Saturday, October 17, 2009

A Shield For Our Solar System: The Ribbon

The heliosphere shields the solar system from 90 percent of energetic cosmic rays — high-speed charged particles that would otherwise bombard the planets and harm life. Understanding more about the heliosphere and its ability to filter out galactic cosmic rays could be critical for assessing the safety of human space travel, Schwadron notes. The new findings may also help predict how the heliosphere varies in shape and size as it moves through the galaxy and encounters regions of space having different densities and magnetic field strengths.

The ribbon found by IBEX, recorded at energies between 200 and 6,000 electron volts, is brightest at about 1,000 electron volts and lies between about 100 and 125 astronomical units from the sun, notes David McComas of the Southwest Research Institute in San Antonio. One astronomical unit is the distance between the Earth and the sun. The atoms recorded by IBEX, which orbits Earth, took a year or two, depending on their energies, to reach the craft from the outer edge of the heliosphere.

The IBEX ribbon runs perpendicular to the direction of the galaxy’s magnetic field at the interstellar boundary, an indication that the field has a much stronger than expected influence on the sun’s environs, report Schwadron and his colleagues. One possibility is that pressure from this external magnetic field has forced particles just inside the heliosphere to bunch together into a ribbon.

Iron and Mercury Not Water on Moon

The Centaur rocket that was deliberately crashed into one of the moon’s southern craters October 9 did in fact kick up a plume, even though the plume was not initially as large as hoped.

The relatively low velocity of the Centaur rocket generated a plume that was difficult to spot — in fact impossible to see by many ground-based telescopes — and smaller than had been predicted, suggests Randy Gladstone of the Southwest Research Institute in San Antonio.

Moments after the impact, as the rocket’s mother spacecraft LCROSS got closer and closer to the crash site of its empty Centaur rocket, the raw images taken by LCROSS showed nothing but darkness.

But enhanced composite images released October 16 do show a faint plume that was not apparent in the raw images.

The enhanced images show the heat flash from the impact, the plume and the creation of a new crater inside Cabeus before LCROSS plunged to its own death 4 minutes after the Centaur, said Anthony Colaprete, LCROSS principal investigator and project scientist at the NASA Ames Research Center in Mountain View, Calif.

The new LCROSS images indicate that the crater forged by the Centaur impact is 28 meters wide. Researchers are still analyzing data taken by the craft’s visible-light and ultraviolet spectrometer to identify the plume’s composition.

In the meantime, far-ultraviolet spectra taken by another craft, the Lunar Reconnaissance Orbiter, as it flew over the impact site shows no obvious signs of water. Instead, the spectra show signs of what may be iron and mercury, says Gladstone, a mission scientist.


The motherboard's main job is to hold the computer's microprocessor chip and let everything else connect to it. Everything that runs the computer or enhances its performance is either part of the motherboard or plugs into it via a slot or port.
The shape and layout of a motherboard is called the form factor. The form factor affects where individual components go and the shape of the computer's case. There are several specific form factors that most PC motherboards use so that they can all fit in standard cases.The form factor is just one of the many standards that apply to motherboards.
Some of the other standards include:

The socket for the microprocessor determines what kind of Central Processing Unit (CPU) the motherboard uses.
The chipset is part of the motherboard's logic system and is usually made of two parts -- the northbridge and the southbridge. These two "bridges" connect the CPU to other parts of the computer.
The Basic Input/Output System (BIOS) chip controls the most basic functions of the computer and performs a self-test every time you turn it on. Some systems feature dual BIOS, which provides a backup in case one fails or in case of error during updating.
The real time clock chip is a battery-operated chip that maintains basic settings and the system time.
The slots and ports found on a motherboard include:

  • Peripheral Component Interconnect (PCI)- connections for video, sound and video capture cards, as well as network cards
  • Accelerated Graphics Port (AGP) - dedicated port for video cards.
  • Integrated Drive Electronics (IDE) - interfaces for the hard drives
  • Universal Serial Bus or FireWire - external peripherals
  • Memory slots
Some motherboards also incorporate newer technological advances:

  • Redundant Array of Independent Discs (RAID) controllers allow the computer to recognize multiple drives as one drive.
  • PCI Express is a newer protocol that acts more like a network than a bus. It can eliminate the need for other ports, including the AGP port.
  • Rather than relying on plug-in cards, some motherboards have on-board sound, networking, video or other peripheral support.

