Archive for the ‘SCIENCE…’ Category
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?
WordPress Tags: life,exploration,cosmos,definition,planet,Here,Throughout,objects,environment,aspect,biology,features,possession,essence,subject,Darwinian,evolution,energy,atom,Together,specimen,quandary,Neil,Tyson,Carl,Sagan,species,Earth,logic,signs,Some,Charley,Lineweaver,virus,example,host,machinery,jungle,Geneticist,Craig,Venter,cell,organism,Should,Scientists,Philosophers,ingredients,creatures,chemistry,carbon
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?
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.
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
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.
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.