Where to Find What?

I have confessed on this blog that I have Mr. Monk DVDs for a reason. We like to categorize, tag, painstakingly re-organize, and re-use. This is reflected in our Innovations in Agriculture …

The Seedbank: Left-over squared timber met the chopsaw.

The Nursery: Rebirth of copper tubes and newspapers.

… as well as in my periodical Raking The Virtual Zen Garden: Updating collections of web resources, especially those related to the heat pump system.

Here is a list of lists, sorted by increasing order of compactification:

But thanks to algorithms, we get helpful advice on presentation from social media platforms: Facebook, for example, encouraged me to tag products in the following photo, so here we go:

“Hand-crafted, artisanal, mobile nursery from recycled metal and wood, for holding biodegradable nursery pots.” Produced without crowd-funding and not submitted to contests concerned with The Intersection of Science, Art, and Innovation.

The Stages of Blogging – an Empirical Study

… with sample size 1.

Last year, at the 4-years anniversary, I presented a quantitative analysis – in line with the editorial policy I had silently established: My blogging had turned from quasi-philosophical ramblings on science, work, and life to no-nonsense number crunching.

But the comment threads on my recent posts exhibit my subconsciousness spilling over. So at this anniversary, I give myself permission to incoherent reminiscences. I have even amended the tagline with this blog’s historical title:

Theory and Practice of Trying to Combine Just Anything.

Anecdotal evidence shows that many people start a blog, or another blog, when they are in a personal or professional transition. I had been there before: My first outburst of online writing on my personal websites predated quitting my corporate job and starting our business. The creative well ran dry, after I had taken the decision and had taken action – in the aftermath of that legendary journey.

I resurrected the old websites and I started this blog when I was in a professional no-man’s-land: Having officially left IT security, still struggling with saying No to project requests, working on our pilot heat pump system in stealth mode, and having enrolled in another degree program in renewable energies.

The pseudonymous phase: Trying out the new platform, not yet adding much About Me information. Playing. In the old times, I had a separate domain with proper name for that (subversiv.at). This WordPress blog was again a new blank sheet of paper, and I took the other sites offline temporarily, to celebrate this moment.

The discovery of a new community: The WordPress community was distinct from all other professional communities and social circles I was part of. It seems that new bloggers always flock together in groups, perhaps WordPress’ algorithms facilitate that. I participated with glee in silly blogging award ceremonies. However, I missed my old communities, and I even joined Facebook to re-unite with some of them. Living in separate worlds, sometimes colliding in unexpected ways, was intriguing.

Echoes of the past: I write about Difficult Things That I Handled In the Past – despite or because I have resolved those issues long before. This makes all my Life / Work / Everything collections a bit negative and gloomy. I blogged about my leaving academia, and my mixed memories of being part of The Corporate World. It is especially the difficult topics that let me play with geeky humor and twisted sarcasm.

The self-referential aspect: Online writing has always been an interesting experiment: Writing about technology and life, but also using technology. As philosophers of the web have pointed out, the internet or the medium in general modifies the message. I play with websites’ structure and layout, and I watch how my online content is impacted by seemingly cosmetic details of presentation.

Series of posts – find our favorite topic: I’ve never participated in blogging challenges, like one article a day. But I can understand that such blogging goals help to keep going. I ran a series on quantum field theory, but of course my expertise was Weird Internet Poetry … yet another demonstration of self-referentiality.

The unexpected positive consequences of weird websites – perhaps called ‘authentic’ today. They are a first class filter. Only people who share your sense of humor with contact you – and sense of humor is the single best criterion to find out if you will work well with somebody.

Writing about other people’s Big Ideas versus your own quaint microcosmos. I have written book reviews, and featured my favorite thinkersideas. I focussed on those fields in physics that are most popular (in popular science). My blog’s views had their all-time-high. But there are thousands of people writing about those Big Things. Whatever you are going to write about, there is one writer who cannot only write better, but who is also more of a subject matter expert, like a scientist working also as a science writer. This is an aspect of my empirical rule about your life being cliché. The remaining uncharted territory was my own small corner of the world.

Skin in the Game versus fence-sitting. Lots of people have opinions on many things on the internet. The preferred publication is a link to an article plus a one-liner of an opinion. Some people might really know something about the things they have opinions on. A minority has Skin in the Game, that is: Will feel the consequences of being wrong, personally and financially. I decided to focus on blogging about topics that fulfill these criteria: I have 1) related education and theoretical knowledge, 2) practical hands-on experience, 3) Skin in the Game. Priorities in reverse order.

