Solution to Global Warming

The proposal is to build a very large orbiting shield which will intercept sunlight before it reaches the Earth and reflect it back into space.  The shield will consist of a very thin metal foil covering a sparse matrix of ribs.  In order to minimize the cost, the materials needed for this shield will come from the Moon.  The shield will be built robotically both to save cost and because humans are not suited to working in space.  How large a shield will be necessary?  Our initial estimate is 6 percent of the cross-sectional area of the Earth.  Since the cross-sectional area of Earth is about 50 million square miles, the shield will need to be about 3 million square miles (roughly the size or area of Australia).  Since the shield will orbit the Earth, it will only intercept sunlight when it is on the sunny side of the Earth.  Thus the effect of the shield will be to reduce incident radiation from the Sun by about 3%.   How long will it take to build this shield?  Suppose that we could build one square mile in the first year of assembly.  By doubling the effort each year thereafter (through the expansion of our Lunar manufacturing facilities), we could complete the shield in about 22 years.  Including three years of startup, the entire project could be completed in 25 years.  One additional year would double the size of the shield to 6 million square miles and give a reduction of 6% in the incident sunlight (if this were deemed necessary).

      The cost of this project would be surprisingly low.   Since the very very vast majority of material would come from the Moon, that part will be FREE.  All we need to pay for is the startup facilities.  The startup facilities would consist of a large electromagnetic projectile launcher (EMPL) built on Earth and configured to throw its payloads to the Moon - as in Jules Vern's Moon gun (cost about $5 billion).  We would require just one robotic mission to the Moon to put in place the initial manufacturing capability (cost about $1 billion).  Other costs include sending additional materials to the Moon via the EMPL. These would include robots, computers, and other parts which could not be built easily on the Moon from materials found there (cost about $2 billion).  We will also require one mission to the orbital site of the shield which would put the initial assembly equipment in place (cost about $1 billion). Finally, there would be the cost of supervising the construction of the shield over 22 years (cost about $1 billion).  Thus the total cost of the Sun shield which would solve the global warming problem would be about $10 billion.   

      Of course there are several major hurdles to overcome before this shield could be built. The first question would be what latitudes would the shield cover.  Assume that we choose to build a shield which is 3000 miles wide and 1000 miles high.  We could orient this either North to South or East to West.  If it were oriented with its long side going around the Earth, it would cover about 50 degrees from East to West and about 17 degrees from North to South.  This could be from 8.5 degrees South to 8.5 degrees North on either side of the equator.  If the shield orbits Earth twice per day, then its shadow would take about 1.5 hours to pass overhead on each orbit.  If the shield were turned 90 degrees, it would cover 17 degrees from East to West and 50 degrees from North to South.  In this case it would cover from 25 degrees South latitude to 25 degrees North latitude and would pass overhead in only a half hour.  The second problem would be to put the proposal before the United Nations in an attempt to secure global approval for the shield.  We feel sure there will be plenty of people who will oppose this plan - either because they don't believe it can be accomplished or because they have some objection - such as worrying about the shield falling or because it will get in the way of astronomical telescopes.  There are even a few people who do not believe that global warming is actually happening.  However, the seriousness of global warming grows greater with each passing year and we need to do something before it is too late.

Problem solved 

      A possible problem with this shield proposal was that it would block satellite signals from satellites which orbit above it.   However, it appears that simply by punching a bunch of holes in the foil, we can eliminate this problem.  Thus the foil would look like a swiss cheese or a checkerboard.  This would allow the satellite signals to pass through with little attenuation.  Obviously this will require a somewhat larger shield area to make up for the holes - but this is not a problem either.

What is the evidence of global warming?

Carbon dioxide (a greenhouse gas) concentration increasing

• The CO2 concentration in the atmosphere has been increasing steadily for 50 years.
• First look at the CO2 concentration over 400,000 years from the Vostok ice cores
• 
• Compare this to Mauna Loa CO2 measurements over the last 50 years
•   

Methane (another greenhouse gas) buildup

• Methane trapped in frozen tundra may be a ticking time bomb. (* new 3/22/06*)  Aparently as much as 400 billion tons of methane may be trapped in the frozen tundra in the arctics.  This is about 3000 times the current methane content of the atmosphere.  Methane is more than 20 times as strong a greenhouse gas as carbon dioxide.  The warming and thawing of the tundra may start a chain reaction which could release billions of tons of methane into the atmosphere which would greatly exacerbate the global warming problem.