Problem with Hp Compaq nc6000

HP Compaq Model nc6000 has a major problem. It just doen't boot because it has a problem in its board just under the keyboard.when you press the keyboard and put it standstill it will boot but if you move it or move the screen it will go blank.Hp repairs but does not guarantee the repair and repaired one go on repeating the problem.
You better watch out.

Space Station Dodges Orbital Junk

The International Space Station fired its rocket engines to dodge space junk for the first time in five years on Wednesday.

According to a daily NASA status report, the European-built cargo ship Jules Verne docked at the station’s aft end fired its rocket engines in a 5-minute, 2-second maneuver to avoid the potential collision with a piece of orbital trash. The last time the station performed the so-called “Debris Avoidance Maneuver” was on May 30, 2003

Space Ribbon Dicsovery

In a discovery that took astronomers by surprise, the first full-sky map of the solar system's edge—more than 9 billion miles (15 billion kilometers) away—has revealed a bright "ribbon" of atoms called ENAs.

The solar system is surrounded by a protective "bubble" called the heliosphere.

The narrow ribbon snakes along this bubble's inner wall between Voyager 1 and 2, twin spacecraft that have been exploring the solar system's boundary since 2004 and 2007, respectively.

Voyager data, taken from specific regions within the boundary zone, had offered no hint that the ribbon existed. But from its orbit around Earth, NASA's Interstellar Boundary Explorer, or IBEX, spacecraft was able to give researchers a wider view.

IBEX team member Eric Christian, of NASA's Goddard Space Flight Center, compared the Voyager spacecraft to weather stations on Earth.

"Can you imagine trying to determine the weather of the entire Earth from two weather stations? You can't do it," Christian told reporters at a press conference this afternoon.

"IBEX is like our first weather satellite, and it gives us the full picture."

IBEX's map shows that the ribbon measures roughly two billion miles (three billion kilometers) long and several hundred thousand miles wide.

The ribbon isn't visible to people and wouldn't harm spacecraft or humans passing through it, IBEX principal investigator David McComas, of the Southwest Research Institute in Texas, told National Geographic News.

Astronomers aren't yet sure how the ribbon formed, but it's possible that the ribbon could be a result of pressure exerted on the heliosphere by our home galaxy's magnetic field.

What to Do If Your Computer Is Infected

There are a number of symptoms which indicate that your computer has been infected. If you notice "strange things" happening to your computer, namely:

  • unexpected messages or images are suddenly displayed
  • unusual sounds or music played at random
  • your CD-ROM drive mysteriously opens and closes
  • programs suddenly start on your computer
  • you receive notification from your firewall that some applications have attempted to connect to the Internet, although you did not initiate this, then it is very likely that your computer has been infected by a virus.

Additionally, there are some typical symptoms which indicate that your computer has been infected via email:

  • your friends mention that they have received messages from your address which you know you did not send
  • your mailbox contains a lot of messages without a sender's e-mail address or message header

These problems, however, may not be caused by viruses. For example, infected messages that are supposedly coming from your address can actually be sent from a different computer.

There is a range of secondary symptoms which indicate that your computer may be infected:

  • your computer freezes frequently or encounters errors
  • your computer slows down when programs are started
  • the operating system is unable to load
  • files and folders have been deleted or their content has changed
  • your hard drive is accessed too often (the light on your main unit flashes rapidly)
  • Microsoft Internet Explorer freezes or functions erratically e.g. you cannot close the application window

90% of the time the symptoms listed above indicate a hardware or software problem. Although such symptoms are unlikely to be caused by a virus, you should use your antivirus software to scan your computer fully.

What you should do if you notice symptoms of infection

If you notice that your computer is functioning erratically

  1. Don't panic! This golden rule may prevent the loss of important data stored in your computer and help you avoid unnecessary stress.
  2. Disconnect your computer from the Internet.
  3. If your computer is connected to a Local Area Network, disconnect it.
  4. If the computer cannot boot from the hard drive (error at startup), try to start the system in Safe Mode or from the Windows boot disk
  5. Before taking any action, back up all critical data to an external drive (a floppy disk, CD, flash memory, etc.).
  6. Install antivirus software if you do not have it installed.
  7. Download the latest updates for your antivirus database. If possible, do not use the infected computer to download updates, but use a friend's computer, or a computer at your office, an Internet cafe, etc. This is important because if you are connected to the Internet, a virus can send important information to third parties or may try to send itself to all email addresses in your address book. You may also be able to obtain updates for your antivirus software on CD-ROM from the software vendors or authorized dealers.
  8. Perform a full system scan.

