it is. There are many websites and applications that I use, like wikipedia and linux / kde that could help if they picked an application like Mastodon and promoted it on their site. I only use social media about once a month so I am far from expert but an ad supported open source facebook clone that stayed non profit by sending its profits to other open source sites would be ideal.
I was just today looking to see who owns Flex and Air. There is Apache Flex but it does not look like it is widely used. And it looks like Air was sold to Harman an audio electronics subsidiary of Samsung.
It would be cool if there was a browser that had a full set of components that would allow fast construction of internal dashboards, CRUD apps, etc. via new html tags. if not that then maybe a custom browser with flex enabled for internal use only. The security and performance would have to be improved but seems like a really fast way to prototype and build internal only sites.
The late Dr. Gerald M. Edelman (Nobel Prize in Physiology or Medicine) had a fascinating theory he called "Neural Darwinism" that relied upon "reentrant mapping" he insisted was not feedback. He had a lab that formulated his ideas into software and a robot called Darwin 4. Does anyone here know what happened to that software? Is it described in detail anywhere? The following is an unflattering but useful discussion of Edelman's robot https://blogs.scientificamerican.com/cross-check/my-testy-en...
I have not heard of this one but there's a similar robotics implementation of a network based on the connectome (neural circuit wiring diagram) of C. Elegans brains(the only complete connectome we have so far). Its still in preliminary phase of doing cool stuff though but the idea is interesting.
Like another thread mentioned, shebang (#!) parsing is non-standard. In macOS, I think what you tried would work like you'd expect, but it'd work differently on linux. The reason is that in linux, after parsing the path to the executable and a space, everything else is taken as a single argument. So if you were in bash, what you did would be the equivalent of doing:
jq "--stream -rf" path/to/script
and jq doesn't know of any one option called "--stream -rf".
I haven't seen the discussions around these design decisions in the different OSes, but I imagine the crux of the matter is that you have to pick somewhere to stop, and where you chose to stop is largely arbitrary.
I mean, you can have the OS interpret shebangs with multiple arguments, but then you'll want to be able to put spaces in these arguments, so you'll want quoting, and then you'll want to put special characters like newlines inside, so you'll want escaping, etc.
The OS can implement all these things in execve()'s logic, but it might also be preferable to keep the logic simple in the interest of avoiding security-harming bugs. You know, less code, less bugs, less vulnerabilities.
If --stream had a single letter option equivalent, you could stick it together with the other ones. However, since it doesn't, your only option to make a portable script is to use a shell shebang like #!/bin/bash, and then do:
exec jq --stream -rf ...
You might feel that this single argument restriction sucks and is definitely inferior to any implementation of multiple argument shebangs. I don't know if macOS shebangs support quoting, but if they don't and simply split on spaces, then I can tell you they can't do hacky stuff like writing code in a shebang like this:
There's a huge difference between voluntarily living in a van in the Google parking lot while saving for a downpayment with your engineering salary or lowering your burn rate for your bootstrapped startup -- and actually being homeless [1].
This is why I rarely post on the internet. So easy to misunderstand tone. I seems as if you are mis-understanding my original post. I was only hoping for the best for Harlanji based upon my personal experience. BTW, I was delivering furniture that first year.
"according to the photons frame of reference, Heeck found that its lifetime would be a rather short three years; however, from our frame of reference, light would live about one billion billion (10^18) years"
Note that this article is assuming, for purposes of argument, that photons actually have mass, equal to the current upper limit for possible photon mass based on experiments. But the experiments are all consistent with the current theoretical belief that photons have zero mass; and if they have zero mass, the concept of "lifetime" for a photon (and indeed the concept of "photons frame of reference") is not even well-defined.
> If they are moving with the speed of light no time passes for photons
No, the concept of "time passing" for an object moving at the speed of light has no meaning. That's why "lifetime" has no meaning for a photon if it has zero mass.
No, because the rules of Lorenz invariant field theories mean that the infinity you’re (presumably) expecting is mapped, via the joy of hyperbolic geometry, onto the propagation speed of that field.
Or, to put it another way, the speed of light is where time dilation and length contraction run into each other and it all goes zero-divided-by-zero.
