves bouncing off the object to be hidden and the cloak.

Next week, how about looking at our versions of phasers – we do have them, just not small enough to be hand held.

Contributed by Mark E. Lasbury, MS, MSEd, PhD
As Many Exceptions As Rules

Choi, J., & Howell, J. (2014). Paraxial ray optics cloaking Optics Express, 22 (24) DOI: 10.1364/OE.22.029465
Fan, P., Chettiar, U., Cao, L., Afshinmanesh, F., Engheta, N., & Brongersma, M. (2012). An invisible metal–semiconductor photodetector Nature Photonics, 6 (6), 380-385 DOI: 10.1038/nphoton.2012.108
Soric, J., Chen, P., Kerkhoff, A., Rainwater, D., Melin, K., & Alù, A. (2013). Demonstration of an ultralow profile cloak for scattering suppression of a finite-length rod in free space New Journal of Physics, 15 (3) DOI: 10.1088/1367-2630/15/3/033037

Thursday, February 19, 2015

Pull Up A Stool And Let's Talk About Your Microbiome

A medical case report recently made headlines supporting the notion that the bacteria inside our gut have something to do with the size of our gut.

Clostridium is a nasty strain of bacteria that is resistant to many antibiotics. Normally, the many other species of bacteria in the gut keep Clostridium in check, but when those friendly bacteria are wiped out during antibiotic therapy, Clostridium can thrive and produce severe inflammation (colitis) and diarrhea. This can develop into a serious illness that claims the lives of 14,000 Americans every year.

A novel way to treat this condition is through use of fecal microbiota transplant (FMT). In other words, the patient ingests the intestinal bacteria from a healthy person to replenish their own stock and get Clostridium back under control. We will leave it to your imagination as to how doctors collect the good bacteria, but let's just say you can make some decent money if you're willing and able to donate. Thankfully for patients, FMT is available in pill form.

As unappealing as it sounds, fecal transplants - which repopulate intestinal bacteria in the recipient - are proving to be very effective in treating some serious ailments. 
As reported recently, a young woman with a stable weight of ~130 pounds had to undergo FMT to fight a Clostridium infection. The good news is that she beat the infection, but the bad news is that she gained 34 pounds in 16 months, classifying her as obese with a BMI of 33. Even more alarming is that she could not lose weight despite being on a supervised liquid diet and exercise program. The donor for the FMT (her teen daughter) was overweight, but otherwise in good health, so doctors are now recommending that FMT donors be of normal weight.

In light of this news, here's a beginner's guide to the tiny creatures calling you "home"...

You are not just a person – you are an ecosystem. Your body is home to trillions of microscopic critters, including viruses, bacteria, and fungi, living on or inside you. Collectively, these communities of microbes constitute what is called your “microbiome”.

And there are more of “them” than “you” – the number of microbes inhabiting your body is larger than the number of cells making up your body! To put this in perspective, it has been estimated that your microbiome weighs about 3 pounds. Good news if you’re on a diet – when you step on the scale tonight, feel free to subtract 3 pounds of stuff that isn’t “you” per se.

A new study concerning our microbiome seems to be coming out each week, so it is time we get to know our microbial roommates.

1. Where does your microbiome come from?

We are born virtually sterile, but quickly receive an infusion of bacteria from our mom, first through the birth canal and then through the milk. Over 900 species of bacteria have been found in breast milk, and these are the pioneers that settle into your gut, which appears to stabilize by the age of 3. Of potential interest are babies born by caesarean section or those who are fed formula instead of breast milk. Babies delivered via C-section do in fact have a different microbiome and may be at higher risk for certain types of allergies and obesity (more on this below). Our microbiome continues to receive fresh new imports as we move through, inhale, and ingest our environment.

How much of you is really you? There are more microbes in your body than the number of cells making up your body. We are just now beginning to appreciate the many things they do for us.
2. Your microbiome is like your own personal “germ cloud”.

You’ve probably noticed that everyone’s home smells a little different. Sometimes this is due to cooking, pets, or the amount of trash they let accumulate, but it is also due in part to the microbiome of the inhabitants. Researchers have found that you are surrounded by a “germ cloud”, and you leave pieces of your microbiome wherever you go like a trail of breadcrumbs. It might even be possible for police to use microbiomes to track people one day like they currently use fingerprints or DNA. In other words, you have a “microbiome fingerprint” that is left behind like a germ echo wherever you go.