Friday, October 16, 2009

How To Avoid Facebook Scams

It's not an exaggeration to say that online social network sites have revolutionized the Web. They're at the forefront of the Web 2.0 movement and Facebook is one of an elite few leading the charge. Every day, hundreds of people join the Web site to reconnect with old acquaintances and make new friends.

But helping people make connections with each other is just one of Facebook's qualities. Another important element is that Facebook allows application developers to create small programs called apps (short for applications) and use Facebook as a platform. In a way, Facebook is acting like an operating system -- it provides the foundation for smaller applications that tap into the social network's resources.

Arguably, the most important resource is Facebook's user base. Building an app can be time-consuming and challenging; however, Facebook's community includes millions of people, and that gives developers a built-in audience for their work. Without this audience, developers could end up working long hours, creating a program that no one sees or uses. But the nature of Facebook's community helps developers spread their work virally. Facebook members grab the application after seeing it on a friend's profile and soon thousands of people are enjoying the app.

Why do developers create apps? Some developers just want to create a fun application for people to enjoy. The app enhances the user experience on a social network. Others are building programs that are part of a marketing strategy -- they hope the application will nudge users to purchase a particular product or subscribe to a service. A few create applications that gather data in order to create targeted advertising. And some are taking advantage of the open nature of Facebook to create malicious programs or run scams in an effort to con users or cause mischief.

How can you avoid these scams? And what should you do if you fall victim to one?

Facebook apps come in dozens of varieties with hundreds of examples in each category. There are quizzes, games, tools and other apps that let you rank everything from your favorite albums to the celebrities you'd like to meet. Each of these apps requires you to install a few lines of code to your Facebook profile. From your point of view, all you have to do is click a button on a page, indicate that you accept the user agreement and install the app.

But not all apps are innocent. You should pay attention to what kind of information the app says it must be able to access to work properly. Facebook's privacy policy is built on two principles: Users should have total control over their personal information and they should be able to access the information other users wish to share [source: Facebook]. When you fill out a Facebook profile, you can include information ranging from your date of birth to your address to personal contact information. Facebook also tracks information about how you use the site. If that information remains private, you feel safe. But what if Facebook shared that information with someone you didn't know?

That was a problem with some early Facebook applications. In order to function, most applications need to access some of your information. Early apps would often access far more information than they required. That meant the developers of those apps could access a great deal of personal information about users. Facebook tried to put a stop to this and demanded that developers only request access to information that was necessary for the app to work the way it should.

Facebook points out in its privacy policy that users can choose which information remains private. But it also points out that although it provides privacy protection, no system is perfect. It's possible for developers to find ways around safeguards and access information. It's a good idea to do a little research about an app before you choose to incorporate it into your profile.

If an app tries to take you to a new page, pay attention to that page's domain name. Some
scammers are clever enough to create a mockup of of a real Fa real FFacebook page with a request for your password. If the domain name seems fishy, you shouldn't insert your our password. Pop-up messages that advise you to download or install an additional application after you've already started the process are another potential sign of malware. Installing these programs may infect your computer with a virus
Sometimes one of your friends will fall victim to a scam and you'll receive m
essages that appear to be from him or her. These messages usually ask you to visit a link included in the note. You should send a message to your friend to confirm that it's a legitimate link. It's possible your friend's profile has been compromised and the message was sent to you automatically. If the wording of the monfirm that it's a legitimate link. It's possible your friend's profile has been compromised and the message was sent to you automatically. If the wording of the message seems odd or unlike your friend's normal style, that's another indicator that something questionable is going on.
There's a special name for the way scammers manipulate victims like this: social engineering. While it's true that malicious hackers known as crackers sometimes pierce a system's security by using various software tricks and hacks, it's also common for people to willingly give up information. The scammer just has to make the victim want to share. There are a couple of common ways scammers trick people into sharing:
  • They appeal to the victim's vanity with a message that suggests the victim can be seen in a compromising or funny way at a certain Web site. The link to the Web site actually leads the victim to downloading malware.
  • They make promises of get-rich-quick schemes.
  • They tempt the victim into sharing a credit card number, then commit credit-card fraud.

