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While planets like Earth and Mars enjoy four seasons a year,
our Sun has its own weather cycles.
They last around 11 Earth-years,
and feature events like sunspots and solar flares instead of blizzards or dust storms.
And last year, scientists announced our Sun entered a new cycle,
but they disagree on how intense it may turn out to be.
Our Sun is mostly made of hydrogen and helium plasma,
a mixture of charged atomic nuclei and free electrons flying around super fast,
with different regions churning at different speeds.
And all that stirred-up charge creates some intense electromagnetic activity.
The Sun’s magnetic field is really complex,
and astronomers are still working to figure out exactly why it looks the way it does,
in part to try and predict what it might do in the future.
That’s because the magnetic field lines can get entangled, then break and reconnect,
leading to space weather events like solar flares and coronal mass ejections,
which can hurl harmful radiation towards the Earth.
The most intense solar storms can threaten not just satellites and astronauts in orbit,
but also electronics and power systems on the ground
if we don’t have enough time to prepare.
The frequency of these storms waxes and wanes over an 11-year cycle.
Or at least approximately an 11-year cycle.
It varies a bit.
And last year, a group of scientists announced that we had
passed the time of minimal activity, beginning Solar Cycle 25.
Since 1755, astronomers have been tracking the Sun’s cycles.
And that tracking requires counting the number of sunspots.
Sunspots are regions on the Sun’s “surface,”
as much as a ball of plasma can have a surface,
where magnetic field lines get all tangled up.
Kind of like those cables we all have that somehow
work themselves into a knot by just sitting in a box in a closet.
These cosmic freckles are hotspots for solar flares and coronal mass ejections,
and across the two dozen previously tracked cycles,
they have averaged from 160 to 240 peppering the Sun’s surface
in a single peak year.
But for the past four cycles, the solar maximum, the year of peak activity,
has seen a steady drop in sunspots.
The most recent was the weakest overall cycle in a century.
But in 2014, the previous peak in activity, there were only 114 spots.
And scientists disagree about how active the Sun is going to be this go around.
Some NASA and NOAA scientists estimate that the maximum,
scheduled to come in 2025, will only hit 115 sunspots.
So, not continuing the drop, but not reversing the change, either.
But other astronomers think there will be a boon of over 200 that year.
And that’s because they’ve noticed that the length of a previous cycle
often correlates with the strength of the next.
If Solar Cycle 24 was shorter than the average,
Cycle 25 should have more sunspots.
You might be inclined to hope for the former.
Fewer sunspots, a lesser chance of nasty space weather.
Or you may have heard of the Maunder Minimum,
a period of minimal sunspot activity that ran from 1645 to 1715,
and lined up with a period on Earth known as the Little Ice Age.
On the other hand, there were probably multiple factors that contributed to
the Little Ice Age that had nothing to do with the Sun, like volcanic activity.
Still, other astronomers say it’s best not to make predictions,
as we still haven’t figured out a definitive model for how the Sun works.
For example, we lack a lot of data on the magnetic fields at the Sun’s poles,
so our models can’t tell the whole story.
Luckily, Earth already has a mission on the case.
ESA’s Solar Orbiter launched back in February 2020,
and will begin sciencing later this year.
In other temporally-distant news, let’s turn the clocks way back…
back to the beginning of the universe.
In the journal SciPost Physics, scientists revealed last week that
the soup of matter in the first moments of our reality were,
at least in one way, similar to water.
Right after the Big Bang, the only matter that existed
was made of particles called quarks.
These are fundamental particles, meaning they’re not made of smaller ones,
but nature uses sets of them to create other subatomic particles…
most notably, protons and neutrons.
And quarks do that by interacting with each other via the strong nuclear force.
Today, the strong nuclear force is responsible for
holding together the nuclei of atoms, but in the universe’s early minutes,
it was too hot for protons and neutrons to form.
We’re talking a million times hotter than the core of our Sun!
And just like the electromagnetic force has a particle to do its bidding called a photon,
basically a particle of light, the strong force has one, too.
It’s called a gluon...maybe because it glues quarks together…
So the soup of plasma made after the Big Bang is called,
very creatively, quark-gluon plasma.
And scientists can actually make some of their own using particle accelerators.
Based on knowledge gathered from those accelerator experiments,
one team took a look at both the density
and the dynamic viscosity of this primordial plasma.
Density measures how much mass is packed into a particular volume,
and dynamic viscosity details how much some of the mass
doesn’t want to move while other bits of mass do.
Throw both into a physics equation, and it tells you the kinematic viscosity,
or how well the fluid...flows.
Now, these properties do vary with temperature,
your maple syrup is runnier after you pop it in the microwave for a minute,
so these scientists focused on the lowest possible viscosity
they could get for a liquid,
which they had tied to more fundamental properties of physics in previous research.
Roughly speaking, quark-gluon plasma has both a dynamic viscosity and density
about ten million billion times larger than the liquids
we normally deal with in the real world, like water.
So, they’re not similar at all, right?
I mean it makes sense.
Water operates on an entirely different level of physics,
with both its atomic and its intermolecular bonds.
But the kinematic viscosity turns out to be almost equivalent.
The plasma at the beginning of the universe,
and liquid water when it’s at its runniest, both appear to flow the same way.
A lot of this is just math so far, but finding this one connection between
such drastically different worlds of physics might reveal further connections
down the line, and might allow us to get better insight into
how this quark-gluon stuff of our past actually acts.
Which will ultimately help us understand how all of that became all of this.
Thanks for watching this episode of SciShow Space!
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check out Patreon.com/SciShowSpace to learn more.
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