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Plant Sciences, Zoology & Evolution / Should pandas be allowed to go extinct?
« on: 23/09/2009 22:15:17 »
Hi,
I've just read an article that sounds to me outrageous
Here it is
Let pandas die out, says noted naturalist
The Naturalist says that the Panda has gone down an evolutionary cul-de-sac
It is a dangerous thought ... if we accept it we could use the same argument for any other species, or even for groups of people.
Your thoughts, please
I've just read an article that sounds to me outrageous
Here it is
Let pandas die out, says noted naturalist
The Naturalist says that the Panda has gone down an evolutionary cul-de-sac
It is a dangerous thought ... if we accept it we could use the same argument for any other species, or even for groups of people.
Your thoughts, please
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Plant Sciences, Zoology & Evolution / Fibonacci series
« on: 24/02/2008 04:01:00 »
Can anyone explain why do we find the Fibonacci in Nature, in genes?
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Physics, Astronomy & Cosmology / Time as a method of physical propulsion
« on: 30/12/2007 17:47:34 »
Is Time slowing down ?
Pls. check the links http://blog.wired.com/wiredscience/2007/12/scientists-time.html
and http://www.google.com/search?hl=en&q=senovilla+basque
Pls. check the links http://blog.wired.com/wiredscience/2007/12/scientists-time.html
and http://www.google.com/search?hl=en&q=senovilla+basque
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Physics, Astronomy & Cosmology / Electron
« on: 01/12/2007 07:39:41 »
Pauli and Dirac matrices show the existence of spin, but this doesn't really explain the physical origins of the spin. One may says that spin is an intrinsic property of the matter.
Can anyone explain the nature of spin?
Can anyone explain the nature of spin?
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Physics, Astronomy & Cosmology / Electron
« on: 01/12/2007 07:19:13 »
why does an electron have intrinsic spin?
There's something I fail to understand.
There's something I fail to understand.
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Chemistry / What is the role of solid surfaces in ...
« on: 29/11/2007 01:41:31 »
What is the role that solid surfaces play in the development of evaporation crystals?
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General Science / Popular science article
« on: 11/11/2007 01:25:45 »
I found an article (in Popular Science) that i want to share with the members of this site:
Mind tricks explained :
DĂ©jĂ Vu
What It Is: Wait, haven't you read this before? I swear, it was in some magazine last week. No, really.
New Research Shows: Biologist Susumu Tonegawa of the Massachusetts Institute of Technology recently located the specific receptors in the hippocampus—a pair of neuronal clusters in the center of the brain—that work to tell similar but different places apart. In mice lacking these receptors, a room they've never seen before evokes the same response as a slightly different room they've seen a lot, a sensation that may be similar to déjà vu.
What It Means:The hippocampus is the part of your brain responsible for both your sense of direction and the formation of new memories. DĂ©jĂ vu could be simply a temporary disorientation rooted there, as your brain confuses a new location with a remembered one.
Out-of-Body Experience
What it is: The disorienting sensation of looking in on one's own body—no near-death experience necessary.
New Research Shows:A do-it-yourself recipe for transcendence comes from neuroscientist Eric Altschuler of the University of Medicine and Dentistry of New Jersey, who noticed the phenomenon in a McDonald's (he later published it in the journal Perception): Set up two mirrors so that they face each other to form an infinite set of images. Now step between them and tilt your head so that in every other image you can't see your eyes. Stroke your cheek. You'll feel as though there's a stranger in front of you who's stroking his or her cheek, because, Altschuler explains, in every other image you can't recognize your own face.
What It Means: The exercise demonstrates how important it is for the brain to receive coordinated feedback from the senses. When a sense is reporting one sensation, and another sense is reporting a different sensation, the brain can't process the incongruity.
Mirror-touch Synesthesia
What It Is: Mirror-touch synesthetes feel sensations they see from a distance: a pleasant caress when a couple hugs on the street corner, pain when Bruce Lee strikes an enemy in Enter the Dragon.
New Research Shows:A study by psychologist Jamie Ward, then at University College London, revealed that although mirror-touch synesthetes are emotionally empathetic—when they see others feeling sad, they feel sad too—they aren't any better than normal people at understanding other people's problems. Their visual empathy is reflexive, not conscious.
What It Means: Sensation is, at its core, just neurons firing. For mirror-touch synesthetes, it happens that their neurons fire in response not only to touch but to visual triggers as well.