Surface temperature increasing

• Global average temperatures are slowly increasing
• Temperatures have risen about 0.7 deg Celsius over the last century.
•      
• Many of the hottest years on record are recent ones. The ten hottest years were:
•  2005, 1998, 2002, 2003, 2004, 2001,  1997, 1995, 1990,  1999
• Graphically you can see the trend starkly.
•     
• Temperature hit 100 in London (August 10, 2003) for the first time in recorded history.

Ocean temperatures increasing

• Recent headline:  Caribbean coral suffers record die-off.    (* 3/31/06 *)
• Costal ocean temperatures are so high that sea corals are being killed globally.
• Up to 90% of corals are dead or dying in many areas.
• It is now too late to derail or delay the disaster.
• The increase in the temperature of the oceans is providing fuel for stronger and more frequent hurricances and typhoons - like last year when we saw a record number of hurricanes in the Caribbean.   Japan also set a record for the number of typhoons to hit Japan.
• Sea levels are slowly increasing, threatening cities such as Venice, Italy
• Sea level as measured at San Francisco, California, USA.
•      

Glaciers melting

• In Montana's Glacier National Park only 27 of the 150 glaciers which existed in 1910 remain today and they will be gone in only 20 years.
• Glaciers are in retreat all over the world.
• Here is a spectacular site by Gary Braasch called " World View of Global Warming"
• He shows numerous "before" and "after" pictures of glaciers - such as the following:
•            
•  Upsala Glacier         Rhone Glacier
• Over 90% of the ice shelf north of Ellesmere Island (Canada) is gone.

Animals are dying 

• Animal ranges are changing due to changes in the local climates.
• Walruses are starving in the Bering Sea because they are adrift on ice flows in water too deep to feed.
• In Canada, polar bears are starving because Hudson's Bay is ice-free too long each year so they cannot catch enough seals to survive. Pregnant females are losing so much weight that they fail to produce enough milk for their cubs, which then suffer increased mortality. Once females fail to attain a minimum weight they won’t give birth at all, and scientists can already document a 15 percent drop in birth rates.
• Also in Canada, river temperatures are so high now that salmon are being killed on their way to their spawning grounds - thus killing off the salmon FOREVER. 
• Frogs are dying all over the world - not just a few frogs here and there but WHOLE SPECIES are dying off FAST.
• Vanishing Frogs
• Recent Amphibian Declines in Lower Central America
• Amphibious Assault

Plants effected

• Plants are germinating earlier and earlier and moving farther and farther North.
• Nearly 4 million acres of mature white spruce forest on the Kenai Peninsula (in Alaska) have been killed by a growing population of spruce bark beetles (Dendroctonus rufipennis) since about 1987.
• Louisiana (USA) is losing land at a rate of about 25 square miles per year.
• This effect has now been shown to be primarily due to subsidence of
• the land.  A new NOAA report  says that the northern part of the Gulf
• of Mexico is sinking at a rate of 60 inches per century or about 0.6 inches
• per year (whereas sealevel is only rising by 8 inches per century).  
• Worldwide there are increases in droughts and forest fires.

 The Sun is getting hotter too

• Nasa satellite data shows that Solar radiation reaching the Earth is 0.036 percent warmer than it was in 1986.
• Confirmed by a Swiss/German research team whose data shows that the sun is brighter now than 100 - 150 years ago.

 Arctic changes are the greatest

• Alaska data
• Average temperature has risen 3 degrees C (= 5.4 degrees F) in the last 30 years.
• The sea level around Alaska has risen a foot in the last century.
• The permafrost is melting - which is causing buildings to sink into the mud.
• 98% of glaciers & sea ice are melting.
• Alaska glaciers
•    Denali 1919        2004
•    Holgate 1909      2004
•    Muir 1941           2004
• Over 90% of the ice shelf north of Ellesmere Island (Canada) is gone.
• Scary pictures of the northern polar regions in 1979 & 2000 
• Polar ice has been decreasing by 1% per year since 1979.

