Till now, 283 posts have been posted in this blog– some of them good, some not so good, some got numerous hits wile some were lost in the crowd. I will be recycling some of these posts in coming days. In today’s post, I will be re-posting 7 posts which, according to me, were good ones but were lost in the crowd and didn’t get as many hits as they should have. So here they are:
The Courageous Life of Sophie Scholl-Now, who is Sophie Scholl? Sohpie Scholl was a member of non-violent student resistance movement against Nazi rule in Germany. The group called itself “White Rose” which was mostly based in University of Munich campus and its main activity was printing and distributing leaflets denouncing Hitler’s rule, which was equivalent to asking for death sentence in Hitler’s regime.
Invictus: The Unconquered Ones-Gandhi, Mandela, Martin Luther King were all Invictus, the unconquered ones, and they were the masters of their souls. The poem “Invictus”by William Henley probably describes very well the struggles of such souls amongst all the obstacles, still emerging victorious.
Hole-Punch Clouds: Mystery Solved- Any guesses what punched that hole in the cloud? Well, researchers have been looking for the answer for a while and airplanes have been the main suspect for this phenomenon.New research studyconfirms that planes, both propellers and jet planes , can cause formation of these shapes in the clouds named as “hole-punched clouds ” or “punched hole clouds” as a result of enhanced precipitation effect. These clouds have also been linked to UFO sightings in past, most famous one being inMoscow during October 2009.
Wait For It…Wait For It- Patience pays, Don’t give in to temptations, Have Self-control: we have been told since our childhood. Well, depending on how much self control or patience we have, determines our success in life. To study these effects and what mental processes lead to self control or delayed gratification, psychologist Walter Mischel conducted a very famous Marshmallow experiment with a group of few 4 year old kids in Stanford in 1960.
Time To Tickle You-Tickling is a very interesting sensation, it can burst you into laughter and on the other hand it can make you agitated as well. We all have tickled someone or have been tickled either by parents or siblings or friends. It’s also interesting to note that you can not tickle yourself implying that an element of surprise is very important.
Prime is in Nature-Magicicadais one of the genus of cicada species and are primarily found in eastern US and they have a very interesting periodic life cycle pattern. They follow either a 13 or 17 year life cycle pattern where after hatching from the eggs, and lying under the ground for 13 or 17 years, all of them emerge at once on the surface. Emergence of all the adult cicadas after 13/17 years is well synchronized.
Photoemission Delay Time-Photoelectric effect has been known to us for a long time. Heinrich Hertz first observed this phenomena in 1887 where a material absorbs electromagnetic radiation and emits electrons. While most of details are clearly understood, one aspect which has been missing is the delay time in emission of electrons after the matter absorbs photon.
Image credit: Flickr user Missbng | Used under Creative Commons License
After exploring surface of Mars for about 7 years, Spirit has been officially declared dead for all scientific purposes. Spirit started it’s Martian journey on Jan 2004 to carry out it’s scientific mission which was supposed to last for 90 days. But Spirit surpassed all the expectations and continued exploring Mars for another seven years. It stopped communicating on Mar 2010 and attempts were being made by NASA to communicate with the rover. Finally,NASA concluded it’s attempts of contacting Spirit today.
“We’re now transitioning assets to support the November launch of our next generation Mars rover, Curiosity,” said Dave Lavery, NASA’s program executive for solar system exploration. “However, while we no longer believe there is a realistic probability of hearing from Spirit, the Deep Space Network may occasionally listen for any faint signals when the schedule permits.” [NASA]
Great job Spirit! Here is xkcd’s take on spirited Martian journey of our beloved scientific instrument:
Image credit: 1) Artist concept of Mars rover| NASA/JPL/Cornell Univ 2)Xkcd
Marie Curie is one of the finest women scientists whose achievements were well recognized by the scientific community, although the recognition did not come easy. She won two Noble prizes, first one for understanding the phenomena of radiation which was shared with her husband while the second one she won solo for discovery of elements radium and polonium. When she won the second Noble prize, the Nobel committee which comprised mostly of men made attempts so that she could not attend the award ceremony, but she did attend the ceremony anyway. But besides her which other famous women scientists we know of that era. Not many! Did you know about Lise Meitner or Emmy Noether? Lise Meitner was part of the team which worked on nuclear fission project. While Otto Hahn won the Nobel prize working on the project, she was conveniently neglected by the Nobel committee. As a consolation prize, an element Meitnerium was named after her. Zombie Marie Curie wants us to know that there were many other women scientists who made groundbreaking contributions to the field of science but were neglected due to gender bias.
