>A glass of wine with dinner is unlikely to significantly disrupt your sleep
it will and it does. anybody who owns a smart watch with heart rate monitor can observe it. the proverbial glass is very visible as a spike of resting heart rate and especially horrible on HRV.
besides, there are "glasses" which can take full 750ml bottle. may be most people don't go such extreme but still very good to fool themselves about alcohol volume consumption
I would guess this is the same reason why one can't change git repo history without affecting people working with the repo. Merkle tree all over the store.
It wasn't restricted per se. Just it didn't exist or produced as a civil appliance, so you won't be able to buy it. But civil defense kits usually had the counter, so if you really wanted one you probably could get it. My dad got one right after Chernobyl disaster.
A bit unorthodox advice, start lifting weights. Heavy. Aim to build strength, not muscles or look. 40s is a great age to do this, better than 50s for sure.
For men, physical strength gives more confidence, and problems which you perceive hard will look less so when you are able to deadlift 500lb. And yeah, don't quit your current job without getting new one. Bad idea. And don't give away anything for free to your employer.If they want to fire you, make them sweat (in some places it is not easy process).
ps: speaking of taking 3-6-12 months off advises. Irrelevant of your situation, I think we are living through interesting part of the "hockey stick" curve when being out for one year could mean end of the tech career. Things move way too fast, and gaining velocity.
re your last paragraph, I'm not sure (another commenter told me to be more positive so here we go!)
In my ~20 year career, a huge amount of tech has just been: servers, frontend, backend, databases, queues, caches, auth etc. The big shifts have been gradual and evolutionary (eg NoSQL, OAuth, React, SaaS, Cloud)
Big fads that were going to disrupt tech work as we know it have not entirely lived up to their hype (at least from my perspective): No Code, Blockchain, Serverless, GraphQL, Big Data.
Tech is a lot of big companies who move very slow. Particularly outside of SV/US where there is less VC hype.
But, it could be different this time. It's of course something to keep an eye on, particular if I feel I need to ride the hype train to get back into things
>it's about money, corporate takeover, money, "efficiency," money, green, money, safety third, money, because fuck them that's why, money, $$$, money...
let me rephrase a bit. It is all about shareholders and how to make more money for them. Every single quarter. and if the CEO is not aligned with these values she will be replaced by new one. Not all CEOs are greedy bastards but the whole system is designed to eliminate every single person who cares about something else except short term returns for the shareholders. So good CEOs are out and bad CEOs are in. Survival of the fittest as it is.
nitpick: I wonder how TSP became NP complete. It would require to polynomial time algorithm to validate the solution. I doubt such algorithm does exist.
Strictly speaking, the only problems in NP are decision problems, so when we say "TSP is in NP", we're talking about the "decision version of TSP": given a graph G, does there exist a Hamiltonian circuit with total length <= K?
And it's straightforward to show that this problem is in NP, because if the answer is "yes", then simply exhibiting such a tour is enough to provide a polynomial-time-verifiable proof of the answer's correctness.
(Note that it is not known whether TSP is in co-NP, so it is not known whether one can produce a polynomial-time-verifiable proof of a "no" answer.)
But note that if it were to turn out that the decision version of TSP was solvable in polynomial time, then the optimization version would also be in P, because you can just binary-search on all of the possible values of K. This results in at most a polynomial slowdown.
As far as I remember Far was always extremely popular. As far as I remember before "free license" there were various cracks readily available. At some point the author gave up and said something along the line, I won't make money from "russians" anyway so please use this "license" and may be you will stop to produce those cracks!
When on Windows, Far becomes tool to go if you are developer. Powerful file browser with shell and quick viewer and editor, also with ability to create shortcuts to dirs and commands. All together it creates this mouse-free flow which many devs like.
If somebody needs to build an intuition about entropy he could think about simple problem.
You are given insulated cylinder with a barrier in the middle. Left side of the cylinder filled with ideal gas A, and the right side filled with gas B. If given a particle one can distinguish A from B. The pressure and temperature on both sides are the same. Then you remove the barrier and gases mix. Question: how much work you need to do to revert the system into the original state?
