Humble Inventions #4: Magnets

In Nuts and Bolts, Roma Agrawal talks of magnets as yet another invention that has had massive applications and impact. Wait a minute, aren’t magnets a discovery, not an invention? Technically, yes, but most magnets that are used for any applications are artificially created from metals or ceramics, or they are electromagnets, i.e., magnets produced by using electricity. (The reason for producing them is that natural magnets are too rare and too weak).

 

To use magnets required humans to first understand magnetism. As if that wasn’t hard enough, magnetism is intertwined with electricity, another phenomenon which took us a long time to get a grasp of. And boy, magnets are everywhere – thermostats, door catches, speakers, motors, brakes, generators, body scanners…

 

Understanding electromagnetism led to the understanding of electromagnetic waves. This combo of electromagnets and electromagnetic waves is what changed communication forever. From telegraphs to Wi-fi. While telegraphs may seem ancient, they changed the speed and distance of communication enormously and were truly transformative technologies in their prime.

 

The first phones worked because of the intertwined effects of magnets and coils (electricity) on each other. Crudely put, your speech causes vibrations in a sensitive diaphragm, whose movement caused a change in the magnetic field around the magnet in the receiver. This change in magnetic field in turn produced an electric current which could be transmitted hundreds/thousands of miles, where the process was reversed to produce speech.

 

As phones became popular, human operators were needed to connect the right two lines at the exchange before people could talk. This was why it took 24 hours to have a trunk call – such connections had to be set in multiple exchanges, and they had to be synchronized, which meant a lot of effort and coordination (and thus the high cost). Eventually, this process was automated – when you dialled a number, electrical pulses were sent to the exchange where they caused electromagnets to rotate. The rotation of the electromagnet caused the arms attached to it to change positions too and connect to a different set of wires (corresponding to the number you dialled), and bingo! You were connected to the person whose number you dialled.

 

The first TV’s (not the flat screen ones of today) too worked on the principle of electromagnetism. The transmission of signal was via electromagnetic waves. The receiver had a cathode ray tube that emitted electrons; and an arrangement of electromagnets in the TV would then deflect the electrons to hit different parts of the screen (based on the incoming signal). The screen had a chemical layer that lit up based on whether or not electrons hit that part of the screen. It was an incredibly precise system that worked so fast that it produced the effect of watching, er, a movie.

 

And we now use powerful electromagnets in physics labs like the Large Hadron Collider (LHC) to produce, confirm and learn about the fundamental particles of the universe and its origin.

“We seem to have come full circle in our understanding of magnetism: from discovering it on earth, to creating our own, to then inventing electromagnets and using them to learn more about our existence.”

Comments

Post a Comment

Popular posts from this blog

The Thrill of the Chase

So many people complain about the difficulty in making decisions while shopping. Do you buy Brand X that gives 20% extra free? Or Brand Y that has 10% off? Or Brand Z that gives something else free with it? Do you buy that flat screen TV today or wait for the sale at Diwali? Now since the customer is king, shouldn’t companies be simplifying pricing choices? Like maybe offering consistently low prices all the time? Not so fast, as the US store, JC Penney discovered to its cost. Turns out that while people do complain about pricing choices, they are irrational. Also, they enjoy the thrill of the chase. Huh? The word “sale” acts like a siren call for many people: it lures them in to make that purchase. Consistently low prices don’t do the same. Besides, if a competitor lowers their prices just one time of the year, and Poof! Suddenly that low price claim becomes suspect in shoppers’ eyes. Then there are those sites that offer coupons: have lunch at Restaurant A on Wedne...
Read more

Chess is too Boring

“Chess has problems at the grandmaster level...They're not getting a great game”, wrote Christian Donlan . Amen to that: Anand and his challenger, Magnus Carlsen drew their first game in just 16 moves. It gets worse: games between the top 20 end in draws 60% of the time. And Donlan adds that “games often end in resignation when an actual victory starts to loom on the distant horizon.” That often means that the average player (or fan) often has no clue why one guy won (since he can’t see that far ahead)! Then there’s all that memorization (of openings, of end games and everything in between). All that memorization is sort of against the spirit of the game, says Zachary Burns, “We want it to be a game of creativity and positional play.” Many have tried to change the rules of the game in the past for these exact reasons, including Bobby Fischer with his Chess960 variant. More recently, David Sirlin tried to make things interesting via his variant, Chess 2. So what are his c...
Read more

Why we Deceive Ourselves

In their book, The Elephant in the Brain , the authors describe this weird aspect of deception that we practice: deceiving ourselves! That is so weird: “If our minds contain maps of our worlds, what good comes from having an inaccurate version of these maps?” The Sigmund Freud school of thought treats self-deception as a defense mechanism, “a way for the ego to protect itself”. The mind seeks to protect itself from anxiety and other negative emotions. Many object to this reasoning: since accurate information is so critical to our survival, surely distorting information would be dangerous. Wouldn’t the goal of protecting our self-esteem have been better achieved by making the brain’s self-esteem mechanism stronger instead? The new school of thought explains self-deception as “primarily outward-facing, manipulative, and ultimately self-serving”. This is based on Thomas Schelling’s work on game theory: “In a variety of scenarios, limiting or sabotaging yourself is the winn...
Read more