|SCIENCE TRIBUNE||Thursday, April 20, 2000, Chandigarh, India|
by Sarabjeet Singh
An object launched from the moon will need 97% less power than an object of the same mass would need if launched from the earth. Therefore the moon, any light gravity planet or an asteroid would prove to be a much cheaper source of raw materials than the earth.
An object launched from the moon will need 97% less power than an object of the same mass would need if launched from the earth. Therefore the moon, any light gravity planet or an asteroid would prove to be a much cheaper source of raw materials than the earth. Substances that would readily be available from the moon include steel, aluminium, magnesium, titanium, glass, ceramics and cement. By chance all these would be most useful in the construction of future space habitats.But these projects would be economic only if we use cheap and efficient methods of launching (obviously not chemical rockets). Much has been suggested by various personalities such as Robert Heinlein, Gerard ONeill, and Arthur C Clarke about Electromagnetic launching. Enthusiasts at Massachusetts Institute of Technology turned this fictional idea into reality in 1977, when they made a test model of worlds first mass driver- (as the Gerard ONeill named it).
Mass driver is an electromagnetic catapult, which consists of a long tubular track made up of many individual coils called drive coils. Floating up in the centre of this coiled track are buckets, which can be of any hard, durable, and non-magnetic material. Buckets are surrounded by one or two superconducting ring magnets. Like ordinary buckets, they can be filled with whatever you like. The drive coils are energised to create strong magnetic pulses due to which the bucket gets more and more acceleration until at the end where the buckets are suddenly stopped! And the contents fly out in space at just the right velocity and in the aimed direction. The test model of 1977 accelerated a 400 gm bucket from 0 to 160 km/hr. in only 6 feet track length, giving 35g acceleration!
But alas... these devices would be of no use on the earth. The reasons strong gravitational pull and high atmospheric resistance! But this system could efficiently be employed on the moon of an asteroid. It has been suggested that the mass driver for the moon would be around a kilometre long and provide acceleration of 130g to the contents, giving lunar escape velocity of 2.4 km/sec. The buckets would then go back to the starting point along a return path to be reloaded (by mining team or automatic machinery) quite like a conveyor belt. Construction crew in space could scoop the ejected material up.
No doubt the mass driver will be very useful tool, in mining the asteroids or moon, it could also become an effective and cheap propulsion device. Scientists have been luring for asteroids, the family of which could be divided into three main categories viz., carbonaceous, rocky and metal rich. And the metal content (e.g. iron & nickel) of even the relatively small ones is high enough making them worth to explore.
A number of such solar powered mass drivers could be attached to an asteroid so that they throw the material away in space to get the asteroid pushed in the opposite direction working like a rocket engine.
During the journey of asteroid towards the earth as much as two thirds of its mass would have been eaten up (used as propellant) but the remaining one one third mass would still be no less than a jackpot!
Once the large asteroids like ceres (now in orbit of such between Mars and Jupiter) are brought, either by nuclear power or by a swarm of mass drivers into earths orbit, they could be farmed to grow food, terraformed to live upon or mined to obtain raw materials.
Moreover, when we would
have mastered such a technology, the forth-coming natural
disasters could happily be concerted into most celebrated
events! A timely step could be taken by sending a swarm
of such mass drivers which will stick to those asteroids
which are on a collision course with the earth, and
thereby altering their travel paths or to disintegrate
them so that they come to earth as a shining rain (meteor
shower). At present we have no choice other than shooting
them with a large nuclear missile.
Cybersurfing with Amar Chandel
Your medical adviser
Many a time you suffer from an ailment which is too small to be taken to a doctor and too painful to be ignored. Professional advice is hard to come by. Internet provides tremendous help. You get a whole lot of material on whatever disease you want to know about. One of the good websites on health matters is www.noah.cuny.edu, which enlightens you not only about your common cold but also about almost all diseases under the sun like the Alzheimers, AIDS, arthritis, asthma, cancer, diabetes and kidney diseases.
NOAH here stands for New York Online Access to Health. The information is obviously meant for those in the USA (many of the over the counter drugs may not be even available here) but the appeal is universal. Particularly useful is the information on healthy living and nutrition.
There are few graphics and that makes sure the pages load fast.
A similar site is www.webmd.com, which too provides you guidance in a simple, easy-to-grasp manner. There is a lot you can learn from the health teacher.
What emerges from this and many other similar sites is the fact that one has to concentrate on prevention rather than treatment.
From hard science, if you want to switch to the so-called supernatural, move over to the aptly named www.witchcraft.net. Yes, it takes you on a journey to the believe it or not world. You realise that the myths and superstitions prevalent in India are nothing as compared to those prevalent in the rest of the world.
You get to read about a recent conference of Chippewa spiritual leaders in Minnesota, where it was underlined by all that weird weather like that caused by El Nino is nothing but a warning from God. Impressed? Read on and on, because there are hundreds of such gems of information.
