I see, where you're coming from, but in that particular case, the "intuitive" explanation (walk on a graph) is far less intuitive for me than the proper explanation, that a Markov process is memoryless.
That said, I used MCMC in the past to do physics simulation, where the Markov property also applies to the underlying physical process. So maybe it's just me.
No single explanation works for most. That's why you need multiple ways to explain things and how the standard education system fails at disseminating information.
For me the defining feature of C++ are its move semantics. It permeates every corner of your C++ code and affects every decision you make as a C++ developer.
Rust's defining feature is its borrow checker, which solves a similar problem as move semantics, but is more powerful and has saner defaults.
Arrow is pretty cool, although I haven't had the opportunity yet to use it.
I skimmed the paper you linked and wondered, how one measures the ser/de time a query takes or more generally how one would estimate the possible speedup of using Arrow Flight for communication with a database.
Do you by chance have any insights in that direction?
At work we have a Java application, that produces a big amount of simulation results (ca. 1Tb per run), which are stored in a database. I suspect, that a lot of time is wasted for ser/de, when aggregating the results, but it would be good to have some numbers.
To get a really precise answer you'd have to profile or benchmark. I'd say it's also hard to do an apples to apples comparison (if you only replace the data format in the wire protocol, the database probably still has to transpose the data to ingest it). And it's hard to do a benchmark in the first place since probably your database's wire protocol is not really exposed for you to do a benchmark.
While we're not using Arrow on the wire here, the ADBC driver uses Postgres's binary format (which is still row oriented) + COPY and can get significant speedups compared to other Postgres drivers.
The other thing might be to consider whether you can just dump to Parquet files or something like that and bypass the database entirely (maybe using Iceberg as well).
We will start a refactoring of the application in a few weeks to get rid of the performance problems. I will keep your advice in mind and do some thorough benchmarks in the meantime.
This is one of those obvious ideas, that sounds good on a first glance, but where it's totally non obvious, if it's really profitable in practice.
The maximum power you can take from the grid depends on the max. power of your electrolysers.
But you only want to run the electrolysers, when they are profitable, that is when the electricity prices are low enough due to oversupply.
On the other hand the whole equipment is probably expensive to buy and keep running, so you want to run them as long and often as possible.
Additionally you may use energy storage to prolong the profitable time windows of your electrolysers.
That said, it would be really great, if hydrogen and/or hydrocarbons would be synthesised at scale. There are many pilot projects and I hope one finds the right tech and trade offs to make this profitable.
The EUV light is produced by shooting a pulsed laser on tin droplets.
You already lose most of the input power in the pulsed laser. Then only a fraction of the energy of the light hitting the tin is converted to EUV light with the correct wavelength.
Finally the EUV light has to be focused on the mask through complicated optics, which is notoriously difficult for EUV light.
I guess, there are other sources of inefficiencies, that I forgot.
I’d just like to comment on how batshit insane the technology is.
“We pulse lasers in sync with dispensing droplets of molten tin to produce light that doesn’t exist outside of stars, then we use mirrors with a sub-angstrom surface roughness to precisely direct it onto wafers.”
Not to mention the fact that this is happening, IIRC, thousands of times per second, and the tool has to take the wafer’s topography into account to focus the beam. Honestly, EUV litho makes every other technology you could describe sound like child’s play.
Roughly similar craziness: Disk drives mechanically position heads less than 1nm above the platter, with horizontal accuracy of significantly less than the 50nm track width, at a retail price of a few hundred $$ or less.
30 years ago I think you could have gotten any number of experts to explain why both EUV lithography and modern disk drives are impossible.
The first time I read about this process, I was convinced aliens were involved. Seriously, it's one of those crazy pitch meeting things that sounds ridiculous so of course it was green lit. "So we fire this laser, pew pew, into a field of molten tin droplets, and bingbangflam, you get this flash of light. So what do you think?" Hold my beer.
It's clearly some people that are very smart that can only be explained by aliens
From what I understand, tin-based sources are easier to work with because they are point-like. All the energy is produced from a tiny droplet. Synchrotron sources produce much wider beams, that need to be re-focused properly.
Synchrotron FELs are already used, and their construction paid for due to their scientific uses. Building new ones would require new synchrotrons, which are more expensive than the crazy "hit molten tin drops with lasers to make a plasma" scheme the ASML machines use.
Definitely not a place or time for extended discussion on this, but I'm quite hopeful that in another century or two it will become a shameful page in history books - the fact that when we were already able to sustain our civilisation without generating unnecessary suffering of other beings - we continued to do so out of convenience.
500 years ago if you were born into peasant family, you usually stayed peasant no matter what personal effort and talent you brought to this world.
200 years ago your sister would be treated as a posession of a guy who married her.
I'm happy that our beautiful traditions evolve into more thoughtful iterations.
And I hope that logic and kindness will continue to increase their impact on our lives and policies.
A theologist like Leibniz is concerned with dogmas, which are like axioms: They are assumed to be true and form the basis of a logical system, that is supposed to consistent.
Beside that Leibniz contributes to a thousands of years old discussion about theodicy, the righteousness of god.
Let's look at the historical context first, because your bible verse is fitting:
In many cultures of the ancient world, misfortunes and disasters are said to be the result of a divine punishment. This can be seen in the old testament on many occasions, but it's basically the same in Greek societies etc.
Christian scholars read the book of Ijob as an instance, where this thought is challenged: Ijob is living a righteous live, why is he punished?
The book itself doesn't really give an answer to that, but in the ancient world view kin liability applies. So even when Ijob was sinless, he inherits the sin of his forefathers, going all the way back to Adam.
Your bible verse (Romans 5:12) is referring to that, but if you read a bit further, this world view of the old testament is contrasted with the new testament. To paraphrase: Where one man (Adam) brought sin into the life of many, now one man (Jesus) takes the sin from all.
So in the Christian doctrine the argument, that bad things happen to us due to inherited sin doesn't apply anymore.
Which leads us to the scholarly discussion, which Leibniz is part of. The central dogmas (axioms) of Christianity relevant for the theodicy question are the following:
* There is only one god
* God is almighty
* God is all-loving
* God is understandable, since God revealed himself through Jesus.
The job of philosopher/theologist is to resolve, the perceived contradiction, that bad things are happening to good people and a loving, almighty God wouldn't allow that.
The most common solution is to drop one of the axioms, e.g. "God wants to help us, but he can't" (not almighty) or "God works in mysterious ways" (not understandable).
Leibniz instead doesn't sidestep the problem and argues, that even the best possible world can't be free from sorrow.
I, personally, really like his line of thought, but this comment is already to long to describe it further.
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