> Wouldn't c have to be infinite for "no time to pass"
You're using a different notion of "time passing". Yes, we, observing photons, certainly observe them to take a finite time to cover a finite distance. But that is not the same as the concept of "time passing" for the photons themselves, for example according to a clock that the photons carried along with them; that is the concept that has no meaning.
If the photons were a conscious subject, would that mean, from their point of view, they are everywhere (everywhere being defined as the entire path the photon will take from its genesis to its final destruction or absorption), all at once? Because if no time is passing for them, doesn't that mean no space is being traversed either?
The flip side of time dilation is Lorentz contraction. As you approach the speed of light objects in your direction of motion will become shortened from your frame of reference.
For example, there are particles from cosmic rays that should not be able to make it to the surface without decaying. However, they're detected all the time. Two valid ways to think of this are:
1. From the Earth's frame of reference time moves more slowly for the particle. This slows down the process of decaying.
2. From the particle's frame of reference the Earth's atmosphere is considerably shorter so it doesn't need to travel as far.
Things get a bit hairy to talk about once you actually reach the speed of light. One way to think of it might be from the photon's frame of reference its entire path has become infinitely short so it had no distance to travel at all.
> One way to think of it might be from the photon's frame of reference its entire path has become infinitely short so it had no distance to travel at all.
From the photons frame of reference, then, they do not move at all?
And the environment that photon "experiences", being the path in the universe that it traverses from our point of view; is the past, present, and future (from our point of view) all in instant simultaneity for the photon?
Unfortunately when talking about physics, sloppy human languages and our tendency to anthropomorphize when describing very non-human-like things cause a lot of communication/learning problems. Concepts like "experiencing an environment" and "time" don't make sense for the photon, which is sort of equivalent to "moving at c" because experiencing something like "time" requires interactions (events) at different places in spacetime.
Saying "neutrino has a very small mass" is roughly equivalent to saying "neutrinos very rarely experience an oscillation event (changing into a different flavor)". The distance between the rare events is the "time" it experiences. These are so far apart in spacetime for the neutrino it's experience of time (the way it evolves over spacetime) is extremely slow. More massive particles are "more massive" because they frequently interact with the Higgs field. More interaction events means their experience of time happens faster.
The photon (and anything else with 0 mass) only experiences two events: it's creation and destruction. It moves at c because it's never being slowed down by experiencing interactions.
For a very good explanation of this (with helpful animations) this[1] short playlist (6 ep) of PBS Spacetime episodes.
edit: TL;DR - When speed-of-light particles pause to interact with things (thus moving < c)slowing it down), we say that particle "has mass". Mass is a measure of how frequently those interactions occur (aka how much "time" it experiences).
> The photon (and anything else with 0 mass) only experiences two events: it's creation and destruction.
This is not correct. The worldline of a photon contains events between its creation and its destruction. The spacetime interval between any such pair of events is zero, but that does not mean the events aren't there.
If you flash a laser at a detector on the Moon, there is a whole continuum of events between the source (the laser) and the destination (the detector on the Moon). The spacetime interval between the source and destination events is zero, but there is still a whole continuum of events between them (all the events the photon passes through between the source and the detector).
> From the photons frame of reference, then, they do not move at all?
There is no such thing as "the photons frame of reference". It is not even a well-defined concept.
> And the environment that photon "experiences", being the path in the universe that it traverses from our point of view; is the past, present, and future (from our point of view) all in instant simultaneity for the photon?
No, none of this is correct. The reason I keep insisting that all these concepts are not well-defined for a photon is to make it clear why you cannot draw all these inferences that you are trying to draw--they are all wrong. The only way to stop drawing them is to recognize what "not well-defined" means. It means the questions you are trying to ask about photons are meaningless; they are like asking how long the color red is or how much time passes for it. Photons are simply not in the category of things for which those questions make sense.
Every single comment you've written on this subject closes all discussion on it. So what is there to discuss? Or shall I remain silent in the ignorant darkness of my status as a (physics) layman?
