For 40 years, psychologists thought that humans and animals kept time with a biological version of a stopwatch. Somewhere in the brain, a regular series of pulses was being generated. When the brain needed to time some event, a gate opened and the pulses moved into some kind of counting device.

One reason this clock model was so compelling: Psychologists could use it to explain how our perception of time changes. Think about how your feeling of time slows down as you see a car crash on the road ahead, how it speeds up when you’re wheeling around a dance floor in love. Psychologists argued that these experiences tweaked the pulse generator, speeding up the flow of pulses or slowing it down.

But the fact is that the biology of the brain just doesn’t work like the clocks we’re familiar with. Neurons can do a good job of producing a steady series of pulses. They don’t have what it takes to count pulses accurately for seconds or minutes or more. The mistakes we make in telling time also raise doubts about the clock models. If our brains really did work that way, we ought to do a better job of estimating long periods of time than short ones. Any individual pulse from the hypothetical clock would be a little bit slow or fast. Over a short time, the brain would accumulate just a few pulses, and so the error could be significant. The many pulses that pile up over long stretches of time should cancel their errors out. Unfortunately, that’s not the case. As we estimate longer stretches of time, the range of errors gets bigger as well.

{ Discover | Continue reading }

The brain does not stop developing until we are in our 30s or 40s – meaning that many people will still have something of the teenager about them long after they have taken on the responsibilities of adulthood.

The finding, from University College London, could perhaps help explain why seemingly respectable adults sometimes just can’t resist throwing a tantrum or sulking until they get their own way.

The discovery that the part of the brain key to getting on with others takes decades to fully form could perhaps also explain why some people are socially awkward well past their teenage years.

Neuroscientist Professor Sarah-Jayne Blakemore said: ‘Until about 10 years ago, it was pretty much assumed that the human brain stops developing in early childhood.

‘But we now know that is far from the truth, in fact most regions of the human brain continue to develop for many decades.

{ Daily Mail | Continue reading }

photo { Fette Sans }

The current pace of population aging is without parallel in human history but surprisingly little is known about the human aging process, because lifespans of eight decades or more make it difficult to study. Now, researchers at the Salk Institute for Biological Studies have replicated premature aging in the lab, allowing them to study aging-related disease in a dish.

In the February 23, 2011 advance online edition of the journal Nature, Juan Carlos Izpisúa Belmonte, Ph.D. a professor in the Salk Institute’s Gene Expression Laboratory, and his team report that they have successfully generated induced pluripotent stem (iPS) cells from skin cells obtained from patients with Hutchinson-Gilford Progeria Syndrome—who age eight to 10 times faster than the rest of us—and differentiated them into smooth muscle cells displaying the telltale signs of vascular aging. (…)

Progeria’s striking features resemble the aging process put on fast-forward and afflicted people rarely live beyond 13 years.

{ EurekAlert | Continue reading }

photo { Brandon Pavan }

{ Scientific American | full story }

related { Astronomers Find First Evidence Of Other Universes }

I wondered for probably the millionth time why I am always running late.

This time, I vowed, I was going to find out.

I turned to an obscure field of neuroscience for answers. The scientists who work on the problem of time in the brain sometimes refer to their area of expertise as “time perception” or “clock timing.” What they’ve discovered is that your brain is one of the least accurate time measurement devices you’ll ever use. And it’s also the most powerful.

When you watch the seconds tick by on a digital watch, you are in the realm of objective time, where a minute-long interval is always 60 seconds. But to your brain, a minute is relative. Sometimes it takes forever for a minute to be over. That’s because you measure time with a highly subjective biological clock.
Your internal clock is just like that digital watch in some ways. It measures time in what scientists call pulses. Those pulses are accumulated, then stored in your memory as a time interval. Now, here’s where things get weird. Your biological clock can be sped up or slowed down by anything from drugs to the way you pay attention. If it takes you 60 seconds to cross the street, your internal clock might register that as 50 pulses if you’re feeling sleepy. But it might register 100 pulses if you’ve just drunk an espresso. That’s because stimulants literally speed up the clock in your brain (more on that later). When your brain stores those two memories of the objective minute it took to cross the street, it winds up with memories of two different time intervals.

