Microsoft Exchange Alternatives – Empower your Organization With Intranet Solutions

An intranet solution that truly works need not be expensive. Recently, an intranet solution, which is fast becoming a “household name” as a Microsoft exchange alternative has proven it can deliver the same functionality of a high-end solution to its clientele composed mainly of small and medium-sized businesses – at a much lower price. Requiring no setup fee and no IT expertise to run the application, it is truly a breakthrough in online collaboration and communication.

How important is an intranet solution to an organization?

Intranet solutions have become indispensable tools in the online management of a business, formerly constrained by distance and time. A business that stations employees overseas, or hires offshore employees for certain projects can identify with the difficulties of running a business hampered by limitations to communicate, inform and collaborate – the safest and fastest way. As projects are usually time-bound, collaboration becomes not just necessary, but a crucial tool.

It promotes productive results. An effective company intranet allows its user-employees, anywhere in the world, to access information that the company has decided to share among them, with the end-view of helping them perform their functions more efficiently, and deliver productive results.

It saves time, encourages efficiency. A suitable company intranet provides a online file storage that saves and secures data and other relevant information, which the company may allow access whenever the authorized employee needs them. This saves time and promotes efficiency, as it makes certain that useful information is available as soon as it is needed.

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Experience the difference an ASP intranet solution can do for your business. Leading providers allow hosted solutions 30 days Free trial. Try one today!

With a company intranet that has powerful features, at user-friendly price, small or medium-sized business has finally found an ally.

Source by: Christiene Villanueva
iphone 7

Wi-Fi Mobile Phones: Data access, Internet, everything without wires

In mobile world, introduction of Wi-Fi is a significant achievement. The mobile technology has evolved significantly. Through last decade, mobile technology went through revolutionary phase. Mobile phones get equipped with touch-screens, music players, camera and videos etc. One such important advancement is Wi-Fi feature. There are many great changes observed in the design, features and performance of handsets. Presence of Wi-Fi feature increases the market value of WiFi enabled handsets.

Wi-Fi Mobile Phones work over the popular wireless technology which is used in video games, PC, mp3 player and home networks. Wi-Fi handsets use radio waves to offer high speed Internet and network without using any wire. PDA’s are also Wi-Fi enabled and can be connected to the Internet anytime within the range of the WiFi or WLAN. PDA users can check out urgent emails, if they are traveling to a distant place. Wi-Fi makes picture and video sharing easy. Wi-Fi mobile phones have their own network. Wi-Fi enabled handsets llow high speed data transfer from anywhere but within the range of local hotspot. A person can exchange data even at a range of 300 feet away from local WLAN.

Wi-Fi network cuts down the cost of cables by setting up wireless LAN connections. LAN wireless connections are highly useful in places where one cannot install or expand the network like outdoor places and historical monuments.  

There is difference between connectivity through Bluetooth and via Wi-Fi. Bluetooth has very short range and so it can only work in a small area like a room and one cannot transfer data beyond that area whereas Wi-Fi handsets can transfer data from one floor of an apartment to another floor. The Bluetooth transfer speed is very slow around 800kbps whereas Wi-Fi transmission speed is around  54Mbps which is much faster. Hence, Wi-Fi handsets transfer data at a much better speed than Bluetooth enabled devices.

Some popular Wi-Fi handsets are Nokia N97, Nokia N86, Nokia 6700 Slide, Blackberry Bold 9700, Blackberry 8520 Curve, Sony Ericsson Xperia X10, Sony Ericsson Vivaz, Samsung Galaxy S, Samsung Jet etc.

Source by: Barry

Instagram introduces automatic blocking of offensive comments

Instagram isn’t as infamous for its toxic user base as other social media services are (looking at you, Twitter), but just like pretty much every online community out there, there exists a specific subset of its users that take advantage of the relative anonymity to abuse others. To combat this problem, Instagram has just launched a new feature: automatic blocking of offensive comments.

