This page is an experimental application of RAG, retrieval-augmented generation.
Over the years, I wrote more than 11,000 answers on the question-and-answer Web site Quora, mostly on the subject of fundamental physics, more specifically gravity, quantum field theory, cosmological physics, and also some more basic topics.
Through this page, you can utilize machine intelligence to extract information. Based on your query, the machine intelligence retrieves my most relevant answers and feeds them to a language model (Google's Gemma, or Qwen by Alibaba) which then synthesizes an answer to your query.
Keep the query short and on-topic, preferably a single phrase like "Schrödinger's cat". Otherwise, the answers will likely be nonsensical. The answers, of course, may not be accurate and may not accurately reflect my views. The relatively small, quantized language model used has somewhat limited capabilities and it may misunderstand complex explanations.
Please use this service sparingly. It runs on my local hardware resources.
Photoplethysmography (PPG) is a method to assess blood flow and other clinical parameters by measuring light absorption and reflection of the skin. Remote photoplethysmography (rPPG), in particular, uses a camera, such as a webcam, for this purpose. Surprisingly, it actually works.
Below is a simple application that demonstrates this capability. What may be remarkable is that this application uses only the native capabilities of the Web browser, and requires well under 400 lines of code, HTML + CSS + JavaScript. This little implementation is entirely self-contained, without relying on any third-party code or library.
Needless to say, you need a Web cam for the app to work, and you must grant permission to use the camera when the browser asks for it.
The software likely works in all recent Chrome-derived browsers and the latest Firefox; may fail with other browsers. Note that this is a technology demonstration, not a clinical tool. The measurements are uncalibrated, "proof-of-concept", not necessarily accurate. No information is transmitted over the Internet: the measurement and its evaluation take place entirely within your Web browser's context on your own local device.
Over the years, I have had several projects that remained unfinished, undeployed. The reasons varied: business decisions, technical merit, you name it. But darn it, the work I have done on at least some of these projects makes me feel proud, their ultimate lack of success notwithstanding.
