# Elpee?

Back with a charged computer and taking up where I left off, I imagine many of you spotted the theme of my last post ‘Elpee!’ was Planck’s Length, L­­­p­­­ and the strange forces that seem to bind the universe together at the same time as preventing it from collapsing in on itself.

You did? Wow!

Anyway for those who might not have done:

The concealed theme in the poem is the four fundamental interactions or forces of Quantum Mechanics (QM): electromagnetic, gravitational, strong, and weak, which make up our universe. They can be hard to understand, as is QM generally, so I pictured them as a flock of starlings.

Electromagnetic radiation is the colours thrown between the sky and starlings wings (by which they know one another and their world).

Gravity is the distant longing, drawing the flock as one (Newton’s apple to the earth).

The strong interaction draws mate to mate, binding families and roosting birds into groups (atoms, molecules, compounds, you).

The weak interaction is the short range interaction between birds, stopping them crashing together but not strong enough to break up the flock (stabilising those groups drawn by the strong interaction).

LP is Planck Length. A starling’s wing-flutter and flight swirls make its position, size and velocity uncertain. If there were no limit to this, if their size could be infinitely small, the flock could collapse or evaporate to nothing. Max Planck, faced with a  problem involving radiation, found there was a limit to the smallness of things; a fundamental length or grain size, even to space, below which the laws of physics will not take us. This length is known as Planck’s Length, or LP, the smallest distance that can be measured.

Because length is effectively granular in this way, so are all those things that depend on it. Speed of travel is length (distance travelled) divided by the time taken, so time is granular in the same way; it literally ticks on in tiny portions of Planck Time (Tp), the time light, the fastest thing in the universe, takes to travel one Planck length. Mass, temperature, and electric charge also share this granular nature.

I hope you find this difficult to follow because physicists do. There is something very strange going on – a conflict between the laws governing the very small and the very large. The sums do not work. When particles, which are seen as the focus or points of action of waves of energy, come together en masse, the Earth and Moon, or an apple falling from a tree, their gravity bends and contracts the space between them and brings them together. Physicists can calculate the mathematics of this and define its laws, but these same particles on their own, in their own tiny inner space do not follow these laws. The laws we find governing the very small and the very big do not agree. Somewhere we have got it wrong.

No poem this time, but I am working on it. A murmuration of starlings is one way of looking at the cosmos with the starlings representing particles of matter in fields of energy. Each starling or particle is a focus or point of action of its field of energy.

There may be another way, a quite different, far more relaxed view, in which starlings are replaced by ‘Eddies in the Stream’ which I shall post in a couple of weeks. If you want to get ahead of me there are two fun and interesting ‘You Tube’ illustrations by ‘Physics Girl’ Dianna Cowernand James Dann here. If you watch James Dann’s setup closely there is something to be seen that he does not mention.

See you in two weeks.

# Elpee! Elpee! Elpee!

First, I am sorry it has taken so long to recover (if we have recovered!) from moving house; nevertheless the title above is not a whoop of celebration but clue to a concealed theme in this poem:

Elpee! Elpee! Elpee! the starlings cry
wheeling home in evening sky,
the folding flock outspread and high
seems beautiful and black.

Beauty yes, and black below,
but could we fly, then we would know
the colours that the sky can throw
on wings that throw them back.

And could we see with starling’s eye
the beauty of the fading sky
fall on each feather, wing and eye,
then would we learn, and would we sing,
Elpee! Elpee! Elpee!
and would we wheel and would we wing
the cosmic dance, the wheeling ring,
of birth and death and everything,
nor know the reason why?

A distant longing draws the flock
from city roof-tops where the clock
chimes evening hours.
A strong force binding mate to mate,
which narrows wider gaps;
a wary, weaker sense prevents,
when bird flies close to bird,
the flock’s collapse.

Each fluttering bird a wheeling heart –
a fundamental part – in one great family,
Elpee! Elpee! Elpee!

Sadly I can explain none of this today as I am sat at a fading computer far from home unable to recharge it. I will just say this, it is a picture which is better seen from another direction entirely: eddies in the stream (to follow).