Newton's First Law

Smile in the sky

Venus, Jupiter, and the Moon, to light up your night.

Image courtesy Martin Cooper in Bangkok, Thailand, published on the BBC website. Original here

'Cars' stunt

I must admit I loved Cars. It was fun, and the message about sportsmanship and teamwork was portrayed very powerfully. I was a bit foxed by a trick that Doc teaches Lightning McQueen -- how to turn right by steering left! So I was happy to find this article on Popular Science which gave me a reasonable explanation.
Link to article

The International Space Station

It's an enormous 300-ton thing orbiting the earth (that's more than a fully loaded Airbus 340). So how did we get something that big up into space? Simple, it was built in space. Rather, it was assembled there. Here's a feature celebrating 10 years of the ISS.
Link to feature

How do spiders cope with weightlessness?

We now know a fair deal about how the human body copes with extended weightlessness. In part, this is thanks to the Soviet cosmonauts who logged epic stays in space. Muscle atrophy and loss of body mass were only some of the learnings.

The International Space Station, which is kept supplied with materials, scientists, and engineers by the space shuttle missions, is presently hosting spiders. One of the objectives is to learn how they cope with zero-gravity.

(Keep in mind that the loss of gravity is not because of distance from earth alone. It is also due to the orbit of the station, which tends to fling objects outwards with about as much force as gravity pulls them inwards. These cancel out, giving you zero gravity.)

The web in space story

Mini Nuclear Reactors

Nuclear Power Plants tend to be these large hemispheres about the size of a small stadium. In the future, though, that may not be the only model. Here's a report on a quite tiny version

Link to original article

Drive or Fly

Apparently, driving in a car with a modest fuel efficiency of 10.5 km/litre generates 215 grams of CO2 per kilometre.

On the other hand, flying 1 km generates 381 grams per person.

Now bear in mind that the per-person rate in a car can be halved or quartered by the occupancy. So if you're one of 4 people in that same car, you are responsible for only 54 grams/km.

Of course, this does not take into account the cost of fuel, or the time taken.

(using source material from popsci.com)

Telemedicine finally coming of age?

Some time ago, I had friends over for dinner, and some were doctors. We had a heated discussion on the feasibility of long-distance medical diagnoses. (Where the doctor is far away, and you rely on the internet/phone to make a diagnosis.)

There seems to be some progress on this front, as this article shows.

http://www.popsci.com/bown/article/2008-11/making-all-right-calls

Chemical powered car competition

Canopologist

Nalini Nadkarni studies forest canopies. Apparently, there is a great deal of flora and fauna up there that scientists just don't get, because they don't climb trees very well. Well, Nalini does, and here's an interview that ran in the Hindustan Times.

Link to original article

New honeycomb tire is "bulletproof"

http://news.cnet.com/8301-13639_3-10098240-42.html?part=rss&subj=news&tag=2547-1_3-0-5

Will this, someday, spell the end of tyre inflation?!

What was it like inside a coal mine?

Old photos from coal mines

(Link to external website. Click on above line.)

The dangers of mining

Coal mining has always been dangerous. Mines can collapse, crushing or trapping miners. Water, always present in the earth, can break through the walls of a mine and drown the workers. Carbon Monoxide, Carbon Dioxide and Nitrogen can suffocate them. Methane and Hydrogen Sulphide gases can explode. In an atmosphere full of combustible coal dust, explosions are catastrophic.

Here is a list of major mining accidents in India since Independence, till 2005.

