New Optical Switch Up to 1000x Faster Than Transistors
spectrum.ieee.org
spectrum.ieee.org
But just like graphene, carbon nanotubes, and other fads, you can publish fancy papers with it.
Maybe there will be some smart way to pre-encode routing information onto packets to reduce processing requirements, but I doubt that such a network could scale.
Basic things like optical muxing/demuxing and serialization/deserialization would be fantastic.
My main point is that to be able to do even the small stuff in the optical domain would be a big win. You don’t need to be able to achieve L2/L3 switching/routing to move the needle.
QC is also not going to replace general purpose electronic computers but augment them for certain classes of problems.
Another benefit of lower density is cooling.
However, all-optical/photonic computing is just intrinsically so much worse than electronics. On top of the issues that I touched on, there are also other fundamental problems, e.g. distribution of power: photons like to get absorbed by nearby electrons. How do you then supply all the active devices (switches/lasers/etc.) with power while maintaining some semblance of signal integrity and dense integration?
https://www.laserfocusworld.com/fiber-optics/article/1655109...
Imagine a CPU with the complexity of Arduino but running at 100 GHz.
The error (in your telling) is equating knowledge with confidence. Knowledge is knowing you might be wrong about it all. The advice to spend one’s life questioning isn’t a smarmy nothing; it’s the only truly sensible approach when you step back and think about it.
that's not a great definition... I know I might be wrong about flying UFOs, but that doesn't count as 'knowledge', does it?
Your broader point is right; obviously if we stop to poke at certain assumptions, the occasional one will collapse.
However, the pathway you’ve just suggested is less practical than you think. The GP is talking about a systematic, coordinated exploration effort of known unknowns.
Metaphorically - he/she is saying that there’s more likely to be gold at the unexplored end of gold mine, not in the excavated dirt.
It’s a fair assumption to keep in practise.
Then, when we have two e.g. physicists, who both know quite well what they are discussing, and one of them is more famous and potentially through their prestige succeed in ridiculing their less recognized colleague, we are at the "appeal to auhority" position.
One famous example is that of Ernst Mach who was was positivist (i.e. did not respect theory whose constituents you could not directly measure) and ridiculed Boltzmanns kinetic theory of gases because Mach did not believe in atom theory (!). Boltzmann's theory was effectively attacked precisely from position of authority.
So, if a layman and a physicist argue what is possible, it is very likely while both of them may be wrong, the layman likely does not have any understanding what their position implies.
So in my opinion, you can have a pathological appeal to authority sort of situation only when two equally skilled persons have an argument an the institutional prestige of one of them is used as an appeal for them.
At the risk of argumentum ad logicam, this is a textbook example of survivorship bias. History is also full of people who were adamant they were correct in the face of ridicule, and turned out to be wrong anyway.
What engineers work with is, maybe, 1/1000 of our physics knowledge (maybe 2/1000 for electronical engineers who need a solid basis of quantum mechanics).
Our physics knowledge is maybe 1/1000 of what we roughly know should be there but cannot be probed (quantum gravity, nonlinear field theories, dark stuff...).
The Universe is so huge that it is pretty impossible to descrive how much bigger than us it is - probably infinitely.
The point is, between the stuff that we know and the stuff that we roughly know but don't really know - we know a lot more than what we can use.
Saying that something is not so useful technologically, as OP stated, is rather a safe statement. We know a lot about fermions and bosons, light and electrons - and we know sufficient information to be able to state when something is overhyped and not really useful as it seems
You can just choose to use light at a smaller wavelength.
Also, less density by itself doesn't mean less performance, the larger optical components can just run faster to end up with higher overal performance.
- MLC flash storage devices use multiple levels to store/retrieve bits [1], - Lots of control systems are implemented with analog PIDs [2]. A trivial example is a jellybean voltage regulator that computes the adjustments needed to maintain a stable output voltage independent of the load.
[1] https://en.wikipedia.org/wiki/Multi-level_cell [2] https://control.com/textbook/closed-loop-control/analog-elec...
