The end of a year and the start of a new year brings many predictions about things to come. Predictive coding has nothing to do with “coding” computers or predicting trends and everything to do with our personal neuroscience.
The classical view of perception states that we experience the world by receiving input from our environment, processing it at the higher levels of our brain, and then responding accordingly.
A newer alternative theory proposes to add to those three steps that our higher faculties often “predict” the input from our environment. That means we have a perception of some things before we experience it. This is called predictive coding or predictive processing.
The next day I noticed a connection when my son’s visiting dog seemed to do some predictive processing. Pepper reacts to her doorbell at home by barking and sprinting to the front window. We were watching the movie Love Actually and in one scene Hugh Grant’s character rang a series of doorbells looking for a woman’s home. Even though these were different doorbell sounds from the sound in Pepper’s home, she reacted to each ring in the same way that she does at home. Her actual experience in my home and her brain’s modeled expectation created a match.
One way scientists look for evidence to support this theory is to look at cases where the brain predicts too much or too little. For example, individuals with autism would presumably have a weak predictive filter. That would mean that they have a harder time categorizing items based on past experiences. They would have an extreme sensitivity to input from the environment and the many “new” experiences could be overwhelming.
A person with schizophrenia would be at the other extreme with an overly strong predictive filter. Their brain would be so certain about what it’s looking at, it will cancel out new information and have false perceptions, possibly even hallucinations.
What is considered “normal” is somewhere in the middle of this spectrum.
Of course, we can change that by changing our brain chemistry. That is why some research uses psychedelic substances. Some neuroscientists might say that our “normal” perception is a “controlled hallucination.” Substances like psilocybin and LSD remove the predictive filter and so when we under that influence someone sees something common to daily life, such as a tree, there is no prediction and it alternative perceptions emerge. The branches moving in the wind are arms and the leaves are flames. The drugs don’t add to perception but by removing the filter they allow other possibilities.
How does this predictive coding affect learning new things?
To learn new things we need to be open to new perceptions which means the filter must be reduced to some extent. But in order to retain the new information and use it in the future, we need a predictive model of that information, which requires that filter to be operating normally. When the two are balanced, learning and memory are optimized.
In a more simplified explanation, being open-minded should lead to greater learning. We don’t put information in a box and move on.
Some of this theorizing isn’t new at all. Back in the 1860s, the framework known as the “Bayesian brain” was introduced and Helmholtz’s concept of unconscious inference emerged. It proposes that the brain makes probabilistic inferences about the world based on an internal model, – it calculates a “best guess” interpretation of what it’s perceiving. The name comes from Bayesian statistics which quantifies the probability of an event based on relevant information gleaned from prior experiences.
These “controlled hallucinations” based on predictions don’t wait for all sensory information to drive cognition. We are constantly constructing hypotheses about the world. We use these to explain new experiences. The brain is constantly generating and updating a mental model of sensory input.
I picked up the book When Einstein Walked with Gödelthis past week at the library because of the title and the photo on the cover of the two mathematicians walking across a campus in Princeton, New Jersey.
I was disappointed that the entire book was not about the two of them, but is instead a collection of essay by Jim Holt. The title essay is one I really like as it deals with one of my favorite topics – our changing notions of time. It comes from a friendship between Albert Einstein and Kurt Gödel when they were both working in Princeton in the 1930s. Einstein had shaken the physical world with his work, and Gödel had shaken mathematics. They ended up taking almost daily walks to their offices at the Institute for Advanced Study.
Gödel would have looked pretty fancy (he liked white linen suits) and Einstein would have looked like the absent-minded genius that we know with his crazy hair and too-big pants.
But what really interests me in reading the essay today was the walking. Today was a very nice spring day that was warmer than it has been. I took the covers of the deck furniture and sat outside with my lunch and coffee. And I went for a walk.
