Monday, June 17, 2013

What are Super-giant stars?

The most massive stars out in the space are termed as Super giants or Supergiant stars. Are you eager to know more about Supergiants? Read this article to know more about these stars.

Super-giants – the super massive stars have masses varying from 10 to 70 solar masses or even more and brightness ranging from thirty thousands to many hundreds of thousands times the solar luminosity. Their radii may vary from thirty to five hundred or as more as one thousand plus solar radii.

An original picture of red super giant from hubble space telescope (topicswhatsoever.blogspot.in)

They are of short lifespan of only ten to fifty millions years because of their extreme masses. They are observed in young cosmic structures (the spiral galaxies’ arms, open clusters and irregular galaxies etc).

Some currently known Super-giants in terms of physical size, however, not the most massive stars in terms of mass or/and luminosity are:
  • VV Cephei
  • V354 Cephei
  • KW Sagitarii
  • KY Cygni
  • The Garmet Star
  • Mu Cephei

 [Source: Wikipedia and WWW]

Red supergiant stars – Explained

Ever wondered what are Red supergiants? What gives red supergiant red color? Read it here know some facts about the massive red giant stars.

Stars become red super-giant during their helium burning phase that takes place after the hydrogen burning phase of stars of about ten solar masses or more.  They have comparatively very cool temperatures of about 3500 to 4500 K.

The red super giant stars are the largest stars in terms of physical size, and are of K-M spectral type. While these are known are the largest stars with respect to their physical size, these are not the most massive stars in the universe. They have enormous radii and a luminosity class of I.

An original picture of red super giant star from Hubble space telescope (topicswhatsoever.blogpsot.com)

An original picture of red super giant star taken from Hubble space telescope (topicswhatsoever.blogpsot.com)



Most of the red super giants have radius of 200 to 800 times the radius of our Sun.

Presently, the four largest known red super giant stars in Milky Way galaxy are:
  • Mu Cephei
  • KW Sagitarii
  • V354 Cephei
  • KY Cygni

All of these four giant stars have a radius nearly 1500 times that of the Sun and are at distance of approximately 7 times the distance between the Earth and the Sun.

Tuesday, June 11, 2013

How does Wi-Fi work – Explained

Have you ever wondered how a Wi-Fi network works? Read it here and unfold the secrets behind working for Wi-Fi.

What is Wi-Fi?

A wireless technology; which can be used to connect computers, mobile phones and other electronic devices with each-other with the help of a wireless network.
The data is encoded (translated) into radio signals by the wireless adapter of a computer, and transmits the same over an antenna. Generally, the transmitting antenna is connected to Local Area Network (LAN) or DSL connection. The signals now are received by a wireless router which decodes it again to data.

Wi-Fi hotspots- The spots or places with Wi-Fi connectivity enabled are termed as Wi-Fi hotspots. Here, one can have access to the Internet through this connection.

Wi-Fi technology is widely used in providing Internet access to employees of a company, students of a class, households etc. One of the main and simplest advantage of Wi-Fi is now we do not need to be limit to the length of wire, in fact, our comfort level and ‘go-anywhere’ ease has come into existence.

Generally, the Wi-Fi has a range of signals of about 120 ft indoors while 300 ft outside. However, ranges may vary depending on the Wi-Fi system you purchase and use. Wi-Fi networks do not panic us while setting up and also saves the expense on setting up and wire expansion.

So this was how WiFi works on a system. More information and queries are welcome in comments.

Monday, June 10, 2013

Twitter tightens security after increased cyber attacks

After a series of activities/attacks from hackers on media organizations and celebrity profiles, Twitter is increasing its security by bringing up a new login verification system. It will ensure if it is really you who is signing in, says Twitter.

In recent time, some twitter feeds were attacked by hackers and even delivered fake tweets from the accounts of various news organizations like Financial Times and The Associated Press etc. Also, some hackers got into AP's Twitter account and posted fake tweets about US President Barack Obama being seriously injured in blasts at White house.

Recently, Twitter said that it is going to implement a brand new login verification system which will surely tighten the security of Twitter accounts. It is actually a type of two-factor authentication I which the second security check will make sure if is you or an automated application or a hacker is trying to get access into your account. However, AP suspended their account on Twitter after the false tweets of bomb blasts at White House by hackers.

Twitter reported that the passwords of nearly 2,50,000 Twitter users were stolen by the hackers after a cyber attack in the month of February, 2013.

"Of course, even with this new security option turned on, it is still important for you to use a strong password and follow the rest of our advice for keeping your account secure" said Jim O'Leary, Twitter Product Security.

O'Leary said, "You will need a confirmed email address and a verified phone number. After a quick test to confirm that your phone can receive messages from Twitter, you're ready to go".

Windows 8: Windows Media Player spies on you

Do you know Windows Media Player in Windows 8 spies on you? WMP’s online privacy statement mentioned it clearly that Windows Media Player will send information about every single file, i.e. song, movie or any extension that you ever play to Microsoft. However, you may change the settings whether to share it with Microsoft or not.

While this news may affect every user in different ways, it is obvious that some users must be feeling it a hole into their privacy. You may or may not care if Microsoft is spying on your activities or not. Well, you may take a few measures if you do not want Microsoft to receive the information of what you are playing on Windows Media Player by changing your privacy settings.

It has been noted that Windows Media Player will not be retrieving artist, artwork, album art and other details of a file from the Internet in case Microsoft does not get the information of what you are playing. Below is a little though useful information about the 'Privacy tab' options:

[On Windows Media Player, Go to 'Organize' >> Click on 'Options' from the drop-down menu >> Go to 'Privacy Tab' ]
  • Display Media Information from the Internet: Selecting this option makes Windows Media Player to send information of what you are playing to Microsoft, and displays the related CD covers, song/track details etc on-screen.
  • Update Music Files by Retrieving Media Info from the Internet: It updates the information and tags of a song/file (if recognizes any), that is examined by Microsoft and hence requires a working and active internet connection.
  • Send Unique Player ID to Content Providers: Selecting this option lets other corporations from where the data is being displayed or updated to track your unique player ID and hence usage of your Windows Media Player. It is recommended to leave it deselected to escape from being tracked or noted in their databases.
  • Cookies: As an Internet browser and other programs, Windows Media Player also weaves the traces of your activity into cookies. However, cookies if enabled on Windows Media Player are nothing bad as it helps the player to keep track of your preferences in its memory.
  • History: It plays an important role is memorizing and displaying the recently played tracks (files-audio/video). If you don’t want your colleagues, co-workers, family members, friends etc to know what were you playing, then deselect all the boxes out there. (Also click the buttons- ‘Clear History’ and ‘Clear Cache’ to ensure you are successfully deleted the old history and cache as well).

By making these changes in 'Privacy' tab, you can decide to let Windows Media player spy on you or not.