This “germ cloud” may also explain how dogs can track people so easily. The byproducts generated by the millions of bacteria living on your skin are aromatic (odorous), producing a scent that is released into the air as you move. Animals with a keen sense of smell can get a whiff of these aromatic compounds and follow them to the source.

Speaking of “germ clouds”, if you ever wondered if it is possible to fart out germs, some brave scientists have sniffed out the answer to this question. You can read about the results here.

3. Antibiotics substantially alter your microbiome.

We take antibiotics to get rid of pathogenic bacteria that make us sick. The problem is they are not selective, so they destroy a lot of our friendly bacteria in addition to the bad guy. We need these friendly bacteria to do all sorts of things – to name just a few:  they help us digest food, make vitamins, and build anti-inflammatory compounds.

Another important thing our microbial friends do is keep infections in check. For example, yeast infections from pathogenic fungi can arise if good bacteria are not around competing for resources. And some bacteria, like the nasty Clostridium difficile, are naturally resistant to many antibiotics. When good bacteria are killed as collateral damage in an antibiotic treatment, the growth of Clostridium can run amok. These bacteria secrete a toxin that causes diarrhea and they can lead to a life-threatening superinfection in some patients.

4. Your microbiome may protect you from allergies or obesity.

Several recent studies have correlated unusual microbiome composition with the presence of certain allergies. Dr. Hans Bisgaard has shown that infants harboring fewer species of gut bacteria have an increased risk of developing certain allergies as they grow up. More recently, Dr. Catherine Nagler has shown that certain bacterial species offer protection from peanut allergies.

Dr. Martin Blaser has found that administration of penicillin to mice soon after birth altered their gut microbiome in such a way that it made them more prone to obesity as adults. Remarkably, the tendency to grow obese is transferrable to germ-free mice – in other words, by transplanting the microbes from the penicillin treated mice to normal mice made the normal mice more susceptible to weight gain.

Studies such as these make it tantalizing to speculate that we may be able to treat certain ailments in humans by altering our microbiome with specific probiotic regimens. Maybe they could even slip these bacteria into our peanut butter instead of deadly Salmonella.

5. How do scientists study the microbiome?

Advances in DNA sequencing have allowed scientists to rapidly map the genomes for many microbial species, which provides us with a “genomic fingerprint”. We can process samples swabbed from the skin or body cavities, or process stool samples, for DNA sequencing. Usually just sequencing the 16S ribosomal RNA gene is enough to distinguish one bacteria species from another.  

It should be mentioned that some scientists are issuing cautions about over-interpreting microbiome studies. Many of the studies altering the microbiome have been performed in mice, so it remains to be determined to what extent the findings can be extrapolated to humans. Furthermore, many of the methods used to alter the microbiome in lab animals do not faithfully mimic what humans do with antibiotics. For example, in some studies the investigators give large doses of antibiotics over unusually long periods of time to see an effect in lab animals, which does not equate to the typical dosing of antibiotics in humans. Finally, many of these studies are correlative and have not yet definitively demonstrated causation. There is a big difference between correlation and causation.

6. So should I take my microbiome into my own hands?

Much more research needs to be done to assess the true impact of the microbiome versus other factors that come into play, such as host genetics, diet, and the environment. It is argued that some microbiome studies are hyped up and way overblown. Long story short:  if you or your child becomes sick with an infectious agent, it is not wise to withhold antibiotic treatment out of fear that it will cause allergies or obesity. If you are overweight, a healthier diet and plenty of exercise is going to do much more than any probiotic pill. In fact, there is little evidence that the popular probiotics on the market do anything to remedy the wide-ranging health problems some claim to treat, although there is data showing potential benefit in treating some gastrointestinal maladies, especially acute diarrhea caused by rotavirus.

Go here to learn more about the NIH human microbiome project.

Contributed by:  Bill Sullivan, Ph.D.
Follow Bill on Twitter.

Lax S, Smith DP, Hampton-Marcell J, Owens SM, Handley KM, Scott NM, Gibbons SM, Larsen P, Shogan BD, Weiss S, Metcalf JL, Ursell LK, Vázquez-Baeza Y, Van Treuren W, Hasan NA, Gibson MK, Colwell R, Dantas G, Knight R, & Gilbert JA (2014). Longitudinal analysis of microbial interaction between humans and the indoor environment. Science (New York, N.Y.), 345 (6200), 1048-52 PMID: 25170151

Bisgaard, H., Li, N., Bonnelykke, K., Chawes, B., Skov, T., Paludan-Müller, G., Stokholm, J., Smith, B., & Krogfelt, K. (2011). Reduced diversity of the intestinal microbiota during infancy is associated with increased risk of allergic disease at school age Journal of Allergy and Clinical Immunology, 128 (3), 646-65200000 DOI: 10.1016/j.jaci.2011.04.060