I love walking and I am a firm believer in the power of walking to spark creativity and thought. (More on that tomorrow) Of course, it would be great to have the content of those walking conversations between Al and Kurt. I imagine that the conversations went beyond math and physics, though I’m sure math and science were the main themes.
I have so far only skimmed a few of the other essays in the book, but each could be a walking conversation. Did you know that the word “scientist” was only coined in 1833? It was a philosopher, William Whewell, who used it in his efforts to “professionalize” science and separate it from philosophy. Holt quotes Freeman Dyson (another person at the Institute who I actually got to meet and talk with briefly when he gave a talk at NJIT) as saying that “Science grew to a dominant position in public life, and philosophy shrank. Philosophy shrank even further when it became detached from religion and from literature.”
I certainly couldn’t keep up with Einstein and Godel on the science of time, but I would love to put in my own ideas and get some feedback from the boys.
Some of Holt’s questions that he attempts to answer in the essay are also intriguing ideas for a walking conversation. Does time exist? What is infinity? Why do mirrors reverse left and right but not up and down? And the biographical sketches of famous and not-so-famous thinkers makes me want to go on walks with them too – Emmy Noether, Alan Turing, Benoit Mandelbrot, Ada Lovelace and others.
As a young boy, I was fascinated by static electricity. Electricity that I could produce! I wondered why some scientist hadn’t figured out how to harness this power to make electrical devices go. Those pops and zaps and sparks when we rub our feet on the carpet or take clothing off or out of the dryer seemed to come from nowhere.
I don’t recall ever having a science lesson in school about static electricity, though I have tenuous memories of rubbing balloons to produce it that may have been a class demonstration.
This morning there was a zap when I kissed my wife good morning. Ah, a spark is still there! I don’t want science to kill romance, but it led me to do some research into what was really happening.
Static electricity is one of the oldest scientific phenomena people observed and described. Greek philosopher Thales of Miletus made the first account; in his sixth century B.C. writings, he noted that if amber was rubbed hard enough, small dust particles will start sticking to it. Three hundred years later, Theophrastus followed up on Thales’ experiments by rubbing various kinds of stone and also observed the “power of attraction.” But neither of these natural philosophers found a satisfactory explanation for what they saw. Source
Of course, it would be another two thousand years before the English word “electricity” was coined (from Latin “electricus,” meaning “like amber”). In that time, static electricity was more of a magic trick used to make things magically attract – like a paper to a charged hand.
Static electricity come from some electrons that are on the surface of any material. When certain materials rub against each other, electrons are pulled from the weaker material to the stronger binding force. Shuffle your feet along a carpet and then touch the metal doorknob and Zap, a small lightning bolt.
In winter or any time when the humidity is low, we notice it more because dry air is an electrical insulator. (Moist air acts as a conductor. )
How much power is in that spark? Typically, the amount is low. Well, the voltage can actually be very high – 100 times that of the outlet on the wall. But voltage is just a measure of the charge difference between objects. The thing you have to worry about is current. That is the measure of how many electrons are flowing and in your static electricity zaps it is just a few electrons. But those few electrons can have an impact.
On one dry winter day, I returned from a walk with my iPod Shuffle earbuds still in my ears listening to a podcast, and pulled off by zip-up sweatshirt and then touched the iPod. Pop! Not only did I feel a charge that ran up the wires to my ears, but the data stored on the device was damaged.
My experience didn’t damage the device itself, but static electricity can deliver a fatal charge to sensitive electronics. When people work on some electronics (such as inside a computer), they often wear an antistatic wristband. The wristband is grounded to some safe metal object nearby that wouldn’t be damaged by a static zap. You could also ground yourself by touch a metal object or holding one (think of Ben Franklin’s key at the end of a kite string). Metal is a great conductor and the electrons are very happy to jump there.
A more serious though less likely threat is when you discharge electricity near flammable gases. My father showed me when I was quite young that when he was working on his car’s engine or around gasoline (including near a gas station pump), he would ground himself before touching the pumps or engine or car battery. I still do it when I’m working around my lawn mower and snowblower, though the risk is probably quite minimal.