As a layperson I found this episode with Jeffrey Shainline an interesting discussion tangential to the topic of optoelectronic computing. The basic gist was that photons are good for communication, electrons are good for compute.
[0]: http://www.fiber-optical-networking.com/the-application-of-e...
The main upside for optical processing (photonics) is in signal switching then, as in this case. Having to receive the multitude of optical signals, converting them to electrical, doing the signal routing and processing in the electrical domain, then converting back to optical for transmission is a lot of busywork.
The keyword here is ‘all’. There are some things optical computing is bad at. However there are some things it is unparalleled at. For example, light can multiplex. It can have much lower energy losses. It can run at much higher frequencies. It is by far the best way to transmit information at extremely high data rates. Even within a chip, free space optical communication has massive theoretical potential.
Your comment would have been an excellent one without the last sentence.
The keyword here might be "all", and there are some applications where optical computing is unparalled at. But research teams, vendors, and the media spin those things are a recplament for every application, not as some niche thing that's good at some niche applications that most people need not care about...
Even just the article's sub-title has tempered predictions: "“Optical accelerator” devices could one day soon turbocharge tailored applications"
And the research has immediate practical applications, again per the article:
> "The most surprising finding was that we could trigger the optical switch with the smallest amount of light, a single photon," says study senior author Pavlos Lagoudakis, [..] Lagoudakis says the super-sensitivity of the new optical switch to light suggests it could serve as a light detector that could find use in lidar scanners, such as those finding use in drones and autonomous vehicles.
It doesn't need this density to be useful or better than electronics in many cases. For instance, photonic quantum computation happens at room temperature, but this doesn't seem like it will be feasible with any other method for long time, if ever.
Light has many inherent advantages over electricity for multiplexing/demultiplexing. Also, optical amplification works quite well too, and people use it on every long distance data cable nowadays.
Also path delay is not an issue if you have a task that can be pipelined for raw through put. Latency is less of issue in such scenarios.
So claiming there is no use for such things seems a stretch. It certainly can have niche uses. Bigger problem with a lot these papers is their tech needs to be at least reasonable to manufacture to have niche uses.
https://arxiv.org/abs/2005.05811
(E.g., both papers contain this [0] text string pointing to the same URI. But, the arXiv preprint doesn't mention the Nature submission).
[0] "All data supporting this study are openly available from the University of Southampton repository at https://doi.org/10.5258/SOTON/D1374."
No, a CPU's clock speed is not the speed at which its transistors can transition. Clocks are multiple gates long (roughly, 10-20), and are not the only delays in a system. So a CPU running at a clock speed of 5 GHz could reasonably be switching each transistor at a rate approaching 100 GHz. (Most of the time each individual transistor is not switching, since only their last switch within a clock cycle is typically meaningful.)
Thanks!
The concept is to break down (algebraic) operators into a single fundamental operator and a single reference value (zero/null). And because there is only one operator and one value, they can be removed from the system. What remains is the "essence of information" in the form of connections, opening a new realm of problem solving, especially in the realm of SAT solving. It's not about what the operator does, it's about how they are connected together.
The "fractal operator" is a switch of which one input is inverted. The expressions/structures are stored as vectors and evaluated by activating them sequentially. For some years I visualised it being implemented with photons instead of electrons. And assuming that only a single photon is needed to set the switch state.
This is a wish come true!
[0] https://github.com/RockingShip/untangleE.g. using this instead of mirror arrays in movie projectors?
1. For electrical circuits we are interested in properties like resistance, capacity, inductance etc. for passive elements and in the characteristic curves for active ones.
What are their equivalents in photonic circuits? Which properties matter here?
2. In digital computing I think we abstracted the electrical analog properties and the differential equation level of the problem away pretty much. Can't we achieve that with photonic ones as well? Or do you mean a paradigm shift in higher level things like memory bandwidth and latency vs caching etc. ?
3. When I look at the state of photonic circuits I think miniaturization and fabrication are the most obvious problems. Let's assume for a moment that these can be solved, what else makes photonic circuits worse than electric ones?
But you should definitely watch this video [0].