So you are getting married and are not too sure about dos and donts? Try www.smartbahu.com. It guides you about everything from wedding terms (what is a milni) to how to plan for a budget wedding.
But the more useful and colourful is the section about wedding customs which tells you about what ceremonies have to be undertaken in various communities like those in Punjab, Kashmir and Bengal.
1. Nature and Natures laws
Lay hid in night,
God said, led Newton be
And all was light!
Who said this about Sir Isaac Newton?
2. When light travels from one fixed point to another, it always follows a path which takes the least time to travel between these two points. What is this principle of optics called?
3. PVP is a synthetic polymer that resembles a viscous lubricant and is used to coat tissue and as a substitute for vitreous humor, a gel-like substance that fills the inside of the eye. What is the full form of PVP?
4. This chromosomal abnormality is caused due to the presence of three copies of chromosome 21 instead the normal two. It results in mental retardation, decrease in life expectancy and may involve heart and respiratory problems. What is this disorder called and why?
5. The number system with base 10 is called decimal system. What is the number system with base 12 called, which has some advantages over the decimal system?
6. If you were a student of carpology, what would you be studying and researching?
7. Some elements like arsenic, hydrogen, silicon and tellurium have characteristics of both metals and non-metals. What general name is given to such elements?
8. What general name is given to a device/control system, such as the autopilot of an aircraft, which automatically detects and corrects directional errors using a mechanical or radio input signal?
9. Ingenious rocks are formed by cooling of magma, the molten mass of the earth. Cooling may take place beneath the surface of the earth or on the surface of the earth. What names are given to these two types of ingenious rocks respectively?
10. Which major space event took place on April 6, 2000.
Pope; 2. Fermats principle, named after Pierre de
Fermat, a French scientist; 3. Polyvinyl pyrrolidone; 4.
Downs syndrome (also called mongolism
and trisomy 21), named after British physician John Down
who first described it. 5. Doudecimal system; 6. Fruits
and their seeds; 7. Metalloids; 8. Servomechanism; 9.
Intrusive (or plutonic) and extrusive (or volcanic); 10.
Russian spacecraft Soyuz carrying cosmonauts Sergei
Zalyotin and Alexander Kaleri docked with the ageing Mir
New products & discoveries
What more is there to be revealed on the moons surface? Plenty, say the space scientists whose imaginations are running amok at the potential the moons surface offers.
Recently, a few top scientists of the NASA Space Centre got together to visualise what the surface would look like say, half a century from now. And the results are fascinating as well as startling.
This is an artists impression of how the cratered surface of the moon will appear around the year 2030. A well established moonbase will be present, which will include research and other facilities, and be a launch base for nuclear powered rockets, which will regularly transport passengers to Mars.
The picture shows rockets and a moonbase.
The new composites, 3DPETM, developed under a project funded by the US and Israel governments, is ideally suited to many applications, from circuit boards for high-frequency communications and radar installations to coatings for human joint implants and bullet proof cars.
It is made from ultrahigh molecular weight polyethylene (UHMWPE), a form of plastic in which hundreds of thousands of atoms are strung together in very long chains. Though it has been manufactured for 15 years as a fiber, according to the researchers for the first time a novel technology has been developed to turn it into a solid composite.
This novel composite, made of a single chemical entity, offers improved performance, particularly at high frequencies required for the broad bandwidth used in high-speed communication, said Yachin Cohen, founder of PolyEitan company, a business incubator of Technion-Israel Institute of Technology, and professor of chemical engineering at the institute.
The energy density of these new fuel cells is 10 times that of conventional rechargeable batteries. At the same time, they will be significantly lighter in weight and less expensive.
The new fuel cells, each measuring about one square inch and less than one-tenth of an inch in thickness, are powered by liquid methanol (wood alcohol) and can be easily installed into numerous existing and future electronic devices. Use of the fuel cells, for example, could safely power a cellular phone for more than a month and eliminate the need for battery chargers and adapters, according to a release from Motorola company.
The new fuel cell uses a reservoir of inexpensive methanol that, when combined with the oxygen in the air, produces electricity.
from dairy waste
Developed by GroPep, an Adelaide-based company, the growth peptide substance can economically be derived from milk whey, the 90 per cent of liquid leftover when milk is made into cheese.
The company is owned jointly by Commonwealth Scientific and Industrial Research Organisation (CSIRO), the University of Adelaide, the Child Health Research Institute, the Dairy Research and Development Corporation, and staff shareholders.
GroPep has completed the first human safety trial of the growth peptide gel, involving 32 patients, afflicted with chronic leg ulcers caused by poor circulation.
The gel could be used for a wide range of medical conditions, including recovery after surgery, and could even be incorporated in band-aid type dressings to speed the healing of everyday cuts and abrasions, according to a report in Ascent Technology Magazine.