      
                                    1979                                                                          2000

---

New picture of Polar Ice Extent in September 2007

                                     Minimum 9/16/2007                        Ice extent 9/21/2006

              You can see that the "Northwest Passage" north of Canada was open for the first time in thousands of years.  Rate of Ice Melting Shocks Warming Experts   In September of 2007, the minimum polar ice extent was 4.13 million square kilometers (1.59 million square miles) on September 16, compared to 5.32 million square kilometers (2.05 million square miles) at the minimum in 2005.  This is a drop of 23% in just two years.  At this rate the Artic will be ice-free by 2020 - not 2050 as previously supposed. 

        Master Plan

• Build a large Earth to Moon electromagnetic projectile launcher.
• Build an Energia HLLV to carry our initial manufacturing facility to the Moon.
• Send the Energia to the Moon with our equipment.
• Set up the first Lunar base and our manufacturing facilities.
• Built a large solar array on the Moon the provide power to run everything.
• Build small EMPLs on the Moon to throw manufactured parts into Earth orbit.
• Assemble Sun shield in orbit using robots.

                              

What is the mass of the shield?

• Assume the mass is 1 ounce per square yard.
• There are 1760 * 1760 = 3097600 square yards per square mile.
• The mass is then 3097600 ounces per square mile = 193600 pounds.
• The mass in Tons is 193600/2000 = 96.8 Tons per square mile. (Round to 100 T)
• Shield mass is 3,000,000 times 100 T = 300 Million Tons.
• The cost to lift it FROM EARTH at $2000 per pound would be $1200 Trillion.
• The cost to lift it from the MOON is NOTHING = NIL = FREE FREE FREE.

Is 300 Million Tons a lot?

• The mass of the shield is equivalent to about 1/16 of a cubic mile of sea water.
• One cubic mile of sea water weighs about 4.718 Billion Tons.
• Equivalently, a cube of sea water 2107 feet on a side weighs about 300 Million Tons.
• There are about 1.37 billion cubic kilometers of water in all the oceans of the world.
• The weight of all that water is about 1.40 billion billion metric tons. (1.4 x 10^21 Kg)
• The total mass of our planet is about 5.976 x 10^24 Kg.
• All Earth's water constitutes 0.0234 % of the mass of our planet.

Baby Conceived on 1989, Born Now

The latest astounding miracle of medical science has come out thanks to the efforts of a medical team in Eastern Virginia.  A human embryo first conceived in 1989 was frozen for twenty years by two parents, and then transplanted to a surrogate mother who then gave birth to it in May of this year.  To date it is the longest time a human embryo has been conceived and frozen before being born successfully.

The incredible announcement was made in a written analysis in the journal Fertility and Sterility.  As the scientists involved declared that thus far the procedure  had been successful.  And of course this isn't the first time a child has been born that had been conceived years prior, but it is certainly an unusual thing to consider for the future.

Will we eventually live in a world where people who have been frozen for several generations are finally brought into a new world?  According to fertility experts, we could even use current technology to preserve embryos for an indefinite period of time.  Some day a person conceived a century before may be brought out of isolation and born to the descendants of his biological parents.

But while the process is incredibly interesting from a purely scientific perspective, will there be challenges to introducing people from generations prior into a new environment?  While it may not have a direct impact on natural selection (or the model currently in use in our society) immediately, it could hold potential for some exciting and perhaps terrifying future innovations and projects.

Consider the Svalbard Seed Vault first created in 2008.  The project was designed so that in the event of a worldwide catastrophe, a great deal of the world's seeds would be accessible eventually and once again reseed the planet.  But what about the fauna of the planet?  Many plants depend on animals and humans in order for them to reach their potential and thrive.  Could the technology used to preserve embryos be used for access by future generations so the human race could survive as well?  Of course in theory the project would also require humans to bring back this vast underground ark.  At least currently it would.

In February of 2009, Nick Otway from New South Wales Department of Primary Industries proposed that an artificial uterus could be created to save Grey Nurse Sharks from extinction.  And with the attention the procedure received at the time, many asked the obvious question, could it ever work with humans?

So the ultimate futuristic proposal, and this is where it enters the world of mad science, could be made that a seed vault carrying hundreds or possibly thousands of embryos frozen deep within the tundras of Greenland or the Arctic could be preserved with little power and then eventually thawed and introduced into an artificial nursing system that would raise human children with a robotic system using technology not far from our current state in the future.  While the scenario is at the moment nothing more than science fiction fodder, could we one day find ourselves in a world where the human race is saved from extinction by a similar system to the seed vault in Svalbard?  Imagine the last of the human race kept alive in a ship in a bottle to be revived hundreds or possibly thousands of years after it was first conceived.  And while it may sound preposterous to those of us living in the year 2010, will those of 2050 consider it a possibility?

