📎 into the personal-website-verse

Personal websites are called personal websites because they are just that: personal. Thus, the primary objective still is to have a place to express ourselves, to explore ourselves, a place that lasts while the daily storms pass by. A place of consideration, and yes, a place of proudly sharing what we do, what we think, and what we care about. A place to contribute your voice and help others. A home on the internet. A place to tell your story.

But on top of that, we have the chance to (re-)establish personal websites also as central elements of online discourse and as entry points for people who are new to the web community. For this, we need to find ways to create an ecosystem that lives up to the diversity of the personal-website-verse. Consequently, what will hold our sites together, is most possibly not one technology to rule them all, but a multitude of different and ever-evolving technologies. Things like hyperlinks, comments, Webmentions, and RSS, of course, but also other technologies that have yet to be invented. Not only would this leave enough room for individual preferences, but it would also make the whole construct more resilient while still being flexible enough to evolve over time.


💡 the limit of human endurance

Researchers studying ultramarathon runners, Arctic explorers and Tour de France bike racers revealed in June the maximum amount of energy a person can expend for a sustained period of time. It’s around 2,5 times your basal metabolic rate — the amount of energy your body uses while just chilling out — which amounts to 4000 kcal per day on average.

The limit seems to come down to how much food you can digest, rather than anything to do with your heart, lungs or muscles. The real champions: pregnant women, whose energy use peaks at 2,2 times their basal metabolic rate.

Source: Nature Briefing, via Science Advances 05 Jun 2019: Vol. 5, no. 6, eaaw0341

✒ philosophy of physics

“In what follows I will therefore take a somewhat different tack from usual review articles: I will introduce the reader to those issues in recent philosophy of physics that might be of special interest to members of other philosophical sub-disciplines. By highlighting aspects of this field that overlap with epistemology, metaphysics, philosophy of mathematics, logic and so on, I hope not only to complement extant reviews (which are typically written for a physics-inclined/trained audience), but furthermore to act as a guide for cross-disciplinary engagement on issues that will surely benefit from the attention of persons from a variety of backgrounds.”

(Non-relativistic) quantum mechanics
(Relativistic) quantum field theories
Thermodynamics and statistical mechanics
Quantum gravity
Particle physics

Elise M. Crull, Philosophy of Physics, Analysis, Volume 73, Issue 4, October 2013, Pages 771–784

💬 dear future generations

This monument is to acknowledge that we know what is happening and what needs to be done. Only you know if we did it.

A plaque penned by Icelandic writer Andri Snær Magnason will memorialize Okjökull, Iceland’s first glacier lost to climate change.

Seems relevant to add this quote:

Dear future generations: Please accept our apologies. We were rolling drunk on petroleum.

― Kurt Vonnegut

✒ semiconductor vs Mott insulator

Finally a nice picture for distinguishing the two:

“In a band insulator, as illustrated on the top-left figure, the valence band is filled. For N sites on the lattice, there are 2N states in the valence band, the factor of 2 accounting for spins, and 2N states in the conduction band. PES refers to “Photoemission Spectrum” and IPES to “Inverse Photoemission Spectrum”. The small horizontal lines represent energy levels and the dots stand for electrons. In a Mott insulator, illustrated on the top-right figure, there are N states in the lower energy band (Lower Hubbard band) and N in the higher energy band (Upper Hubbard band), for a total of 2N as we expect in a single band. The two bands are separated by an energy U because if we add an electron to the already occupied states, it costs energy U.

Perhaps the most striking difference between a band and a Mott insulator manifests itself when the Fermi energy EF is moved to dope the system with one hole. For the semiconductor, the Fermi energy moves, but the band does not rearrange itself. There is one unoccupied state right above the Fermi energy. This is seen on the bottom-left figure. On the bottom-right figure, we see that the situation is very different for a doped Mott insulator. With one electron missing, there are two states just above the Fermi energy, not one state only. Indeed one can add an electron with a spin up or down on the now unoccupied site. And only N−1 states are left that will cost an additional energy U if we add an electron. Similarly, N−1 states survive below the Fermi energy.”

arXiv:1310.1481 [cond-mat.supr-con] (2013)