Quantum logic Puns

QuantumQ

I made a simple puzzle game about quantum circuit and quantum gates. It's free and available for Android, Windows, and Linux

Homepage : https://ray-ph.github.io/quantumQ/
Android : Google Play
Windows, Linux : Itch.io

The project is open source and the source code is available on Github

I'm writing a fic set during an early season 4 episode, showing what the leapee is doing at Project Quantum Leap while Sam is doing his thing in the past. The slight twist is I am showing the final revision of the timeline after the series finale, mostly so I can have the leapee interact with several female characters that weren't originally at the Project - or didn't exist at all! - until Sam altered the timeline, so they can talk about how their lives were touched by him.

How would this work from a logical standpoint, though? If history has already been changed for the better, wouldn't the people at Project Quantum Leap be aware of it? How does that affect what Al tells Sam that he's supposed to accomplish?

I just came across the Wikipedia page on quantum logic and it describes how the identity p and (q or r) = (p and q) or (p and r) doesn't always hold in QM because of the uncertainty principle. e.g. If p = “the particle has momentum between 0 and 1/6”, q = “the particle has position between -1 and 1”, and r = “the particle has position between 1 and 3”, the left side of the equation could be true but the right side wouldn't be because the interval [-1,3] for position is allowed given the momentum interval, but the two smaller intervals are too small to be allowed by HUP.

I can understand the reasoning there, but it just feels wrong that such a fundamental identity could be violated, so I started thinking about why it fails here, and my thought is that the statement “the particle has a momentum/position in some interval [prior to measurement]” simply isn't well-defined and so we can't even give it a definite truth value. Afterall, we still don't know if it even makes sense to talk about particles having classical properties prior to measurement because we don't know the nature of the wavefunction, whether it even corresponds to a physical thing or is just a useful mathematical tool. In that light, I think both sides of the equation would actually be indeterminant(or whatever the analogous term is in propositional logic) simply because the statements are ambiguous.

If we instead reinterpret the statements to mean what the position/momentum will be after some hypothetical measurement, I think both sides of the equation would be true. That is, in terms of the math, we can't say that the position of a particle will either be in the first interval or the second interval given the specific momentum interval, but we CAN say that, were we to measure it, the measurement would be in one of those intervals.

Additionally, even if we assume the statements themselves are well-defined, I'm still not sure it makes sense to say the left side of the equation is true -- afterall, saying the left side of the equation equals "the momentum is between 0 and 1/6 and (the position is between -1 and 3)" relies on being able to say that "(the position is between -1 and 3)" = "the position is between -1 and 1 or between 1 and 3". I don't that that's consistent with the reasoning for the right side of the equation being false, as that seems to rely on the idea that the position can be narrowed down only to the larger interval and

On pg 29 of Nielsen and Chuang, we were introduced to how to simulate a classical logic circuit using a quantum circuit. It's said that we can't directly replace classical gates with quantum gates as quantum gates are reversible while classical gates aren't. To my understanding, we therefore first replace classical circuits w equivalent classical circuits containing only reversible elements. then replace this circuit with quantum circuit?

1. I'm confused about how it's possible to replace classical circuits w circuits containing only reversible elements - isn't it stated earlier that classical gates are inherently irreversible?
2. When we simulate a classical circuit by an equivalent reversible circuit, isn't we changing the non-reversible property of the original classical circuit?
   1. Shouldn't we aim to produce a circuit that's also non-reversible just like our original classical circuit as the product of our simulation? Why is it okay that we don't?
   2. Also, if we don't aim to keep the non-reversible property of the original classical circuit, why don't we just directly simulate the classical circuit using quantum circuit instead of replacing the classical circuit w reversible classical gates first?

Any explanations would be appreciated!

Like how do you actually physically alter the phase and magnitude of a superposition? I know it is done using matrix multiplication but how the fuck do you multiply a photon??

I am really intrigued by building non electronic logic gates and turing machines by physical objects such as dominos, legos or wooden gears. In principe a mechanical domino computer is turing complete, and could perform any calculation your pc can do, albeit slower. Is there a way to do something similar with a quantum logic gate? I would guess you can't since you rely on the superposition of two particles, and reading those states in a mechanical way would be non trivial. But could one construct a logic gate with to inputs and two outputs, where some physical process could randomize and hide the four possible states, thus demontstrating in a physical way how a quantum logic gate works? Edit: mixed up the number of outputs and number of possible states

What I mean by "quantum logic" is that for example (much like an elementary particle exhibiting multiple behaviours simultaneously) something might, for instance, be true and not true at the same time. Would this even be a sensible addition to regular logic?

I have heard of fuzzy logic before, but I don't think it fits the bill (though I could be wrong).

I want to learn the why and how of this, if this is a real thing. Experiments with water molecules on a speaker have yielded interesting results and the results may be of some correlation... or not. What do you guys have to say? (Actual physics stuff only, plz and thx)

I just don't get it. I understand all the steps up to when you are in the shrine, and the Logic behind flowing the 'sixth location's step doesn't make sense to me, even after looking it up. Specifically, >!how was I supposed to know to go to giants deep, walk around, get back in the shrine, go to ash twin, walk around, then go to the eye? I don't understand the logic behind this!<

Just took my first logic class and loved it, have been trying to get into quantum mechanics and consciousness for a while, I read Nagel’s bat essay today and loved it, wondering if you guys have anything that’s along those lines. Also have read some papers by Tim maudlin in the past few weeks. I know the parameters are vague and broad and that’s intentional. Thanks for the help.

