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Eye


Planetary effects on Earth

By Dr. Kavan Ratnatunga
The gravitational effects of the Sun, Moon, and other planets in our Solar system on Earth are very simple to compute.
Any A-level Physics student should be able to do so. The Gravitational Force is proportional to the Mass/(Distance)2 and the resulting tidal Force is proportional to its first derivative i.e. Mass/(Distance)3. When dealing with such large quantities, it is more convenient to express Mass in units of the Mass of the Earth (approximately 6x1024 kg) and distance in Astronomical Units (AU) which is the average distance from the Earth to the Sun (approximately 150 Million km). Distance between the Earth and Planets varies depending on the location in orbit, but to maximise the possible effect of planet use minimum possible distance between Earth and Planet.
From this Table you see that the Tidal effect of the Moon is 2 to 3 times that of the Sun and more than 10,000 times the combined maximum perturbation of all of the Planets, which will be lost inside much larger tidal variations caused by the Sun and the Moon. Note the importance of distance. The Sun is about 27 Million times as massive as the Moon, but exerts less than half the tidal effect, since the Sun is 400 times more distant than the Moon. This is very well understood, simple physics, which any scientist should understand.
Energy of earthquakes is measured by magnitude known as the Richter scale. A unit increase magnitude is a Tenfold increase in energy of the earthquake. For example a magnitude 8 earthquake is a 1,000 times more powerful than magnitude 5.

Recently in the news, there have been attempts to relate Planets to earthquakes. The Daily News on April 9 reported that a Peradeniya University Geologist had predicted an earthquake larger than five, between April 5 and April 8. They reported the success of this prediction after 7.1 earthquake of April 7. What they did not report was that there were five earthquakes larger than five during those days and 10 during the four days before and 12 during the four days after from the same area. After a great earthquake like the 9.0 in Japan on March 11, there are many smaller after-shocks for many weeks. Earthquakes are not uncommon. Recorded each year on average there is one earthquake larger than eight, 16 larger than seven, 150 larger than six and about 1,500 larger than five.

There were no earthquakes above six as predicted by the Geologist between April 10 and 20 and published in the Times of India on April 9. There has been little press about the failure of the predictions of which I am sure there would have been a lot, if it had randomly come true. None of the previous claimed success has a documented recorded of being predicted before the event.

In an interview by Nalaka Gunawardena with this Geologist, published in online in groundviews.org on April 19, he had claimed to have found a statistical correlation of 136 major earthquakes over last 100 years, with the planetary alignment of Mars, Jupiter, Saturn, and Uranus within a small angle, with the Sun and Moon close to the same line. He had not found any direct co-relation with the Sun and Moon.
There are few papers in the refereed scientific litereature which discuss the possible tidal effect of the moon and sun on earthquakes. For example there is a 2001 paper published by Hu Hui and Li Xiaoming of Yunnan Observatory in China in Natural Hazards, Volume 23, Numbers 2-3, pages 339-348, with some possible correlations of earthquakes with the approximately 18 year cycle of the earth and moon’s orbit around the sun. They state that the effect of planets is negligible, as I have shown above.

In the interview with Nalaka, the Geologist had also suggested magnetic interaction with the molten core of the Earth. Magnetic fields are complex, but also decrease as inverse of the (Distance)3. Relative to their mass, the magnetic fields of the massive Gas Planets (Jupiter, Saturn, Uranus and Neptune) are much smaller than the less massive rocky planets with a molten core like Earth and Mercury. The magnetic fields of other planets as the Earth, are more negligible than that of their gravity. Earthquakes are clearly not caused by alignment of solar system planets, whatever misleading statistical correlation anyone appears to find. Any correlation that was seen must clearly be an error in the statistical analysis. To put it in more understandable terms, a bridge which can handle heavy trucks, does not collapse by dogs or ants walking across it.

Prof Max Wyss of the University of Alaska in his 2001 review paper in Tectonophysics Volume 338, pages 217-233 says To make significant progress in earthquake prediction research, we must learn how to conduct rigorous science in a field where amateurs use a slipshod approach with the dream of helping mankind quickly.
The Nation article on March 27 said the 136 earthquakes analysed measured over 6 on the Richter scale. Since there have been about 15,000 earthquakes larger than 6 in the last 100 years, it is not clear how the subset of 136 was selected. When I spoke to the Geologist briefly over the phone on April 19th, he said, a random subset over selected regions. An analysis of over 15,000, will be statistically more than 10 times better and also unbiased, than a selected 136. That should have been done, before speaking to the press, which unfortunately resulted in scaring the public living along the coast of Sri Lanka, from a peaceful Sinhala and Thamil New Year.

