Archive for the ‘SCIENCE…’ Category

What is life?

What-is-life_19826001_2012 12 24_231114

What is life? It’s a deceptively simple question. Philosophers and scientists have pondered it for millennia, and they have yet to settle on a satisfactory answer. And as we venture into a new era of scientific exploration, the inevitable question arises: will we recognize life if we find it elsewhere in the cosmos? How would you define life? Would that definition hold up on a distant planet around a distant star? Here’s a deceptively simple question—what is life? What does it mean for something to be–you know–alive? Throughout the ages, philosophers and scientists have posed this question, but the answer? Well, that’s not so straightforward. Living things are entities. They’re bounded objects separated from the environment, and they are built on particular chemistries and there’s one aspect of that chemistry which is very important, and that’s carbon. So since biology is, literally, the study of life, it seems as though scientists can’t settle on a single definition, because there are almost always exceptions to the rule. There are some central features, of course, like the possession of genetic material and the ability to pass it along to offspring by reproduction, which means, in essence, that life is subject to Darwinian evolution. Living things are also highly organized, and they use energy to carry out their biological processes. But fundamentally, the answer seems to keep coming back to chemistry.

What are the ingredients of life? The number one atom in your body is hydrogen. The number two atom is oxygen. Together, they’re making mostly water that’s in you. Next is carbon (in this order), next is nitrogen, and next is other stuff. Life is just a kind of chemistry of sufficient complexity to permit reproduction and evolution. I wonder if we’ll ever find a specimen of life based not on organic molecules, but on something else, something more exotic. Here’s the quandary. As Neil deGrasse Tyson and the late, great Carl Sagan point out, there are fundamental building blocks of life across all species on Earth. It’s hard to put our finger on just what life is—I mean, it’s sort of intuitive, we pretty much know it when we see it—but can we expect to use that same logic when seeking out life on other worlds? We’ve entered a new era where scientists called astrobiologists are actively searching for signs of life on other planets, near and far. Some cosmologists, like Charley Lineweaver, think the line between life and non-life may be fuzzier than previously thought. There is non-life, and it evolves somehow into life and we’re trying to understand that. That means that the idea that there’s black and then white should be replaced by how alive is something.

A virus, for example, is sort of alive. It has its own genetic material, but it can’t reproduce without the help of a host, and it’s missing the other biochemical machinery usually found in living things. If a coral reef or a jungle can die, is it operationally alive? Geneticist Craig Venter made DNA from scratch and injected it into a hollowed out cell to create the first ever synthetic organism. Should we call that life? Scientists were stunned the first time they came across the bizarre creatures we now know thrive at deep-sea hydrothermal vents. They’re obviously alive, but they were definitely unpredictable. Which leads me to what’s perhaps the most pressing question as we’re thrust into a new era of space exploration—will we recognize life if we find it elsewhere in the cosmos? What do you think?

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Posted December 24, 2012 by dranilj1 in SCIENCE…

Live Forever

Given the chance, would you want to live forever? In the Epic of Gilgamesh, written over 4,000 years ago, a Sumerian king seeks eternal life. And 500 years ago, Spanish explorer Ponce de Leon came to the Americas searching for the fountain of youth. Every generation, a new ploy for outsmarting the reaper emerges–always futile, always in vain. But is the key to immortality within reach? Some people think that technology will help us cure diseases, build new organs, and essentially reprogram our bodies’ faulty software. Futurist Ray Kurzweil calculates that 20 years is all it’ll take for this exponential boom in computing power to help us live forever. But other scientists are more skeptical. They say that to understand immortality, we must understand our own DNA.

Have you heard of the Turritopsis nutricula? It’s a type of jellyfish, said to be biologically immortal. Now, this doesn’t mean that it’s immune to disease or injury, but it is immune to the leading cause of death: aging. That’s because it can revert back to the polyp stage even after it reaches sexual maturity. In essence, it can stay alive forever, since every time it grows up, its cells undergo trans-differentiation to become young and sexually immature again. That’s one way to live forever. So if this special jellyfish can do it, why can’t we?

