Tag: Nature
There are roughly 900 mountain Gorillas remaining on earth and baby Shamavu (shown above) is one of them. Baby Shumavu was recued from the hands of poachers by a team from Virunga National Park in Congo led by Christian Shumavu. The team busted a poaching racket and were able to rescue this baby Gorilla, He was then named after the man who rescued him. As you can see from picture, Shumavu looks confused and scared. The rescue team found him stuffed inside a small backpack. He is about one and half years old and it is not sure if his mother survived from the hands of poachers. The baby was so terrfied from the whole experience that he would not leave the arms of his recuer or let any doctor treat him. It took a while until he earned the confdence of other humans.
For more pictures visit this facebook page or website of Virunga National Park.
October 27, 2011
In the picture you can see baby elephant Shukuru wearing a custom made raincoat in order to protect him from cold and rain. Baby Shukuru is a victim of incessant poaching and human-wildlife conflict occurring in the jungles of Kenya. Elephants who used to walk free in the jungles are now endangered. Like many other baby elephants in these jungles, Shukuru is an orphan and is being taken care at David Sheldrick Wildlife trust in Nairobi where he is being fed, protected and rehabilitated. Once they are no longer milk-dependent they are moved from this elephant nursery to other centers. Slowly they are moved to their natural habitat, but this can take few years (8-10) before they are ready to move in the wild. Baby elephants are dependent on their mother’s milk for about 2-4 years and that causes serious problems in raising young orphan elephants. You can read more about Shukura and many other baby elephants in NatGeo article. These beautiful pictures have been taken by Michael Nichols and if you are interested in some good Nature pictures, you might consider getting his App for your iPad.
Image Credit: Michale Nichols | National Geographic
September 6, 2011
In a new study published today in Nature Photonics, scientists from Wellman Center for Photomedicine and Harvard Medical school have developed a “living laser” by using biological materials- human cell and jellyfish fluorescent protein. In order to get coherent beam of light from a lasing device, three things are required- a pump source (typically flash lamp, electric current or other laser source), a ‘gain media’ for amplifying the source (optical gain) and an ‘optical cavity’ for concentration and alignment of the laser beam. Typically, crystals, dyes, gas mixtures and even alcohol have been used as gain media to amplify the light. Pumping source produces population inversion in the gain media wherein majority of the atoms and molecules are in excited state. When a photon of appropriate wavelength interacts with such a system of atoms/molecules, stimulated emission occurs. In a very novel approach, researcher Malte Gather has used Green Fluorescent Protein (GFP) and inserted the protein in living human embryonic kidney cell. Bioluminiscent GFP was first isolated from jellyfish in 1962 which ultimately resulted in Noble prizes for it’s discoverers. The kidney cell-GFP combo (gain medium) was then kept in between an optical cavity made of mirrors kept 20 microns apart. The dimension of single cell gain media was also about the same. When researchers hit the cell with low energy pulses of blue light using a microscope, typical diffused ordinary fluorescence was observed. But after reaching a certain threshold of input energy (~0.9 nJ), the light output from the cell changed drastically and resulted in bright, directional and narrowband emission of green light, which are the characteristics of a laser beam. Certain regions of cell showed intense lasing action (as shown in picture above) which occurred at different but close range of wavelengths (~514-519 nm). Researchers also reported that even after prolonged lasing action, the cell was still alive. The lasing action lasted for few nanonseconds and was easily detectable. The cell was able to lase about 100 pulses at excitation pulse energy of 50 nJ after which photobleaching occurred and depleted the GFP. But an interesting aspect of GFP infused cell is that the cell is able to heal itself and replenish GFP with time.
Here is an output emission spectra of the laser filled with purified GFP solution when pumped using different wavelengths of light. As can be seen that the output spectra is independent of the pump wavelength. This spectra tells two things i) independence of excitation wavelength on the emission rules out any stimulated scattering process as an explanation for lasing action by GFP, ii) FWHM ( Full Width at Half Maximum) of about 12 nm signifies the presence of simultaneous oscillations of various longitudinal modes.
