Jan 29, 2019 01:59 AM
Combining physics & biology will reveal a pattern of information management
https://www.theguardian.com/science/2019...aul-davies
EXCERPT: . . . If biology is defined as the study of life, on this it has failed to deliver. But enlightenment may come from another direction. Rather than biology, some scientists are now looking to physics for answers, in particular the physics of information. Buried in the rules that shape information lie the secrets of life and perhaps even the reason for our existence. That, at least, is the bold proposal from Paul Davies, a prominent physicist who explores the idea in his forthcoming book, The Demon in the Machine....
[...] “The basic hypothesis is this,” Davies says. “We have fundamental laws of information that bring life into being from an incoherent mish-mash of chemicals. The remarkable properties we associate with life are not going to come about by accident.”
The proposal takes some unpacking. Davies believes that the laws of nature as we know them today are insufficient to explain what life is and how it came about. We need to find new laws, he says, or at least new principles, which describe how information courses around living creatures. Those rules may not only nail down what life is, but actively favour its emergence.
To understand what bothers Davies, consider a hypothetical device: a life meter. Wave it over a sterile rock and the dial stays at zero. Wave it over a purring cat and it swings over to 100. But what if you dunked it in the primordial soup, or held it over a dying person? At what point does complex chemistry become life, and when does life revert to mere matter? Between an atom and an amoeba lies something profound and perplexing.
Davies suspects that information is the answer because it seems increasingly fundamental to both physics and biology. In recent years, physicists have shown that information is more than the bits and bytes that course through computers. [...]
Davies believes that life will turn out to bear telltale patterns of information processing that distinguish it from non-life. Few people would argue that a computer is alive no matter how the ones and zeroes zip around inside it. What Davies suspects is that life exploits, and arises from, particular patterns of information flow.
“When you look at a living system, the way information is managed is very far from random. It will show patterns that could lead us to a definition of life,” he says. “We talk about informational hallmarks and these might be used to identify life wherever we look for it in the universe.”
It is not always easy to convert speculation into science. One of the hurdles Davies raises is the difficulty in describing biological information in terms of mathematics. It is a necessary move if new laws of life are to have any meaning. “I really think we need new physics to understand how information couples to matter and makes a difference in the world,” he says....
MORE: https://www.theguardian.com/science/2019...aul-davies
How the brain perceives colors: The limitations of being a vertebrate?
http://brainblogger.com/2018/07/23/how-t...es-colors/
EXCERPT: . . . We can argue that colors are not real—they are “synthesized” by our brain to distinguish light with different wavelengths. While rods give us the ability to detect the presence and intensity of light (and thus allow our brain to construct the picture of the world around us), specific detection of different wavelengths through independent channels gives our view of the world additional high resolution. For instance, red and green colors look like near identical shades of grey in black and white photos.
An animal with black and white vision alone won’t be able to make a distinction between, let’s say, a green and red apple, and won’t know which one tastes better before trying them both based on color. Evolutionary biologists believe that human ancestors developed color vision to facilitate the identification of ripe fruits, which would obviously provide an advantage in the competitive natural world.
Why certain wavelengths are paired with certain colors remains a mystery. Technically, color is an illusion created by our brain. Therefore, it is not clear if other animals see colors the same way we see them. It is likely that, due to shared evolutionary history, other vertebrates see the world colored similarly to how we see it. But color vision is quite common across the vast animal kingdom: insects, arachnids, and cephalopods are able to distinguish colors.
Human color vision relies on three photoreceptors that detect primary colors—red, green, and blue. However, some people lack red photoreceptors (they are “bichromates”) or have an additional photoreceptor that detects somewhere between red and green colors (“tetrachromates”). Obviously, having only 3 photoreceptors doesn’t limit our ability to distinguish other colors.
[...] However, invertebrates that have developed color vision (and vision in general) completely independently from us demonstrate remarkably different approaches to color detection and processing. These animals can have a exceptionally large number of color receptors. The mantis shrimp, for instance, has 12 different types of photoreceptors. The common bluebottle butterfly has even more—15 receptors.
Does it mean that these animals can see additional colors unimaginable to us? Perhaps yes. Some of their photoreceptors operate in a rather narrow region of light spectrum. For instance, they can have 4-5 photoreceptors sensitive in the green region of the visual spectrum. This means that for these animals the different shades of green may appear as different as blue and red colors appear to our eyes! Again, the evolutionary advantages of such adaptations are obvious for an animal living among the trees and grasses where most objects, as we see them, are colored in various shades of green...