It’s a complicated question, and scientists think the answers may be deep within the nuclei of our cells, where the building blocks of life are stored. See, every time one cell replicates to become two, its DNA also has to replicate, and when it does that, little bits at the end break off. These areas are called telomeres, and they’re there for that very reason: to buffer against breakage when DNA replicates, so the important bits don’t get lost. But eventually, after enough replication, the telomeres get broken off too. It’s called the Hayflick limit, named for Leonard Hayflick, the first dude to notice that there is finite number of times a cell can divide. But if we can use special enzymes, like telomerase, to increase the life of the telomere, we may also be able to prolong the life of the cell.

If we can get a handle on how to prevent cellular aging, in theory, we can extend life, potentially indefinitely. We may also be able to fight cancer, since the cellular mechanism involved in this deadly disease is closely related to that in aging. In fact, cancer is a type of cell that simply doesn’t die. That’s why it’s so hard to treat. This wouldn’t be a problem, except that cancer cells also divide uncontrollably and invade the healthy cells around them. In fact, biomedical researchers routinely use HeLa cells in their studies. They’re named for Henrietta Lacks, a woman dying of cervical cancer in 1951. Her cells were harvested without her permission, and grown in culture. Since they are so hearty and easily divide; this exact same cell line is used today in labs all around the world and if that doesn’t blow your mind, think about this.

In a way, we’re all already immortal. Think about it: there’s a line of cells, traceable to the earliest human being–in all of us. See, before I became me, with ten fingers and toes, brown hair and eyes, and a funny birthmark on my arm, I was a single cell. That cell eventually divided over and over to make the person you see today. But that single cell was nothing more than a combination of my father’s sperm (with half the chromosomes necessary to make me) and my mother’s egg (also with half of my chromosomes). Together, they made a single cell, and that single cell divided to become all the cells in my entire body, including my own eggs. One day, one of those eggs may combine with sperm to make another human being and so it goes, down the line, until those branches of the family tree end. But if you trace the branches backward, earlier and earlier in time, you’ll find a common ancestor to us all. Really think about it. The cells in your body, in my body, are traceable to the earliest cells of the very first humans and not just figuratively. We are literally made of the same DNA, the same cytoplasm, the same molecular ingredients as those who harnessed the energy of fire, invented tools, developed language, and first stepped out of Africa, the seat of all humanity. They are physically within us. We are made of them and in that way, we are all immortal.

So you tell me. Would you want to live forever? Or do you feel that you already are, being part of the great lineage of humankind, a lineage that will never die?

Can Free Will Ever be Truly Free?

 

As neuroscience continues to uncover more and more of the brain’s interconnected functioning we—the general public—are forced to consider a pretty big philosophical dilemma. As far as our behavior, thoughts actions are concerned are “we” in charge here, or is “our brain” in charge? Research done with teenagers has proven that a lot of their reckless thinking and subsequent irresponsible behavior can be attributed to the immature frontal lobes of the brain. In other words, their brains are limited. They literally don’t know any better. But does this remove them of responsibility? Even in the eyes of the law? How do we even make such a decision?

According to John Monterosso, associate professor of psychology and neuroscience at the University of Southern California, who has written about the way the public views individual responsibility once they learn about brain limitations and other biological causes for certain actions believes we inherently forgive those actions explained as having a biological cause versus a life-experience cause, even though the two are intertwined. In his view we cannot have a “my brain made me do it” excuse since it is always the case that our brains made us “do” something.

We have two ways that we think about teens. We have the traditional limitations that are part of normal development and then we have limits of the individual. When a teenager behaves in a reckless way, at least in any period of time that I’ve been alive, it’s natural to talk about it as part of development. But these days we bring in neuroscience and now we see that in teens the prefrontal cortex is not yet at full development during the teen years. So now we’ve got a different type of explanation for the same phenomenon of risky behavior. And this sort of explanation has different implications in people’s minds than the first sort of explanation. We’re built to understand causality when it’s applied to intention. That’s part of our makeup and it’s not something we can turn off. If somebody cuts me off on the road, I get angry at them even though I know very little about them. I’m just built to react to people in a certain way.