The revolutionary experiment: Blogging without the motivational trigger of upcoming change. Now I have lacked the primary blogging impulse for a while. I am contented and combine anything in practice since a while. But I don’t have to explain anything to anybody anymore – including myself. I resorted to playing with data – harping on engineering details. I turn technical questions I get into articles, and I spend a lot of time on ‘curating’: creating list of links and overview pages. I have developed the software for my personal websites from scratch, and turned from creating content to structure for a while.

Leaving your comfort zone: I do edit, re-write, and scrutinize blog postings here relentlessly. I delete more content again than I finally publish, and I – as a text-only Courier New person – spend considerable time on illustrations. This is as much as I want to leave my comfort zone, and it is another ongoing experiment – just as the original stream-of-consciousness writing was.

But perhaps I will write a post like this one now and then.

Pine trees in Tenerife.

Same Procedure as Every Autumn: New Data for the Heat Pump System

October – time for updating documentation of the heat pump system again! Consolidated data are available in this PDF document.

In the last season there were no special experiments – like last year’s Ice Storage Challenge or using the wood stove. Winter was rather mild, so we needed only ~16.700kWh for space heating plus hot water heating. In the coldest season so far – 2012/13 – the equivalent energy value was ~19.700kWh. The house is located in Eastern Austria, has been built in the 1920s, and has 185m2 floor space since the last major renovation.

(More cross-cultural info:  I use thousands dots and decimal commas).

The seasonal performance factor was about 4,6 [kWh/kWh] – thus the electrical input energy was about 16.700kWh / 4,6 ~ 3.600kWh.

Note: Hot water heating is included and we use flat radiators requiring a higher water supply temperature than the floor heating loops in the new part of the house.

Heating season 2015/2016: Performance data for the 'ice-storage-/solar-powered' heat pump system

Red: Heating energy ‘produced’ by the heat pump – for space heating and hot water heating. Yellow: Electrical input energy. Green: Performance Factor = Ratio of these energies.

The difference of 16.700kWh – 3.600kWh = 13.100kWh was provided by ambient energy, extracted from our heat source – a combination of underground water/ice tank and an unglazed ribbed pipe solar/air collector.

The solar/air collector has delivered the greater part of the ambient energy, about 10.500kWh:

Heating season 2015/2016: Energy harvested from air by the collector versus heating-energy

Energy needed for heating per day (heat pump output) versus energy from the solar/air collector – the main part of the heat pump’s input energy. Negative collector energies indicate passive cooling periods in summer.

Peak Ice was 7 cubic meters, after one cold spell of weather in January:

Heating season 2015/2016: Temperature of ambient air, water tank (heat source) and volume of water frozen in the tank.

Ice is formed in the water tank when the energy from the collector is not sufficient to power the heat pump alone, when ambient air temperatures are close to 0°C.

Last autumn’s analysis on economics is still valid: Natural gas is three times as cheap as electricity but with a performance factor well above three heating costs with this system are lower than they would be with a gas boiler.

Is there anything that changed gradually during all these years and which does not primarily depend on climate? We reduced energy for hot tap water heating – having tweaked water heating schedule gradually: Water is heated up once per day and as late as possible, to avoid cooling off the hot storage tank during the night.

We have now started the fifth heating season. This marks also the fifth anniversary of the day we switched on the first ‘test’ version 1.0 of the system, one year before version 2.0.

It’s been about seven years since first numerical simulations, four years since I have been asked if I was serious in trading in IT security for heat pumps, and one year since I tweeted:

Internet of Things. Yet Another Gloomy Post.

Technically, I work with Things, as in the Internet of Things.

As outlined in Everything as a Service many formerly ‘dumb’ products – such as heating systems – become part of service offerings. A vital component of the new services is the technical connection of the Thing in your home to that Big Cloud. It seems every energy-related system has got its own Internet Gateway now: Our photovoltaic generator has one, our control unit has one, and the successor of our heat pump would have one, too. If vendors don’t bundle their offerings soon, we’ll end up with substantial electricity costs for powering a lot of separate gateways.

