Follow the curve of the Plough's handle away from the bowl, keep going, and
the arc lands on an orange star sitting low and steady in the west after
sunset. That is Arcturus, fourth brightest in the sky, and the brightest thing
in Boötes by a margin that makes the rest of the constellation look like
scaffolding.
It is 36.7 light-years away, plus or
minus two tenths, a figure that comes from a parallax shift of 88.83
milliarcseconds measured by Hipparcos. Convert that distance into a date and
the light entering your eye tonight left the star around Christmas 1989. The
error bars are narrow enough to be worth stating: mid-October 1989 at the
earliest, early March 1990 at the latest. Nothing here is exact to the day, and
it does not need to be.
Which is before. Before the two evenings of 29 and 30 November 1990 spent
playing the lead in Caryl Churchill's Serious Money at the Bowen West
Theatre in Bedford, a building since
demolished and replaced with flats. The light landing on the town tonight is
about eleven months older than the thing it feels like it should belong to. It
left while all of that was still ahead of everyone involved.
Run the arithmetic the other way. The light that left Earth on those two
nights, the streetlamps and the stage wash and whatever escaped through the
windows, is now 35.78 light-years out, and it reaches Arcturus in eleven
months. That is not a second coincidence. It is the same eleven months, and it
could not be anything else: the amount by which the incoming light predates the
evenings is exactly the amount of journey the outgoing light has left to run.
Being behind and being awaited are one measurement read from either
end.†
Which leaves a third parcel, and it is the one that matters. Arcturus was also
shining in November 1990. Photons left its surface during those same weeks,
started across the same gap, and have not arrived. They are somewhere out there
this evening, closing at the only speed on offer, and they land here on exactly
the day Bedford's light reaches the star, both being that one moment plus the
same distance. That coincidence survives the uncertainty in a way the calendar
does not. Whatever the true figure turns out to be, the two arrivals share it
and stay simultaneous; it is only the date they share that can move by a
season.
The timetable is unglamorous and specific. Light that left Arcturus at the
start of September 1990 gets here in the middle of next May, the 1st of
November arrives in mid-July, and the 30th, the second night, arrives around 11
August 2027. So for those few weeks between mid-July and mid-August the star
overhead will not be a way of thinking about November 1990. It will be November
1990, delivered, thirty-seven years late and on schedule.
The inversion held at the time, too. Anyone who stepped outside the theatre on
those nights and looked up was seeing Arcturus as it had been in about March
1954, while the star's actual output that week was already in flight toward an
audience that did not yet exist. No two points in the sky report the same date.
A single view of a single night is a staggered archaeology, every object filing
from its own distance, with the word "now" doing no work at all.
The two beams passed each other around October 2008, roughly 17.9 light-years
out, in a stretch of nothing with no name.
In 1933 a city built a ceremony out of this and got it slightly wrong. The
Century of Progress exposition opened in Chicago on 27 May, and at 9:15 that
evening the fair's floodlights came on under starlight from
Arcturus,
gathered by telescopes at Yerkes, Harvard, Allegheny and Illinois, dropped onto
photoelectric cells and run as a thread of current down a telegraph wire to the
lakefront. The Tribune's man wrote it up next morning as a beam of light which
forty years ago started from the star
Arcturus. Forty years was
the entire point. Arcturus was reckoned to sit forty light-years out, so the
beam would have departed during Chicago's previous world's fair in 1893, and
the city could open its future with a signal sent by its own past.
The distance was wrong. At 36.7 light-years that beam left around 1896, three
years adrift, and thousands of people stood in the dark and cheered a piece of
arithmetic that did not hold. The idea is credited to Edwin Frost of Yerkes,
who was by then blind, and who stood outside the Hall of Science and asked the
crowd whether this was not a fitting demonstration of a century of progress. It
was fitting, though not in the way he meant. A ceremony hung on light that left
at the wrong time is exactly what tonight is, scaled up and sold tickets for.
The exchange is even but the bookkeeping is not. Arcturus's light arrives and
is collected: you can stand outside and
take delivery of December 1989 with your own eyes, and next August take
delivery of November 1990. Bedford's light will arrive too, that same day, on
time, and find no receiver and no flux worth the name, spread so thin across
an expanding sphere that no
instrument could reassemble an image from it. Both directions transmit. Only
one of them is ever read.
The star is indifferent to the arrangement. It is around seven billion years
old, older than the Sun, and moving fast enough at 122 kilometres a second that
Halley caught it shifting in 1718 by setting its position against the one
Ptolemy had written down, which is the same trick as everything above. That
motion also means next summer's delivery is not an old picture of the current
star. Arcturus has slid about eighty arcseconds across the sky since 1990, a
little over a minute of arc, so the light will have set out from a position the
star has already left.
Hauntology usually runs the other way. The past reaches you as residue, as
things that outlasted their moment
or as the holes where they used to be: a demolished theatre, a recording, a
smell, the flats that went up on the site. This is the exception. Nothing about
it survived, was kept, or was reconstructed. It has simply been in transit the
whole time, and it is not behind anyone. It is inbound.
The date is in the diary now, which is the only part of this that ever needed
anyone. Next summer the sky will look exactly as it does tonight, one orange
star at the end of an arc, giving no indication whatever that what left in
November 1990
has finally got here.
Amendment, 8 September 2026. This post was expanded on the day of publication. The original ran to the outbound half of the arithmetic only, tracing Bedford's light toward Arcturus; the inbound half, the star's own November 1990 still on its way here, was added along with the 1954 backward view and the proper-motion figure. Nothing in the first version was retracted. ↩