No	Dates of Accident	Name of Mines	Fatalities	Cause
1	12/07/1952	Dhemomain	12	Roof fall
2	05/08/1953	Majri	11	Inundation
3	14/03/1954	Damra	10	Explosion of fire damp.
4	10/12/1954	Newton Chikli	63	Inundation
5	05/02/1955	Amlabad	52	Explosion of fire damp.
6	26/09/1956	Burra Dhemo	28	Inundation
7	19/02/1958	Chinakuri	175	Explosion of fire damp.
8	20/02/1958	Central Bhowra	23	Inundation
9	05/01/1960	Damua	16	Inundation
10	28/05/1965	Dhori	268	Coal dust explosion
11	11/04/1968	West Chirmiri	14	Premature collapse of workings
12	18/03/1973	Jitpur	48	Explosion of fire damp.
13	08/08/1975	Kessurgarh	11	Roof fall
14	18/11/1975	Silewara	10	Inundation
15	27/12/1975	Chasnala	375	Inundation
16	16/09/1976	Central Saunda	10	Inundation
17	04/10/1976	Sudamdih	43	Explosion of fire damp.
18	22/01/1979	Baragolai	16	Ignition of fire damp
19	24/08/1981	Jagannath	10	Water gas explosion
20	16/07/1982	Topa	16	Roof fall
21	14/09/1983	Hurriladih	19	Inundation
22	13/11/1989	Mahabir	6	Inundation
23	25/01/1994	New Kenda	55	Fire/suffocation by gases
24	26/09/1995	Gaslitand	64	Inundation
25	06/07/1999	Prascole	6	Fall of roof/collapse of workings
26	24/06/2000	Kawadi	10	Failure of OC bench
27	02/02/2001	Bagdigi	29	Inundation
28	05/03/2001	Durgapur Rayatwari	6	Collapse of partings/workings
29	16/06/2003	Godavari Khani-7LEP	17	Inundation
30	16/10/2003	GDK-8A	10	Roof fall
31	15/6/2005	Central Saunda	14	Inundation

Inside a coal mine

A video visit to the interiors of a coal mine.

Coal Mining Animation

This is a nice animation about coal mining made by kids at an Edinburgh school.

Chandrayaan-1 enters lunar orbit

(This is a link to the website of ISRO -- the Indian Space Research Organisation. It features a graphic animation showing how the earth orbit was boosted, how it transferred to an elliptical lunar orbit today, and how it will eventually settle into a circular lunar orbit.)

Galileo's experiment on the moon

Aristotle (384-322 BC) was one of the great Greek philosophers, who speculated on many fields of human experience, including motion. Although one of the most important names in western philosophy, his scientific thinking was sometimes fatally marked by a lack of experimental work. This led him to make curious blunders, such as the assertion that the human male has more teeth than the female! However, he laid the foundations of logical reasoning, made some rigorous observations of marine creatures, and is rightly regarded as one of the great thinkers of all time.

Such was his fame that for nearly 2000 years, if anyone disagreed with Aristotle, their ideas never took root. The earth was accepted as being at the centre of the universe, even though some of Aristotle's contemporaries believed otherwise. Again, according to Aristotle, a falling objects gains speed, based on its weight. A heavier object will fall faster, and a lighter one will fall slower.

Sometime around 1589, an Italian scientist named Galileo Galilei advanced a theory that contradicted Aristotle, and stated that "the velocity of moving bodies of the same composition, but of different weights, moving through the same medium, do not attain the proportion of their weight as Aristotle decreed, but move with the same velocity."

Essentially, what he meant was that bodies of different weights would fall at the same velocity. Bodies of different materials, though, initially fell at slightly different rates, but attained the same velocity. Galileo is then believed to have gone on and dropped a cannonball and a musket ball from the Leaning Tower of Pisa, demonstrating the truth of his theory.

Apparently Galileo was not the first to challenge Aristotle. But he was the first to muster both theory and experiment in his cause. As for Galileo's observation about objects with different densities, there are two points of view. One is that denser objects would be less affected by air. The second is that human error while holding and dropping a heavy load would ensure that the heavier object was dropped slightly after the lighter one.

Whatever the exact truth, Aristotle's assertion now belonged only in scientific history.

If you try this experiment with the lighter object being something like paper or a feather, air resistance would slow it down severely. So what would happen in a vacuum? Theory, as well as experiments in vacuum chambers tell us that a feather and a steel weight would fall at the same rate. Imagine then, the excitement when this experiment was tried on the Moon which, as you know, has no atmosphere!

Transcript of broadcast from the lunar surface, on 2 August, 1971

Commander David R Scott: "Well, in my left hand I have a feather; in my right hand, a hammer. And I guess one of the reasons we got here today was because of a gentleman named Galileo, a long time ago, who made a rather significant discovery about falling objects in gravity fields. And we thought: 'Where would be a better place to confirm his findings than on the Moon?'

[Camera zooms in on Scott's hands. One is holding a feather, the other a hammer. The camera pulls back to show the Falcon the Apollo 15 landing craft and the lunar horizon.]

Scott: "And so we thought we'd try it here for you. The feather happens to be, appropriately, a falcon feather for our Falcon. And I'll drop the two of them here and, hopefully, they'll hit the ground at the same time." [Scott releases hammer and feather. They hit the ground at about the same time.]

Scott: "How about that! Mr Galileo was correct in his findings."

Ecopsychology - what is it?