Experts have warned for years that the Internet of Things (IoT) comes with security challenges. Many Things’ owners still keep default or blank passwords, but the most impressive threat is my opinion is not hacking individual systems: Easily hacked things can be hijacked to serve as zombie clients in a botnet and lauch a joint Distributed Denial of Service attack against a single target. Recently the blog of renowned security reporter Brian Krebs has been taken down, most likely as an act of revenge by DDoSers (Crime is now offered as a service as well.). The attack – a tsunami of more than 600 Gbps – was described as one of the largest the internet had seen so far. Hosting provider OVH was subject to a record-breaking Tbps attack – launched via captured … [cue: hacker movie cliché] … cameras and digital video recorders on the internet.

I am about the millionth blogger ‘reporting’ on this, nothing new here. But the social media news about the DDoS attacks collided with another social media micro outrage  in my mind – about seemingly unrelated IT news: HP had to deal with not-so-positive reporting about its latest printer firmware changes and related policies –  when printers started to refuse to work with third-party cartridges. This seems to be a legal issue or has been presented as such, and I am not interested in that aspect here. What I find interesting is the clash of requirements: After the DDoS attacks many commentators said IoT vendors should be held accountable. They should be forced to update their stuff. On the other hand, end users should remain owners of the IT gadgets they have bought, so the vendor has no right to inflict any policies on them and restrict the usage of devices.

I can relate to both arguments. One of my main motivations ‘in renewable energy’ or ‘in home automation’ is to make users powerful and knowledgable owners of their systems. On the other hand I have been ‘in security’ for a long time. And chasing firmware for IoT devices can be tough for end users.

It is a challenge to walk the tightrope really gracefully here: A printer may be traditionally considered an item we own whereas the internet router provided by the telco is theirs. So we can tinker with the printer’s inner workings as much as we want but we must not touch the router and let the telco do their firmware updates. But old-school devices are given more ‘intelligence’ and need to be connected to the internet to provide additional services – like that printer that allows to print from your smartphone easily (Yes, but only if your register it at the printer manufacturer’s website before.). In addition, our home is not really our castle anymore. Our computers aren’t protected by the telco’s router / firmware all the time, but we work in different networks or in public places. All the Things we carry with us, someday smart wearable technology, will check in to different wireless and mobile networks – so their security bugs should better be fixed in time.

If IoT vendors should be held accountable and update their gadgets, they have to be given the option to do so. But if the device’s host tinkers with it, firmware upgrades might stall. In order to protect themselves from legal persecution, vendors need to state in contracts that they are determined to push security updates and you cannot interfere with it. Security can never be enforced by technology only – for a device located at the end user’s premises.

It is horrible scenario – and I am not sure if I refer to hacking or to proliferation of even more bureaucracy and over-regulation which should protect us from hacking but will add more hurdles for would-be start-ups that dare to sell hardware.

Theoretically a vendor should be able to separate the security-relevant features from nice-to-have updates. For example, in a similar way, in smart meters the functions used for metering (subject to metering law) should be separated from ‘features’ – the latter being subject to remote updates while the former must not. Sources told me that this is not an easy thing to achieve, at least not as easy as presented in the meters’ marketing brochure.

Linksys's Iconic Router

That iconic Linksys router – sold since more than 10 years (and a beloved test devices of mine). Still popular because you could use open source firmware. Something that new security policies might seek to prevent.

If hardware security cannot be regulated, there might be more regulation of internet traffic. Internet Service Providers could be held accountable to remove compromised devices from their networks, for example after having noticed the end user several times. Or smaller ISPs might be cut off by upstream providers. Somewhere in the chain of service providers we will have to deal with more monitoring and regulation, and in one way or other the playful days of the earlier internet (romanticized with hindsight, maybe) are over.

When I saw Krebs’ site going offline, I wondered what small business should do in general: His site is now DDoS-protected by Google’s Project Shield, a service offered to independent journalists and activists after his former pro-bono host could not deal with the load without affecting paying clients. So one of the Siren Servers I commented on critically so often came to rescue! A small provider will not be able to deal with such attacks.

WordPress.com should be well-protected, I guess. I wonder if we will all end up hosting our websites at such major providers only, or ‘blog’ directly to Facebook, Google, or LinkedIn (now part of Microsoft) to be safe. I had advised against self-hosting WordPress myself: If you miss security updates you might jeopardize not only your website, but also others using the same shared web host. If you live on a platform like WordPress or Google, you will complain from time to time about limited options or feature updates you don’t like – but you don’t have to care about security. I compare this to avoiding legal issues as an artisan selling hand-made items via Amazon or the like, in contrast to having to update your own shop’s business logic after every change in international tax law.