India will have over hundred million 3G broadband subscribers by 2015

Indian telecom market has been growing at a CAGR of approximately 30% since 1995 and still growing strong. With additions of more than 14 million subscribers per month in the pas years, the wireless subscriber base has grown to 635.51 million in present year, second only to China.However, the recently concluded 3G spectrum and BWA auction saw intense competition among the bidders resulting in a revenue inflow of Rs.1.06 trillion for the government, surpassing most estimates.

In this context, the report examines the potential for Mobile Broadband Services, its impact on the telecom industry and other allied sectors in India.

“The transformative power of mobile broadband lies in its ability to enable greater access to the internet in India. Everyone from telecom industry, Government to other industries will be able to leverage a ubiquitous platform to reach out to a wide range of customers and provide diverse products and services more effectively.”

Key highlights of the report:

1. Mobile Services: Positive Outlook- The mobile subscriber base is projected to cross 1 billion in 2014 driven by high subscriber additions in mostly rural areas.

2. More than one hundred million 3G/HSPA broadband subscribers by 2015 and growing: Given the context of non-scalable wire line infrastructure, broadband in India is expected to be delivered on a wireless platform. Mobile broadband using technologies in the BWA spectrum band, such as TDD LTE, are expected to address enterprises and high net worth individuals; while broadband volumes are likely to be driven on the mobile platform leveraging 3G and HSPA technology.

3G subscriber numbers are projected to cross 107 Mn by 2015. Initially, the uptake of mobile broadband services will almost exclusively be in urban India; however by 2015 rural subscribers are likely to comprise 24 percent of overall 3G subscriber base in 2015.

Introduction of new innovative applications, enhanced user experience, decreasing prices of 3G/HSPA enabled handsets would be key driver for mobile broadband in India.

3 Mobile broadband will be a catalyst for changing business dynamics: In terms of service offerings, currently content is largely restricted to film based entertainment and cricket. High speed access will enable content developers and aggregators to generate additional revenue by offering diverse interactive content including local language content.
Content owners will move beyond operator portals and onto direct services via internet. This will also see advertising driven models, offering benefits to the users, with advertisers partly footing the bill. This will also reflect in increased bargaining power of content developers and aggregators vis-à-vis operators.

New partnerships will emerge; handset vendors will be partnering with content owners and aggregators to embed various applications in their devices to create product differentiation. In addition, mobile operators will be using content /application brands to launch new services.

4 Cascading impact of mobile broadband services: Mobile broadband services will generate incremental revenue of Rs.940 Ban in 2015 Ban for telecom industry as a whole.

5 Financial Services, Media & Entertainment, Agriculture and other allied sectors to benefit from mobile broadband: Financial services sector could effectively leverage the platform to reach out to a large base of unbanked customers across India.

In agriculture, mobile broadband would play a role in integrating rural India with rest of the country and help widen markets, create better information flows, lower transaction costs.

Novel X-ray machine is unveiled

Scientists have demonstrated a refined X-ray technique which can spot tiny variations in bone structures.

The technique uses X-rays delivered by powerful light sources and complex computer algorithms to resolve structural variations as small as 100 nanome

tres across.

Using the technique, the researchers have mapped in detail a bone fragment narrower than a human hair.

Synchrotron scale

Hospital X-ray machines work by passing an X-ray pulse through a body onto radiographic film.

The X-rays pass through softer tissue but are mostly absorbed by hard bone - leaving an image in which the skeleton and tissue are clearly distinguishable.

In recent years, scientists have been scaling up the power of the X-ray, using massive particle accelerators or synchrotrons to deliver much larger radiation doses.

While these cannot be used on humans for obvious reasons, they can be used in research work to reveal details in materials which are too thick for use in electron microscopes.

But X-ray imaging has its own problems, with X-rays difficult to focus or manipulate even with corrective lenses.

What Martin Dierolf and a team of scientists based in Germany and Switzerland have done is to refine these X-ray techniques.