People have humidifiers in their homes in winter for the positive effect it has on your skin and nasal passages, but it also reduces charge buildups. You might add fabric softener sheets to your dryer load to not only soften the clothing but to lessen static charges that make clothing cling. They actually tend to help balance out the electrons.
Woolen winter clothing and rubber-soled shoes will give you more of a static charge than cotton clothing and leather-soled shoes.
Does static electricity have any practical uses, as I had wondered in my childhood? We have probably all seen a electrostatic generator make someone’s hair stand up or touched a ball that then produced lightning bolts from our fingers. But we can’t use it to power our smartphone – high voltage, low current. Still, it does have practical applications.
Electrostatic generators such as the Van de Graaff generator, and variations as the Pelletron, are used in physics research.
Many photocopiers use electric attraction to adhere charged toner particles onto paper. Some air fresheners (such as Fabreze) add more than a nice artificial fragrance because they are also discharging static electricity on dust particles which dissembles the bad smell.
Charged plates are used in some home heating and cooling systems and in industrial applications to capture dust, smoke and other minute particles. As particles move through the system, they pick up negative charges from a metal grid and are attracted to plates that are positively charged where they can be disposed of manually.
Static electricity is used in nanotechnology to pick up single atoms by laser beams. Nanoballoons can be switched between an inflated and a collapsed state using static electricity, and one day they might be used to deliver medication to specific tissues within the body.
On a more personal level, you may also see some more New Age than scientific applications, such as wearing a negative ion band on your wrist. These wristbands are promoted as being useful for sports and any time or activity where you need a power boost or increased energy. In this stressed world, that probably means all day, every day.
The claim – which may be definitively unproven but has some science behind it – is that the negative ions can “balance” you and can help sleep, sinuses, hay fever, asthma, the immune system, relaxation, stability, energy levels, concentration, joint and muscle aches, arthritis, circulation and more. Sounds rather miraculous.
Negative ions are odorless, tasteless, and invisible molecules and we inhale them in abundance in certain places (those waterfalls, beaches, mountain streams). When I’m watching the ocean waves on a beach or standing by falling water, I do feel “better.” Of course, some of that feeling comes from the natural beauty of the setting, but research also seems to indicate that some of that positivity in me comes from the higher number of negative ions there. Yes, this negative is positive in another sense. The opposite effects occur in a sealed office building: more positive ions, less aesthetics, more stress.
On the website webmd.com, I read that negative ions that get into our bloodstream are believed to produce biochemical reactions that increase levels of the mood chemical serotonin, helping to alleviate depression, relieve stress, and boost our daytime energy.
We know that the dispersion of water from waterfalls, waves, or even lightning and water evaporation from plants, create hydrogen ions by splitting water molecules. The negative electrons join up with other free positive electrons in the air neutralizing their electrical charge.
An air ionizer (or negative ion generator) is a device that uses a high voltage charge to ionize air molecules and generate negative ions. Air ionizers are often used in air purifiers so that particles are attracted to the electrode in an effect similar to static electricity. These devices can cost hundreds of dollars for “professional” ionizers and less for household room devices.
One trendy application I see in offices lately are Himalayan salt lamps. These are made from Himalayan pink salt which has minerals and is supposedly free from toxins. Lit and heated by a small lightbulb inside the hollowed out salt, it releases negative ions.
In a new Age way, these are said to create harmony and balance mind, body, and soul , and so make a good addition to a place used for meditation, yoga, or sleeping. I suppose the idea of having them in offices is to balance the positive ions that dominate those sterile spaces. Maybe they add some earth and fire elements to the feng shui of the space.
I say “New Age” when explaining these lamps because I could find no scientific evidence that they have any positive effects on people near them. But I don’t dismiss any possible placebo effect.