The term ecopsychology, first coined by writer and theorist Theodore Roszak in his 1992 book, Voice of the Earth, is loosely defined as the connection between ecology and human psychology. Roszak argues that humans can heal what he calls their "psychological alienation" from nature and build a more sustainable society if they recognize that we all have an innate emotional bond with the natural world.
The basic premise is that we operate under an illusion that people are separate from nature, and that humans are more apt to derive comfort and even inspiration from contact with the natural world -- with which they evolved over the millennia -- than with the relatively recent construct of modern urban society. Distancing ourselves from nature, Roszak maintains, has negative psychological consequences for people and also leads to ecological devastation at the hands of a society that, as a result, lacks empathy for nature.
In a more recent essay called "Ecopsychology: Eight Principles," Roszak, who went on to start the non-profit Ecopsychology Institute, states that the core of the mind is the ecological unconscious, which, if repressed, can lead to an "insane" treatment of nature. "For ecopsychology, repression of the ecological unconscious is the deepest root of collusive madness in industrial society," he writes, adding that "open access to the ecological unconscious is the path to sanity."
While many psychotherapists have adopted aspects of ecopsychology in treating various mental illnesses and psychological disorders, the teachings of Roszak and other contributors to the still-evolving field can be helpful even for those not in need of a therapist's care. John V. Davis, a Naropa University professor who teaches and writes about ecopsychology, for example, says that meditating in the outdoors, participating in wilderness retreats, involving oneself in nature-based festivals or celebrations of the seasons or other natural phenomena, joining in Earth-nurturing activities such as environmental restoration or advocacy work, and spending time around animals (including pets, which have been shown to have healing effects with the elderly and with people with psychological disabilities) are just a few ways in which the discipline can be used by everyday people to the benefit of their psychological health.
Getting kids involved with nature and the outdoors is viewed by ecopsychology fans as key to their development, especially in the technological age we occupy now. Richard Louv, author of the book Last Child in the Woods: Saving Our Children from Nature Deficit Disorder, argues that kids are so plugged into television and video games that they've lost their connection to the natural world. This disconnect, Louv maintains, has led not only to poor physical fitness among our youth (including obesity), but also long-term mental and spiritual health problems. His work has sparked a worldwide movement to introduce more kids to the wonders of nature through various planned and spontaneous activities.
©www.popsci.com

How Chandrayaan-1 is raised to higher orbits

(an article by R. Prasad in The Hindu on October 30, 2008)

Chandrayaan-1 could have been fired to reach the moon, which is about 3,84,000 km from earth, in one shot. But that was not done. Instead the spacecraft is being moved towards the moon in increasingly elliptical orbits with an apogee (farthest point from the earth) increasing many times more than the perigee.

“We could have done it one shot, but there is a possibility of missing the moon,” said M. Annadurai, Project Director of Chandrayaan-1 to this Correspondent. “So we have adopted an incremental increase in the orbits’ perigee.”

That probably explains why the Indian Space Research Organisation (ISRO) has decided to settle for five increasingly elliptical orbits before Chandrayaan-1 reaches the moon’s sphere of influence. Why is the firing always undertaken at the perigee position?

Firing at perigee
“To increase the apogee, we must fire at the perigee [position]. And firing should consume less energy. So the firing is done at the perigee,” Dr. Annadurai explained.

One more reason to fire at the perigee is to ensure that the spacecraft can be tracked by 3-4 ground stations. “The spacecraft is allowed to complete one or more orbits till such time 3-4 ground stations can track it. But we will fire it at the earliest opportunity,” he said.

But not always can one assume that the firing will happen as planned. So any change in this will in turn affect the apsidal line (imaginary line that connects the apogee and perigee). This should be corrected and maintained if the rendezvous with the moon is to happen.

Increasing the apogee
And what ensures that the apogee increases many hundred kilometres after every firing while the perigee changes by only a few kilometres? “When the firing is done exactly at perigee, the velocity increases and the apogee keeps increasing. There will be no change in the perigee position,” he said.

But firing the spacecraft exactly at the perigee position is only theoretically possible. This results in a small change in the perigee altitude.

Duration of firing
“It is not an instant firing [at the perigee]. It takes a few hundred seconds to complete the firing,” he said. But great effort is however taken to centre the firing around the perigee position.

For instance, the first firing to take Chandrayaan-1 from the initial orbit to the first orbit (with an apogee of 38,000 km) took about 1060 seconds to complete. The second firing to take the spacecraft to the nearly 75,000 km apogee took 920 seconds. And the third firing to raise it to about 1,65,000 km apogee took 560 seconds.