Instead of relying on how X-rays are absorbed by different materials, they have instead focused on how they are diverted or refracted as they pass through different substances. This "phase contrast" signal gives much clearer and detailed results.

They also abandoned using any corrective lenses, firing the X-ray pulse through a pinhole and then collecting the diffracted rays after they pass through the sample.

They then used a powerful computer programme to rebuild a 3D image of the object scanned by rewinding the passage of the X-rays.

"It's like reconstructing a broken cup by playing the movie backwards and by doing that you bring all the X-rays into the sample to see how they've reacted," says Professor Henry Chapman of the University if Hamburg, who reviewed the study.

The sample is scanned with an X-ray beam and a 3D image is constructed by computer

The prototype was tested at the Swiss Light Source synchrotron near Zurich, using a mouse femur fragment narrower than a human hair.

The images obtained show detail down to the cavities in which osteocytes or bone cells reside, and the interconnective channels which are only some 100 nanometers in diameter.

A nanometre is a billionth of a metre.

Pierre Thibault of the Technical University of Munich, who is a member of the research team, says the likely applications are in medical research.

"Our method doesn't scale easily to hospitals and I'm not sure that's what we're aiming at anyway.

"It would be more for pre-clinical studies that are looking for instance at the onset of osteoporosis at the nano scale to see what happens at the scale of the bone cells. That's something we're going to look at in the next few months."

He says there could also be applications in engineering.

"You can look at alloys, how at this scale two different metals combine together because you have such a good sensitivity to different densities you can differentiate the two metals that are in the alloy, or maybe look at fractures inside the materials and see at this scale what's happening."

India Bans Bulk SMS For 3 Days

The Ayodhya verdict has been postponed till September 28th. Rediff reports that the order has been extended till September 29th. 

Update: According to the Hindu, “For individuals, bulk SMS would be above 10 per day, while for companies it could be 100 or more.”
We’re not sure if this information is correct. I was able to send 11 SMS earlier today. We now have a copy of the DoT notification to telecom operators – download it here (pdf). There’s no mention of peer-to-peer (P2P) SMS being restricted.


Earlier: The Indian government has issued a ban on Bulk SMS and MMS services for the next 72 hours; it’s not about providing relief from SMS Spam, but about preventing a widespread panic and mob uprising given the impending verdict on the Babri Masjid land issue in Ayodhya, from the Allahabad High Court. There is fear that, given the unregulated nature of SMS and the widespread use of mobile phones in India, panic could be spread.
However, they haven’t taken into account two factors:


– SMS’ can be viral: messages have, in the past, spread from person to person across the country. It isn’t necessary that such SMS are always sent out as Bulk SMS from telecom service provider (which, incidentally, would make it easier to identify the source of the messages).


– Modem Farms: you might have noticed that at times, you get SPAM SMS’ from specific mobile numbers; for example, on 21st of September, I got a message from +918087674039, for 3 Star Hotels in Goa. At times, then the throughput requirement is not very high, or if the cost of peer-to-peer SMS is lower than Bulk SMS, modem farms are set up, wherein you just buy SIM cards, put them in modems, and fire away, paying regular SMS charges.
Banning Bulk SMS can contain mass messaging (the alternatives above cost more, have lower throughput), but can’t stop it.


Press Release from the Indian Government
Bulk SMS & MMS Messages Banned for Next 72 Hours
Ministry of Communications & Information Technology has today issued orders in consultation with the Ministry of Home Affairs to all Mobile Telecom Services Providers in the country for banning all bulk SMS & all bulk MMS Messages in all service areas with immediate effect for next 72 hours.

Drugs 'could target asthma genes'

A large international study has revealed several genetic variants which are linked to people with asthma.

In all, more than 500,000 tests were performed on the genes of 10,000 children and adults with the condition, and 16,000 non-asthmatics.

The Imperial College-led research, published in the New England Journal of Medicine, could point to new targets for drugs.

Experts said gene testing could not predict who would get the condition.

One in seven children in the UK suffers from asthma, which causes the airways to become irritated and narrow, making it harder for them to breathe.

The reasons why people develop the disease are not yet fully clear, although scientists suspect a roughly equal mixture of genetic susceptibility and environmental factors.

The latest genetic variants discovered by the international research appeared in more than a third of children with asthma.

However, the gene with the strongest impact on children did not affect people who developed asthma in adulthood, suggesting that the two versions of asthma may differ biologically.

