14 | NewScientist | 3 November 2018NEWS & TECHNOLOGY
Leah CraneTHE Higgs boson may have
stopped the early universe from
collapsing into black holes.
Shortly after the birth of the
universe, all matter was still
crammed into a tiny region. Then,
a process called inflation took
over, rapidly expanding space.
Most cosmologists agree that
this inflation happened, but it’s
not clear how. David Sloan at the
University of Oxford and George
Ellis at the University of Cape
Town in South Africa reason that
the Higgs boson may offer an
explanation.
Inflation requires a particular
kind of particle that permeates
every point in space, and the only
particle we have seen like this is
the Higgs boson. According to
Sloan and Ellis’s calculations, if
the Higgs boson is actually the
right kind of particle, it would
solve an important sticking point
in our understanding of inflation:
what the universe must have
been like just before it happened.
They suggest that the
pre-inflation universe, just
micromoments after the big bang,
probably started in a fairlydisorganised or high-entropy
state, simply because there are
more such states than highly
ordered ones.
Sloan illustrates this point by
imagining rolling a million dice:
There’s only one way to get all
sixes, but once you introduce one
number that’s not a six, there are
5 million permutations, he says.
One of the highest-entropy
states is that of a black hole, but
suggesting the pre-inflation
universe was filled with blackholes creates a problem. This is
because black holes often clump
together and wouldn’t lead to
the smooth universe we see now,
with matter equally spread out
everywhere.
For similar reasons, a single
mega black hole wouldn’t be
right either. “You’d have this one
singularity and you wouldn’t be
able to expand it into trees and
birds and all the wonderful things
we see in the universe,” says Sloan.
While we still don’t fully
understand the Higgs boson, one
suggested property is useful to
the work of Sloan and Ellis. The
particle has an associated Higgsfield, and as this field strengthens,
gravity weakens.
Sloan and Ellis’s calculations
show this would allow the
problem of black holes in a
pre-inflation universe to be
avoided entirely. That’s because
the Higgs field would have been
stronger shortly after the big
bang, so gravity would have been
much weaker. This would keep
matter from being crushed into
black holes before inflation began
to spread everything out (arxiv.
org/abs/1810.06522).
It is a big step beyond the
standard model of particle
physics, but it is plausible because
of the ways we think gravity and
the Higgs field interact now, says
David Wands at the University of
Portsmouth, UK.
However, one downside of the
idea that the Higgs played this
role is that we may be unable to
test it. “Inflation is so extravagant
in the amount of space that it
produces that we only get to see a
tiny portion of the whole universe
as inflated,” says Wands. “It is hard
to test these ideas about what
happens before inflation in the
patch of the universe that we see.”
Sloan believes we shouldn’t
write off testing the idea yet. He
says we may be able to see its
effects in the areas of the
observable cosmos that are most
like the super-dense pre-inflation
universe, such as just outside a
black hole. ■Did Higgs bosons
save the universe?
HENNING DALHOFF / SCIENCE PHOTO LIBRARY“ It looks more likely that
Archaeopteryx really is
somewhere on the lineage
towards recent birds”WE HAVE identified a new species
of Archaeopteryx, the famous “first
bird” – and it supports the idea that the
extinct animal really is a transitional
form between dinosaurs and their
bird descendants.
Archaeopteryx was named in the
1860s. It had wings and feathers, but
teeth instead of a beak, which helped
make the case that birds evolved fromFossil reopens
debate over
the first bird
dinosaur ancestors. However, over
the past decade its first-bird status
has been questioned following the
discovery of similar winged dinosaurs
in China. This led to a 2011 study that
concluded Archaeopteryx was not
technically an early bird after all.
Now it’s all change again. Martin
Kundrát at the University of Pavol
Jozef Šafárik in Slovakia and his
colleagues have studied a hitherto-
unexamined Archaeopteryx fossil
which they say overturns that idea.
The fossil contains most of the
skull, plus parts of the shoulders and
left wing. It was found in the early1990s, reportedly in a quarry near
Daiting, Germany, and ended up
with a private collector. In 2009,
palaeontologist Raimund Albersdörfer
bought it and it is now at the Bavarian
State Collection of Palaeontology and
Geology in Munich, Germany.
The team found subtle differences
between its bones and teeth and
those of other known fossils of
Archaeopteryx. The researchers saythat the specimen is a new species,
Archaeopteryx albersdoerferi.
When they built a new family tree
of birds and dinosaurs, they placed
the new species of Archaeopteryx
at the base of the bird (or avian) line.
“It’s in an important position to tell
us about the early evolution of avian
dinosaurs,” says Kundrát (Historical
Biology, doi.org/cwbs).
“It looks more and more likely that
Archaeopteryx really is somewhere
on the lineage towards recent birds,”
says Oliver Rauhut of the Bavarian
State Collection of Palaeontology
and Geology. Michael Marshall ■Inflation saw the universe go from
a speck to humongous rather fast