I have no conclusion to offer. Whenever I read news these days – on technology, energy, IT, anything in between, The Future in general – I feel reminded of this tension: Between being an independent neutral netizen and being plugged in to an inescapable matrix, maybe beneficial but Borg-like nonetheless.

Self-Sufficiency Poetry

Our self-sufficiency quota for electrical energy is 30%, but what about the garden?

Since I haven’t smart metered every edible wildflower consumed, I resort to Search Term Poetry and random images. This is a summer blog post, lacking the usual number crunching and investigative tech journalism.

(Search terms are from WordPress statistics and Google Tools)

Direct self-consumption quota was nearly 100% last year (no preservation), and self-sufficiency was very low, with one exception: Yarrow tea.

This year we will reach 100% herbal tea self-sufficiency:

Yarrow TeamThe solar/air collector is boosting yarrow harvest – and we have yet to include its cosmic quantum free energy focusing effect in the marketing brochure.

fringe science theories
can efficiency be greater than 1

Collector, yarrow, poppy

But it also boosts vitality of other life forms:

alien energy

Slimey Aliens near collector

I cannot prove that these particular slimy aliens – edible and a protected species in Austria – are harmful as I never caught them red-handed. You just need to be careful when collecting vegetables to avoid the slimy parts.

We are self-sufficient re green ‘salad’ and ‘fake spinach’ for about half a year. Our top edible wild flowers in terms of yield are Dandelion, Fireweed, Meadow Goat’s Beard …

why does the grim reaper have a scythe

Meadow Goat's Beard

… and White Stonecrop: both tasty …

jurassic park jelly

White Stonecrop and snail

… and ornamental:

zeitgeisty

White Stonecrop, Sedum Album

With standard vegetables (accepted as edible by the majority) we did crop rotation – and the tomatoes look happiest as solitary plants in new places …

analyzing spatial models of choice and judgment

Tomatoe Plant

The Surprise Vegetable Award goes to an old heirloom variety, called Gartenmelde in German:

slinkyloop antenna
physics metaphors

Gartenmelde

Last year exactly one seedling showed up, and we left it untouched. This year the garden was flooded with purple plants in spring:

virtual zen garden

Gartenmelde in spring

There are two main categories of edible plants – and two different branches of the food chain: Things we mainly eat, like tomatoes, herbs, onion, and garlic …

old-fashioned

Garlic, tomatoes, herbs

… and the ones dedicated to alien species. Top example: The plants that should provide for our self-sufficiency in carbohydrates:

simple experiment

Potatoes

In the background of this image you see the helpful aliens in our garden, the ones that try to make themselves useful in this biosphere:

force on garden hose
so called art

Helpful Alien

But looking closer, there is another army of slimy life-forms, well organized and possibly controlled by a superior civilization in another dimension:

the matrix intro
protocol negotiation failed please try again

Slimey aliens and potatoes

microwaving live animals

This garden is fertilizer- and pest-control-free, so we can only try to complement the food chain with proper – and more likeable – creatures:

solutions to problems

Hedgehog, Potatoes

Yes, I have been told already it might not eat this particular variety of aliens as their slime is too bitter. I hope for some mutation!

But we are optimistic: We managed to tune in other life-forms to our philosophy as well and made them care about our energy technology:

so you want to be an engineer

Blackbird and air pump

This is a young blackbird. Grown up, it will skillfully de-slime and kill aliens, Men-in-Black-style.

Life-forms too quick or too small for our random snapshot photography deserve an honorable mention: Welcome, little snake (again an alien-killer) and thanks mason bees for clogging every hole or tube in the shed!

It is a pity I wasted the jurassic park search term on the snail already as of course we have pet dinosaurs:

Pet Dinosaur

So in summary, this biotope really has a gigantic bug, as we nerds say.

sniff all internet access

Bug or Feature

Have I Seen the End of E-Mail?

Not that I desire it, but my recent encounters of ransomware make me wonder.

Some people in say, accounting or HR departments are forced to use e-mail with utmost paranoia. Hackers send alarmingly professional e-mails that look like invoices, job applications, or notifications of postal services. Clicking a link starts the download of malware that will encrypt all your data and ask for ransom.

Theoretically you could still find out if an e-mail was legit by cross-checking with open invoices, job ads, and expected mail. But what if hackers learn about your typical vendors from your business website or if they read your job ads? Then they would send plausible e-mails and might refer to specific codes, like the number of your job ad.