Recovering from a Scam

There are a few things you can do if you're the victim of a scam. What you do depends on what the scammer has done to you.
If you've divulged your password, you should post a message to your friends to warn them that your account was compromised. This might prevent your friends from following any links that will compromise more accounts. Change your password to something hard to guess -- a string of unrelated characters is best. Avoid using the same password for multiple accounts or services -- otherwise you could leave even more of your information vulnerable. You can report the scam to Facebook through the Help Center.
Facebook provides a form for victims of phishing attacks. Phishing refers to the practice of tricking people into sharing private information like credit card numbers and social security numbers. One of the more common phishing scams is known by two names: the Nigerian scam or the 419 scam.
The basic scam goes like this: The person sending the message claims that he or she has a large sum of money that's being held up in another country. With your help, this person will be able to free up the money and will give you an enormous reward. But to get the money, the person needs some of your money first. This is just a cover story -- the person is really trying to steal your money. If you see a message like that, you should use the form provided by Facebook to make them aware of the problem.
If you're a U.S. citizen and the victim of identity theft, you should file a police report, contact your bank and alert the fraud departments of the major credit bureaus. You can report financial scams or identity theft to other agencies as well. In the United States, this includes:
  • Federal Bureau of Investigation (FBI)
  • Federal Trade Commission (FTC)
  • Internet Crime Complaint Center (IC3)
Facebook is a powerful social networking site that can help you stay in touch with friends on the other side of the world. There are lots of genuinely fun and useful applications on Facebook. With a little caution, you can enjoy the best Facebook has to offer and avoid being the victim of a scam. Just think twice before you install an app or click on a link.

What is Global Warming?

Global warming is the increase in the average temperature of the Earth's near-surface air and oceans since the mid-20th century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the last century. The Intergovernmental Panel on Climate Change (IPCC) concludes that most of the observed temperature increase since the middle of the 20th century is caused by increasing concentrations of greenhouse gases resulting from human activity such as fossil fuel burning and deforestation. The IPCC also concludes that variations in natural phenomena such as solar radiation and volcanoes produced most of the warming from pre-industrial times to 1950 and had a small cooling effect afterward. These basic conclusions have been endorsed by more than 40 scientific societies and academies of science, including all of the national academies of science of the major industrialized countries. A small number of scientists dispute the consensus view.

Climate model projections summarized in the latest IPCC report indicate that the global surface temperature will probably rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the twenty-first century.[1] The uncertainty in this estimate arises from the use of models with differing sensitivity to greenhouse gas concentrations and the use of differing estimates of future greenhouse gas emissions. Some other uncertainties include how warming and related changes will vary from region to region around the globe. Most studies focus on the period up to the year 2100. However, warming is expected to continue beyond 2100 even if emissions stop, because of the large heat capacity of the oceans and the long lifetime of carbon dioxide in the atmosphere.

An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, probably including expansion of subtropical deserts. The continuing retreat of glaciers, permafrost and sea ice is expected, with warming being strongest in the Arctic. Other likely effects include increases in the intensity of extreme weather events, species extinctions, and changes in agricultural yields.

Political and public debate continues regarding climate change, and what actions (if any) to take in response. The available options are mitigation to reduce further emissions; adaptation to reduce the damage caused by warming; and, more speculatively, geoengineering to reverse global warming. Most national governments have signed and ratified the Kyoto Protocol aimed at reducing greenhouse gas emissions.

Black hole

In general relativity, a black hole is a region of space in which the gravitational field is so powerful that nothing, not even light, can escape. The black hole has a one-way surface, called an event horizon, into which objects can fall, but out of which nothing can come. It is called "black" because it absorbs all the light that hits it, reflecting nothing, just like a perfect black-body in thermodynamics.[1] Quantum analysis of black holes shows them to possess a temperature and Hawking radiation.

Despite its invisible interior, a black hole can reveal its presence through interaction with other matter. A black hole can be inferred by tracking the movement of a group of stars that orbit a region in space which looks empty. Alternatively, one can see gas falling into a relatively small black hole, from a companion star. This gas spirals inward, heating up to very high temperatures and emitting large amounts of radiation that can be detected from earthbound and earth-orbiting telescopes. Such observations have resulted in the scientific consensus that, barring a breakdown in our understanding of nature, black holes exist in our universe.