The filter will work both in posts and live video, and will block comments it finds abusive or offensive. Together with it, a new spam filter is also being introduced, and both of them will be …

BLU readying another affordable smartphone with 3,000 mAh battery

It looks like a BLU R1 HD sequel is now in the works and will probably be officially introduced in the coming weeks. Few details about its specs are available at the moment, but at least we have several pictures showing the smartphone from all angles.

BLU R2 has been recently listed at FCC (Federal Communications Commissions), so it will probably not be long until the smartphone gets revealed. The documents filed at FCC confirm the R2 will be powered by a 3,000 mAh battery.

Also, the affordable smartphone will sport a 5-inch display and a rear-mounted fingerprint sensor. The …

Amazon announces its 2017 Prime Day shopping event – 30 hours of deals in 13 countries

The previous two Prime Days have been a runaway success for Amazon, so the e-tail juggernaut just announced the third. Prime Day is quickly becoming one of the biggest shopping events of the year, and the upcoming one will be very soon, on Tuesday, July 11, with hundreds of thousands of deals exclusively for members of Amazon’s Prime club, wherever they might reside.

What’s cracking? Well, for the first time those with a Prime account will be able to access no less than 30 hours of deal shopping, starting at 6pm PT/9pm ET on Monday, July 10. The deals will …

Huawei Mate 10 could feature a powerful Kirin 970 chipset built on 10nm technology

The upcoming Huawei Mate 10 could shape up to be one beastly device. A recent post from an industry analyst on Chinese website Weibo indicates that the high-end handset could be the first to feature Huawei’s in-house Kirin 970 chip that will be built on a 10nm process.

For comparison, the Kirin 960 found on the Huawei P10 uses a 16nm manufacturing technology. Generally speaking, a smaller semiconductor size translates to greater power efficiency and performance, which suggests that the Chinese manufacturer could make a sizable technological …

These were the best phones… before the iPhone

At the 10-year anniversary of the launch of Apple’s original iPhone, we take a walk down memory lane to see the best phones that people could buy right before the iPhone came… and changed the landscape completely. 

From the devices with a full QWERTY keyboard to the best Nokias and the devices coming from the fruitful partnership between Sony and Ericsson, these phones seemed in one or other way superior to the iPhone, at least on paper. Some had a 3G connection, others claimed to be better for work, yet others shipped with superior cameras. And …

Camera apps: do you use your stock one or do you download a 3rd party one?

Nowadays, most mid- to top-tier phones have pretty elaborate camera apps. They can feature filters, manual settings, and various shooting modes among any unique goodies the manufacturers may have thought of. And that’s definitely a welcome thing — smartphone cameras have been getting better and better and some manual tweaks can go a long way to get that perfect scene.

But there’s also a plethora of 3rd party apps out there, many of which bring their own stuff to the table. Be it a super-handy interface or focus peaking, or even a 24 FPS mode for more cinematic-looking videos. …

How to Unlock the iPhone 5 for Other Carriers

Owning an iPhone is by itself a status statement, but the experience is way different from one person to another—thanks to lousy carriers. With the upcoming release of the iPhone 5, it is again another horror story to be locked up by exclusive distributors with bad services—giants in the communications industry who do not really give a flying fig about their customers. So what do you do? The solution sounds simple: unlock the iPhone 5 for other carriers.

What is Jailbreaking?
Since Apple placed limitations on its devices, technicians from around the world had to develop a way to override these limitations. The process of removing these limitations is called jailbreaking. It is done through hacking the root system of the iPhone so people can download applications and use the phone for other carriers.

This, however, requires software for each iPhone release. An unlocking program will not be available until after the model is released because hackers have to study its programming system. With this said, we just have to wait a few weeks for them to come up with a new software that has the capability to unlock the iPhone 5 for other carriers.

How Do You Unlock iPhone 5?
As with the previous versions, the system or process to unlock iPhone 5 for other carriers will be same. A convenient way to do this is perform a GSM unlock. To do this, you first need to install an application called Unlock.App. Other programs that you can download and install are Lockdownd, and CyberDuck.