And yet, we all have an intuitive sense of how long it takes to cross a street. But how do we know, if every time we do something it feels like it a slightly different amount of time? The answer, says neuroscientist Warren Meck, is “a Gaussian distribution” - in other words, the points on a bell curve. Every time you want to figure out how long something is going to take, your brain samples from those time interval memories and picks one. (…)

Your intuitive sense of how much time something will take is taken at random from many distorted memories of objective time. Or, as Meck puts it, “You’re cursed to be walking around with a distribution of times in your head even though physically they happened on precise time.”

Your internal clock may be the reason why you can multitask. Because nobody - not even the lowly rat - has just one internal clock going at the same time.

At the very least, you’ve got two internal clocks running. One is the clock that tracks your circadian rhythms, telling you when to go to sleep, wake up, and eat. This is the most fundamental and important of all your internal clocks, and scientists have found it running even in organisms like green algae. The other clock you’ve likely got running is some version of the interval time clock I talked about earlier - the one that tells you how long a particular activity is going to take.

{ io9 | Continue reading }

photo { Logan White }

Circular patterns within the cosmic microwave background suggest that space and time did not come into being at the Big Bang but that our universe in fact continually cycles through a series of “aeons.” That is the sensational claim being made by University of Oxford theoretical physicist Roger Penrose, who says that data collected by NASA’s WMAP satellite support his idea of “conformal cyclic cosmology”. This claim is bound to prove controversial, however, because it opposes the widely accepted inflationary model of cosmology.

According to inflationary theory, the universe started from a point of infinite density known as the Big Bang about 13.7 billion years ago, expanded extremely rapidly for a fraction of a second and has continued to expand much more slowly ever since, during which time stars, planets and ultimately humans have emerged. That expansion is now believed to be accelerating and is expected to result in a cold, uniform, featureless universe.

Penrose, however, takes issue with the inflationary picture and in particular believes it cannot account for the very low entropy state in which the universe was believed to have been born – an extremely high degree of order that made complex matter possible. He does not believe that space and time came into existence at the moment of the Big Bang but that the Big Bang was in fact just one in a series of many, with each big bang marking the start of a new “aeon” in the history of the universe.

{ PhysicsWorld | Continue reading }

related { In an experiment to collide lead nuclei together at CERN’s Large Hadron Collider physicists discovered that the very early Universe was not only very hot and dense but behaved like a hot liquid. }

photo { Young Kyu Yoo }

related:

{ The Scale of the Universe }

{ xkcd }

{ A new look at traffic lights | more | via copyranter | Related: Control Safety Traffic Light Concept }

Older people may have always existed throughout history, but they were rare. Aging as we know it, and the diseases and disorders that accompany it, represent new phenomena—products of 20th century resourcefulness. When infectious diseases were largely vanquished in the developed world, few anticipated the extent to which chronic degenerative diseases would rise. We call them heart disease, cancer, stroke, arthritis, Alzheimer’s disease, and many more, but we might as well collectively use one word to describe them all—aging.

Aging may be defined as the accumulation of random damage to the building blocks of life—especially to DNA, certain proteins, carbohydrates, and lipids (fats)—that begins early in life and eventually exceeds the body’s self-repair capabilities. This damage gradually impairs the functioning of cells, tissues, organs, and organ systems, thereby increasing vulnerability to disease and giving rise to the characteristic manifestations of aging, such as loss of muscle and bone mass, decline in reaction time, compromised hearing and vision, and reduced elasticity of the skin. (…)

Humanity is paying a heavy price for the privilege of living extended lives—a new and much more complicated relationship with disease.

{ Slate | Continue reading }

related { Some animals live for 400 years. What can they teach us about extending life? }

photo { Misha De Ridder }

Einstein presented what is referred to as the “block universe” – the notion that all times exist equally. So, what you see just depends on what you set t to in any given equation. “The distinction between past, present and future is only an illusion, however persistent,” the genius of relativity mused. He was so clear about the illusory nature of time that the thought even provided him with comfort in the face of death.