Cox, L., Yamanishi, S., Sohn, J., Alekseyenko, A., Leung, J., Cho, I., Kim, S., Li, H., Gao, Z., Mahana, D., Zárate Rodriguez, J., Rogers, A., Robine, N., Loke, P., & Blaser, M. (2014). Altering the Intestinal Microbiota during a Critical Developmental Window Has Lasting Metabolic Consequences Cell, 158 (4), 705-721 DOI: 10.1016/j.cell.2014.05.052

Stefka, A., Feehley, T., Tripathi, P., Qiu, J., McCoy, K., Mazmanian, S., Tjota, M., Seo, G., Cao, S., Theriault, B., Antonopoulos, D., Zhou, L., Chang, E., Fu, Y., & Nagler, C. (2014). Commensal bacteria protect against food allergen sensitization Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1412008111

Williams NT (2010). Probiotics. American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists, 67 (6), 449-58 PMID: 20208051

Alang, N., & Kelly, C. (2015). Weight Gain After Fecal Microbiota Transplantation Open Forum Infectious Diseases, 2 (1) DOI: 10.1093/ofid/ofv004

Tuesday, February 17, 2015

I’ll Beam Right Over

The latest iteration of Star Trek movies have a
pretty cool transporter signature. The original
was kind of goofy with speckles and blue light.
But the question remains, what about
teletransporting requires the sounds effects?
One of the most iconic pieces of technology from Star Trek was actually a compromise. It was also the reason why the third episode made was shown first. Originally, Gene Roddenberry wanted the Enterprise, or a shuttle craft, to land on a planet’s surface each time there was the need for an away team.

But that was a budget buster (sets, models, etc.). They had to think of a cheaper way of getting crew members down to a planet and back the ship. Voila – the transporter. How did it change the order of the first season? The third episode (The Man Trap) began with Kirk and cohorts transporting down to the planet surface. By showing this first, they didn’t have to go to the time and effort of explaining the transporter – you just saw just what it was for and how it worked.

Star Trek’s transporter moved stuff, animate or inanimate, from one place to another, without them every being located anywhere between the two points. The matter was converted to energy and this was moved at the speed of light (or similar) to the destination. Once there, the matter was reassembled into the object again.

Well…. That’s one way it might have worked. It might also be that the information about the object was transmitted from one place to the destination, and the object was built from atoms at that location. This second possibility is kind of like faxing –

Faxing has been around for years, it got its start with the work of Captain Richard Howland Ranger (from Indianapolis, by the way) transmitting pictures via telegraph in 1924. The picture was one place, and then it was reproduced in another place. If you destroyed the first, then that would be like a Star Trek transporter. But there are problems to solve before we get to the destruction issue.

Triangulation works in many systems. On the left
is how the police can locate a cell phone by the
cell towers that bounce the signal. With just two,
the overlap is two places, , but the third eliminates
one of the two possibilities. It’s the same with GPS.
Three satellites are need to locate a person or thing
on the face of the Earth.
The first question in transporting a person to a specific location is honing in on that location. You need a way to define a single point in space. Here we have made great strides. It’s called the global positioning satellite (GPS) system.

GPS uses a system of 30 satellites in geosynchronous orbit around the Earth. Any one point on the planet can be located using a GPS locator at that point. It will triangulate the distance to each of three of the satellites and this will define the point where the locator is. A signal is sent from the locator to the satellites and the time is measured for the signal to return. Time and speed are used to calculate distance.

In space, defining a certain point would take more than 30 satellites - try millions. Untenable at best, impossible more likely - a different method is needed. Each solar system could have a different coordinate system, using the central star as the 0,0,0 point. Then any point at a given time could be defined by directions x, and y, and a distance z from the 0,0,0 point.

Going from solar system to solar system will be even harder, so the science of astrometry has developed things like the International Celestial Reference System (ICRS). It's not easy to explain, but suffice it to say our Star Trek transporter officer will have to be pretty darn good at math.

In the first two movies about flies and transporters,
the result was a switching of parts. In the 1986 film
with Jeff Goldblum, the fly and the scientist were
merged into one being. In Star Trek, they overcame
this problem with pattern separators to keep
peoples’ information separate and biofilters to
destroy infections agents and such.
Now that you have a way to beam someone to infinity and beyond, how do you bring them back? Star Trek used a pattern lock – they tracked those they transported so that they would have their position at all time. This way, they could beam them back from wherever they were; they didn’t have to go back to the same spot at which they arrived.