Even Einstein inserted an anthropomorphized frame of reference into the thought experiments of the celestial objects he contemplated, to explain to others. If we can't ask questions about photons in relation to spacetime as we know it, then what questions can we ask? We certainly don't know spacetime as photons "know" it, since its not "well defined."
Interestingly still, you use the term worldline to describe the totality of the temporal-spatial existence of a photon, so clearly there are concessions to be made and all this is more defined than you assert... and you're lightly reproving us for not using the same dictionary as you...
I'm interested in this subject but not interested enough (or rather, have the time and energy) to become a physicist to understand, if that's what you're going to ultimately suggest to get even a dim, but accurate understanding of the nature of light.
> Every single comment you've written on this subject closes all discussion on it
I have done no such thing. I have only closed discussion based on a fallacious premise. If you drop the fallacious premise there is plenty to discuss.
> We certainly don't know spacetime as photons "know" it, since its not "well defined."
I did not say spacetime is not well-defined. Spacetime is not "as photons know it" or as any observer "knows" it. Spacetime is the underlying geometric entity; it requires no "point of view" to exist, or even to be described; you can describe spacetime without ever using inertial frames, which are what your "points of view" actually are.
> you use the term worldline to describe the totality of the temporal-spatial existence of a photon
That's because "worldline" is the standard physics term for it, as used in physics textbooks and peer-reviewed papers.
> you're lightly reproving us for not using the same dictionary as you.
If you want to discuss physics, it helps a lot to use the standard language of physics.
> I'm interested in this subject but not interested enough (or rather, have the time and energy) to become a physicist to understand
You don't have to become a physicist. But you do have to be willing to drop fallacious premises.
Just note that however you try to define "the photon's frame of reference" you end up with a division by zero, so the definition becomes meaningless.
Eg distance traveled is 0 due to length contraction. Time taken is 0 due to time dilation. So what's its velocity? 0/0 = undefined, the question is meaningless. But the velocity is arguably more fundamendal than the distance travelled or time taken, so those aren't truly 0. They're also undefined quantities.
> One way to think of it might be from the photon's frame of reference its entire path has become infinitely short so it had no distance to travel at all.
No, that is not a correct way to think of it. See my other responses to the poster you responded to.
They can't be. You can't make a conscious subject out of something that has zero mass and moves at the speed of light, and therefore does not have a well-defined concept of "time passing".
> if no time is passing for them, doesn't that mean no space is being traversed either?
It is not the case that no time is passing for a photon. What is the case is that the concept of "time passing for a photon" is not well-defined. That concept not being well-defined means that "space being traversed for a photon" is not well-defined either. That does not mean "no space is being traversed". It means the concept of "space being traversed for a photon" is not well-defined.
No, outside observer will measure clocks of photon run slower by a factor of γ (Lorentz factor), which (in scalar form) is equal to 1/sqrt(1 - v^2 / c^2 ). It diverges at v = c.
> outside observer will measure clocks of photon run slower by a factor of γ
This is not correct since "clocks of photon" is a meaningless concept (at least if photons have zero mass, which they do according to our best current models).
> I did not mean to imply that you can attach a clock on a photon.
The issue isn't that you can't attach a clock to a photon in a practical sense. The issue is that even in principle, the concept of "the clock of a photon" is not well-defined. For it to be well-defined, there would need to be an inertial frame in which a photon was at rest. But that is impossible.
> Speed of light is for-all-practical-purposes infinite in the reference frame of the moving object (i.e. photon), thanks to special relativity.
This is not correct, because there is no "reference frame" for a photon moving at the speed of light. The concept of "reference frame" is not well-defined for such objects.
This conversation sounds like it's running into the linguistic barrier that we tend to think of "speed of light" in terms of, well, light, so becomes recursive when talking about photons with mass, which naturally travel slower than what should be thought as "the speed of massless particles".
This according to measured upper limits on photon mass. Strong theory postulates absolute zero mass for the fundamental particle and in this case it will have an infinite lifetime.
I have to mention Dmitry Soshnikov's "JavaScript. The Core" webpage. The concepts explained in version one published in 2010 helped me land several contracts. Now I see he has "JavaScript. The Core: 2nd Edition". Thank you Dmitry!