But the block universe, and the notion of God’s timelessness, have been challenged by scientists who also work on the relationship between science and religion. I’m thinking here of two physicists who are also well known as theologians, John Polkinghorne and Ian Barbour. Their questioning of the classical idea of God’s timeless nature presents an enormous challenge to received ideas about God. Interestingly, it’s a challenge that stems from both scientific and theological concerns. (…)

Scientifically, time is an oddity. Relativity theory treats it as one dimension of reality. Time is tantamount to the movement of mass in spacetime. So, time reversal, or retrocausality, has been proposed as a way to interpret antimatter — a positron being an electron that’s traveling backwards in time. Also, at a theoretical level, the equations that govern electromagnetic radiation don’t distinguish between time going forwards or backwards. And yet, in the macro-world of the everyday, we clearly can’t move temporally backwards, but only forwards. So how can this existential difference be reconciled?

{ Big Questions | Continue reading }

So why do women live longer than men? One idea is that men drive themselves to an early grave with all the hardship and stress of their working lives. If this were so, however, then in these days of greater gender equality, you might expect the mortality gap would vanish or at least diminish. Yet there is little evidence that this is happening. Women today still outlive men by about as much as their stay-at-home mothers outlived their office-going fathers a generation ago.

Furthermore, who truly believes that men’s work lives back then were so much more damaging to their health than women’s home lives? Just think about the stresses and strains that have always existed in the traditional roles of women: a woman’s life in a typical household can be just as hard as a man’s.

Indeed, statistically speaking, men get a much better deal out of marriage than their wives—married men tend to live many years longer than single men, whereas married women live only a little bit longer than single women. So who actually has the easier life?

It might be that women live longer because they develop healthier habits than men—for example, smoking and drinking less and choosing a better diet. But the number of women who smoke is growing and plenty of others drink and eat unhealthy foods. In any case, if women are so healthy, why is it that despite their longer lives, women spend more years of old age in poor health than men do? The lifestyle argument therefore does not answer the question either.

As an experimental gerontologist, I approach this issue from a wider biological perspective, by looking at other animals. It turns out that the females of most species live longer than the males. This phenomenon suggests that the explanation for the difference within humans might lie deep in our biology.

{ Scientific American | Continue reading }

Matter and Memory (1896) is one of the four main works by the French philosopher Henri Bergson (1859-1941). Its subtitle is “Essay on the relation of body and spirit”, and the work presents an analysis of the classical philosophical problems concerning this relation. (…)

Bergson distinguishes two different forms of memory. On the one hand memories concerning habitude, replaying and repeating past action, not strictly recognized as representing the past, but utilizing it for the purpose of present action. This kind of memory is automatic, inscribed within the body, and serving a utilitarian purpose. Bergson takes as an example the learning of a verse by rote: Recitation tending toward non-reflective and mechanical repetition. The duration of the habitual recitation tends toward the regular and one may compare this kind of memory to a practical knowledge or habit. “It is habitude clarified by memory, more than memory itself strictly speaking.” Pure memory, on the other hand, registers the past in the form of “image-remembrance”, representing the past, recognized as such. It is of a contemplative and fundamentally spiritual kind, and it is free. This is true memory. Bergson takes as his example the remembrance of the lesson of learning the same verse, a dated fact that cannot be recreated. Pure memory or remembrance permits the acknowledgment that the lesson has been learned in the past, cannot be repeated, and is not internal to the body.

{ Wikipedia | Continue reading }

Bergson’s famous (or infamous) image of the memory cone. The image of the inverted cone occurs twice in the third chapter of Matter and Memory (pp. 152 and 162). The image of the cone is constructed with a plane and an inverted cone whose summit is inserted into the plane. The plane, “plane P,” as Bergson calls it, is the “plane of my actual representation of the universe.” The cone “SAB,” of course, is supposed to symbolize memory, specifically, the true memory or regressive memory.