Now we come to the crux of the transporting problem. Can you send an object from one place to another without it ever being anywhere in between? It’s not like sending something by microwave pulse, by optical cable and light pulse, or even by radio wave. You can follow those pulses of information from one place to another or even intercept them at some point along the way.

For teletransporting, the object needs to be here…. and then be there. Can we do that? Yes and not yet. Yes for information and energy, not yet for matter. What we have been able to send is information about certain electrons, photons of light, or atoms. The information is their quantum states (like in relativity and quantum mechanics). Quantum states define the unique characteristics of a particle in terms of its energy.

Quantum entanglement is indeed spooky. When
two particles come near one another, they become
linked. Because two particles CANNOT have the
same quantum numbers, one will always have the
opposite values of the other for each characteristic.
Then, no matter how far apart, when one switches,
so will the other.
Sending the information to another place allows the scientists to then create that same quantum state for a photon, etc. at a different point in space. In reality, you just sent that particle (and all its information) to a different place. What makes this possible? Quantum entanglement – what Einstein called spooky action at a distance.

If one particle ever has a relationship (trades energy or even bumps into) another particle, their quantum states are linked (entangled) forever. Change the states of one, and the states of the other will automatically changes as well. This occurs even if they are very far from one another at a later time. This is how information and energy of the particles can be sent from one place to another, but never exist in between.

Many recent papers have shown the progress we have made in sending quantum information and energy from place to place. A recent distance record was set for sending a photon of light – 143 km. This is important because that's about the distance from Earth to low flying satellites, so beaming quantum information could help in communications. Also, improvements have been made in amplifying the signal without losing entanglement.

The principal reason for all this research is to develop quantum computing not a transporter. Regular computing uses 1’s and 0’s; using quantum information would allow for a bit being a 1 and 0 at the same time! With quantum computing you could solve huge mathematical problems where variables could be in multiple states, or do millions of problems all at once, using a small number of qubits (quantum bits). In fact, a computer of just thirty qubits would have the same processing power of a 10 teraflop (trillions of operations per second) classical computer. Your laptop runs about 10,000-100,000 times slower than that.

Scientists recently made a 10,000 qubit “circuit board” in a demonstration, and another group showed how single photons could be used as routers on a circuit board to send information different ways. Maybe quantum computers aren’t so far off.

Mike Teavee was the first person sent by television
in Charlie and the Chocolate Factory. He was sent from
one place to the other with a receiver needed to stop
the signal and interpret it. The biggest problem for
Star Trek teleportation is that there is no receiver to
stop the signal and reassemble the person. Ever try to
get a light beam to stop at a certain place on its own?
You see the problem.
So, can quantum teleportation and quantum computing be used for transporting people or macroscopic objects? Maybe. Matter is just energy in a different form (E=mc2, there's Einstein again). Each atom in your body can be defined in terms of its position and its quantum states, so maybe we could harness all that information into a pattern (like on Star Trek).

Every person is made up of about 1029 particles, each with multiple elements of quantum information. That's a whole bunch of information to transport. It might be necessary to invent quantum computing in order to transfer the massive amount of information needed to transport a human being to another place. Of course, this means that we are accepting our second description of transporting from above - sending just the information and building a new person at the destination point based on the defined quantum states of their every atom. Only quantum computing could manage that trick.

But what do you do with the first version of the person being transported? Would they be destroyed while obtaining their pattern? The first one would have to be destroyed or there would be two of them. Nobody wants two Dr. McCoy's around to complain twice as much about their atoms being scattered all over the galaxy. But wouldn't it be murder to get rid of the original? I like the idea of transporting both the information and the atoms; no crime committed there.

Next week, how close are we coming to making a cloaking device, and would we know it if we did? We couldn't see it.

Contributed by Mark E. Lasbury, MS, MSEd, PhD

Filippov, S., & Ziman, M. (2014). Entanglement sensitivity to signal attenuation and amplification Physical Review A, 90 (1) DOI: 10.1103/PhysRevA.90.010301

Ma, X., Herbst, T., Scheidl, T., Wang, D., Kropatschek, S., Naylor, W., Wittmann, B., Mech, A., Kofler, J., Anisimova, E., Makarov, V., Jennewein, T., Ursin, R., & Zeilinger, A. (2012). Quantum teleportation over 143 kilometres using active feed-forward Nature, 489 (7415), 269-273 DOI: 10.1038/nature11472