In quantum physics there is such thing as a "quantum collapse," which is basically where a quantum system is transformed from a superposition of states into a single specific state. The key thing here is that this collapse occurs once the system is observed.

This seems to strike an obvious parallel to how video game rendering works, in which the game only renders objects that are currently being observed or otherwise interacted with by the main character's system, in order to save resources. This seems to be another piece of correlation between simulations and reality.

Going along with this, it is plausible that an idea such as solipsism could actually be a reality, since having only one main character who the simulation has to render actions for would save significant resources, compared to simulating 7.5 billion individual perspectives.

Thoughts?

Anybody here have any experience with these? Can you link me some interesting books or papers to read? :∩)

Example from Springer, cited for keyword « quantum »

Tanaka, cited for keyword « database »

Hey, guys. I have a project for a physics class I'm taking that incorporates explaining the operating principles of quantum computers, and I need a bit of help. I've been researching quantum logic gates for the project, and can't figure out a way to visually compare them to classical logic effectively for my peers (I'm still in high school, and I'm the only person in my class who understands this shit).

Is there a way to either:

1. Compare quantum gates to their classical counterparts with some version of a truth table, or
2. Write out classical logic gates as matrices, similar to the way quantum gates are written

Thanks in advance!

Most people are familiar with the ideas of quantum superposition, the collapse of the wave function, and Schrodingers Cat. They’ve become nearly commonplace. There are obviously a lot of interpretations of quantum mechanics including Many Words, Copenhagen, and Pilot Wave Theory. My personal favorite from a physics standpoint is the “Two State Vector Formalism” which is an offshoot of Pilot Wave Theory popularized by David Bohm’s student Yakir Aharonov followed by HIS student, Avshalom Elitzur. It holds curtain similarities to Pilot Wave except it posits that final measurements on a system result in “cancellation waves” or “void branches” moving back in time toward the source that cancel out a particle’s presence on a path retroactively. These void branches can create odd effects in special setups such as interfering to create “mirage particles” in the middle of a path with negative energy and even resulting in whole histories of the system’s evolution giving signs of having been “rewritten” to result in inconsistent histories.

Let me describe two of the interesting experiments involved in Elitzur’s and Aharonov’s writings. My main question is how, IF for the sake of argument we can take a realist view and assume that they reflect some genuine ontological reality, these results affect our views on the laws of logic and the fixity of the past.

There’s a certain apparatus used in quantum experiments called a Mach-Zehnder interferometer. A photon or electron is randomly sent along one of two paths, an upper and a lower. The two paths run parallel for a time and then are directed to be perpendicular by mirrors set in the middle of the paths which direct both paths toward a single meeting point. At this meeting point is a special device that we’ll call an “interference tuner” that causes anything on the two paths to interfere constructively toward one detector, A and interfere destructively toward B such that you always get a click at A and never at B if you have interference between the two paths. By virtue of the randomness of the paths, the single photon is split into a superposition of both paths and interferes with itself toward detector A if it’s superposition remains undisturbed.

If you put an atom superposed between two boxes on the lower path of the MZI in this setup, such that it is superposed of being in box A which intersects the lower path and being in box B which lies completely outside of the MZI, then run the experiment, you’ll occasionally

This is a post from someone who is clearly not a quantum computing expert, nor really even somewhat versed in the field. I'm looking for someone to tell me this idea won't work or someone to work with me as a collaborator on the implementation of such an idea as follows.

I am a researcher at the university of Minnesota who works with synthetic cells, one of our research aims is to develop genetic circuits in synthetic minimal cells. For instance a basic system might be: add compound A and B and drive expression of C (AND gate). I however, wonder whether there might be a trove of possibility in multi-value logic or a quantum parameterization of a system; that is to say, I wonder whether, because biological systems are not binary, if different logic gates could be used. I have no background in quantum computing though I get the basic level concept and have read some stuff about quantum biocomputing. Is there someone on here who wants to collaborate? With the down time due to the pandemic, I've been spinning up collaborations and projects and planning future work.

If anyone is interested in developing theoretical ideas surrounding bio-based quantum gates and simple systems thereof, feel free to reach out to me at vener015@umn.edu. The goal would be to show a quantum gate or a combination of quantum logics in a synthetic cell.

Hey, everyone. So, I'm a high school senior taking a general physics class. Right now everybody is doing a project on physics of the last 100 years, and as the title suggests, I'm doing mine on quantum computing.

There's just one problem here: I'm the only person in my class who understands quantum mechanics. I'm not trying to sound arrogant here. I'm actually planning on a career working with quantum computers, so I've been studying this stuff on my own for about a year or two.

So how would any of y'all explain things like linear algebra, calculus, Fourier transforms, differential equations, among other concepts, to a mostly uninitiated audience. Also, how would y'all suggest I compare quantum logic gates to classical ones (e.g explaining how to translate the concept of an AND gate to quantum terms, or how to directly compare CNOT to XOR)?

Thanks in advance!

Edit: I'm also a bit stuck on how I would want to go about explaining coherence and entanglement at a really basic level.