None of the home team had ever won the cricket World Cup, and no World Cup final century had ended in defeat but that was until yesterday– Team India are the world champions in cricket!!! It came after a long gap of 28 years, but what a tournament it has been for Team India. Congrats Team India, Congrats Indian cricket fans. Now it’s time to savor this well deserved victory.
The cup also adds one of the only missing laurels in legendary Sachin Tendulkar’s illustrious career of 21 years. As fellow teammate Virat Kohli rightly put it after carrying him on their shoulders for the victory lap around the stadium ” “Sachin Tendulkar has been carrying the burden of a billion fans for the past 21 years and it was time we carried him”. Well done Men in Blue!
No Jayawardene ton had ended in defeat. No World Cup final ton had ended in defeat. No home team had won the WC. Until today.
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.
The picture above is an X-ray image of supernova remnant, Tycho, produced from the explosion of a white dwarf star in our galaxy. The image has been taken by Chandra X-ray observatory. The supernova remnant is about 13,000 light years away from earth and is located in Cassiopeia constellation in the Northern hemisphere. If you ask, how big is the explosion, it’s roughly 55 light years across (1 light year= 9.5 x 10^15 m). This supernova remnant was first observed by Danish astronomer Tycho Brahe, in 1572 and that’s how it got it’s name.
Now let’s get to some science behind the image. The blue color seen on the rim of the circular blob is from high energy X-rays (blast wave which contains high energetic electrons), while the interior red color is from the low energy X-rays (which contain expanding debris from the supernova). The interesting phenomenon observed in this image is the presence of stripes in the outer regions of the exploding star. Such “X-ray” stripes have never been observed in any other supernova remnant.
These X-ray stripes are beleived to form due to high turbulence and magnetic field entglements as compared to surrounding regions. In these regions, the electrons get trapped and get energized and emit X-rays as they sprial along the magnetic lines. In the image below, the black lines are the magnetic field lines, while the red lines show the path of the electrion. The spacing between these stripes is determined by the radius of the spiralling high energy proton (path shown in yellow), the energy of which can be over 100 times larger than what can be gerenrated in Large Hadron collider! These high energy particles are believed to be the source of cosmic rays on earth. So that’s for the science behind this beautiful image!
In the wake of looming nuclear crisis, we keep hearing or reading about the units Sievert or Sv for the amount of radiation exposure. So what is Sievert and what to make of it when media reports that 0.6 μSv radiation per hour has been detected (as seen in the picture above).
Scientists use different terms to report the radiation measurement depending upon the context. For eg, unit Curie (Ci) or Becquerel (Bq) is used to measure the amount of radiation which is being released or emitted by a radioactive material, while unit rad or Gray (Gy) is used to measure the amount of radiations absorbed and deposited in the human tissue. A person’s biological risk which means the risk that person will suffer health effects due to radiation exposure is measured and reported in units rem (roentgen equivalent man) or Seivert (Sv). Biological risk depends upon the type of ionizing particles emitted (alpha, beta, gamma, X-rays) and their ability to transfer energy to the cells. Based on this energy transfer function, each particle has been assigned a Quality factor (Q). In order to asses the biological risk this factor is multiplied by the radiation dose measured.