Shomroni, I., Rosenblum, S., Lovsky, Y., Bechler, O., Guendelman, G., & Dayan, B. (2014). All-optical routing of single photons by a one-atom switch controlled by a single photon Science, 345 (6199), 903-906 DOI: 10.1126/science.1254699

Yokoyama, S., Ukai, R., Armstrong, S., Sornphiphatphong, C., Kaji, T., Suzuki, S., Yoshikawa, J., Yonezawa, H., Menicucci, N., & Furusawa, A. (2013). Ultra-large-scale continuous-variable cluster states multiplexed in the time domain Nature Photonics, 7 (12), 982-986 DOI: 10.1038/nphoton.2013.287

Thursday, February 12, 2015

Happy Valentine's Day! What Is Love, Anyway?

Many an ‘80s band has pondered the timeless question:  Howard Jones asked “What is Love”, Foreigner lamented “I Want To Know What Love Is”, and both Survivor and Whitesnake wondered “Is This Love”, just to name a few. Recently, a pair of skeletons was discovered in Leicestershire, England, holding hands for the past 700 years. Well, either that or they were thumb-wrestling enthusiasts.

"I wanna hold your hand"
It is hard for us humans to imagine a world without love, but the universe has been going about its business with complete dispassion for billions of years. The appearance of life on Earth did little to change that at first, but after a couple billion years, life forms began to emerge with brains sophisticated enough to make love possible. So it is clear that love is not requisite for life; for every animal that can experience love, there are billions of bacteria living with that animal that do just fine without it.

Many of Earth’s creatures thrive without any need for love.

Granted, bacteria divide asexually, so there is no need to wine and dine a partner who is probably not going to return your 33 calls anyway. You might think that love is needed for sex, but many life forms that have sex, including parasites, plants, insects, and frat boys, do so without love, further begging the question:  why does love exist?

At first sight, love would seem to be counterintuitive to evolution, which is often characterized as the “blind watchmaker” driven by “selfish genes” tinkering to build the fittest survival machine. However, love can confer extraordinary benefits to its practitioners, which is especially important when their offspring are unfit to survive on their own after birth. Most scientists agree that love evolved to prompt species to protect their offspring (this is known as kin selection*), and this altruistic behavior often extends to others who share similar genes. A recent study from April of this year has indeed shown that spouses tend to have similar DNA, and we reported a study a few weeks ago about friends having similar DNA. In other words, an objective analysis reveals that love is a stealthy manipulation orchestrated by selfish genes in order to trick us into protecting their legacy.

Certain dating web sites are capitalizing on the discovery that spouses share highly similar DNA. You can find your genetic soul mate by viewing the genes of potential partners as you check out what they look like in tight jeans.

Back in the 80s we didn’t have technology that could identify our genetically compatible companion, so we had to rely on the wisdom of the great philosopher Sammy Hagar to teach us how we know “When It’s Love”.

Scientists have also made great strides in elucidating the biochemical basis for love with the discovery of oxytocin, aka the “love hormone” or the “cuddle chemical”, which floods the brain during pair-bonding events, such as sex, childbirth, or eating a Reese's Peanut Butter Cup. In addition to forging pair bonds during sex, oxytocin appears to be instrumental in causing moms to love and care for their kids. Rat mothers given an agent that blocks oxytocin release disregard their newborn pups. There is even a review article on oxytocin written by a Dr. Love – no joke!

Lou Gramm of Foreigner once crooned, “I want to know what love is, I want you to show me.” Here you go, Lou.

So there you have it:  love is an evolutionary tactic that helps us propagate our genetic legacy. Let’s see Barry White work that into a song. It is not the most romantic answer, but remember…just because we know how the roller coaster works doesn’t make the ride any less thrilling.

*It should be noted that kin selection is seen in many species, and not just animals. For example, kin selection is seen in insects and even in plants!
Contributed by:  Bill Sullivan
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Love TM (2014). Oxytocin, motivation and the role of dopamine. Pharmacology, biochemistry, and behavior, 119, 49-60 PMID: 23850525

van Leengoed E, Kerker E, & Swanson HH (1987). Inhibition of post-partum maternal behaviour in the rat by injecting an oxytocin antagonist into the cerebral ventricles. The Journal of endocrinology, 112 (2), 275-82 PMID: 3819639

Domingue, B., Fletcher, J., Conley, D., & Boardman, J. (2014). Genetic and educational assortative mating among US adults Proceedings of the National Academy of Sciences, 111 (22), 7996-8000 DOI: 10.1073/pnas.1321426111