Some of the genes identified are involved in the body's system for telling the immune system about damage to the lining of the airways, while others appear to control how quickly the airways heal.

Professor William Cookson, from Imperial College London, who co-ordinated the research, said: "Asthma is a complex disease in which many different parts of the immune system can become activated.

"Our study now highlights targets for effective asthma therapies and suggests that therapies against these targets will be of use to large numbers of asthmatics in the population."

However, parents have been warned that although genes make a contribution to asthma development, there is no way to use a genetic test to predict the condition.

Leanne Metcalf, from Asthma UK, said: "This unique study helps us to understand in much more detail how the genetic side of things works.

"Importantly, it has also shown that genetic testing does not help to predict who is susceptible to developing asthma, meaning that early diagnosis and intervention, and effective treatment for everyone who is affected by asthma, are even more vital.

"However the most exciting part is that these results will now help to ensure that scientists are able to focus their research on the most influential targets for asthma, with the important long-term aim of preventing a condition which is responsible for the deaths of three people every day."

OpEn SoUrCe :: A Tech. Update.

Open source refers to a program or software in which the source code (the form of the program when a programmer writes a program in a particular programming language) is available to the general public for use and/or modification from its original design free of charge.

Open source code is typically created as a collaborative effort in which programmers improve upon the code and share the changes within the community. 

The Open Source Initiative (OSI):

Open Source is a certification standard issued by the Open Source Initiative (OSI) that indicates that the source code of a computer program is made available free of charge to the general public. OSI dictates that in order to be considered "OSI Certified" a product must meet the following criteria:

• The author or holder of the license of the source code cannot collect royalties on the distribution of the program.
• The distributed program must make the source code accessible to the user.
• The author must allow modifications and derivations of the work under the program's original name.
• No person, group or field of endeavor can be denied access to the program.
• The rights attached to the program must not depend on the program's being part of a particular software distribution.
• The licensed software cannot place restrictions on other software that is distributed with it.  

  Open source software is normally distributed with the source code under an open source license. The Open Source Initiative sets the following distribution terms that open-source software must comply with::

The Open Source Definition, as provided by the Open Source Initiative is as follows:

Introduction
Open source doesn't just mean access to the source code. The distribution terms of open-source software must comply with the following criteria:

1. Free RedistributionThe license shall not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license shall not require a royalty or other fee for such sale.

2. Source Code
The program must include source code, and must allow distribution in source code as well as compiled form. Where some form of a product is not distributed with source code, there must be a well-publicized means of obtaining the source code for no more than a reasonable reproduction cost preferably, downloading via the Internet without charge. The source code must be the preferred form in which a programmer would modify the program. Deliberately obfuscated source code is not allowed. Intermediate forms such as the output of a preprocessor or translator are not allowed.

3. Derived Works The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software.

4. Integrity of The Author's Source CodeThe license may restrict source-code from being distributed in modified form only if the license allows the distribution of "patch files" with the source code for the purpose of modifying the program at build time. The license must explicitly permit distribution of software built from modified source code. The license may require derived works to carry a different name or version number from the original software.

5. No Discrimination Against Persons or GroupsThe license must not discriminate against any person or group of persons.

6. No Discrimination Against Fields of EndeavorThe license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.

7. Distribution of License
The rights attached to the program must apply to all to whom the program is redistributed without the need for execution of an additional license by those parties.

8. License Must Not Be Specific to a Product
The rights attached to the program must not depend on the program's being part of a particular software distribution. If the program is extracted from that distribution and used or distributed within the terms of the program's license, all parties to whom the program is redistributed should have the same rights as those that are granted in conjunction with the original software distribution.

9. License Must Not Restrict Other SoftwareThe license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be open-source software.

10. License Must Be Technology-NeutralNo provision of the license may be predicated on any individual technology or style of interface. 

Free Software Licensing:

All open source software is not distributed under the same licensing agreement. Some may use a free software license, a copyleft, or GPL compatible. The GNU GPL license is a free software license and a copyleft license, while a "GNU Lesser General Public License" is a free software license, but not a strong copyleft license. There are many different types of licenses for free software . some GNU GPL compatible, some not.

The Open Source Initiative approves open source licenses after they have successfully gone through the approval process and comply with the Open Source Definition (above). There is currently well over fifty licenses that have been approved by the OSI.