Once downloaded and installed, browse your unit to the General Settings and look for Auto-Lock. Set this to Never and get your IP address. You can get this address by going to Settings, WiFI, and then tap Network. Write the IP address on a piece of paper and set aside.

Go back to the home screen and launch the downloaded application. Tap the Open Connection button, select SFTP under the Secure File Transfer and then type the IP address that you just copied. For username, type “root,” all in lower case. For the password box, type the word “dottie,” also all in lower case.

You will then get connected, after which you have to choose the “/item” then find “/user/libexec.” Once there, drag the file called “lockdownd” into it. Tap continue. Turn off your phone then remove the SIM card. Turn the phone on again and select the application called “Unlock.” This should tell you that “All files are ready.” Press Start and all files will begin installing. Once the installation is complete, you can now use to the iPhone with other SIM!

In the United States, it is legal to unlock the iPhone 5 for other carriers. It is also legal to jailbreak iPhones because the laws that govern locking of phones only apply to copyright issues. Unlocking one does not violate a copyright of an artist and besides, limiting a person’s capability to choose what applications to download and what carrier to use is just plain bad business ethics.

Source by: Jared D. Ingram

Neutrino- a Nobel discovery in Astrophysics

An ingenious way of measuring low mass and neutral neutrinos may allow astronomers to obtain information of the core of Galaxy’s evolution. Current methods for measuring the neutrinos rely on to detect the conditions at the core of the Sun as well as to use for probing astrophysical sources beyond our solar system. Because they are the only known particles those are not significantly attenuated by their travel through the interstellar medium.  

Neutrino is an electrically neutral, weakly interacting elementary subatomic particle with half-integer spin. The neutrino (meaning “small neutral one” in Italian) is denoted by the Greek letter ν (nu). All evidence suggests that neutrinos have mass but that their mass is tiny even by the standards of subatomic particles. Their mass has never been measured accurately. Neutrinos do not carry electric charge, which means that they are not affected by the electromagnetic forces that act on charged particles such as electrons and protons. Neutrinos are affected only by the weak sub-atomic force, of much shorter range than electromagnetism, and gravity, which is relatively weak on the subatomic scale. They are therefore able to travel great distances through matter without being affected by it (1).

Neutrinos are created as a result of certain types of radioactive decay, or nuclear reactions such as those that take place in the Sun, in nuclear reactors, or when cosmic rays hit atoms. There are three types, or “flavors”, of neutrinos: electron neutrinos, muon neutrinos and tau neutrinos. Each type is associated with an antiparticle, called an “antineutrino”, which also has neutral electric charge and half-integer spin. Whether or not the neutrino and its corresponding antineutrino are identical particles has not yet been resolved, even though the antineutrino has an opposite chirality to the neutrino. Most neutrinos passing through the Earth emanate from the Sun. About 65 billion (6.5 ×1010) solar neutrinos per second pass through every square centimeter perpendicular to the direction of the Sun in the region of the Earth (1).

Antineutrinos are the antiparticles of neutrinos, which are neutral particles produced in nuclear beta decay. These are emitted in beta particle emissions, where a neutron turns into a proton. They have a spin of ½, and are part of the lepton family of particles. The antineutrinos observed so far all have right-handed helicity (i.e. only one of the two possible spin states has ever been seen), while the neutrinos are left-handed. Antineutrinos, like neutrinos, interact with other matter only through the gravitational and weak forces, making them very difficult to detect experimentally. Neutrino oscillation experiments indicate that antineutrinos have mass, but beta decay experiments constrain that mass to be very small. A neutrino antineutrino interaction has been suggested in attempts to form a composite photon with the neutrino theory of light. Because antineutrinos and neutrinos are neutral particles it is possible that they are actually the same particle. Particles which have this property are known as Majorana particles. If neutrinos are indeed Majorana particles then the neutrino less double beta decay process is allowed. Several experiments have been proposed to search for this process. Researchers around the world have begun to investigate the possibility of using antineutrinos for reactor monitoring in the context of preventing the proliferation of nuclear weapons. Antineutrinos were first detected as a result of their interaction with protons in a large tank of water. This was installed next to a nuclear reactor as a controllable source of the antineutrinos (1).

