MONIAC



"The MONIAC — short for Monetary National Income Analogue Computer — was a machine that analyzed economic data using, yes, hydraulics. Basically, it pumped water through pipes and tanks in an effort to simulate an economy and make predictions about its future. [..]
The machine’s various tanks and flows represent different parts of an economy, such as banks, consumer spending, personal savings, taxes, foreign holdings, and more. As McRobie explains, if you find that the personal savings tank is getting too full and you want to encourage more investment, you can simulate a drop in interest rates by widening the bank’s valve so that money flows more freely through the system."
Wired

I guess MONIAC is the wet dream of every Keynesian central planner; I suspect Mr. Abe is using his right now to figure out where all that Yen-water went that he printed. Perhaps he should have closed the carry trade valve to avoid recession?

Artiste and vectors

I just read Henning Dekant's blog post contemplating an alternative history with William K. Clifford enjoying a longer life and more influence on physics. It introduces us to 'geometric algebra' with the central idea to define the non-commutative product of two vectors as
AB = A*B + A/\B
where * is the usual scalar product and /\ the anti-commutative wedge product.

In a conventional textbook this is a big no-no, because it adds a scalar to a vector, but it nicely relates to complex numbers in 2D and quaternions in 3D and it supposedly simplifies everything in 2D and a lot in 3D.
I added this to my to-do list of things I need to understand better, which already contains an entry about algebraic topology and another about non-commutative geometry (more about that perhaps later).

Btw it seems that Henning Dekant and Robert R. Tucci have (re)created Artiste as a company to develop software and software patents for quantum computers. Of course, the necessary hardware does not really exist yet, but perhaps it is not such a bad idea to try this time to think about software before quantum computers become available. (Is 'hardware' really a good term for a quantum computer?)
How would classical computers look like if e.g. Python would have been developed already in the 1940s? Or in a less distant alternative universe - how would computers look like if a Lisp interpreter had been implemented before the first Fortran compiler?

Interstellar - less than stellar (spoilers!)

I am pretty sure that an astronaut who falls into a black hole would not end up behind the bookshelf of his daughter - even if it turns out that the bookshelf is actually part of a 5-dimensional lattice.
So where exactly was the physics expertise of Kip Thorne used in this movie? Was it in the scene where sparks appear in the black hole, which rip the spacecraft apart but leave the spacesuit of the astronaut intact? Or was it in an earlier scene, when the spaceship takes off from the water planet? Supposedly gravitation was really strong there, so the rocket engines had to be quite powerful - but they left only a few ripples on the water. (Btw Newton's law of action and reaction was mentioned later.) This takeoff looked to me like a scene from Star Trek and I am talking about the 1960s tv series. And the earlier trip through the wormhole was Star Trek quality too imho.
Btw the whole sequence about Dr. Mann could have been cut out without any loss of precious quantum information, which would have accelerated the plot and spared us from watching Matt Damon's acting skills.
So here I am, left to wonder about the nature of space-time and in particular where those 3 hours went that I wasted with this movie. I am afraid that I will not find them behind my bookshelf.