You're Being Watched
What It Is: The eerie sense that a person is lurking behind you can make you spin around—only to find an empty room.
New Research Shows:Neurologist Olaf Blanke and his group at the Swiss Federal Institute of Technology in Lausanne were studying an epileptic patient's brain when they stimulated her left temporoparietal junction. Suddenly the subject felt someone just behind her. The apparition mirrored her movements—sometimes it sat silently; other times it wrapped its arms around her.
What It Means:This part of the brain may explain schizophrenics who blame their actions on illusory companions and, as the study authors note, may help us understand "psychiatric manifestations such as paranoia, persecution and alien control."
Seeing Sounds
What It Is: Aural vision. The blind can learn to "see" with the help of voice software that represents an object's height with pitch and its brightness with volume.
New Research Shows:There's more to vision than raw visual data about an object's brightness and height. Our brains have to be able to discern an object's depth and position as well—for example, your eyes naturally interpret a bright, tall object as being nearby. Neurologist Amir Amedi of Harvard Medical School demonstrated that the brain can learn to interpret sound in the same way it interprets light. He exposed subjects to a variety of objects and their corresponding sounds. With practice, they could "see" a grayscale world—the height, brightness, depth and position of objects—simply by listening to the software's version of their surroundings.
What It Means:Vision doesn't have to come from your eyes. As long as you train your brain to relate specific sensory information like sound to physical surroundings, those inputs can activate the brain's sight centers.
I wasn't familiar with Mirror-touch Synesthesia. Your thoughts?
Mind tricks explained :
DĂ©jĂ Vu
What It Is: Wait, haven't you read this before? I swear, it was in some magazine last week. No, really.
New Research Shows: Biologist Susumu Tonegawa of the Massachusetts Institute of Technology recently located the specific receptors in the hippocampus—a pair of neuronal clusters in the center of the brain—that work to tell similar but different places apart. In mice lacking these receptors, a room they've never seen before evokes the same response as a slightly different room they've seen a lot, a sensation that may be similar to déjà vu.
What It Means:The hippocampus is the part of your brain responsible for both your sense of direction and the formation of new memories. DĂ©jĂ vu could be simply a temporary disorientation rooted there, as your brain confuses a new location with a remembered one.
Out-of-Body Experience
What it is: The disorienting sensation of looking in on one's own body—no near-death experience necessary.
New Research Shows:A do-it-yourself recipe for transcendence comes from neuroscientist Eric Altschuler of the University of Medicine and Dentistry of New Jersey, who noticed the phenomenon in a McDonald's (he later published it in the journal Perception): Set up two mirrors so that they face each other to form an infinite set of images. Now step between them and tilt your head so that in every other image you can't see your eyes. Stroke your cheek. You'll feel as though there's a stranger in front of you who's stroking his or her cheek, because, Altschuler explains, in every other image you can't recognize your own face.
What It Means: The exercise demonstrates how important it is for the brain to receive coordinated feedback from the senses. When a sense is reporting one sensation, and another sense is reporting a different sensation, the brain can't process the incongruity.
Mirror-touch Synesthesia
What It Is: Mirror-touch synesthetes feel sensations they see from a distance: a pleasant caress when a couple hugs on the street corner, pain when Bruce Lee strikes an enemy in Enter the Dragon.
New Research Shows:A study by psychologist Jamie Ward, then at University College London, revealed that although mirror-touch synesthetes are emotionally empathetic—when they see others feeling sad, they feel sad too—they aren't any better than normal people at understanding other people's problems. Their visual empathy is reflexive, not conscious.
What It Means: Sensation is, at its core, just neurons firing. For mirror-touch synesthetes, it happens that their neurons fire in response not only to touch but to visual triggers as well.
You're Being Watched
What It Is: The eerie sense that a person is lurking behind you can make you spin around—only to find an empty room.
New Research Shows:Neurologist Olaf Blanke and his group at the Swiss Federal Institute of Technology in Lausanne were studying an epileptic patient's brain when they stimulated her left temporoparietal junction. Suddenly the subject felt someone just behind her. The apparition mirrored her movements—sometimes it sat silently; other times it wrapped its arms around her.
What It Means:This part of the brain may explain schizophrenics who blame their actions on illusory companions and, as the study authors note, may help us understand "psychiatric manifestations such as paranoia, persecution and alien control."