The first use of a hydrogen bubble chamber is used to detect neutrinos, on November 13, 1970. A neutrino hit a proton in a hydrogen atom. The collision occurred at the point where three tracks. But they –or more precisely an antimatter variant called electron antineutrinos are also spewed out in vast numbers by chains of radioactive decays originating with uranium and thorium nuclei, in rocks far down in Earth’s interior(2).  In the solar nebula, smaller amount of silicon, uranium, thorium etc were present and they would have condensed out in different amounts at different temperature. If we knew how much uranium and thorium went into making Earth, we would know what these conditions were and could extrapolate how much of everything else we would expect to find inside (2).

A practical method for investigating neutrino oscillations was first suggested by Bruno Pontecorvo in

1957 using an analogy with kaon oscillations; over the subsequent 10 years he developed the mathematical formalism and the modern formulation of vacuum oscillations. In 1985 Stanislav Mikheyev and Alexei Smirnov (expanding on 1978 work by Lincoln Wolfenstein) noted that flavor oscillations can be modified when neutrinos propagate through matter. This so-called Mikheyev– Smirnov–Wolfenstein effect (MSW effect) is important to understand because many neutrinos emitted by fusion in the Sun pass through the dense matter in the solar core (where essentially all solar fusion takes place) on their way to detectors on Earth (1).

Neutrinos traveling through matter, in general, undergo a process analogous to light traveling through a transparent material. This process is not directly observable because it doesn’t produce ionizing radiation, but gives rise to the MSW effect. Only a small fraction of the neutrino’s energy is transferred to the material (1).

Neutrinos cannot be detected directly, because they do not ionize the materials they are passing through (they do not carry electric charge and other proposed effects, like the MSW effect, do not produce traceable radiation). A unique reaction to identify antineutrinos, sometimes referred to as inverse beta decay, as applied by Reines and Cowan (1950), requires a very large detector in order to detect a significant number of neutrinos. All detection methods require the neutrinos to carry the minimum threshold energy. So far, there is no detection method for low energy neutrinos, in the sense that potential neutrino interactions (for example by the MSW effect) cannot be uniquely distinguished from other causes. Neutrino detectors are often built underground in order to isolate the detector from cosmic rays and other background radiation (1).

Antineutrinos were first detected in the 1950s near a nuclear reactor. Reines and Cowan used two targets containing a solution of cadmium chloride in water. Two scintillation detectors were placed next to the cadmium targets. Antineutrinos with an energy above the threshold of 1.8 MeV caused charged current interactions with the protons in the water, producing positrons and neutrons. This is very much like β + decay, where energy is used to convert a proton into a neutron, a positron (e) and an electron neutrino (ν) is emitted:

From known β decay:

Energy + p → n + e + ν (1).

In the Cowan and Reines experiment, instead of an outgoing neutrino, we have an incoming antineutrino (ν) from a nuclear reactor:

Energy (>1.8 MeV) + p + ν → n + e (1).

The resulting positron annihilation with electrons in the detector material created photons with an energy of about 0.5 MeV. Pairs of photons in coincidence could be detected by the two scintillation detectors above and below the target. The neutrons were captured by cadmium nuclei resulting in gamma rays of about 8 MeV that were detected a few microseconds after the photons from a positron annihilation event. Since then, various detection methods have been used. Super Kamiokande is a large volume of water surrounded by photomultiplier

Tubes that watch for the Cherenkov radiation emitted when an incoming neutrino creates an electron or muon in the water (1).