Predictions when published by an academic who is an associate professor of a reputed university are obviously taken seriously by the public who may not understand the details of the Science. Statistics and Astrophysics are popular topics, since it is understood by even smaller fraction of the public. The speakers to the Press themselves probably unaware of the limits of their popular understanding of modern Astrophysics they abuse.
I hope the Sri Lankan University authorities will put in place a proper referee system to ensure that such nonscience is not released to the press, and harm the reputation of the University. The Minister of Disaster Management has said that legal action will be taken against astrologers, academics or others who make predictions on natural disasters and thereby cause panic among the people (Sunday Times April 17). I hope the press in all local languages will also show restraint particularly as we approach 2012 and all that Mayan nonsense sweeping across the Internet, and even leaking to the local print and electronic media.

(The writer is an Astrophysicist who has done 25 years of research in many leading universities in the USA, Canada and Australia, after a Physics Honors degree from the University of Ceylon)

 

NASA probe shows Einstein theory was correct

WASHINGTON (AFP) – Huge objects in the universe distort space and time with the force of their gravity, scientists said recently after a NASA probe confirmed two key parts of Albert Einstein’s theory of general relativity.
“Einstein survives,” chuckled Francis Everitt, Stanford University physicist and principal investigator for Gravity Probe B (GP-B), one of the US space agency’s longest running projects.
The physics experiment was more than four decades in the making, and finally launched in 2004.
“In Einstein’s universe, space and time are warped by gravity. The Earth distorts the space around it very slightly by its gravity,” he said, explaining the Jewish physicist’s theory devised nearly 100 years ago, long before the technology existed to test it.
“Imagine the Earth as if it were immersed in honey. As the planet rotates, the honey around it would swirl, and it’s the same with space and time,” said Everitt.
“GP-B confirmed two of the most profound predictions of Einstein’s universe, having far-reaching implications across astrophysics research,” he said, predicting the mission would “have a lasting legacy on Earth and in space.”
The satellite carried four advanced gyroscopes to measure geodetic effect, or the warping of space and time around a gravitational body, and frame-dragging, or how much a spinning object pulls space and time with it when it turns.
If Einstein’s theory were disproved, the “gyroscopes would point in the same direction forever while in orbit,” NASA said in a statement.
“But in confirmation of Einstein’s general theory of relativity, the gyroscopes experienced measurable, minute changes in the direction of their spin as they were pulled by Earth’s gravity.”
The probe’s measurements came remarkably close to Einstein’s projections, according to the findings published in the journal Physical Review Letters.
The satellite, which wrapped up its data mission last year, was first envisioned in 1959.
Leonard Schiff, head of Stanford’s physics department, and George Pugh of the Defence Department, dreamed up a satellite that would orbit the Earth and test the notion.
Everitt joined the project in 1962, followed by NASA in 1963.
“Forty-one years later, the satellite was launched into orbit about 400 miles above Earth,” NASA said.
The technologies created in the development of the gravity probe have been used in making precise global position systems (GPS) and in gauging the background radiation of the universe.
“That measurement is the underpinning of the ‘big bang theory’ and led to the Nobel Prize for NASA’s John Mather,” NASA said.
Hundreds of university students and dozens of high schoolers have worked on the project, including famous names such as Sally Ride, who was the first American female astronaut in space, and Nobel Laureate Eric Cornell.