For example, the GNU General Public License (GPL) is one license that accompanies some open source software that details how the software and its accompany source code can be freely copied, distributed and modified. The most widespread use of GPL is in reference to the GNU GPL, which is commonly abbreviated simply as GPL when it is understood that the term refers to the GNU GPL. One of the basic tenets of the GPL is that anyone who acquires the material must make it available to anyone else under the same licensing agreement. The GPL does not cover activities other than the copying, distributing and modifying of the source code. 

Other open source licenses include the following:

Academic Free License 3.0 (AFL 3.0)
Affero GNU Public License
Adaptive Public License
Apache Software License
Apache License, 2.0
Apple Public Source License
Artistic license
Artistic license 2.0
Attribution Assurance Licenses
New and Simplified BSD licenses
Boost Software License (BSL1.0)
Computer Associates Trusted Open Source License 1.1
Common Development and Distribution License
Common Public Attribution License 1.0 (CPAL)
Common Public License 1.0
CUA Office Public License Version 1.0
EU DataGrid Software License
Eclipse Public License
Educational Community License, Version 2.0
Eiffel Forum License
Eiffel Forum License V2.0
Entessa Public License
Fair License
Frameworx License
GNU General Public License (GPL)
GNU General Public License version 3.0 (GPLv3)
GNU Library or "Lesser" General Public License (LGPL)
GNU Library or "Lesser" General Public License version 3.0 (LGPLv3)
Historical Permission Notice and Disclaimer
IBM Public License
Intel Open Source License
ISC License
Jabber Open Source License
Lucent Public License (Plan9)
Lucent Public License Version 1.02
Microsoft Public License (Ms-PL) Microsoft Reciprocal License (Ms-RL)
MIT license
MITRE Collaborative Virtual Workspace License (CVW License)
Motosoto License
Mozilla Public License 1.0 (MPL)
Mozilla Public License 1.1 (MPL)
Multics License
NASA Open Source Agreement 1.3
NTP License
Naumen Public License
Nethack General Public License
Nokia Open Source License
Non-Profit Open Software License 3.0 (Non-Profit OSL 3.0)
OCLC Research Public License 2.0
Open Group Test Suite License
Open Software License 3.0 (OSL 3.0)
PHP License
Python license (CNRI Python License)
Python Software Foundation License
Qt Public License (QPL)
RealNetworks Public Source License V1.0
Reciprocal Public License
Reciprocal Public License 1.5 (RPL1.5)
Ricoh Source Code Public License
Simple Public License 2.0
Sleepycat License
Sun Industry Standards Source License (SISSL)
Sun Public License
Sybase Open Watcom Public License 1.0
University of Illinois/NCSA Open Source License
Vovida Software License v. 1.0
W3C License
wxWindows Library License
X.Net License
Zope Public License
zlib/libpng license 

Some Successful Open Source Projects:

 

Sendmail
Sendmail is an open source mail transfer agent (MTA) used for routing and delivery e-mail. The original version of Sendmail was written by Eric Allman in the early 1980s. It is estimated that Sendmail is installed on 60 to 80 percent of the Internet's mail-server computers.

Apache Web server
Often referred to as simply Apache, a public-domain open source Web server developed by a loosely knit group of programmers. The first version of Apache, based on the NCSA httpd Web server, was developed in 1995. Core development of the Apache Web server is performed by a group of about 20 volunteer programmers, called the Apache Group. However, because the source code is freely available, anyone can adapt the server for specific needs, and there is a large public library of Apache add-ons.

Linux
(Pronounced lee-nucks or lih-nucks). A freely distributable open source operating system that runs on a number of hardware platforms. The Linux kernel was developed mainly by Linus Torvalds. Because it's free, and because it runs on many platforms, including PCs and Macintoshes, Linux has become an extremely popular alternative to proprietary operating systems.


GNOME
Acronym for GNU Network Object Model Environment. (Pronounced guh-nome) GNOME is part of the GNU project and part of the free software, or open source, movement. GNOME is a Windows-like desktop system that works on UNIX and UNIX-like systems and is not dependent on any one window manager. The current version runs on Linux, FreeBSD, IRIX and Solaris. The main objective of GNOME is to provide a user-friendly suite of applications and an easy-to-use desktop.