Until recently I figured that only medium or larger companies would be subject to targeted attacks. One major Austrian telco was victim of a Denial of Service attacked and challenged to pay ransom. (They didn’t, and were able to deal with the attack successfully.)

But then I have encountered a new level of ransomware attacks – targeting very small Austrian businesses by sending ‘expected’ job applications via e-mail:

  • The subject line was Job application as [a job that had been advertised weeks ago at a major governmental job service platform]
  • It was written in flawless German, using typical job applicant’s lingo as you learn in trainings.
  • It was addressed to the personal e-mail of the employee dealing with applications, not the public ‘info@’ address of the business
  • There was no attachment – so malware filters could not have found anything suspicious – but only a link to a shared cloud folder (‘…as the attachments are too large…’) – run by a a legit European cloud company.
  • If you clicked the link (which you should not so unless you do this on a separate test-for-malware machine in a separate network) you saw a typical applicant’s photo and a second file – whose name translated to JobApplicationPDF.exe.

Suspicious features:

  • The EXE file should have triggered red lights. But it is not impossible that a job application creates a self-extracting archive, although I would compare that to wrapping your paper application in a box looking like a fake bomb.
  • Google’s Image Search showed that the photo has been stolen from a German photographer’s website – it was an example for a typical job applicant’s photo.
  • Both cloud and mail service used were less known ones. It has been reported that Dropbox had removed suspicious files so it seemed that attackers tuned to alternative services. (Both mail and cloud provider reacted quickly and sht down the suspicious accounts)
  • The e-mail did not contain a phone number or street address, just the pointer to the cloud store: Possible but weird as an applicant should be eager to encourage communications via all channels. There might be ‘normal’ issues with accessing a cloud store link (e.g. link falsely blocked by corporate firewall) – so the HR department should be able to call the applicant.
  • Googling the body text of the e-mail gave one result only – a new blog entry of an IT professional quoting it at full length. The subject line was personalized to industry sector and a specific job ad – but the bulk of the text was not.
  • The non-public e-mail address of the HR person was googleable as the job ad plus contact data appeared on a job platform in a different language and country, without the small company’s consent of course. So harvesting both e-mail address and job description automatically.

I also wonder if my Everything as a Service vision will provide a cure: More and more communication has been moved to messaging on social networks anyway – for convenience and avoiding false negative spam detection. E-Mail – powered by old SMTP protocol with tacked on security features, run on decentralized mail servers – is being replaced by messaging happening within a big monolithic block of a system like Facebook messaging. Some large employer already require their applications to submit their CVs using their web platforms, as well as large corporations demand that their suppliers use their billing platform instead of sending invoices per e-mail.

What needs to be avoided is downloading an executable file and executing it in an environment not controlled by security policies. A large cloud provider might have a better chance to enforce security, and viewing or processing an ‘attachment’ could happen in the provider’s environment. As an alternative all ‘our’ devices might be actually be part of a service and controlled more tightly by centrally set policies. Disclaimer: Not sure if I like that.

Iconic computer virus - from my very first small business website in 1997. Image credits mine.

(‘Computer virus’ – from my first website 1997. Credits mine)

 

Anniversary 4 (4 Me): “Life Ends Despite Increasing Energy”

I published my first post on this blog on March 24, 2012. Back then its title and tagline were:

Theory and Practice of Trying to Combine Just Anything
Physics versus engineering
off-the-wall geek humor versus existential questions
IT versus the real thing
corporate world’s strangeness versus small business entrepreneur’s microcosmos knowledge worker’s connectedness versus striving for independence

… which became

Theory and Practice of Trying to Combine Just Anything
I mean it

… which became

elkemental Force
Research Notes on Energy, Software, Life, the Universe, and Everything

last November. It seems I have run out of philosophical ideas and said anything I had to say about Life and Work and Culture. Now it’s not Big Ideas that make me publish a new post but my small Big Data. Recent posts on measurement data analysis or on the differential equation of heat transport  are typical for my new editorial policy.

Cartoonist Scott Adams (of Dilbert fame) encourages to look for patterns in one’s life, rather than to interpret and theorize – and to be fooled by biases and fallacies. Following this advice and my new policy, I celebrate my 4th blogging anniversary by crunching this blog’s numbers.