{ Stanford Encyclopedia of Philosophy | Continue reading }

photo { Robb Johnson }

{ Douglas Huebler, Duration piece #31, Boston, 1974 | On December 31st, 1973, Douglas Huebler photographed a woman, an eight of a second before midnight. The exposure time was one fourth of a second, so the woman had half of her body in 1973 and the other half in 1974. }

Scientists found that humans exhibit two types of memory. They call one “verbatim trace,” in which events are recorded very precisely and factually. Children have more “verbatim trace,” but as they mature, they develop more and more of a second type of memory: “gist trace,” in which they recall the meaning of an event, its emotional flavor, but not precise facts. Gist trace is the most common cause of false memories, occurring most often in adults. Research shows that children are less likely to produce false memories, because gist trace develops slowly.

{ ScienceDaily | Continue reading }

Psychological scientists have discovered all sorts of ways that false memories get created, and now there’s another one for the list: watching someone else do an action can make you think you did it yourself. (…)

They found that people who had watched a video of someone else doing a simple action — shaking a bottle or shuffling a deck of cards, for example — often remembered doing the action themselves two weeks later.

{ ScienceDaily | Continue reading | Related: People can easily create false memories of their past and a new study shows that such memories can have long-term effects on our behavior. }

photo { František Drtikol }

Look out into space and the signs are plain to see. The universe began in a Big Bang event some 13 billion years ago and has been expanding ever since. And the best evidence from the distance reaches of the cosmos is that this expansion is accelerating.

That has an important but unavoidable consequence: it means the universe will expand forever. And a universe that expands forever is infinite and eternal.

Today, a group of physicists rebel against this idea. They say an infinitely expanding universe cannot be so because the laws of physics do not work in an infinite cosmos. For these laws to make any sense, the universe must end, say Raphael Bousso at the University of California, Berkeley and few pals. And they have calculated when that is most likely to happen.

Their argument is deceptively simple and surprisingly powerful. Here’s how it goes. If the universe lasts forever, then any event that can happen, will happen, no matter how unlikely. In fact, this event will happen an infinite number of times.

This leads to a problem. When there are an infinite number of instances of every possible observation, it becomes impossible to determine the probabilities of any of these events occurring. And when that happens, the laws of physics simply don’t apply. They just break down. “This is known as the “measure problem” of eternal inflation,” say Bousso and buddies. (…)

When might his be? Bousso and co have crunched the numbers. “Time is unlikely to end in our lifetime, but there is a 50% chance that time will end within the next 3.7 billion years,” they say.

{ The Physics arXiv Blog | Continue reading }

This timeline of the Big Bang describes the history of the universe according to the prevailing scientific theory of how the universe came into being. (…) The best available measurements as of 2010 suggest that the initial conditions occurred between 13.3 and 13.9 billion years ago.

{ Wikipedia | Continue reading }

It may be possible to glimpse before the supposed beginning of time into the universe prior to the Big Bang, researchers now say.

Unfortunately, any such picture will always be fuzzy at best due to a kind of “cosmic forgetfulness.”

The Big Bang is often thought as the start of everything, including time, making any questions about what happened during it or beforehand nonsensical. Recently scientists have instead suggested the Big Bang might have just been the explosive beginning of the current era of the universe, hinting at a mysterious past.

{ Space | Continue reading }

The Chaotic Inflation theory is a variety of the inflationary universe model, which is itself an extension of the Big Bang theory. It was proposed by physicist Andrei Linde. (…)

The Chaotic Inflation theory is in some ways similar to Fred Hoyle’s Steady state theory, as it employs the metaphor of a universe that is eternally existing, and thus does not require a unique beginning or an ultimate end of the cosmos.