Next figure shows that replacing the GFP solution with GFP-transfused cell resulted in much narrow output spectra. At energy threshold of 0.9 nJ, single emission peak was observed at 516 nm (FWHM <0.04 nm). As the energy was increased, multiple emission peaks were observed which can be attributed to multiple longitudinal oscillation modes. The spectral spacing between these emission line was in the range of 5 nm.
Researchers speculate that the resulting light could be used to study various intercellular processes. Before producing output light, the light travels several times through the cell placed inside the optical cavity and the resulting lasing light should contain information regarding the intercellular processes. Another possible use could be to produce such lasing beams inside the body itself to kill certain cancerous cells .
Creators of living laser, Yun and Gather, have some broad and speculative ideas about how the technology might be used.
They suggest that biologists could turn cells of interest into lasers to study them. The light produced has a unique emission spectrum related to both the structure of the cell and the proteins inside it. “By analysing the pattern you can get some idea of what is happening inside the cell,” says Yun.
The researchers also suggest possible medical applications. Doctors today shine lasers into the body to gather images or to treat disease by attacking cells. Yun thinks that lasers could instead be generated or amplified inside the body, where they could penetrate the relevant tissues more deeply. [Nature News]
Image credit: 1) Malte Gather | Nature Photonics | Wired 2) From the supplement files of the article provided on Nature website 3) Snapshot of the plots as seen at Nature website
Reference: Single-cell biological lasers: Nature PhotonicsYear (2011) DOI: 10.1038/nphoton.2011.99
June 13, 2011
This is an image from recent volcaninc eruption in Chile. On June 4th, Puyehue volcano started erupting sending plumes of volcanic ash as high as six miles leading to evacuation of more than 3,500 people and shutting down of the airports in the area. The ash has majorly affected nearby cities in chile and Argentina. The volcano which was dormant since 1960 also produced some spectacular and mighty lightning bolts (few miles long) as seen in the picture above. Such lightning shows have been also documented in other volcanic eruptions including Mt Vesuvius, Eyjafjallajökul, Mt St Augustine volcano in Alaska, Chaiten volcano in Chile and many more. But not all volcanoes lead to lightning display. Volcanic lightning can be roughly divided into three types depending on the length of lightning bolt and how and where they are formed: i) Large volcanoes which spew out large amount of ash deep into the sky can lead to formation of lightning bolts many miles long. ii) Mid range lightning bolts can sometimes come directly from the volcanic vents. iii) Small range sparks (few meters long ) can occur in the plume which are short lived (few milliseconds). But what is the main mechanism of volcanic lightning. The answer is not clear yet.
For lightning to occur, a potential difference need to developed and then an ionization channel need to be created for the charges to flow from highe potential to lower potential. But how do you create a potential difference in the volcanic cloud or ash plume? Charge separation is the answer according to one theory. Volcanic plume is extremely hot and energetic and collision causes particles to get charged. Positive and negative charged particles have different aerodynamic properties which lead to their separation in different zones in the volcanic cloud. Probably, positive charged particles settle down in the lower cloud while negative particles move in the upper regions of the cloud. This charge separation keeps on occurring until enough voltage difference has been created to form an ionization channel (streamer, leader head formation) and boom- lightning bolt occurs! Since the potential difference is between different regions in the clouds , you can see the bolts originating as well as ending up within the cloud itself. But again, this is just one of the explanations and the process is still not clearly understood. This doesn’t explain how lightning sometimes start from the vents, during the beginning of eruption itself, as in this short time it’s not possible for charge separation to occur. Interestingly, there has not been many scientific studies explaining the phenomenon. It was not until 2007, when scientific observations were documented in a Science paper where the authors studied Mt St Augustine eruption. Here is an abstract of the article:
Electrical Activity During the 2006 Mount St. Augustine Volcanic Eruptions
Thomas et al | Science 23 February 2007:
DOI: 10.1126/science.1136091
Abstract
By using a combination of radio frequency time-of-arrival and interferometer measurements, we observed a sequence of lightning and electrical activity during one of Mount St. Augustine’s eruptions. The observations indicate that the electrical activity had two modes or phases. First, there was an explosive phase in which the ejecta from the explosion appeared to be highly charged upon exiting the volcano, resulting in numerous apparently disorganized discharges and some simple lightning. The net charge exiting the volcano appears to have been positive. The second phase, which followed the most energetic explosion, produced conventional-type discharges that occurred within plume. Although the plume cloud was undoubtedly charged as a result of the explosion itself, the fact that the lightning onset was delayed and continued after and well downwind of the eruption indicates that in situ charging of some kind was occurring, presumably similar in some respects to that which occurs in normal thunderstorms.
