sciencecapsules

           Do you know, our house bulbs are switched on-off 100 times in one second?  The reason is AC.  Let us explore.      Take a cell in a remote device.  It supplies a steady 1.5 volt.  Here current flows in only one direction.  That is, the negative electrons flow from negative to positive.  And the conventional current said to flow from positive to negative.  This is what is called direct current or DC.  All chemical batteries, cells supply DC.  And all the electronic devices will only function using DC.          Producing DC is still a costly affair.  Faraday gave us a 'method' (AC) to produce electricity cheaply and easily.       The method:  " If there is relative motion between a coil of wire and a magnetic field, the electric volt is generated in the coil."      If a coil is rotated within a magnetic field or magnet rotates within the coil, an electric current start to flow in the coil.  The rotations can be done by a wind flow, rush of wat

                Dubai has impressive  skyline  with many skyscrapers .  How to add one more building that will stand out.  Hence a design competi tion  was  held .  A building de sign  was sel ected .  It is just a picture frame.  It  owns  an award.  The idea  is:  It will frame the landscape of old  Dubai  on one side and will frame the skyline of modern D ubai  on the  other side .        The construction took five years (2013-2018).  Its heigh t is   150   meters-equal to 45   story   building.  It is  now standing  majestically.     An experience:        The entrance ti cket   i s bi t   costly.        After usual security check , we   a re allow ed t o   enter one of the towers of frame.  After short ride in escalator , we   w ere  show n   some past  Dubai .  Then elevator took us to the top.   We   w ere  give n   a short speech by a guide there.  We got a clear  360-degree  view of  Dubai .  The  highlight  is the glass bridge.  One can walk on it and see 150 meters below.  I

             81% of spam e mails are based on pharmaceutical products.  Other subjects used by spammers are weight loss, casino, college degree, phishing, performance enhancers, replica goods, and others.  A software in the email system  separate  the spam mails based on certain words and phrases and push them into junk folder.     HOW DO THEY MAKE MONEY?        There are two factors working in the scammers  favor . 1. It costs nothing to send thousands and thousands of emails.  2. If  one sends  millions of emails, some mails will  d efinitely land   in the in-boxes of fools who are ready to part with money to iron out some 'little problems'.        Estimates say that around 75000 people fall prey to spammers every year.  A victim pays out 20000 dollars on average and the spammers make around 1.5 billion dollars a year.     THE PYRAMID SCAM       Say, you   a re recruite d   to pyramid scheme by a friend.  You pay 10  dollars  to the friend and another 10 dollars to the person