The fourth firing to take Chandrayaan-1 to 2,67,000 km will take about 190 seconds and finally the last raise to 3,80,000 will take 150 seconds.

Though the original plan was to reach 2,00,000 km apogee in the third orbit, ISRO could only raise it to 1,65,000 km. So will that lead to any problems? “This can be made up for in the next firing,” Dr. Annadurai said.

Use of propellant

Will the change in the orbit-transfer strategy from five-and-half days to nearly a fortnight lead to increased fuel consumption and hence reduced mission life? “The amount of propellant required to fire the spacecraft to 4,00,000 km is less, whether it is done in one shot or in stages. And the propellant is used only for changing the orbits and not for orbiting around the earth,” he explained.

Orbiting around the earth is mainly through the gravitational force of the earth. But the gravitational influence of sun and moon would still play a role, though minor. Since the spacecraft goes around only for a few days in each orbit, there will not be any change in the orbits and hence the need to use propellant to correct the orbits would not arise.

But that will not be case when Chandrayaan-1 orbits the moon for two years. “There will be a need to correct the orbit once in two weeks to maintain a 100 km circular orbit,” said Dr. Annadurai.

Less energy required
While earth’s gravitational force will exist even when the spacecraft moves further and further away from the earth, the force will decrease with distance. “So firing it to the fourth and fifth orbit will require less energy,” said Dr. Annadurai. “Since some propellant is already used in the previous firings, the overall mass would come down. So the effort required to fire reduces.”

Reverse firing
Five-and-half days after the fifth firing, Chandrayaan-1 will have its rendezvous with the moon. Chandrayaan-1 will get nearer to the moon on November 8 when it reaches the 3,81,000 km apogee.

Though the moon’s influence will be predominant, the velocity of Chandrayaan-1 has to be reduced to enable the moon to capture it. Else, it can fly past the moon.

Once captured by the moon’s gravity, the velocity of the spacecraft has to be reduced to help it reach its final destination of 100 km circular orbit around the moon.

This is achieved by reversing what was done to raise its orbits.

“First, the firing is resorted at both perigee and apogee positions. And the firing takes place only after the orientation of the spacecraft is reversed — turned 180 degrees,” he said.

While the momentum of the spacecraft allows it to move in the same direction, the reverse firing helps it to reduce the velocity. The reduction in velocity is again undertaken in an incremental manner to reach the predetermined 100 km circular orbit around the moon.

© 2008, The Hindu

Chemistry Nobel

Peering into the processes of life, into cells and what goes on there, is not just a matter of looking into microscopes. Science needs help, some kind of insider that can report back on what's happening in there. 3 scientists working in America have won this year's Chemistry Nobel Prize for discovering and developing GFP (Green Fluorescent Protein).

Read more.

Large Hadron Collider for dummies

Okay, it's not actually for dummies, but here's a rap video made by geeks for the rest of us. Kate McAlpine, the 'physics rapper', works at CERN, the European Centre for Nuclear Research, which runs the famous Large Hadron Collider. She has a website here . And here's the famous video:

Your battery's charge is in your blood!

Can blood be used to power batteries?

Blood batteries as thin as a sheet of paper are currently under development by scientists at Rensselaer Polytechnic Institute.This type of battery uses the electrolytes naturally found in bodily fluids such as blood or sweat.

http://electronics.howstuffworks.com/blood-battery.htm

How important is the Atomic Theory?

Suppose something terrible were to happen to Earth, and we the living could only pass one sentence to the next generation. What would it be? Nobel Prize winning physicist Richard Feynman in his book, Six Easy Pieces, nominates the first sentence of this paragraph.

All things are made of atoms. They are the little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another.

The concept of atoms is that important.

For energy, why look further than your body?

So it was only a matter of time before someone came up with this. Charge your iPod as you dance!

http://crave.cnet.com/8301-1_105-9979040-1.html?part=rss&subj=news&tag=2547-1_3-0-5

Can Algae produce oil for our energy needs?

Of all the potential sources for petroleum and oil, this is one of the most interesting that I have come across.

http://news.cnet.com/2300-13840_3-6242586-1.html?hhTest&tag=ne.gall.pg

Eclipses

Just thought I'd share this map of future total solar eclipses. Apparently, the next one to be visible in India is on July 22, 2009. Just over a year away.

There's one on August 1, 2008, but that won't be visible in India. 

Photo credit: www.exploratorium.edu