should freak you out
famous Canadian Science Fiction writer
Mark A. Carter reprints an article from
Space.com penned by
Astrophysicist Paul Sutter from
August 14, 2015 to give the reader a greater appreciation
of the dynamics underlying Black Holes
and there ilk. In
this article, Dr. Sutter states:
"In a magnetar's field, you just kind of dissolve."
Now imagine Joe Cooper
falling into the black hole
named Gargantua in
Christopher Nolan's film Interstellar,
and tell me if you believe it.
Right. Sure. You bet.
This artist's impression shows a magnetar in the very rich and
young star cluster Westerlund 1.
Image is courtesy of Wikipedia: the free encyclopedia.
cluster contains hundreds of very massive stars, some shining
with a brilliance of almost one million
suns. European astronomers have for the first time demonstrated
that this magnetar, an unusual
type of neutron star with
an extremely strong magnetic field, probably was formed as part
of a binary star system. The
discovery of the magnetar's
former companion elsewhere in the cluster helps solve the mystery
of how a star that started off so massive could become a
magnetar rather than collapse into a
I'll be honest:
Magnetars freak me out. But to get to the why,
I have to explain the what.
Magnetars are a special kind of
neutron star, and neutron
stars are a special kind of dead star.
They're easy enough to make if
you're a massive star. All stars fuse hydrogen into helium deep
in their cores. The energy released supports the stars against
the crushing weight of their own gravity and, as a handy by-product,
provides the warmth and light necessary for life on any orbiting
planets. But eventually, that fuel in the core runs out, allowing
gravity to temporarily win and crush the star's core even tighter.
With the greater pressure, it
becomes helium's turn to fuse, combining into oxygen and carbon,
until the helium, too, gives out. That's where our own sun gets
off the fusion train, but more massive stars can keep on chugging
along, climbing up the periodic table in ever more intense and
short-lived reaction phases, all the way up to nickel and iron.
Once that solid lump of nickel
and iron forms in the stellar core, a lot of things
go haywire fast. There's still a lot of
star stuff left in the atmosphere, pressing into that
core, but further fusion doesn't release energy, so there's nothing
left to prevent collapse.
And collapse it does: The nickel
and iron nuclei (yes, just nuclei; don't even think about entire
atoms at these temperatures and pressures) break apart. They
just can't handle this nuclear mosh
pit. Stray electrons get shoved into the nearest protons,
converting them to neutrons. The neutrons stay neutrons. And
those neutrons are mighty good at preventing further collapse,
for reasons I'll explain in a bit. The infalling gas, trying
to crush the core into oblivion, bounces off that neutron core
and goes kablamo! (Note:
I don't know what it actually sounds like.)
The neutron ball:
What happens during the supernova event is an exciting discussion
for another day. What we're concerned with now is the
leftovers: a soupy, ball-like
mixture of neutrons and a few
straggler protons. This ball is supported against its
own weight by degeneracy pressure,
which is a fancy way of saying that you can only pack
so many neutrons in box or, in this case, a ball. It may seem
obvious that neutrons, well, take up space, but things didn't
have to turn out this way. It's this
degeneracy pressure that causes the big bounce that puts
the super in supernova.
I should note that, if there's
still too much stuff left hanging out around this leftover neutron
ball, the weight can overwhelm even
degeneracy pressure. And now, look what you've done:
You've gone and made a black hole.
But that, too, is another story. We wouldn't want to
be like our poor star and get overwhelmed.
The neutron ball, which I should
now call by its proper name: a neutron
star, is weird. Seriously, that's the best word I can
find to describe it. Neutron stars
are basically city-size atomic
nuclei, which makes them among the densest things in
the universe. The pressure of gravity inside these stars has
squeezed apart even atomic nuclei, allowing their bits to float
It's mostly neutrons down there,
hence the name, but there are also a few surviving protons floating
around. Normally, those protons would repel one another, being
like-minded charges and all, but they are forced close together
as the Strong Nuclear Force
tries to bunch them up with their fellow neutrons.
neutron star's interior is a complicated
dance of physics under extreme conditions, resulting
in very odd structures. The oddity starts near the surface, with
blobs of a few hundred neutrons
that are best described as neutron
gnocchi. Below that, the neutron
blobs glue together into long chains. We have entered
the spaghetti layer. Underneath
that, at even more extreme pressures, the spaghetti strands fuse
side by side and form lasagna sheets.
