[♪ INTRO]
Most human eyes can see a vast range of objects,
from a single strand of hair between our fingertips to stars lightyears away.
But with the help of tools like particle accelerators and telescopes,
we can detect tinier objects like neutrons and larger celestial objects like other galaxies.
These two ends of the size spectrum actually
have more in common than you might think.
After all, we can find these tiny particles just about everywhere in the universe,
including in neutron stars.
So some scientists are using particle accelerators
to turn astrophysics on its head by applying what they learn
from neutrons in the smallest things on Earth
to some of the most massive things in the universe.
A particle accelerator works by speeding up neutrons, protons, and electrons,
which make up atoms, to do things like see how much energy
they generate and figure out what they’re made of.
And researchers are constantly working to improve particle acceleration.
At the start of 2022, the new FRIB particle accelerator opened for experimentation.
This particle accelerator adds to the toolbox that scientists
can use to study tiny phenomena with huge implications.
For example, by looking at the properties of uncharged neutrons
in specific molecules like different variations of lead,
researchers can come up with an idea of how big that lead molecule is.
And that can tell us a lot about molecules and the things made of them.
In one 2021 study, researchers focused on a version of lead
with 82 protons and 126 neutrons.
In this atom, neutrons are farther from the center of the lead’s nucleus than its protons.
This arrangement happens because
there are way more neutrons than protons,
and they don’t all fit in such close quarters.
As the outermost particle of these lead atoms’ nuclei,
neutrons can give us an idea of how big the lead molecule is.
But we can learn even more from the space
where the protons stop and the neutrons start.
There’s a layer of neutrons surrounding the outermost layer of protons,
acting as a neutron skin.
And that neutron skin on the outside of the nucleus is super thin.
But despite looking slim at first glance, the researchers uncovered
that it’s not as thin as they had previously thought it was.
In fact, it’s thicker than they thought was even possible!
This is making researchers rethink the size limits of all sorts of things.
If we’ve been wrong about how far a tiny atom can expand
and how much space it takes up,
then we might be wrong about the same properties in giant neutron stars.
See, neutron stars are the leftovers from a collapsed massive star.
In its collapse, all of the star’s protons and electrons
got crushed into neutrons.
So the resulting neutron stars are essentially dense balls of neutrons in our sky.
And those are no different from the neutrons
that we can detect using particle accelerators.
Now, these super-dense neutron stars are estimated
to be 40% more massive than our sun, but way smaller.
And given the error bars in the recent lead experiment,
this could still be an accurate estimation for neutron star size.
But the results from the lead experiment suggest that neutron stars
also could be way bigger than we thought.
The difference of only a few quadrillionths of an inch in the neutron skin
could be a huge deal scaled up to the astrophysics level.
And who knows, with new tools,
researchers could find more data supporting this thicker skin idea.
So the researchers who conducted this lead experiment plan
to conduct follow-up experiments using the FRIB particle accelerator.
FRIB is the first-ever particle accelerator to use a liquid lithium film
to charge up heavy-ion beams using less power,
making it super powerful.
That kind of power might be just what researchers need
to reduce uncertainty in their measurements
and make better models for neutron stars.
Using FRIB, scientists will be able to investigate neutrons
in lead and all sorts of other particles to gain a better understanding of,
you know, pretty much everything in the universe.
Thank you to our patron, Naomi, for suggesting that we look into FRIB.
If you would like to join our Patreon community,
go to patreon.com/SciShow.
And if you’d like to display your love of all things space,
remember to check out this month’s Pin of the Month, Deep Space 1!
You can pre-order this snazzy pin until the end of February,
when orders will close and we’ll ship them out.
And then, it’ll be time for you to keep an eye out for March’s pin!
You can check out the link in the description to learn more.
Thanks for watching this episode of SciShow Space!
[♪OUTRO ]