We are built to see behavior in a certain way, and that’s a lot of what our brain does: It provides a functional understanding of the social world. But when objects bump into each other and move around, or somebody drops a rock, we understand as being different. They don’t involve an individual’s agency. So we naturally have these two ways of making sense of things in the world, one that applies to intentional creatures and one that applies to everything else like objects and identifying physiological antecedents can push our perspective from the agency type to the object type. So if we go back to this adolescence question, we’ll come up with mental states to explain the behavior.

We tend to remove individuals of responsibility when there is a biological or physiological explanation for their actions. The study gave people examples of bad behavior, either bad with respect to causing harm to others or to their self. In each case there was some cause of the behavior identified. Half the time it was something of the physical world and half the time it was something described in terms of experience. For instance, if I am unloved by my parents I’m giving that explanation in experiential terms rather than physical terms. If I talk about it in terms of a gene then I’m giving it in physical terms. In all cases the behavior is described as motivated. It wasn’t as though the person didn’t have the urge to do what they did. When varied strength of connection between the antecedent cause and the action, meaning variation in the number of people who have that gene act in that way, or the number of people who are unloved by their parents act in that way. The factor that made the biggest difference, by far, was whether it was a biological or an experiential explanation. And it was asked people, okay, not everybody with the antecedent behaves this way. A difference in character of will power was selected when they had an experiential antecedent. If you and I had the same bad upbringing, and I behave badly but you did not, people wanted to explain that difference as you have better “character” than me. But if we both had the same biological antecedent—for example we both had this gene that was associated with it—but only fifty percent of people with this gene were themselves known to exhibit violent behavior, and I was violent and you weren’t…very few people would select difference in will power or character between us because they are thinking of this now as a cause like an object’s behavior in the world. As if the individual’s self has no part in it? The interpretation here was there was something categorically different about these two types of explanations. I think the cleanest way to see the effect of that difference is the inapplicability of character and willpower once there was a biological antecedent.

The idea of intent or character is a really big deal in the legal world, and it’s often the difference between guilt and innocence. I think intent in the legal sense is generally workable. It’s consistent with your goals. I don’t think these issues are really typically a problem for the law because the law generally takes a pragmatic approach. I’m not an expert in this. But my understanding is that intent requires that something closer to the behavior was of the person, considering the person’s goals, than it requires metaphysical agency. Presumably, if intent is in line with a person’s goal; that is the person’s own conscious awareness of “I am doing this.” Is there intent when there’s someone who’s schizophrenic and having some sort of delusion? Ah, yes, right so there’s all sorts of considerations that I think are part of the sausage making for laws. For a case where somebody is schizophrenic, the behavior could be totally consistent with their goals. Say they were under the impression that someone was trying to kill them. But we don’t want to hold them accountable for that behavior because we can see where it comes from, and we’re sympathetic to it. I agree that’s a challenge. I think illness is separate category; at least it introduces other issues that I think could make a difference in how the legal system works.

If we talk about justice, we cannot ignore intent. If we want to introduce the idea that we want legal punishments to be commensurate with the wrongdoing, now we’re operating in the zone of the intentional stance. This is putting into legal code what is our automatic reaction to behavior. This is the same stuff of the person cut me off and I want to yell at them, and make them feel bad and punch them. The justice piece is the piece that has gone through the trouble with respect to creeping boundaries of causality in neuroscience. I think it’s because it’s built on this starting point that’s itself not scientific. It’s part of our natural intentional stance. The concern is that the general public doesn’t have this clear line between mind and body and this creates issues because there’s this idea of different blame based on whether it’s biological or personality. This is not something that will go away. There’s some quote from a philosopher, Nagel, I’m not going to get it exactly right, but it’s something like the philosopher who thinks the will is free is a bad philosopher. The person who feels his will is not free is pathological. We can’t help it. It’s like seeing depth. I can know that I’m putting on 3-D glasses and it’s not really a 3-D world. But it doesn’t matter, I can’t turn it off. I’ve been set on this view that metaphysical agency—what some people view as “free will”—doesn’t exist, and in twenty-five years of being an adult, I don’t respond any differently to somebody who cuts me off on the road. It’s not something that goes away with insight.