Under it all, even neutron lasagna loses its shape, becoming
a uniform mass. But that mass has gaps in it, in the form of
long tubes. At last: delicious penne.
I wish I was making these names
up, but physicists must be especially hungry people when coming
up with metaphors.
Did I mention the spinning? Oh
yes, neutron stars spin, up to a few hundred times per second.
Let all of this sink in for a bit. An object with such strong
gravity that hills are barely a few
millimeters tall, rotating with a speed that could rival
your kitchen blender. We're not playing games anymore.
stars are scary:
All this action: the insane densities, the complicated structures,
and the ridiculously fast rotation rates, means that
neutron stars carry some pretty nasty magnetic fields.
But don't magnetic fields require charged particles, and aren't
neutrons neutral? That's true, smarty
pants, but there are still a few protons hanging out
in the star, and at these incredible densities, physics gets
complicated. So, yes: neutron stars,
despite their name, can carry magnetic fields.
How strong are they? Take a star's
normal magnetic field, and squish it down. Every time you squish,
you get a stronger field, just as you get higher densities. And
we're squishing something from star size (a
million kilometers or miles, take your pick) to
city-size (like, 25 kilometers
or just 15 miles.) Plus, with all the interesting physics
happening in the interiors, complex processes can operate to
amplify the magnetic field. So you can imagine just how strong
those fields get.
Actually, you don't have to imagine
because I'm about to tell you. Let's start with something familiar:
the Earth's magnetic field.
That's around 1 gauss. It's
not much different for the sun: a few to a few
hundred gauss, depending on where on the surface you
are. An MRI is
10,000 gauss. The strongest
human-made magnetic fields are about a few
hundred thousand gauss. In fact, we can't make magnetic
fields stronger than a million gauss
or so without our machines just breaking down from the
cut to the chase. A neutron
star carries a whopping trillion
gauss magnetic field. You read that right. I'm talking
a trillion, with a t.
Now, we finally get to magnetars.
You may guess from the name that they're especially magnetic:
up to 1 quadrillion gauss.
That's 1,000 trillion times
stronger than the magnetic field you're sitting in right now.
That puts magnetars in the
number one spot, as the reigning champions in the universal
Strongest Magnetic Field competition. The numbers are
there, but it's hard to wrap our brains
Those fields are strong enough
to wreak havoc on their local environments. You know how atoms
are made of a positively charged nucleus surrounded by negatively
charged electrons? Those charges respond to magnetic fields.
Not very much under normal conditions, but
this ain't Kansas anymore, is it, Toto? Any unlucky atoms
stretch into pencil-thin rods
near these magnetars.
It doesn't stop there. With the
atoms all screwed up, normal
molecular chemistry is just a no-go.
Covalent bonds cease to exist. Ha. And the magnetic fields
can drive enormous bursts of high-intensity radiation. So, it's
bad business generally.
Get too close to one (say, within
1,000 kilometers or about 600 miles,)
and the magnetic fields are strong enough to upset not just your
bioelectricity, rendering your nerve impulses hilariously useless,
but your very molecular structure.
In a magnetar's field, you just kind of dissolve.
We're not exactly sure what makes
magnetars so frighteningly
magnetic. Like I said, the physics of
neutron stars is a little bit
sketchy. It does seem, though, that
magnetars don't last long, and after
10,000 years, give or take, they settle down into a long-term
normal neutron star retirement: still insanely dense, still freaky
magnetic, just not so bad.
So, as scary as they are, at
least they won't stay that way for long.
About the author:
Paul Sutter is a research fellow at the
Astronomical Observatory of Trieste and a visiting scholar
at The Ohio State University's Center
for Cosmology and Astro-Particle Physics. Sutter is also
host of the podcasts: Ask a Spaceman
and RealSpace, and the
YouTube series Space In
Your Face. He contributed this article to
Space.com's Expert Voices: Op-Ed & Insights.