Hint: the work is equal to entropy difference between two states.
More generally, if you have proper insulated system and leave it be for a while. All of sudden you will have to do some work to come back to the original state despite energy conservation law holds.
If you need to do work in order to revert to the previous state, does it imply you can extract work when going to the first to the second state?
Given the scenario you just laid out it seems no work can be extracted just by letting mix two substances that are at the same temperature and pressure. But there is something about it that doesn't quite add up to my intuition of symmetry and conservation laws. Could you please elaborate more on that?
I think you can very well extract work from having a membrane and selectively let one substance mix into the other but not the other in the first [0]. It is called Osmosis [1].
I guess what's confusing me in this scenario is that we're not saying that the two halves of the cylinder contain particles with different properties (e.g. different velocities) but only that we can "tell them apart" as if they were coloured differently, but otherwise behaving in exactly the same way.
The former scenario is famously the setting for Maxwell's daemon. I was assuming this scenario is something else.
I'm confused because on one hand I can see that it requires work to reorder the particles once they have been shuffled around. On the other hand I don't see how one could extract work while they get shuffled around if they all have the same momenta.
Perhaps the answer is that we cannot have a system where the microscopic entities are at the same indistinguishable but also distinguishable. Perhaps if they had different "colours' it means they do interact differently with the environment? I'm still confused frankly
Historically this caused a lot of confusion, so you aren't the only one. You may find E. Jaynes' classic paper on the Gibbs mixing paradox helpful, especially from page 7 onwards:
That is irrelevant, we don't need to be able to tell them apart, the membrane needs to be able to. Besides that, they can be completely identical.
> I'm confused because on one hand I can see that it requires work to reorder the particles once they have been shuffled around. On the other hand I don't see how one could extract work while they get shuffled around if they all have the same momenta.
In the illustration with the cylinder from Wikipedia you can see that the level of the one fluid (which the other fluid is selected into) rises. It performs work against gravity and builds up potential energy / increases the pressure. You can harvest that.
> The former scenario is famously the setting for Maxwell's daemon. I was assuming this scenario is something else.
In Maxwell's daemon you start with a substance which is already mixed and separate it into its components. That requires work and is the exact opposite of what is happening here. In fact it is called reverse Osmosis [0]. Osmosis gives you pressure which you can harvest, so reverse osmosis needs pressure back to operate. That completes the cycle.
Indeed you can extract work from this system. But because of energy conservation it will result to temperature drop. In case if you want to revert the system to its original state you will have to reheat it (return previously extracted work back) AND also spend some work to reorder particles (reduce entropy).
>If you need to do work in order to revert to the previous state, does it imply you can extract work when going to the first to the second state?
Nope. The work comes from the system coming from ordered state into unordered.
Why the problem above is good for intuition because you can work out how to reverse the state. You invent semi-magical barrier which is fully transparent for particles A and reflects particles B, then you start to push such barrier from left to right up to the middle, compressing gas B (and making work!) and leave left part with gas A only, then repeat similar exercise on the right side.
>Given the scenario you just laid out it seems no work can be extracted just by letting mix two substances that are at the same temperature and pressure. But there is something about it that doesn't quite add up to my intuition of symmetry and conservation laws. Could you please elaborate more on that?
As far as I understand this asymmetry was the exact reason why entropy was introduced. Then later explained by Boltzmann via a measure of number of microscopic states.
Naturally second law of thermodynamics forbids perpetual engines.
Enter Maxwell's demon as a completely valid solution to this problem showing you can decrease entropy within that system (but you need to exclude the demon from the system).
it will and it does. anybody who owns a smart watch with heart rate monitor can observe it. the proverbial glass is very visible as a spike of resting heart rate and especially horrible on HRV.
besides, there are "glasses" which can take full 750ml bottle. may be most people don't go such extreme but still very good to fool themselves about alcohol volume consumption
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