So, 1 Sv = 100 rem = Q x rad
Are these nuclear disasters the only source of radiation dose to humans? No. we constantly get slight dosage of radiation from variety of sources including cosmic rays (more when we are flying), naturally occurring radioactive minerals in soil, medical X-rays etc. In order to get some sense of what these numbers mean, here are few typical numbers from various sources (CDC):
Hopefully these numbers will give us some idea the radiation exposures being reported in the media. So on average, we receive about 300-350 mrems (3-3.5 mSv) of radiation dose per year, sometimes even higher if we are undergoing medical treatments. International law permits exposure of about 2000 mrems per year for those who work with or around radioactive materials. Here is an excellent chart by XKCD and another by BoingBoing which can be helpful in understanding radiation exposure and health effects.
So how much are the radiations from the failed Japanese plants. It was reported that radiation level shot to about 0.8 rem per hour on March 15th. There have been conflicting reports on the correctness of amount of radiation exposure reported by various media as well as by Govt agencies. According to NRC, if a person is exposed to 500 rems of radiation at once, person will likely die without any medical treatment. Single dose of 100 rem will cause nausea and skin reddening and 25 rem of single dose can cause temporary sterility in men. However, NRC also says that if the radiation is spread out over time instead of being delivered at once, the affects are less severe.
More about how radiations are measured and the current status in Japan in later post.
Image credit: Boston.com/Bigpicture| AP photos|Kyodo News: A radiation detector measures 0.6µSv, exceeding normal day data on Mar 15 near Tokyo station.
There is a huge media-hype going around concerning the “supermoon” which is going to happen on March 19th, 7 PM UT, which is about 3 PM US Eastern time. So what is this supermoon and what is the hype about. As we all know, moon orbits around the earth in an elliptical orbit with one side of the orbit being closer to earth (perigee; 363,000 Km from earth) while the other being farther (apogee; 410,000 Km from earth). At it’s perigee, moon is closer to earth by about 50,000 km than the average distance at apogee. This distance fluctuates due to various reasons and influences and on March 19th, moon will be at a distance of 357,000 km from earth which is about 6,000 km closer than usual perigees which happens every month. At apogees, moon looks bigger and brighter, and tonight moon will appear to be about 14% bigger than usual and about 30% brighter, permitting weather conditions and your viewing location. Coinciding with the closest perigee is the full moon event which makes the event very rare. Last such full moon event occurred during March of 1983. Manymedia outlets and individuals are linking this event as a reason for Japan’s earthquake. They are even predicting that many more natural disasters can happen due to moon’s increased effect of gravity on earth. All this is hoax and pseudoscience and moon has nothing to do with Japan’s earthquake nor this supermoon event (or perigee-Syzygy as it is scientifically called) is going to cause any serious natural disaster. Just like any other perigee moon, which happens every month, tides will be higher. Perigee full moon will result in additional 3-5% gravity pull by moon resulting slighlty higher tides than usual. Due to lunar effect at perigee, tides are higher by few cms than usual. Geographical locations can amplify the effect to about 15 cms, but none of these is going to cause Tsunami, or floods or massive earthquakes. The supermoon event of March 1983 did not cause any havoc, but this doesn’t stop people like Richard Nollefrom circulating wrong information andcreating panic. He, by the way, is an astrologer with no scientifc background as such.
Moon does have an effect on earth, but not to the level of causing 9 level earthquake. If that was the case, we would be witnessing a massive earthquake or strom every month whenever the moon is at it’s perigee. If moon was the reason for Japan’s earthquake, why it happened on the date when moon was closer to apogee rather than perigee?? More than 1,000 earthquakes occur every year and moon revolves around the earth every month and we have been studying moon for ages; if there was any correlation between moon and major earthquakes, we would have deciphered it by now. So, let’s look at the full perigee moon tonight, possibly at the horizon with objects in foreground to get an awesome view, and not panic or spread panic.
Image credit: Boston.com/Bigpicture |AP Photo/Keystone, Alessandro Della Bella
May 20, 2012 1799 Honore De Balzac 1851 Emile Berliner 1908 James Stewart 1920 Betty Driver 1942 Lynn Davies 1944 Joe Cocker 1946 Cher 1961 Nick Heyward