Fortunately, scientists have spent the past decade developing that. The Kamioka Liquid-Scintillator Antineutrino Detector (KamLAND), which came into service near the central Japanese city of Hida in 2002, the better to shield it from cosmic-ray muons, whose signals mimic those of neutrinos (2).

The Super-Kamiokande detector is a 50,000 ton tank of water, located approximately 1 km underground. The water in the tank acts as both the target for neutrinos, and the detecting medium for the by-products of neutrino interactions. The inside surface of the tank is lined with 11,146 50-cm diameter light collectors called “photo-multiplier tubes”. In addition to the inner detector, which is used for physics studies, an additional layer of water called the outer detector is also instrumented light sensors to detect any charged particles entering the central volume, and to shield it by absorbing any neutrons produced in the nearby rock. In addition to the light collectors and water, a forest of electronics, computers, calibration devices, and water purification equipment is installed in or near the detector cavity (3).

Super-Kamiokande Cherenkov RadiationTo detect the high-energy particles which result from neutrino interactions, Super-Kamiokande exploits a phenomenon known as Super-Kamiokande Cherenkov radiation. Charged particles (and only charged Particles) traversing the water with a velocity greater than 75% of the speed of light radiate light in a conical pattern around the direction of the track. Bluish Cherenkov light is transmitted through the highly-pure water of the tank, and eventually falls on the inner wall of the detector, which is covered with photo-multiplier tubes (PMT’s). These PMT’s are each sensitive to illumination by a single photon of light – a light level approximately the same as the light visible on Earth from a candle at the distance of the moon! (3).

Fig: Super-Kamiokande Cherenkov Radiation(3)

Each PMT measures the total amount of light reaching it, as well as the time of arrival. These measurements are used to reconstruct energy and starting position, respectively, of any particles passing through the water. Equally important, the array of over 11,000 PMTs samples the projection of the distinctive ring pattern, which can be used to determine the direction of a particle. Finally, the details of the ring pattern – most notably whether it has the sharp edges characteristic of a muon, or the fuzzy, blurred edges characteristic of an electron, can be used to reliably distinguish muon-neutrino and electron-neutrino interactions (3).

In 2005, KamLAND saw the first, faint signal of electron antineutrinos from Earth’s bowels, but it was drowned in a din of antineutrinos produced by nearby nuclear power plants. In 2007, a detector upgrade and the temporary shutdown of one of the largest plants allowed the signal to shine through. By the end of 2009, KamLAND had recorded 106 electron antineutrinos with the right energy to come from decays of uranium and thorium within Earth (2).

The Sudbury Neutrino Observatory is similar, but uses heavy water as the detecting medium, which uses the same effects, but also allows the additional reaction any-flavor neutrino photo-dissociation of deuterium, resulting in a free neutron which is then detected from gamma radiation after chlorine-capture(1).

Meanwhile, the Borexino experiment was also getting glimpses. Situated at the GranSasso National Laboratory in central Italy, this smaller detector was built to pick up neutrinos from nuclear processes in the sun.  Combining data from the two experiments was enough to produce the first concrete geophysical predictions from geo-neutrinos alone: that the decay of uranium and thorium in mantle and crust contributes about 20 terawatts (TW) to the heat escaping from Earth’s interior (2). The Borexino experiment at the Gran Sasso National Laboratory in Italy has put an upper limit on such neutrinos from a natural reactor in the Earth’s core, attributing at most a comparatively measly 3 terawatts of surface heat to such processes (2).

These are the sorts of numbers we need if we are to start outlining what lies beneath. Each radiates about 46 TW of heat through its surface, from two sources: “radiogenic” heat produced in radioactive decays, and “primordial” heat stored up during Earth’s formation as particles collided and iron sank to the core. Establishing how much surface heat comes from each sources has wide ramifications for our of Earth. For example, if material in the mantle is converting slowly, or in layers with limited heat transfer between them, little primordial heat will be transported from Earth’s innards to its surface. If so, the lion’s share of Earth’s heat flux -30 TW or more- must be of radiogenic origin. The neutrino experiments suggest the true figure is lower, implying that the mantle is mixing relatively thoroughly (2).