 

By Shabna Cader
The second annual LIRNEasia Disaster Risk Reduction Lecture was held last week at the BCIS Auditorium, BMICH. The lecture was also held in commemoration with the 25th anniversary of the Kantale Dam Disaster that occurred in April 1986.
Sri Lanka has 12,000 small dams, and 350 medium and large dams. Dams have been in existence since the age of the kings that ruled the country. They believed that not a single drop of rainwater need be wasted, instead used for the benefit of the people. Today, like in the ancient days, the dams provide thousands of people ample water supply used for agricultural needs, domestic purposes, etc. However it must be acknowledged that if the dams are to be used to provide beneficial support and aid in the daily lives of the people, they in return need to be well preserved, observed, analyzed, and maintained.
If Mother Nature is not taken care of, she will not take care of you. In the past few months alone, this has proved to be accurate and true, as climate change and natural disasters have plagued various parts of the world, as well as larger parts of Sri Lanka. The month of January saw more 200 small dams breach, causing immense damage and destruction during the heavy rainfall and flooding. Lives were lost, property damages and livelihoods destroyed. And what have we learned?
The Kantale dam breached 25 years ago; survivors still struggle to live a normal life but yet, they continue to live in fear. They fear the dam would breach yet again, as there are signs and evidence to leaks. They have not been trained to protect themselves against flooding and possible breach of the dam, no evacuation drills, no safety measures have been taken, no crisis management organized. The people in the areas of dams are not prepared for breaches or possible flooding. Why not?
Dr. Aad Correlje, a professor from the Kingdom of the Netherlands was present at the lecture. He gave a wonderful insight as to how the Dutch have prepared themselves, well over the years, to sustain or even if possible, avoid flooding.
“The Netherlands is a low lying country and often flooded by water if precautions and safety measures are not taken. There is a great history of flood protection. What needs to be done is that the right people need to take responsibility, have an assessment and a plan on how to prepare or prevent a possible flooding.
“Our prevention policy includes disaster management, evacuation and preparedness, sustainable flood proof planning and building, and prevention of flooding (reduction of possibility of flooding). There needs to be a sound governance of flood risks, maintenance and crisis management. Assessments and structures brought up should and need to address the right scale from the right scope. We cannot always blame it on the climate change – climate change is only one of the several factors demanding enhanced flood protection,” said Dr. Correlje.
As mentioned, many Sri Lankans’ lives depend on dams as much as they fear them today. There is a great urgency to protect both the people and the dams. Most dams have malfunctions and cracks, leaks that could be threatening to livelihoods nearby, and barely any operational improvements.
Unfortunately Sri Lankan engineers do not have the expert knowledge to ensure hundred percent safety. It is crucial however that something is done, before it is too late. No one can truly predict when disaster can strike. No one can say if the dam will stand as it is tomorrow or breach in the next hour. If they cannot be maintained and well preserved, let’s assume that it is the people who need to be prepared for the worst. Yet again, nothing has been done to provide or ensure risk management or evacuation drills. The people are powerless so it is vital that dam safety emergency plans are prepared and appropriate warning information and maps are provided.
There needs to be qualified, trained and experienced personnel who will engage with emergency response agencies as well. The same goes for persons who engage in dam design, construction, operation and maintenance. They need to regularly review the dams, conduct inspections and make records of these that should be assessed by professional teams who could possibly or probably predict if anything hazardous could occur. Unfortunately Sri Lanka is not equipped with the most current technologies of detecting a possible breach. As of now, they are not detected by devices; instead by visual inspections alone which has proved to be inadequate in the past. This means that actions need to be taken as soon as possible; locals need the support to ensure that all those who work with regard to preservation, observation, and maintenance of dams.
Chairman of the Sri Lanka National Committee on Large Dams, S. Karunaratna who was also present at the lecture, highlights the very malpractices.
“All major dams in the country are interconnected, have several usage patterns and no operational improvements. Unfortunately, Sri Lanka is not entirely equipped with proper engineers who have expert knowledge and are able to provide methods of precautions to ensure safety. The panel has selected 32 major dams to currently work on – to inspect, observe and also renovate if needed, to assure safety. It is a very challenging program that we have embarked on, but by the end of the programme we hope that we may be able to protect the lives of the people who live in the very areas of the dams,” he said.
As spontaneous and encouraging as that sounds, he further mentioned that it would take 30 years to complete the project. The two biggest questions that arise are, why would it take that long and what has this panel been doing for the past 25 years after the breach of the Kantale dam? Is this fair to the people who have lived for over two decades, hoping for some change and precautionary measures to be taken? With the recent heavy showers and damage and destruction to homes and property as well as the loss of a few lives, what do the Disaster Management Centre and National Committee on Large Dams hope to do?
Stay tuned for more information in the coming weeks.