No, this does not mean I will show off the humbling statistics of views provided by WordPress 🙂 I am rather interested in my own evolution as a blogger. Having raked my virtual Zen garden two years ago I have manually maintained lists of posts in each main category – these are my menu pages. Now I have processed each page’s HTML code automatically to count posts published per month, quarter, or year in each category. All figures in this post are based on all posts excluding reblogs and the current post.

Since I assigned two categories to some posts, I had to pick one primary category to make the height of one column reflect the total posts per month:Statistics on blog postings: Posts per month in each main category

It seems I had too much time in May 2013. Perhaps I needed creative compensation – indulging in Poetry and pop culture (Web), and – as back then I was writing a master thesis.

I had never missed a single month, but there were two summer breaks in 2012 and 2013 with only 1 post per month. It seems Life and Web gradually have been replaced by Energy, and there was a flash of IT in 2014 which I correlate with both nostalgia but also a professional flashback owing to lots of cryptography-induced deadlines.

But I find it hard to see a trend, and I am not sure about the distortion I made by picking one category.

So I rather group by quarter:

Statistics on blog postings: Posts per quarter in each main category

… which shows that posts per quarter have reached a low right now in Q1 2016, even when I would add the current posting. Most posts now are based on original calculations or data analysis which take more time to create than search term poetry or my autobiographical vignettes. But maybe my anecdotes and opinionated posts had just been easy to write as I was drawing on ‘content’ I had in mind for years before 2012.

In order to spot my ‘paradigm shifts’ I include duplicates in the next diagram: Each post assigned to two categories is counted twice. Since then the total number does not make sense I just depict relative category counts per quarter:

Statistics on blog postings: Posts per quarter in each category, including the assignment of more than one category.

Ultimate wisdom: Life ends, although Energy is increasing. IT is increasing, too, and was just hidden in the other diagram: Recently it is  often the secondary category in posts about energy systems’ data logging. Physics follows an erratic pattern. Quantum Field Theory was accountable for the maximum at the end of 2013, but then replaced by thermodynamics.

Web is also somewhat constant, but the list of posts shows that the most recent Web posts are on average more technical and less about Web and Culture and Everything. There are exceptions.

Those trends are also visible in yearly overviews. The Decline Of Web seems to be more pronounced – so I tag this post with Web.

Statistics on blog postings: Posts per year in each main category

Statistics on blog postings: Posts per year in each category, including the assignment of more than one category.

But perhaps I was cheating. Each category was not as stable as the labels in the diagrams’ legends do imply.

Shortcut categories refer to
1) these category pages: EnergyITLifePhysicsPoetryWeb,
2) and these categories EnergyITLifePhysicsPoetryWeb, respectively, manually kept in sync.

So somehow…

public-key-infrastructure became control-and-it

and

on-writing-blogging-and-indulging-in-web-culture is now simply web

… and should maybe be called nerdy-web-stuff-and-software-development.

In summary, I like my statistics as it confirms my hunches but there is one exception: There was no Poetry in Q1 2016 and I have to do something about this!

________________________________

The Making Of

  • Copy the HTML content of each page with a list to a text editor (I use Notepad2).
  • Find double line breaks (\r\n\r\n) and replace them by a single one (\r\n).
  • Copy the lines to an application that lets you manipulate strings (I use Excel).
  • Tweak strings with formulas / command to cut out date, url, title and comment. Use the HTML tags as markers.
  • Batch-add the page’s category in a new column.
  • Indicate if this is the primary or secondary category in a new column (Find duplicates automatically before so 1 can be assigned automatically to most posts.).
  • Group the list by month, quarter, and year respectively and add the counts to new data tables that will be used for diagrams (e.g. Excel function COUNTIFs, using only the category or category name  + indicator for the primary category as criteria).

It could be automated even better – without having to maintain category pages by simply using the category feeds (like this: https://elkement.wordpress.com/category/physics/feed) or by filtering the full blog feed for categories. I have re-categorized all my posts so that categories matches menu page lists, but I chose to use my lists as

  1. I get not only date and headline, but also my own additional summary / comment that’s not part of the feed. For our German blog, I actually do this in reverse: I create the HTML code of a a sitemap-style overview page on wordpress.com from an Excel list of all posts plus custom comments and then copy the auto-generated code to the HTML view of the respective menu page on the blog.
  2. the feed provided by WordPress.com can have 150 items maximum no matter which higher number you try to configure. So you need to start analyzing before you have published 150 posts.
  3. I can never resist to create a tool that manipulates text files and automates something, however weird.