Other detectors have consisted of large volumes of chlorine or gallium which are periodically checked for excesses of argon or germanium, respectively, which are created by electron-neutrinos interacting with the original substance. MINOS uses a solid plastic scintillator coupled to photomultiplier tubes, while Borexino uses a liquid pseudocumene scintillator also watched by photomultiplier tubes and the proposed NOVA detector will use liquid scintillator watched by avalanche photodiodes. The Ice Cube Neutrino Observatory uses 1 km3 of the Antarctic ice sheet near the South Pole with photomultiplier tubes distributed throughout the volume (1).

Geoneutrino hunting takes skill and a lot of patience (2). Geophysicists thought that there was enough uranium in the core of Earth to make it a giant nuclear fission reactor. But simulations done by William  McDonough, Huang’s supervisor and his colleagues show that at the high temperatures and pressures found in the magma oceans that filled early Earth, uranium almost exclusively prefers the company of elements found in mantle-like rocks to the iron and nickel of the core. Nuclear fission also produces neutrinos that are higher in energy than those produced by the radioactive decay of uranium and thorium (2).

The third detector, due to switch on in 2013, could make a decisive difference. This is SNO+, situated deep underground at the Sudbury Neutrino Observatory in Ontario, Canada. It is about the same size as KamLAND, but because it is less than 2 kilometres of rock, it will be better protected from cosmic ray moons. And, says McDonough , “it is not surrounded by a thousand neutrino flashlights”: there are far fewer nuclear reactors in Ontario than Japan. With lower background counts, SNO+ should observe geoneutrinos by the bucketful- by neutrino standards, anyway. “It will probably get 25 geoneutrinos per year,” says Dye. Over a few years, that might be enough to shrink the error on the radiogenic heat measurement and start building some certainties (2).

An ambitious project proposed by John Learned of the University of Hawaii at Manoa, supported by Dye and McDonough, would help settle such questions. The Hawaiian Antineutrino observatory, or Hanohano, is a detector designed to be taken out on a barge and dropped down to the ocean floor. The water overhead would protect the detector from confounding cosmic-ray muons. What’s more, the ocean floor has the thinnest crust, with a uranium content 10 times less than that of the continental crust. A detector there will essentially see a pure mantle signal (2).

Neutrinos are part of the natural background radiation. In particular, the decay chains of U and Th Isotopes, as well as K, include beta decays which emit antineutrinos. These so-called geoneutrinos can provide valuable information on the Earth’s interior. A first indication for geoneutrinos was found by the KamLAND experiment in 2005.  KamLAND’s main background in the geoneutrino measurement are the antineutrinos coming from reactors. Several future experiments aim at improving the geoneutrino measurement and these will necessarily have to be far away from reactors (1).

According to Einstein’s 1905 special theory of relativity, nothing is meant to be able to go faster than the speed of light — 186,282 miles per second (299,792 kilometers per second). But the researchers said in September that their neutrinos traveled the distance from Geneva to Gran Sasso 60 nanoseconds faster, when the margin of error in their experiment allowed for just 10 nanoseconds. A nanosecond is one-billionth of a second (4).

The European Organization for Nuclear Research said more precise testing has now confirmed the accuracy of at least one part of the experiment. “One key test was to repeat the measurement with very short beam pulses,” the Geneva-based organization, known by its French acronym CERN, said in a statement. The test allowed scientists to check if the starting time for the neutrinos was being measured correctly before they were fired 454 miles (730 kilometers) underground from Geneva to a lab in Italy. The results matched those from the previous test, “ruling out one potential source of systematic error,” said CERN. Still, scientists stressed that only independent measurements by labs elsewhere would allow them to declare that the results of their experiment were a genuine finding. “A measurement so delicate and carrying a profound implication on physics requires an extraordinary level of scrutiny,” said Fernando Ferroni, president of Italian Institute for Nuclear Physics. “The positive outcome of the test makes us more confident in the result, although a final word can only be said by analogous measurements performed elsewhere in the world” (4).

