The Atomic Clock is beyond accurate!
Atomic clocks are super accurate timekeeping devices that use the vibrations of atoms to measure time. Unlike regular clocks that might lose seconds over time, atomic clocks are precise to within billionths of a second! They work by using atoms, usually cesium or rubidium, which resonate at specific frequencies. So, make sure your teacher doesn’t have one to track your homework deadlines!
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In a world where timing can impact everything from navigation to technology, atomic clocks are like the superheroes of timekeeping! This cartoon I crafted pokes fun at the metrologists that are leading the charge in accurate timekeeping!
LIGO is so cool!
Laser Interferometer Gravitational-Wave Observatory
For over a century, Albert Einstein’s theory that gravitational waves existed couldn’t be proved, until LIGO. It was designed to detect ripples in the fabric of spacetime, caused by cosmic events like black holes colliding.
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Observatories in Washington State and Louisiana each have two long, straight arms that form an "L" shape where super precise lasers bounce back and forth, identifying tiny distortions, or ripples, smaller than an atom! Some call it the world’s most precise measuring stick, revealing some of the world’s hidden secrets.
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Check out my comic in which I aim to bring LIGO to life through art.
Thanks for checking out my comics. Read more about them in my blogs below!
The story behind the Atomic Clock
When I developed the above comic on the atomic clock, I poked fun at the metrologists who specialize in accurate measurement. I just did some extra reading on the clock and learned about its applications beyond just timekeeping. I also did some research into the next generation of clock technology and am really excited to share my excitement about what I learned.
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Atomic clocks measure the exact length of a second. They do so by monitoring the resonant frequency of atoms, measuring the different energy levels of their electron states. In an atomic clock, the natural oscillations of atoms between these levels act kind of like a pendulum in a grandfather clock. Most atomic clocks use caesium atoms that are cooled to near absolute zero.[1]
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It might surprise you that the atomic clock has actually been around for a long time, first taking shape in the late 1930s following the work of Columbia University scientist Isidor Isaac Rabi, who won he Nobel Prize for his discovery of nuclear resonance (which is also used in magnetic resonance imaging, MRIs).[2] According to the National Institute of Standards and Technology (NIST), the clock’s first model was accurate to within one second every 8 months[3]. That’s pretty accurate and has enabled the realization of global navigation satellite systems like Global Positioning System (GPS), which now has lots of commercial applications. And the technology continued to improve.
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The latest technology used today is from an Optical Clock that is accurate to 1 second every 30 billion years. Wow, that’s way older than the universe itself. Recently, physicists are looking at building a nuclear clock that would build on optical technology but using lasers.
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In 2024, researchers began using lasers to “excite quantum jumps within the thorium nucleus”. It’s still years away from becoming the next generation of clocks but has lots of promise of supporting tests of the fundamental principles of physics.[4] According to a recent study published in IOPScience, this would include searches for “violations of Einstein's equivalence principle and for new particles and interactions beyond the standard model.” [5]
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I’m looking forward to seeing this science take shape in the coming years.
[1] https://en.wikipedia.org/wiki/Atomic_clock
[2] https://en.wikipedia.org/wiki/Isidor_Isaac_Rabi#:~:text=Israel%20Isaac%20Rabi%20was
[3] https://www.nist.gov/atomic-clocks/brief-history-atomic-time#:~:text=The%20atomic%20clock%20truly%20began%20to%20take%20shape,early%201940s%2C%20as%20the%20world%20careened%20toward%20war.
[4] https://iopscience.iop.org/article/10.1088/1367-2630/14/8/083019/meta
[5] https://iopscience.iop.org/article/10.1088/2058-9565/abe9c2/meta
LIGO: Listening to the world's secrets
I hope you like my comic strip above on the truly mind-blowing Laser Interferometer Gravitational-Wave Observatory (LIGO). LIGO is a groundbreaking experiment that allows scientists to "listen" to the ripples in space and time created by some of the universe’s most extreme events. I want to share with the story behind it in a bit more detail than I could in my comic.
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I choose to do a comic on LIGO because it was designed to answer the universe’s biggest mysteries. It helps us understand events that we never had the tools to study before, like massive cosmic collisions that don’t emit light and are invisible to telescopes. It is one of today’s coolest new science experiments.
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LIGO works by detecting and measuring gravitational waves caused by colliding black holes or neutron stars, which are the sphere-shaped remains of stellar explosions. Their merging causes ripples in the fabric of spacetime. Spacetime is like a huge, invisible trampoline that ripples when something giant like a black hole moves on it.[1] Thanks to LIGO, we can “hear” gravitational waves from these events and explore deep into space.[2]
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There are two LIGOs: one in Washington State and another in Louisiana. Each observatory has two straight 4-kilometer-long arms connected in an L-shaped, perpendicular configuration. Inside these arms are super precise lasers that bounce back and forth against mirrors, measuring tiny changes in distance or distortions caused by gravitational waves.[3] These changes are so small they are less than one ten-thousandth the diameter of a proton.[4] That’s hard to even imagine!
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In September 2015, LIGO reached a major breakthrough for science when it detected its first black hole collision, providing direct proof for the first time ever of the existence of gravitational waves. Albert Einstein had predicted them in his theory of general relativity but doubted their existence for most of his life.[5] The conclusive detection has been hailed as “the crowning achievement of classical physics”[6]
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To date, LIGO, along with Virgo instruments in Europe, has observed gravitational waves from over 10 cosmic events, including collisions of black holes and neutron stars.[7] LIGO is continuing to improve and expand. At this moment, scientists are busy upgrading it to detect even fainter and more distant waves. And a new LIGO Scientific Collaboration, including more than 1,000 scientists from 83 institutions around the world, is dedicated to detecting even lower frequency waves and uncovering even more secrets about the universe.[8] These include plans to launch a space-based version called LISA to study the movements of massive galaxies.
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LIGO is one of the coolest examples of how physics can unlock the mysteries of existence. It’s helping us understand the universe in ways we never dreamed possible, uncovering secrets about its most mysterious and violent events. And the impact of LIGO goes beyond astrophysics to include the advancement of precision measurement and laser technology, with a boatload of applications in fields like medicine and engineering.
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Thanks for joining me to learn more about LIGO. I hope you’re as excited as I am about what it has already discovered, what it will find next and the changes it will make to our lives here on Earth.
[2] https://media.ligo.northwestern.edu/
[3] https://pubs.aip.org/physicstoday/article/69/4/14/415505
[4] https://en.wikipedia.org/wiki/LIGO
[6] https://link.springer.com/article/10.1007/s10699-017-9526-y
[7] https://media.ligo.northwestern.edu/
[8] https://pubs.aip.org/physicstoday/article/69/4/14/415505