MORE: http://brainblogger.com/2018/07/23/how-t...es-colors/
https://www.theguardian.com/science/2019...aul-davies
EXCERPT: . . . If biology is defined as the study of life, on this it has failed to deliver. But enlightenment may come from another direction. Rather than biology, some scientists are now looking to physics for answers, in particular the physics of information. Buried in the rules that shape information lie the secrets of life and perhaps even the reason for our existence. That, at least, is the bold proposal from Paul Davies, a prominent physicist who explores the idea in his forthcoming book, The Demon in the Machine....
[...] “The basic hypothesis is this,” Davies says. “We have fundamental laws of information that bring life into being from an incoherent mish-mash of chemicals. The remarkable properties we associate with life are not going to come about by accident.”
The proposal takes some unpacking. Davies believes that the laws of nature as we know them today are insufficient to explain what life is and how it came about. We need to find new laws, he says, or at least new principles, which describe how information courses around living creatures. Those rules may not only nail down what life is, but actively favour its emergence.
To understand what bothers Davies, consider a hypothetical device: a life meter. Wave it over a sterile rock and the dial stays at zero. Wave it over a purring cat and it swings over to 100. But what if you dunked it in the primordial soup, or held it over a dying person? At what point does complex chemistry become life, and when does life revert to mere matter? Between an atom and an amoeba lies something profound and perplexing.
Davies suspects that information is the answer because it seems increasingly fundamental to both physics and biology. In recent years, physicists have shown that information is more than the bits and bytes that course through computers. [...]
Davies believes that life will turn out to bear telltale patterns of information processing that distinguish it from non-life. Few people would argue that a computer is alive no matter how the ones and zeroes zip around inside it. What Davies suspects is that life exploits, and arises from, particular patterns of information flow.
“When you look at a living system, the way information is managed is very far from random. It will show patterns that could lead us to a definition of life,” he says. “We talk about informational hallmarks and these might be used to identify life wherever we look for it in the universe.”
It is not always easy to convert speculation into science. One of the hurdles Davies raises is the difficulty in describing biological information in terms of mathematics. It is a necessary move if new laws of life are to have any meaning. “I really think we need new physics to understand how information couples to matter and makes a difference in the world,” he says....
MORE: https://www.theguardian.com/science/2019...aul-davies
How the brain perceives colors: The limitations of being a vertebrate?
http://brainblogger.com/2018/07/23/how-t...es-colors/
EXCERPT: . . . We can argue that colors are not real—they are “synthesized” by our brain to distinguish light with different wavelengths. While rods give us the ability to detect the presence and intensity of light (and thus allow our brain to construct the picture of the world around us), specific detection of different wavelengths through independent channels gives our view of the world additional high resolution. For instance, red and green colors look like near identical shades of grey in black and white photos.
An animal with black and white vision alone won’t be able to make a distinction between, let’s say, a green and red apple, and won’t know which one tastes better before trying them both based on color. Evolutionary biologists believe that human ancestors developed color vision to facilitate the identification of ripe fruits, which would obviously provide an advantage in the competitive natural world.
Why certain wavelengths are paired with certain colors remains a mystery. Technically, color is an illusion created by our brain. Therefore, it is not clear if other animals see colors the same way we see them. It is likely that, due to shared evolutionary history, other vertebrates see the world colored similarly to how we see it. But color vision is quite common across the vast animal kingdom: insects, arachnids, and cephalopods are able to distinguish colors.
Human color vision relies on three photoreceptors that detect primary colors—red, green, and blue. However, some people lack red photoreceptors (they are “bichromates”) or have an additional photoreceptor that detects somewhere between red and green colors (“tetrachromates”). Obviously, having only 3 photoreceptors doesn’t limit our ability to distinguish other colors.
[...] However, invertebrates that have developed color vision (and vision in general) completely independently from us demonstrate remarkably different approaches to color detection and processing. These animals can have a exceptionally large number of color receptors. The mantis shrimp, for instance, has 12 different types of photoreceptors. The common bluebottle butterfly has even more—15 receptors.
Does it mean that these animals can see additional colors unimaginable to us? Perhaps yes. Some of their photoreceptors operate in a rather narrow region of light spectrum. For instance, they can have 4-5 photoreceptors sensitive in the green region of the visual spectrum. This means that for these animals the different shades of green may appear as different as blue and red colors appear to our eyes! Again, the evolutionary advantages of such adaptations are obvious for an animal living among the trees and grasses where most objects, as we see them, are colored in various shades of green...
MORE: http://brainblogger.com/2018/07/23/how-t...es-colors/