Seeing Sounds
What It Is: Aural vision. The blind can learn to "see" with the help of voice software that represents an object's height with pitch and its brightness with volume.
New Research Shows:There's more to vision than raw visual data about an object's brightness and height. Our brains have to be able to discern an object's depth and position as well—for example, your eyes naturally interpret a bright, tall object as being nearby. Neurologist Amir Amedi of Harvard Medical School demonstrated that the brain can learn to interpret sound in the same way it interprets light. He exposed subjects to a variety of objects and their corresponding sounds. With practice, they could "see" a grayscale world—the height, brightness, depth and position of objects—simply by listening to the software's version of their surroundings.
What It Means:Vision doesn't have to come from your eyes. As long as you train your brain to relate specific sensory information like sound to physical surroundings, those inputs can activate the brain's sight centers.
I wasn't familiar with Mirror-touch Synesthesia. Your thoughts?
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General Science / finite average level of complexity??
« on: 04/11/2007 00:05:31 »
Let's consider an image of a natural scene ;we 've got some individuals (pixels) that may differ one from another (different colors).
the entropy E of the system is E=sigma(-p.logp), where the sum is computed over the colors and p is the probability of occurence of a given color.
the issue here is that E simply does not depend on the location of the pixels within the image and thus does not depend on the "shapes" or "object" that one can perceive in the image (tress, etc): E only depends on the histogram of the pixels but not on the geometry of the image...
Can anyone suggest a way to estimate the complexity of images of the world?
the entropy E of the system is E=sigma(-p.logp), where the sum is computed over the colors and p is the probability of occurence of a given color.
the issue here is that E simply does not depend on the location of the pixels within the image and thus does not depend on the "shapes" or "object" that one can perceive in the image (tress, etc): E only depends on the histogram of the pixels but not on the geometry of the image...
Can anyone suggest a way to estimate the complexity of images of the world?
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General Science / Re: Question of the Week - Old Version
« on: 03/11/2007 21:51:50 »
Could you create a forum for mathematics?
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General Science / How to Measure the Speed of Light with a Bar of Chocolate
« on: 01/11/2007 23:53:48 »
Science and chocolate... can there be a better combination....
Quote taken for Times On Line. The link's at the bottom if you want to see the other stuff
I'm open to suggestions on any other fascinating home experiments. In fact, it could be rather a good thread....
HOT CHOCOLATE
Is it true that you can measure the speed of light using nothing more than a chocolate bar and a microwave oven? The answer is yes. This is an astounding experiment that actually allows you to measure one of the fundamentals of science in your own home.
What do I need? A bar of chocolate (the longer the better). A metric rule. A microwave oven.
What do I do? Remove the turntable from your microwave oven – the bar of chocolate needs to be stationary. Put the chocolate in the oven and cook at high power until it starts to melt in two or three spots. This usually takes about 40 seconds. You should stop after 60 seconds maximum for safety.
What will I see? Because the chocolate is not rotating, the microwaves are not evenly distributed throughout the bar and spots of chocolate will begin to melt in the high-intensity areas, or “hotspots”. Remove the bar from the oven and measure the distance between adjacent globs of melted chocolate.
What’s going on? The frequency of the microwaves is the key. A standard oven will have a frequency of 2.45 gigahertz (the figure should be on the back of the oven or in the user manual). If your oven is 2.45GHz, the microwaves oscillate 2,450,000,000 times a second (you can adjust this figure depending on your oven). Microwaves are a form of electromagnetic radiation and therefore travel at the speed of light. If you know the frequency of the microwaves, finding out their wavelength will help you to calculate how fast they are travelling.
This is where the chocolate comes in. The distance between the globs of molten chocolate is half the wavelength of the microwaves in your oven, so double the measurement you have taken of the gap between the molten globs to find the microwave wavelength. In the New Scientist microwave oven the distance between the globs of molten chocolate was 6cm, so the wavelength in our 2.45 GHz oven is 12cm. To calculate the speed of light in centimetres a second you need to multiply this wavelength by the frequency of the microwaves: 12x2,450,000,000 = 29,400, 000,000, which is near to the true speed of light of 29,979,245,800cm a second (or 299,792,458 m per second).
Try it yourself, measuring as accurately as possible to get a figure even nearer to the true speed. If your chocolate bar is chilled beforehand, the molten areas tend to be more distinct when they first appear. You may find different chocolate bars, all of which taste delicious slightly melted, will aid your research. True scientists know that it is always important to double-check results.
