View cookies policy. Zoom Zoom. Availability Usually despatched within 2 weeks. With Free Saver Delivery. Basically, this feels far more like an art book than a math book in its layout and design — it even has one of those built-in cloth bookmarks attached to the spine.
But enough about the physical book — what is it about?
He also writes at length on an analogy between scientific inquiry and falling in love, both of which often begin with a chance discovery and grow into something much deeper. It would be easy to interpret what I have written thus far as meaning that I did not like the book, but that would not be entirely accurate.
Risk and Meaning is a quirky book, both in its topic and its physical layout and the writing style that the author adopts, but it is certainly not a bad book — I found parts of it to be annoying, but I also had trouble putting it down.
My guess is that the quirkiness will turn many readers off, and that might be for the best, as this is not a book for everyone who reads MAA Reviews. It is certainly not a mathematics book, but it is a book that is mathematics-adjacent, and I think that anyone who is able to get past or even relish some of the quirkiness in the book will certainly find themselves with plenty to think about. Entrance: Interpretation and Paradigms. Cicero and Divination. Mathematical Probabilities. Democracy by Chance. Lack of sleep is also directly tied to obesity: Without enough sleep, the stomach and other organs overproduce ghrelin, the hunger hormone, causing us to eat more than we need.
Not a refugee or a homeless shelter—at the Philharmonie de Paris, these couples sleep soundly while composer Max Richter leads a performance next photo of Sleep, a minimalist, scientifically informed piece that aims to guide listeners through a rejuvenating rest. It lasts eight hours. Ellenbogen and other experts argue against shortcuts, especially the original one—the notion that we can mostly do without sleep.
Some thought we might not need it at all.
[Download] Risk and Meaning: Adversaries in Art Science and Philosophy Read Online
That period turns out, instead, to be the wellspring of a completely separate but just as essential form of sleep, practically another type of consciousness altogether. Rapid eye movement, or REM, sleep was discovered in —more than 15 years after stages 1 through 4 had been mapped—by Eugene Aserinsky and Nathaniel Kleitman at the University of Chicago. Before then, because of its unremarkable pattern on early EEGs, this period was usually thought of as a variant form of stage 1, and not particularly significant.
But once the distinctive eye darting was documented, and the engorgement of sexual organs that always goes with it, and it was understood that virtually all vivid dreaming takes place in this phase, the science of sleep was upended. Generally, a healthy sleep begins with a spiral down to stage 4, a momentary return to wakefulness, and a five- to minute REM session. With each ensuing cycle, REM time roughly doubles.
Overall, REM sleep occupies about one-fifth of total rest time in adults.
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At the cellular level, protein synthesis peaks during REM sleep, keeping the body working properly. REM sleep also seems essential for regulating mood and consolidating memories. Every time we experience REM sleep, we literally go mad. By definition, psychosis is a condition characterized by hallucinations and delusions. Dreaming, some sleep scientists say, is a psychotic state—we fully believe that we see what is not there, and we accept that time, location, and people themselves can morph and disappear without warning.
From ancient Greeks to Sigmund Freud to back-alley fortune-tellers, dreams have always been a source of enchantment and mystery—interpreted as messages from the gods or our unconscious. They believe that dreams result from the chaotic firing of neurons and, even if imbued with emotional resonance, are devoid of significance.
Other sleep scientists strongly disagree. Even if you never recall a single image, you still dream. Everyone does. Lack of dream recollection is actually an indication of a healthy sleeper. Dreams also occur in NREM sleep, especially stage 2, but these are generally thought to be more like overtures. Only in REM sleep do we encounter the full potent force of our nighttime madness. Dreams, often falsely said to be just momentary flashes, are instead thought to span almost all of REM sleep, typically about two hours per night, though this decreases as we age—perhaps because our less pliant brains are not learning as much while awake and have fewer new memories to process as we sleep.
Newborn infants sleep up to 17 hours a day and spend about half of that in an active, REM-like condition. And for about a month in the womb, starting at week 26 of gestation, it seems that fetuses remain without pause in a state very similar to REM sleep. All this REM time, it has been theorized, is the equivalent of the brain testing its software, preparing to come fully on line.
The process is called telencephalization. We are truly out cold. Our heart rate increases compared with other sleep stages, and our breathing is irregular. Our muscles, with a few exceptions—eyes, ears, heart, diaphragm—are immobilized. Belief in the unbelievable happens because in REM sleep, stewardship of the brain is transferred away from the logic centers and impulse-control regions.
Production of two specific chemicals, serotonin and norepinephrine, is completely shut off. REM sleep is ruled by the limbic system—a deep-brain region, the untamed jungle of the mind, where some of our most savage and base instincts arise. Freud was right, in effect, that dreams do tap our primitive emotions.
The limbic system is home to our sex drive, aggression, and fear, though it also allows us to feel elation and joy and love. Frightening dreams are simply more likely to trigger our override system and wake us. Down in the brain stem, a little bulge called the pons is supercharged during REM sleep. Electrical pulses from the pons often target the part of the brain that controls muscles in the eyes and ears. Our lids usually remain shut, but our eyeballs bounce from side to side, possibly in response to the intensity of the dream.
Our inner ears too are active while we dream. A Centers for Disease Control and Prevention study found that older Americans are more likely to use prescription sleep aids than their younger counterparts. Women were also slightly more likely than men to report they used sleep aids. A Rand study found that lack of sleep can result in reduced productivity as well as more work absences, industrial and road accidents, health care expenses, and medical errors.
Sources: U. The ultimate virtual-reality machine resides inside our head. Above, Mike Morris, an Army veteran of two tours in Iraq, is part of a study by Jeffrey Ellenbogen of Johns Hopkins University at right that explores how companionship and the sounds a sleeper is exposed to affect recovery from trauma. Below, he wears an EEG cap as he sleeps with his therapy dog, Olive.
When you dream, your brain is actually trying to produce movements, but a system in the brain stem completely shuts down the motor-neuron gate. This often results in injuries to the sleeper and his or her bedmate. The end of a REM session, like the end of stage 4, is usually marked with a brief awakening. If we rest naturally, without an alarm clock, our last dream of the night often concludes our sleep. When light seeps through our eyelids and touches our retinas, a signal is sent to a deep-brain region called the suprachiasmatic nucleus. This is the time, for many of us, that our last dream dissolves, we open our eyes, and we rejoin our real life.
Or do we? Perhaps the most remarkable thing about REM sleep is that it proves the brain can operate independently of sensory input. Like an artist ensconced in a secret studio, our mind appears to experiment without inhibition, let loose on its own personal mission. The money-earning, the child-rearing. It self-activates. It dreams. This, one could say, is the playtime of the brain.
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Some sleep theorists postulate that REM sleep is when we are our most intelligent, insightful, creative, and free. And the answer might be that we need to attend to the basics of life—the eating and mating and fighting—only to ensure that the body is fully ready for sleep.
While embedded with U. Our floodlit society has made sleep deprivation a lifestyle. But we know more than ever about how we rest—and how it keeps us healthy. Read Caption. Joe Diemand, 76, has spent the past 20 years as a truck driver, sometimes driving all night. By Michael Finkel. Photographs by Magnus Wennman. This story appears in the August issue of National Geographic magazine.
Nearly every night of our lives, we undergo a startling metamorphosis. Sleep is seen as interrupting life, but the real scourge is chronic sleeplessness. In Japan about 40 percent of the population sleeps less than six hours a night.
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