I will try to find more details about the process and would add more information in my later posts. For now, here is one more picture from the Puyehue volcano.
Inage credit: 1) Boston.com/Bigpicture|Carlos Gutierrez/Reuters 2) Boston.com/Bigpicture|Claudio Santana/AFP/Getty Images
June 9, 2011
Well, you decide whether the above image is a photograph or painting. First guess will say that it’s a beautiful painting, but the fact is that it’s a photograph of landscape in Namibia. This magnificent picture was taken by Frans Lanting for a National Geographic magazine article about Namibia and it’s environmental protection laws. Beautiful landscape combined with perfect lighting resulted in this amazing picture. Here is what Frans has to say about the photograph:
“Here’s a short summary about the making of the photo. It was made at dawn when the warm light of the morning sun was illuminating a huge red sand dune dotted with white grasses while the white floor of the clay pan was still in shade. It looks blue because it reflects the color of the sky above. Because of the contrast between the shady foreground and the sunlit background I used a two-stop graduated filter which reduced the contrast. The perfect moment came when the sun reached all the way down to the bottom of the sand dune just before it reached the desert floor. I used a long telephoto lens and stopped it all the way down to compress the perspective” [By the way, the white dots in the picture are grasses on the sand dunes.You can read more about this photograph here].
Image credit: Frans Lanting | National Geographic
June 3, 2011
As promised, here comes another fantablous video, this time from photographer Randy Halverson featuring none other than our own Milky Way. The stop-motion video beautifully shot in the farms of South Dakota gives you an edge on view of our galaxy. Enjoy the video, more videos to come soon!
June 3, 2011
It’s been a while since I have posted “Weekend Videos”. I will try to make up by posting some of the most amazing videos you have ever seen. To begin with here is a beautiful mesemerizing time-lapse video titled “The Arctic Light” by nature photographer Terje Sørgjerd. The video was shot between 29th April and 10th May 2011 in the Arctic, on the archipelago Lofoten in Norway. The video captures the moment before the”mudnight sun”, the days when sun almost never sets in some locations in the Arctic. The sun just keeps bouncing in the sky between nights and days and practically never sets! As Terje says, “The Sunset and Sunrise are connected in one magnificent show of color and light lasting from 8 to 12 hours. The sun is barely going below the horizon before coming up again. This is the most colorful light that I know, and the main reason I have been going up…” He broke several cameras and even hurt himself while taking the shots, but the passion to capture these beautiful moments kept him going against all the odds. Enjoy the video.(I had previously posted another very beautiful video cerated by Terje, “The Aurora“, so check out that as well)
June 1, 2011
In order to make up for the reduced number of posts during the last month, here are some bonus videos for this weekend. The vidoes are so amazing that I couldn’t wait for the next weekend to post them. The first video is an amazing time-lapse video of the full moon (supermoon event), beautifully shot by Frédéric Lagléra in Tignes France. Great work Fredric and thanks for submitting the video to “science is beautiful” vimeo blog. Second video was shot by Norwegian photographer Terje Sorgjerd. He shot about 22,000 mesmerizing pictures of Aurora Borealis event (Northern Lights) and put together the pictures to create a breathtaking time-lapse video for us to enjoy and cherish. You can read my earlier posts (here and here) to understand the science behind the origin of green and violet colors as seen in Aurora Borealis. As the Sun is now entering into a more active phase after a period of lull, more such beautiful events will occur owing to strong solar storms.
March 27, 2011
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