Travelling by YouTube during the Lockdown

During the lockdown, and not even able to take a bus to the centre of town, I
have perforce been getting about more by YouTube.  Here are three of my
“discoveries” which I hope will be interesting and pleasing to readers.

Buzz Aldrin

I am always eager to hear about space programmes, and here from the
Science Musuem channel is yet another video showing what a nail-biting
event was the first Apollo Moon landing.

You can see the effect of the

PGNCS trouble on the Apollo Guidance Computer, which was
neither a programming error in the AGC, nor pilot error, but rather a peripheral
hardware design bug that had already been known and documented by Apollo 5
engineers. However, because the problem had only occurred once during testing,
they concluded that it was safer to fly with the existing hardware that they had
already tested, than to fly with a newer but largely untested radar system.

Quark Matter

In “Sky and Telescope” August 2001, on page 32, there is an article about
neutron stars, and are they composed of quark matter or strange matter? If made
of quark matter, then the idea is that underneath an iron crust there is a
mantle of neutron matter, which gradually gives way to quark matter at higher
pressures where hyperons are stable. With increasing depth and concentration,
the quark matter would form first droplets, then rods, then sheets, followed by
the reverse phase structure until 100% quark matter is found at the core. 
The article is by Norman K. Glendenning, author of

Compact Stars: Nuclear Physics, Particle Physics, and General Relativity.

This intrigued me, because such phase morphologies are characteristic of many
block copolymers, with a similar transition sequence as one varies the ratio of
the two components of the block copolymer.

So I was intrigued to watch this video by
Anton Petrov,
who gives us a daily dish of mostly astronomical news:

I wonder, though, what is the difference between quark matter and strange matter? 

Virtual Choir

 With Covid-19 upon us, we have seen a vast output of virtual choirs.

Here is a virtual choir in Ghana singing “Come, My Way, My Truth, My Life” by

George Herbert (1593 – 1633), a Welsh-born English poet and orator.
Herbert's poetry is associated with the writings of the metaphysical poets, and
he is recognized as “a pivotal figure: enormously popular, deeply and broadly
influential, and arguably the most skillful and important British devotional
lyricist.”

A 400 year old British poem, but I would say that this choir have certainly
“made it their own”.