Can any type of device that produces negative ions have a positive effect on people and perhaps even act like a mild antidepressant? It seems too early to know for sure. Does filtering out dust mites and dander improve health? Sounds logical. Does putting negative ions into the air improve your mood? There is some evidence that it does.
Of course, the negative ions when I’m standing next to the Great Falls of the Passaic River blow away the ones coming off a salt lamp, so I will stick to natural negative ion producers for the time being.
Did you see in the news that Canadian astronomers have revealed some details about mysterious signals emanating from a distant galaxy. They don’t really know the exact nature and the origin of the radio waves. But don’t they pick up these signals all of time?
Actually, they don’t get these kinds of signals. This has only been reported once before.The 13 FRBs (fast radio bursts) had a very unusual repeating signal. They were all coming the same source about 1.5 billion light years away. Let’s repeat that – 1.5 billion light years away.
These cosmic puzzles were picked up by the CHIME observatory, located in British Columbia. It has four 100-metre-long, semi-cylindrical antennas, which scan the entire northern sky each day. The telescope only went into operation last year and almost immediately detected the radio bursts.
At least a quarter of the stars in the Milky Way galaxy have a planet with surface conditions very similar to Earth and the chemistry of life as we know it could develop. With tens of billions of stars in the Milky Way, it is quite likely we are not alone.
Are the aliens trying to contact us? Contact? They may already be visiting.
The solidly unscientific The New Yorker asks “Have Aliens Found Us?” in an interview with a Harvard astronomer about a mysterious interstellar object.
This story starts back in October 2017 when astronomers at the University of Hawaii spotted something strange out there in our solar system. They named it ‘Oumuamua which is the Hawaiian word for a scout or messenger. They described it as “a red and extremely elongated asteroid.”
Big deal. I write about asteroids all the time. Ah, but this was the first interstellar object to be detected within our solar system.
The interview was with Avi Loeb, the chair of Harvard’s astronomy department, who was co-author on a paper about ‘Oumuamua’s “peculiar acceleration.” That is, it wasn’t moving like most asteroids.
Loeb suggested that the object “may be a fully operational probe sent intentionally to Earth’s vicinity by an alien civilization.” Whoa.
Headline #2: He later said that we might communicate with the civilization that sent the probe, and “If these beings are peaceful, we could learn a lot from them.”
I’m a bit suspicious of those scientists who detected ‘Oumuamua said that they saw it “too late” in its journey to photograph it.
There is no photo of the object, but based on how it spins and how its brightness changes, it is assumed to look like a cigar. Or a pancake.
It was the deviation from the expected orbit that interested Loeb and some others. Where is it getting the extra push in acceleration? Maybe it is the light from the sun. That would happen with a solar sail. But that would mean it would have to be less than a millimeter thick in order for that to work. And that would be mean that someone had made it. A scout from a technological civilization?
Loeb admits that if some other distant civilization sent out ‘Oumuamua, they might not exist any more. We have sent out lots of stuff from the Voyager spacecrafts to episodes of I Love Lucy and by the time those aliens outside our solar system discover our stuff and figure out how to play that Voyager record and why Lucy always wanted to be in Ricky’s shows, we may not exist.
I hope one of us makes contact before it’s all over.
When Douglas Adams wrote The Hitchhiker’s Guide to the Galaxy, he wrote that “The answer to the ultimate question of life, the universe and everything is 42.” He was joking, but I wonder if the answer really might be 137.
Take a look at one thing about 137 in mathematics: Using two radii to divide a circle according to the golden ratio yields sectors of approximately 137° (the golden angle) and 222°.
In physics, 137 is the approximate denominator of fine-structure constant. Being a dimensionless physical constant, it is approximately 1/137 and has the same numerical value in all systems of units.
Physicists have postulated for more than a hundred years that 137 might be at the center of a grand unified theory, relating theories of electromagnetism, quantum mechanics and, especially, gravity. It’s the DNA of an atom.
As the inverse of the fine-structure constant, it is related to the probability that an electron will emit or absorb a photon (Feynman’s conjecture).