But from a distance we can know that we ought not pay attention to whether there’s a biological antecedent to a behavior. I think as far as the legal system is concerned, it will become increasingly irrelevant because it’s not workable. It won’t be part of our legal system that a person is exonerated if they have a biological cause to their behavior. It won’t be part of our legal system because it doesn’t work and the legal system is subject to a kind of natural selection. Things get suggested and don’t work and then they get returned. And finally you arrive at something that’s stable. And I don’t think that it will be stable to maintain that the identification of a biological antecedent makes a difference when it comes to responsibility.

We All are a Bit Psychic

 

Scientists understandably don’t have much patience for the notion of extrasensory perception. Yet evidence persists in the psychological literature that people’s bodies sometimes unconsciously “predict” unpredictable future events. These visceral responses don’t appear to be the result of sheer chance. That’s the result of a meta-analysis of earlier papers on this subject conducted by a trio of researchers led by Julia Mossbridge of Northwestern University.

They started with 49 articles but, in bending over backwards to take the most conservative possible approach, tossed out 23 that, for various reasons, didn’t meet their standards. The effect remained. By “effect,” I’m not talking about people having the ability to read palms or tea leaves. What the studies measured was physiological activity—e.g., heart rate or skin conductance—in participants who, for instance, might have been shown a series of images, some harmless and others frightening. Using computer programs and statistical techniques, experimenters have found that, even before being shown a troubling image, participants sometimes display physiological changes —a faster heart rate, for example—of the kind that would be expected only after seeing the image, and not just because the subjects know a scary snake picture is coming sooner or later.

Nobody has been able to explain this phenomenon, although some scientists believe it’s the result of researchers somehow tipping off their subjects. In quality studies, however, images have been randomized and even the experimenters don’t know what’s coming—unless the same physiological prediction mechanism is at work in them. The remarkably significant and homogenous results of this meta-analysis suggest that the unexplained anticipatory effect is relatively consistent, even if small in size. The cause of this anticipatory activity, which undoubtedly lies within the realm of natural physical processes as opposed to supernatural or paranormal ones, remains to be determined.

Unfortunately, people aren’t very good at hearing what their bodies may be telling them, even when getting the message could mean averting disaster—which has led Mossbridge to wonder if there might be value in a feedback device of some kind, perhaps in the form of a Smartphone app attuned to your body’s alerts.

Live Science

 

Orange ClusterCredit: NASAThe star cluster Cygnus OB2 contains more than a thousand young stars, according to observations by NASA’s Chandra X-ray Observatory. Chandra has observed more than 1,700 sources of X-ray emissions in this star cluster, with about 1,450 of those thought to be baby stars. Here, the x-ray emissions are visible in blue. Red in the image comes from infrared data collected by NASA’s Spitzer Telescope, and the orange clouds are optical data from the Isaac Newton

Guardian of the Lava

What are you doing at my rock outcrop? Geology fieldwork sometimes brings scientists face-to-face with local fauna, like this curious red fox living in a lava field on Iturup Island. This volcanic island is part of the disrupted territory between Russia and Japan, with both nations claiming it as their own

Icy Paradise

Snow, ice and clouds blend together in this dreamy image of Antarctic mountains taken by a NASA ice survey team. NASA’s Operation IceBridge aims to study our planet’s polar ice. This photo comes from an IceBridge DC-8 flyover of the Getz Ice Shelf

Seriously Spooky Squid

Talk about a sea monster. This 1889 illustration of a vampire squid paints these mysterious creatures in a creepy light — fitting, given that the scientific name for vampire squid, Vampyrotheuthis infernalis translates roughly to "vampire squid from hell."
In fact, vampire squid are the only known cephalopods that don’t hunt for their prey (so much for their namesake). Instead, they’re the
sea’s garbage disposals, eating marine detritus that floats down to the depths like snow.

Beautiful Bay

Clew Bay, Ireland, is said to have an island for every day of the year. In fact, these islands are drumlins, elongated ridges formed by retreating glaciers. The "drowned drumlins" in Clew Bay are being eroded on their seaward side.

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