The chances have risen that Einstein was wrong about a fundamental law of the universe. Scientists at the world’s biggest physics lab said Friday they have ruled out one possible error that could have distorted their startling measurements that appeared to show particles traveling faster than light. Many physicists reacted with skepticism in September when measurements by French and Italian researchers seemed to show subatomic neutrino particles breaking what Nobel Prize-winning physicist Albert Einstein considered the ultimate speed barrier. The European Organization for Nuclear Research said more precise testing has now confirmed the accuracy of at least one part of the experiment(4).

While the Standard Model, which very accurately describes the interactions of elementary particles will most definitely nothave to be rewritten, there will be less dramatic effects. The question of how particles acquire mass is one of the deepest unsolved mysteries of elementary particle physics. Neutrinos had been thought to be the only fundamental constituent of nature which did not have a mass. In light of this discovery, that long-standing belief will have to be revised.

However, the Standard Model itself does not “predict” one way or another whether neutrinos have mass – this one of the many parameters of the model which must be input by hand. This is in fact one of the universally recognized shortcomings of the Standard Model, and why most physicists doubt it is the complete, final theory. A truly complete theory would predict the masses of the elementary particles rather than requiring them as inputs.

The effects of the very small neutrino mass implied by the Super-Kamiokande result will probably be minimal in terms of affecting the quantitative predictions of the Standard Model. More promising is the prospect that knowledge of the existence of neutrino masses, and an estimate of their magnitude, will shed light on the larger question of how the particles have the mass that they do. With the discovery of neutrino mass, it now appears that mass is a property common to all matter – in itself a highly significant discovery (4).

Astrophysicists are very much interested to use the neutrinos as a probe to detect the core of Earth, environments that other radiation such as light or radio waves which cannot penetrate easily.

Using neutrinos as a probe was first proposed early in the 20th century as a way to detect conditions at the core of the Sun. The solar core cannot be imaged directly because electromagnetic radiation (such as light) is diffused by the great amount and density of matter surrounding the core. On the other hand, neutrinos pass through the Sun with few interactions. Whereas photons emitted from the solar core may require 40,000 years to diffuse to the outer layers of the Sun, neutrinos generated in stellar fusion reactions at the core cross this distance practically unimpeded at nearly the speed of light. Neutrinos are also useful for probing astrophysical sources beyond our solar system because they are the only known particles that are not significantly attenuated by their travel through the interstellar medium. Optical photons can be obscured or diffused by dust, gas, and background radiation. High-energy cosmic rays, in the form of swift protons and atomic nuclei, are unable to travel more than about 100 megaparsecs due to the Greisen–Zatsepin–Kuzmin limit (GZK cutoff). Neutrinos, in contrast, can travel even greater distances barely attenuated. The galactic core of the Milky Way is fully obscured by dense gas and numerous bright objects. Neutrinos produced in the galactic core should be measurable by Earth-based neutrino telescopes in the next decade (1).

Another important use of the neutrino is in the observation of supernovae, the explosions that end the lives of highly massive stars. The core collapse phase of a supernova is an extremely dense and energetic event. It is so dense that no known particles are able to escape the advancing core front except for neutrinos. Consequently, supernovae are known to release approximately 99% of their radiant energy in a short (10-second) burst of neutrinos. These neutrinos are a very useful probe for core collapse studies. The rest mass of the neutrino is an important test of cosmological and astrophysical theories (1).

Ongoing and future large scale survey of neutrinos from different sources may provide a valuable tool for exploring this anticipated wealth of information.


  2. Ananthaswamy. A. NewScientist, 28 April 2012, pp 33-35.

Source by: Dr. Manisha Majumdar (De)