Some physicists has suggested that if the number that unified the relationship between all these concepts turned out to be 1 or 3 or a multiple of pi, that would make more “sense.” But why 137?
Leon Lederman thought that because the number 137 “shows up naked all over the place,” that means that scientists on any planet in the universe using whatever units they have for charge or speed, and whatever their version of Planck’s constant may be, will all come up with 137, because it is a pure number.
But it shows up frequently outside of math and physics.
In mysticism, the Hebrew word קבלה (Kabbalah) has a Gematria (numerical value) of 137. It describes the “corresponding loops” which clasped together enjoin the two sections of the Tabernacle’s ceiling. These loops divided the Holy Place and the Holy of Holies – the physical dimension and the spiritual dimension – and at the boundary line of the physical world, the number 137 emerges.
Moses’ Tabernacle, the earthly dwelling place of God, was 13.7 meters long. NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) has taken the best measurement of the age of the Universe to date. and ”scientists now have the best estimate yet on the age of the Universe: 13.7 billion years.”
Some people have therefore connected the science, math and mysticism. 137 refers to electrons and the odds of an electron absorbing a single photon, so in simple Kabbalah language, 137 is about Vessel and Light. It is about the physical body of man (Vessel) and our ability to ignite the Light in the soul.
One of the important physicists of the 20th century, Richard Feynman, wrote about the number 137:
“It has been a mystery ever since it was discovered more than fifty years ago, and all good theoretical physicists put this number up on their wall and worry about it. It’s one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man. You might say the ‘hand of God’ wrote that number, and ‘we don’t know how He pushed his pencil.”
According to the Bible, Abraham died at age 175, but when he was commanded by God to offer his son up as a sacrifice, he was 137. According to the Torah, Moses’ father lived to 137, so did Ishmael and Levi.
Physicist Leon M. Lederman numbered his home near Fermilab 137. He tried to unite the Ancient Greeks’ earliest scientific observations, Einstein, and the Higgs boson, which is nicknamed the God Particle.
“One hundred thirty-seven is the inverse of something called the fine-structure constant. …The most remarkable thing about this remarkable number is that it is dimension-free. …Werner Heisenberg once proclaimed that all the quandaries of quantum mechanics would shrivel up when 137 was finally explained.” ― Leon M. Lederman, The God Particle: If the Universe Is the Answer, What Is the Question?
Wolfgang Pauli, a pioneer of quantum physics, died in a hospital room numbered 137, a coincidence that disturbed him.
Physicist Pauli and psychoanalyst Carl Jung were both obsessed with the power of certain numbers, including 137. They were fascinated by the atom’s fine-structure constant and its Kabbalistic significance. They formed an unlikely friendship and began a mystical quest that led them through medieval alchemy, dream interpretation, and the Chinese Book of Changes.
They were two people who believed 137 was at the intersection of modern science with the occult, and that it was a mystical number with a meaning beyond physics.
No one wants to be stung by a bee, but if you had to be stung, where would the sting inflict the least and the most pain?
The Schmidt pain index measures the painfulness of stings from 78 species of insects on a scale of 0 to 4. Thankfully, bees don’t get up to 4. That level is saved for the bullet ant and the tarantula hawk.
Of course, what I find very painful might not seem very painful to you. Mr. Schmidt rated all of the stings himself. A study that came later wanted to see if the pain level of a sting varied depending its location on the body.
What locations hurt the most? The most painful location for being stung by a bee is on the nostril. Next is the close by lip. Not everyone will worry about the third place pain winner (loser?). It is the penis. The subject being stung was a man, but I imagine the female equivalent area might rank up there also.
So, if you have to be stung, which locations are the least painful? The three least painful locations were the skull, middle toe tip, and upper arm which all scored only 2.3 on a scale of 10. The study did not draw any conclusions on how to get that honey bee to avoid the nostril and lip and drift over to your skull instead.