I think I walked past this in a European capital city, could that have been your doorbell (city not specified for obvious reasons)? Or are other people already using this?
This article mentions that the speed of light seems fast to humans living daily lives, but is not so fast on an astronomical scale.
The best demonstration of this I've ever seen is on "If the Moon Were Only 1 Pixel - A tediously accurate map of the solar system" [1].
If you've not seen it before, I recommend opening it, using your mouse wheel to scroll from the beginning (near the Sun) to Earth. It should take about a minute, but there's some commentary on the way. Then, to save your mouse and your finger some work, try clicking the icon in the bottom right hand corner to auto-scroll the map at the speed of light.
These videos were super fun to make and kept me sane when I found myself with far too much free time and a bunch of world news to avoid. I never did the fifth (and final) walk but it's only about 100 meters long so I hope one day to do it in person (if I ever end up with that much free time again).
It’s always crazy to me how empty most of space is, and that yet despite that gravity is strong enough on large timescales to pull a lot of stuff together. Then I get concerned as to why EVERYTHING wasn’t pulled together and it’s literally just this little bit of angular momentum conserved across vast distances and added together from all these little particles that is keeping everything apart just enough for us to exist.
This is something I find incredibly counter-intuitive. At the photon’s reference frame (speed of light), time stops. In our reference frame, I’d expect some kind of “divide by zero” error in nature, resulting in the infinite speed of light. But it’s not infinite. It’s just… some constant.
It's the maximum speed through space and time. The speed of light through time is just 1s/s. Einstein says space and time are equivalent, so as your velocity through space approaches c, your velocity through time approaches zero and vice-versa.
The photon has zero velocity through time because its velocity through space is c. In its reference frame, no time passes between creation and destruction, but from all other reference frames it appears to be moving through space in discrete time but with high velocity.
This was awesome. It's strange to know that I already understood this (conceptually at least), yet seeing how slow it really is at this scale is confusing. Maybe that's not quite the right word. It makes my brain pause and go "that can't be right", but... It's right.
Brains are bad at these scales. Maybe mine is worse than average. I can't fully believe how impossibly far away so many things truly are.
I thought light in a vacuum was (outside of some corner cases) the fastest you could get in this universe? That seems pretty fast on an astronomical scale to me. I mean it’s probably just that we have extremely short lives on an astronomical scale.
The speed of light is actually the speed of causality. No matter, or more importantly information can go faster than that. This has some real consequences even on human scales.
For example, if you've ever opened an electronic device and seen squiggly traces everywhere, it's because of light speed[0]. When signals get fast enough, you have to make sure the traces have the same length to within a fraction of a millimeter. Otherwise, the signals on two traces arrive at different times and nothing works.
[0](electrons move at ~c, more or less)
There's a significant delay in satellite communications, on the order of milliseconds. It takes several seconds to reach the moon. 20 minutes to Mars, a few hours to Jupiter. Famously 8 minutes to the sun. The nearest galaxy is 1.5 million years away.
Consider how stupefyingly large our solar system is. Then consider how insanely huge the galaxy is: 90,000ly. It takes ninety thousand years for a photon to go from one edge of the galaxy to another. Then compared to the universe at large, our galaxy is essentially a single point.
Light is extremely slow and the universe is vast beyond our meat brain's ability to comprehend.
Pedantic: electrons (in a wire) move at relatively ordinary speeds. Wikipedia says this [0]:
>The drift velocity in a 2 mm diameter copper wire in 1 ampere current is approximately 8 cm per hour. AC voltages cause no net movement. The electrons oscillate back and forth in response to the alternating electric field
Think of it more like a long row of billiard balls. You hit the first one, it moves a little, then it hits the next one, that one moves a little etc. Except the "hit" is just getting closer to the next electron to make it move (like if they were magnets).
At least that's my understanding of it.
---
Maybe "hit" is the correct word? Isn't it the same forces at play that stop my hand from going through the table?
You are correct, electrons (aka current) through a wire move at relatively low speeds at room temperature because of wire resistance. Changes of voltage however, like if you flip a data pin from 0V to 5V move at the speed of light.
So switching circuits need to take into account "transmission line" effects.
I don’t think you understood my point? Why did you type all of that, when it’s basically what everyone else has said. I know about max speed of information and causality and have for decades. I was talking that light in a vacuum speed is basically “fast” since nothing is fast, in both and absolute and a relative sense, at least in my take :)
Actually more interesting to me than Stockholm Syndrome, as the captors of Patty Hearst had demands which would have sounded completely eye opening and reasonable if you'd had her upbringing.
It can be refused, but you can't sue someone for non payment if they've offered to settle the debt with the right amount of legal tender. Pendantic, i know, but that's this whole thread. :)
This initially looks like a light weight alternative to Feedly (which was the most popular alternative to Google Reader), with the option of self hosting if need be. If so, I'm keen to get involved.
This is a nice comment and speaks to the notion that every medium has its own characteristic feel even is not "better" by some metric (e.g. vinyl vs CDs, vs cassettes, vs live radio, vs mp3, etc.).
A similar feeling of immediacy without any intervening concerns is hacking away at a Processing [https://processing.org/] sketch. In some sense it's the complete opposite of retro computing, but it engenders similar experiences. Such as a programming novice typing in a few numbers and being amazed that they've immediately made something interactive and colorful, and temptingly close to being called a game.
Turing's life and work was a big part of my research and I was involved with a number of academic Turing memorial events, I've had dinner with his closest living relative. I'm well aware of all the inaccuracies.
I was given 114 minutes I don't think I could have done a better job of giving a feel for the guy, his work, and the situation to an intelligent person who has a passing interest in tech (e.g. my wife) than they did in the film.
This may just say more about me as a story-teller than as a genuine appraisal of the film.
If you want detail, read Turing's biography by Andrew Wiles, such a great work and impressively comprehensive. If you just like code breaking and WWII history, read The Hut Six story by "Turing's boss" Gordon Welchman, the publication of which lost him his American and British security clearances.
>I was given 114 minutes I don't think I could have done a better job of giving a feel for the guy, his work, and the situation to an intelligent person who has a passing interest in tech (e.g. my wife) than they did in the film.
I feel like I'm fairly forgiving when it comes to glossing over some details in order to serve the greater narrative, but I feel all of the film's points of conflict were fabricated to the point of being misleading.
Turing was a genius, but he wasn't a sole genius loner - he was a much liked and integral member of the team. Much of the plot is about him supposedly single handedly and against the will of Bletchley working on the Bombe when the Polish Bombe was a tried and true solution to Enigma-sans-plugboard already. This image of him being some kind of rebel is absolutely not giving you a "feel" for his situation.
The idea that the machine wasn't working and they had no idea how it was going to work until they "suddenly had the idea of using a crib" is trying to add a peril and a Eureka moment that didn't exist. From a "let's not get waded down in the details" point of view, sure but again this really adds more of a sole genius factor on Turing specifically when he was but one genius in a factory of geniuses.
Things like having one bombe in the corner of a room quietly breaking all the Nazi's codes? Sure, why not. It's very silly and downplays the roles of hundreds of Wrens, but you can have that for the sake of storytelling.
We may have different things that we wanted from this film, but honestly rewatching it it just felt like it was muddying the waters of what I already knew rather than being a fun accessible glimpse into the life of one of History's greatest minds.
Their argument for not watching 99% of their output is even stronger. Most of that tripe is overpriced even when pirated. I'm sure that know that global free distribution is doing them some good else this crack down on it even harder.
