Tag Archive: Physics


A “potpourri” of mindbenders

A “potpourri” of mindbenders!

        These are various brainbenders that I happened to have crossed while reading. They consist of a panopli of questions from physics to mathematics, from simple to complex and from solved to “still being researched”. Some of the sources are from Mathematics Problem Books, others from the “Mad About Physics” series while the sources of the remaining are still a mystery!

       I will add new puzzles and the previous answers in due time. Again, some of the questions have yet to be answered fully(we’ve got a bunch of crazy looking mathematicians and physicists still scratching the heads over them!). So, the answer may not always be so clear. Take your time and enjoy the ride into the unknown world that surrounds you.

1.      Okay, for starters, I’ll just ask you a simple question-one that most are well-acquainted with. If you take one pound of feathers and one pound of iron(or gold or anything metallic), which one weighs the most? (They weigh the same is, of course, not acceptable!) [reference: Mad about Physics-the classical edition]

2.     Now, for a bit of math.To number the pages of a bulky volume, the printer used 1890 digits. What’s the number of pages in the book?(simple algebra does the job!)[reference:The Stanford Mathematicians Problem Book]

3.     This one requires a bit more abstract thinking. The Green-Eyed dragons. So, you happen to visit a remote desert island inhabited by one hundred very friendly dragons(they won’t eat you),all of whom have green eyes. They haven’t seen a human for centuries and are very excited about your visit. The courteous D.s show you around and even talk to you about stuffs(Let’s say they can talk).

     Everything’s fine till now until you find something very strange. If a dragon finds out that he/she has green eyes, then at precisely midnight on the day of this discovery, he/she turns into a parrot after abandoning all powers. But, the dragons never talk to each other about eye color and there are no mirror on the island. So, everything’s been just fine.

     As you prepare to leave, all dragons come to see you off and you thank them for being so kind. You then tell them something they all already know(since they can all see the eyes of other dragons). You tell them that atleast one of them has green eyes(you really shouldn’t have done that). Then you leave, not thinking about the consequences. Assuming that the dragons are infallibly logical, what happens? And, if something does happen, what is this new information that you gave the dragons?[reference:Harvard Physics]

4.     How about a physics classic? This one is known the Newton’s Cradle(the toy in the picture). So, this is a popular toy consisting of five steel balls of the same size and mass, hanging side by side in contact in a row on bifilar support. Pull one back at one end and release it, one ball moves off the other end,…If two are pulled back at the same end and dropped together, two move out together at the other end. Pull back three, release together, and three move out at the other end. Pull back four and…Five and…How do they do that?! The balls can count, right? How do they know?[reference:Mad about physics]

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               “I was like a boy playing on the sea-shore, and diverting myself now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.” Sir Issac Newton

      Trying to combine quantum physics and blogging may sound very strange (well, it is!)  and is possibly the fruit of a deranged mind(well, that also is!). This a simply a post for bloggers (and future bloggers) out there.Ever wondered what bloggers will be like in, say, 50 or so years. What will be the most important tool they would be using (classically called the computer).The title’s the answer- they could be Quantum Bloggers(…or maybe not!)

     So, what’s all the fuss about being a Quantum Blogger? Or, more importantly what will be the tool that our future GrandBloggers (that means the grandchildren of bloggers) would be using? The answer may be Quantum Computers (Of course, that doesn’t mean that all our GrandBloggers will have to be Quantum Physicists!).

      The salient thing here is the Quantum Computer. Allow me to add a bit of historical perspective. Long ago (that’s in the 50s), computers were fat (even that is euphemistically speaking). With the advent of better tech, computer parts shrunk (and with the advent of more tech, parts shrunk even more). So came a little dilemma (a theoretical one) posed by the thinking people- we cannot possibly shrink these parts infinitely, there’s got to be a limit to it, right? (we have yet to reach that limit though). Fact is, there is (classically speaking). So came our very dear Quantum Computers (atleast in concept).

     Very strangely, though, the concept of quantum computing dates back to the 1960s. It is the brainchild of Richard Feynman(he crops up everytime, doesn’t he?). Now, before you start accusing our scientists of indolence and ‘not doing anything’, allow me to clarify, it is the strange Quantum World that we’re talking about here and by the time I explain, you’ll see how strange everything is!

      The Quantum computer is a hybrid of Quantum Physics and Computing. And when these two combine..These computers will have the computing efficiency of many classical computers put together(exponentially) and will have the ability to toy with as many figures as there are atoms in the Universe (phew!) instantly. They operate on Qubit(that’s quantum bits). While we are familiar with the 1s and 0s of classical computers, quantum computers use both at the same time(that’s the strange world of quantum physics and superposition).

      Now, let’s address the question of whether our GrandBloggers would be Quantum Bloggers? The answer(quite unfortunately or… not) is a NO! At present, the most that Quantum Computers could do is like looking up a name [very fast] in a phonebook or doing prime factorisation. That does not make them very useful (and that’s why we do not see them today on our tables)

      But let’s not just be negative about this. There might be a generation of Quantum Bloggers one day. For now, let’s just enjoy a good old Beatles song on our Macs. Who knows when these might become obsolete? Cheers to that!

                         “I, a universe of atoms, an atom in the universe.” Richard P. Feynman
 
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As an endnote, for those interested in the strange world of Quantum Computing, see:
http://arstechnica.com/science/2010/01/a-tale-of-two-qubits-how-quantum-computers-work/ or
http://computer.howstuffworks.com/quantum-computer.htm