{ Wikipedia | Continue reading }

semantic bonus:

Some people are surprised, even disturbed, by the idea that our vision does not give us an accurate picture of what we look at. For example, the colours we experience are not a measure of the wavelength of the light entering our eyes. But accuracy is not the point of vision; the function is to be useful and colour consistency is far more useful then fidelity to wavelength spectra. The same surprise is shown in the reaction to the idea that our memories are reworked continuously so that over time they lose their accuracy. (…)

A great deal of biological energy is used to create memories and to re-consolidate them and therefore we can assume that they have a very important biological role. (…)

We first have to have the experiences to remember – we create consciousness experiences which become stored as temporary memories. These are soon made more permanent as an event or an episode. Over weeks, months, years, decades they are continually reworked and re-consolidated. They are packaged together and lose their individuality, they are up-dated by newer memories, they are categorized and lose detail not related to their category. Eventually they lose their character as episodic memory and became more a factual or semantic type of memory.

{ Janet Kwasniak | Continue reading }

I’m sure most of you have heard of the twin paradox “in which a twin makes a journey into space in a high-speed rocket and returns home to find he has aged less than his identical twin who stayed on Earth.” This paradox has been worked out for special relativity in Minkowski spacetime. Recently, Boblest et al. worked out the details using general relativity for an expanding universe. (…)

The twins in the paper have names: Eric and Tina. Eric stays on Earth while Tina accelerates away from Earth with constant acceleration α = 9.8 m/s² until her clock shows 5 years have past. Then she decelerates by the same magnitude coming to a complete stop after ten years then begins her journey back to earth accelerating then decelerating in the same 5 year intervals. Finally, after 20 years has transpired on her clock she has returned to earth being now 20 years old. (…) Eric is nearly 350 years old when Tina returns.

{ The Eternal Universe | Continue reading }

I used to have cello lessons on Saturday morning. I would play a certain piece in front of my teacher and then she would give me a new piece to practice for next week.

Some weeks, I practiced for half an hour the following Sunday, then half an hour on Monday, the same on Tuesday, etc., so that when my next lesson would be up, I would have practiced for a total of three hours (6 days; half an hour each). And I usually would be able to play the piece in front of my teacher reasonably well.

Some weeks, however, I forgot about it altogether. By the time it was Friday, I would realize, “It’s my cello lesson tomorrow and I haven’t practiced at all yet!”

What I would usually do then is think, “I will just practice for three hours in a row now. That’s the same amount of time as half an hour each day for six days, and I am sure I will be fine.” But I never was. It never worked. I would be terrible, and my teacher’s ears would hurt for hours after she sent me away.

I couldn’t understand at the time how that was possible. Three hours is three hours, right?

Of course, as adults, we realize that our brain needs rest in between practice sessions. It needs to recuperate before you can put new information and skills into it, and the periods of “inactivity” are just as important as the practice itself. Practice sessions are much less effective if you don’t have the slow periods in between them.

Now, as an adult examining corporate strategies, I see that firms often fall into the same trap.In order to catch up with competitors, for instance, they enter new markets at double the speed, undertake twice as many acquisitions, or hire double the number of employees. But, unfortunately, it doesn’t work that way. Just like me practicing the cello, organizations need rest and time in between growth spurts to recuperate and digest the effort. Trying twice as hard does not mean you’ll get twice the benefits. There are limits to how fast you can grow, without starting to suffer from it.

We call this “time compression diseconomies” - a term coined by professors Dierickx and Cool from INSEAD.

{ Freek Vermeulen/Harvard Business Review | Continue reading }

Psychologists and philosophers have long debated whether language shapes the way we think. While the most drastic viewpoint – that thought can’t exist without language — has fallen out of favor, psychologists still study more subtle effects.

The first study has to do with gender in language. Many languages assign genders to words. For example, in Spanish, the word for “key” is feminine, while the German word for” key” is masculine. Gender for the most part is arbitrary and varies from language to language, which allows for some interesting experiments. (…) German speakers described keys as hard, heavy, jagged, metal, and useful, while Spanish speakers described them as golden, intricate, little, lovely, and shiny. (…)

In a second experiment, Boroditsky looked at language and the conception of time. English speakers primarily speak of time in horizontal terms. For example, we talk about moving meetings forward, or pushing deadlines back. Mandarin speakers, on the other hand, use up/down metaphors as well. So a Mandarin speaker would refer to the previous week as “up week” and next week as “down week.”

{ Livia Blackburne | Continue reading }