While it’s true that Hackaday scribes and their families are sadly unable to compete in our contests, Hackaday alum are more than welcome to throw their hat in the ring. [Legionlabs] even made a game of it — they used only parts from the scrap heap, and even played beat the clock to build a real, science-fictiony, working thing in eight hours or less.
Okay, cool, but what does it do? Well, put simply, a rising edge on the input drives one of two outputs, lighting one of two drool-worthy flanged LEDs. Which output will [alight] is unknowable until observed, thus the Schrodinger’s aspect. In practice, the output is determined by sampling. In this case, the sampling is of the time difference between three electron-tunneling events.
Stage one of Schrodinger’s Trigger is a pair of inputs — one variable 10-15 VDC input and 5 VDC input. Then comes the electron-tunneling event generator. [Legionlabs] is reverse-biasing a semiconductor junction (a 2N551 transistor). What does that mean? If we consider the junction as a diode and apply voltage in the wrong direction, what happens? At best, nothing; at worst, the smoke monster appears to admonish us.
But with a semiconductor acting as a diode, some electrons are bound to jump across the junction. This is known as tunneling, and is a useful phenomenon as it is purely random.
Stage three consists of amplifying the signal from these rebel electrons via hex inverters. Why not op-amps? The CD4069s were cheaper and within reach. Finally, the amplified signals are sampled with an ATtiny12, and some assembly logic figures out which LED to light.
It’s nice to see an entry that leans more toward the science side of things while winning aesthetically. We dig the nice ABS enclosure, and are totally envious of [Legionlabs]’ access to flanged LEDs and those glass table top mounting point discs in the corners.
The story of Schrodinger’s cat is well known, and one of quantum theory’s most popular phrases on the world stage. You can find his cat on t-shirts, bumper stickers, internet memes and the like. However, few know the origins of the cat, and how it came into being. I suspect many do not understand it beyond the “dead and alive at the same time” catchphrase as well. Not surprisingly, it was Einstein who was at the center of the idea behind Schrodinger’s cat. In a vibrant discussion between the two via letters across the Atlantic, Schrodinger echoed Einstein’s concerns with the following:
Contained in a steel chamber is a Geiger counter prepared with a tiny amount of uranium, so small that in the next hour it is just as probable to expect one atomic decay as none. An amplified relay provides that the first atomic decay shatters a small bottle of prussic acid. This and -cruelly- a cat is also trapped in the steel chamber. According to the wave function for the total system, after an hour, sit venia verbo [pardon my language], the living and dead cat are smeared out in equal measure.
This was the first mention of Schrodinger’s cat, and one would not be incorrect in stating that this paragraph from a letter was where the cat was born. However, the original idea behind the thought experiment was from Einstein and his loathing of the wording of the Einstein-Podolsky-Rosen (EPR) paper. He expressed his frustrations with Schrodinger with a few simple examples, who then catapulted it into his famous paradox . In this article we’re going to explore not so much the cat, but the meaning behind the thought experiment and what it is meant to convey, while keeping it simple enough for anyone to understand. So next time you see it on a t-shirt, you will be able to articulate the true meaning and know the real Schrodinger’s cat.
Continue reading “Will The Real Schrodinger’s Cat Please Stand Up”
Not long after [Hitler] took control of Germany, his party passed laws forbidding any persons of Jewish descent from holding academic positions in German Universities. This had the effect of running many of the world’s smartest people out of the country, including [Albert Einstein]. Einstein settled into his new home in Princeton, and began to seek out bright young mathematicians to work with, for he still had a bone to pick with [Niels Bohr] and his quantum theory. It wasn’t long until he ran into an American, [Nathan Rosen] and a Russian, [Boris Podolsky]. The trio would soon lay before the world a direct challenge that would strike at the very core of quantum theory’s definition of reality. And unlike the previous challenges, this one would not be so easily dismissed by [Bohr].
Need a bit of catching up? You can check out Complimentarity as well as Tunneling and Transistors but that is just some optional background for wrapping your head around Quantum Computing.
The EPR Argument
On May 4th, 1935, the New York Times published an article entitled “Einstein Attacks Quantum Theory”, which gave a non technical summary of the [Einstein-Podolsky-Rosen] paper. We shall do something similar.
Continue reading “Quantum Mechanics In Your Processor: Quantum Computing”