Solar Flares and a Virtual Universe

Solar Flares and a Virtual Universe


I’m Hank Green; this is SciShow News, and
I’m wondering: Do you enjoy the sun? And the fact that it exists? Me too! Although I’m not always sure the
feeling is mutual. Last week on May 8th, for instance, a big
solar flare lashed out from the sun, practically punching us in the face. A solar flare, an explosive release of magnetic
energy on the surface of the sun. The sun’s magnetic fields are complex, intertwining,
and ever-changing. And sometimes when those fields intersect, pressure builds and eventually
releases jets of electrons, ions, and atoms — more energetic than millions of hundred-megaton
bombs going off at once. Last week’s flare was considered only a
moderate one, a so-called M-class flare. It was only a tenth as powerful as what happened
back in March. That’s when we witnessed an X-class flare
— the most energetic kind — and astronomers said last week that it was the best-observed
solar flare in history. On March 29th, four different space telescopes
and one ground-based observatory were all trained on the sun when the flare happened,
and together, they were able to monitor different features, observing it in different wavelengths,
to give us a fuller-than-ever picture of a solar flare. Thanks to some excellent planning, astronomers
with The National Solar Observatory in California, Japan’s Hinode satellite, and a whole alphabet
soup of NASA telescopes were able to coordinate in advance to focus their instruments on the
same, active region of the sun that was looking like it was gonna blow. They’re now studying that data to better
understand exactly what catalyzes this release of pressure, and hopefully predict when the
next one will happen. Radiation from a solar flare is absorbed in
Earth’s atmosphere, so it doesn’t harm us directly. But it can disturb things like GPS
and communications signals, which circulate in the outer atmosphere, not to mention astronauts
in orbit. So the better we understand solar flares,
the better we can be at preparing for them. And here’s another thing we can now visualize
better than ever: The formation of the universe. For the first time, we can test all of the
theories we have about how the universe formed and the laws that govern it, by plugging them
into a new, Web-based virtual model of the cosmos. A model that YOU can play with yourself! Last week a team of physicists led by the
Harvard-Smithsonian Center for Astrophysics released Illustris, a simulation so complex
that it took the team five years to design, and the calculations had to be run on the
equivalent of 8,000 desktop computers for three months. More than just cool graphics and animations,
Illustris is a working visualization of LOTS of physical data, which allows us to see how
they play out based on our current understanding of the physical universe. Because there’s a lot we don’t know about
the universe, but there’s also a lot that we think we DO know. Like, we think it started with a Big Bang.
And fractions of a second after that, space itself expanded faster than the speed of light,
marbling spacetime with shock waves of gravity. Dark matter began to clump where gravity was
strongest, developing into a web-like pattern. This is where Illustris begins, a mere 12
million years after the big bang. From there it models the universe’s evolution
— pretty accurately — to the present day. You can watch visible matter collect into
webs, stars form from clouds of hydrogen and helium, and planets begin to form as well. As time goes on, more than 41,000 galaxies
form in familiar shapes–spiral galaxies like our own, and elliptical ones. All of this happens in Illustris, which represents
a cube of space 350 million light-years wide–large enough, astronomers think, to be representative
of the known universe. And it leaves us with a present-day cosmos
remarkably similar to ours. But only similar, not exactly the same, of
course, and therein lies the beauty of the simulation. Certain details, like how galaxies
merge, are occurring differently in Illustris than they do in the observed universe. Astronomers have yet to comb through the simulation
thoroughly enough to pinpoint the reasons for these discrepancies. But when we do, these will let us refine our
theories about the universe–places where we can begin to look closer, and rethink what
we think we know. Thanks for watching this episode of SciShow
Space News — especially to our Subbable subscribers. If you want to keep exploring the universe
with us, go to Subbable.com/scishow to learn how you can contribute. And if you want to keep getting smarter with
us, you can go to youtube.com/scishowspace and subscribe.

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