Tinkering, Science, and (Not) Sharing It

I stumbled upon this research paper called PVC polyhedra: We describe how to construct a dodecahedron, tetrahedron, cube, and octahedron out of pvc pipes using standard fittings. … In particular, if we take a connector that takes three pipes each at 120 degree angles from the others (this is called a “true wye”) and we…

Simulations: Levels of Consciousness

In a recent post I showed these results of simulations for our heat pump system: I focused on the technical details – this post will be more philosophical. What is a ‘simulation’ – opposed to simplified calculations of monthly or yearly average temperatures or energies? The latter are provided by tools used by governmental agencies…

You Never Know

… when obscure knowledge comes in handy! You can dismantle an old gutter without efforts, and without any special tools: Just by gently setting it into twisted motion, effectively applying ~1Hz torsion waves that would lead to fatigue break within a few minutes. I knew my stint in steel research in the 1990s would finally…

No, You Cannot ‘Power Your Home’ by One Hour of Cycling Daily

In the past days different versions of an article had popped up in my social media streams again and again – claiming that you could power your home for 24 hours by cycling for one hour. Regular readers know that I craft my statements carefully in articles about energy, nearly as in the old times…

Heat Pump System Data: Three Seasons 2012 – 2015

We have updated the documentation of monthly and seasonal measurement data – now including also the full season September 2014 to August 2015. The overall Seasonal Performance Factor was 4,4 – despite the slightly lower numbers in February and March, when was the solar collector was off during the Ice Storage Challenge. Edit: I have…

An Efficiency Greater Than 1?

No, my next project is not building a Perpetuum Mobile. Sometimes I mull upon definitions of performance indicators. It seems straight-forward that the efficiency of a wood log or oil burner is smaller than 1 – if combustion is not perfect you will never be able to turn the caloric value into heat, due to…

How to Evaluate a Heat Pump’s Performance?

The straight-forward way is to read off two energy values at the end of a period – day, month, or season: The electrical energy used by the heat pump and the heating energy delivered. The Seasonal Performance Factor (SPF) is the ratio of these – the factor the input electrical energy is ‘multiplied with’ to…

Ice Storage Challenge: High Score!

Released from ice are brook and river By the quickening glance of the gracious Spring; The colors of hope to the valley cling, And weak old Winter himself must shiver, Withdrawn to the mountains, a crownless king. These are the first lines of the English version of a famous German poem on spring, from the…

“An Unprecedented Test for Europe’s Electricity System”

And we will not be able to contribute – by a hair. We have just ordered our photovoltaic generator, and installation is planned for April. It is the (partial) Solar Eclipse on March 20 that made Europe’s Transmission System Operators (TSOs) release an announcement: Under a clear morning sky on 20 March 2015, some 35000…

A Sublime Transition

Don’t expect anything philosophical or career-change-related. I am talking about water and its phase transition to ice because … …the fact that a process so common and important as water freezing is not fully resolved and understood, is astonishing. (Source) There are more spectacular ways of triggering this transition than just letting a tank of water…

All Kinds of Turbines

I got an interesting question, related to the heat-from-the-tunnel project: Has anyone considered the fact that the water can be used to first drive turbines and then distributed to supply the input source for the heat pumps? I am a water turbine fan, and every time I spot a small hydro power plant on a…

Pumped Heat from the Tunnel

The idea to use a reservoir of water as a heat pump’s heat source is not new. But now and then somebody dares to do it again in a more spectacular way. Provided governmental agencies give you permit, lakes or underground aquifers could be used. Today a (German) press release about a European research project called Sinfonia…

Grim Reaper Does a Back-of-the-Envelope Calculation

I have a secondary super-villain identity. People on Google+ called me: Elke the Ripper or Master of the Scythe. [FAQ] No, I don’t lost a bet. We don’t have a lawn-mower by choice. Yes, we tried the alternatives including a reel lawn-mower. Yes, I really enjoy doing this. It is utterly exhausting – there is no…

Non-Linear Art. (Should Actually Be: Random Thoughts on Fluid Dynamics)

In my favorite ancient classical mechanics textbook I found an unexpected statement. I think 1960s textbooks weren’t expected to be garnished with geek humor or philosophical references as much as seems to be the default today – therefore Feynman’s books were so refreshing. Natural phenomena featured by visual artists are typically those described by non-linear…

Greatest Innovation Ever

I like silly Top Something Lists. In a more serious state of mind I wondered what a list of the top inventions or top innovations of humankind might comprise. Random googling yields list items such as The Internet, Money, Plumbing, and The Power of Story. This list contains what my biased mind was searching for:…

The Falling Slinky and Einstein’s Elevator

I have not known that this toy has a name at all. The ‘spring’ that can walk down the stairs is called Slinky! We all know how the Slinky walks – but how does it fall? This video might come as a surprise! The authoritative article on The Falling Slinky is this one: Modelling a…

The Twisted Garden Hose and the Myth of the Toilet Flush

If you have wrapped your head around why and how the U-shaped tube in the flow meter (described in my previous post) is twisted by the Coriolis force – here is a video of a simple experiment brought to my attention by the author of the quoted article on gyroscope physics: You could also test it…

Microwave Ovens Are Not Rodent-Ready

It happened again.  It took me four years to cope with, and now I have to start again from day zero. (Insert 2 minutes of silence and grieving here) Any device we use on a daily basis is designed for safety. You find hundreds of little logos near the serial number of the device which tell…