PS: The hotspots – and consequent cold spots – that occur in ovens thanks to the wavelength of microwaves are the reason why ants can survive unscathed and uncooked inside a switched-on oven. They immediately scurry to the cooler areas and ride out the microwave storm.
http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/books/article2538281.ece
Quote taken for Times On Line. The link's at the bottom if you want to see the other stuff
I'm open to suggestions on any other fascinating home experiments. In fact, it could be rather a good thread....
HOT CHOCOLATE
Is it true that you can measure the speed of light using nothing more than a chocolate bar and a microwave oven? The answer is yes. This is an astounding experiment that actually allows you to measure one of the fundamentals of science in your own home.
What do I need? A bar of chocolate (the longer the better). A metric rule. A microwave oven.
What do I do? Remove the turntable from your microwave oven – the bar of chocolate needs to be stationary. Put the chocolate in the oven and cook at high power until it starts to melt in two or three spots. This usually takes about 40 seconds. You should stop after 60 seconds maximum for safety.
What will I see? Because the chocolate is not rotating, the microwaves are not evenly distributed throughout the bar and spots of chocolate will begin to melt in the high-intensity areas, or “hotspots”. Remove the bar from the oven and measure the distance between adjacent globs of melted chocolate.
What’s going on? The frequency of the microwaves is the key. A standard oven will have a frequency of 2.45 gigahertz (the figure should be on the back of the oven or in the user manual). If your oven is 2.45GHz, the microwaves oscillate 2,450,000,000 times a second (you can adjust this figure depending on your oven). Microwaves are a form of electromagnetic radiation and therefore travel at the speed of light. If you know the frequency of the microwaves, finding out their wavelength will help you to calculate how fast they are travelling.
This is where the chocolate comes in. The distance between the globs of molten chocolate is half the wavelength of the microwaves in your oven, so double the measurement you have taken of the gap between the molten globs to find the microwave wavelength. In the New Scientist microwave oven the distance between the globs of molten chocolate was 6cm, so the wavelength in our 2.45 GHz oven is 12cm. To calculate the speed of light in centimetres a second you need to multiply this wavelength by the frequency of the microwaves: 12x2,450,000,000 = 29,400, 000,000, which is near to the true speed of light of 29,979,245,800cm a second (or 299,792,458 m per second).
Try it yourself, measuring as accurately as possible to get a figure even nearer to the true speed. If your chocolate bar is chilled beforehand, the molten areas tend to be more distinct when they first appear. You may find different chocolate bars, all of which taste delicious slightly melted, will aid your research. True scientists know that it is always important to double-check results.
PS: The hotspots – and consequent cold spots – that occur in ovens thanks to the wavelength of microwaves are the reason why ants can survive unscathed and uncooked inside a switched-on oven. They immediately scurry to the cooler areas and ride out the microwave storm.
http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/books/article2538281.ece
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General Science / finite average level of complexity??
« on: 01/11/2007 19:38:35 »
another_some, could you expand on this?
Doesn't it depend on the whim of the one doing the calculation?
It is in no way obvious what is even meant with complexity in the absolute sense needed to calculate a total complexity level. right?
I watched on PBS (Public Broadcasting Service) the program NOVA, which featured Emergence of Complexity.
Did you watch it?
Doesn't it depend on the whim of the one doing the calculation?
It is in no way obvious what is even meant with complexity in the absolute sense needed to calculate a total complexity level. right?
I watched on PBS (Public Broadcasting Service) the program NOVA, which featured Emergence of Complexity.
Did you watch it?
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General Science / finite average level of complexity??
« on: 01/11/2007 16:07:58 »
Complexity can only be merely defined. Anyway, the world is somewhat complex. But not so much, it could have been more intricate. We can make some fractal interpolation in nature (e.g. Fractals and Chaos in Geology and Geophysic, Turcotte, Cambridge University Press, Cambridge, 1997) and understand the complexity of some shapes from basics law (e.g. basics erosion and tectonics yield the fractal behavior of numerous landscapes).
Question : is there an approach to estimate the average global complexity?
Question : is there an approach to estimate the average global complexity?
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I heard a while ago of a substance found in graphite which acts alike to it yet is a semi conductor that may replace silicon as it can be made extremely thin,I did a google search, but couldn't find any article. Could anyone provide info on graphol?
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