Podcaster: Dr. Pamela Gay;
Title: Escape Velocity Space News – EVSN: Magnetic Fields Help Find Ocean Worlds
Organization: Cosmoquest
Link: http://dailyspace.org/
Description:
Researchers have determined how to effectively measure the magnetic fields at Neptune to determine if any of the moons are ocean worlds… in just twelve minutes. Plus, lasers recreate galaxy cluster conditions, some mind-bending new math, how the Earth’s crust developed, and a look at the long history of Daylight Saving Time.
Bio: Dr. Pamela Gay is a Senior Scientist at Planetary Science Institute and a Director of CosmoQuest.
Today’s sponsor: Big thanks to our Patreon supporters this month: Paul M. Sutter, Chris Nealen, Frank Frankovic, Frank Tippin, Jako Danar, Michael Freedman, Nik Whitehead, Rani Bush, Ron Diehl, Steven Emert, Brett Duane, Don Swartwout, Vladimir Bogdanov, Steven Kluth, Steve Nerlich, Phyllis Foster, Michael W, James K Wood, Katrina Ince, Cherry Wood.
Please consider sponsoring a day or two. Just click on the “Donate” button on the lower left side of this webpage, or contact us at signup@365daysofastronomy.org.
Please visit our Patreon page: https://www.patreon.com/365DaysOfAstronomy
or you can consider to sponsor a day of our podcast : https://cosmoquest.org/x/365daysofastronomy/product/sponsor-an-episode-of-365-days-of-astronomy/
Transcript:
[Eric Mattis]
We’ve hit that time of year when the clock betrays us. Weekend by weekend, we going to spring our clocks ahead, lose an hour of sleep, and shake our fists at that piece of history that has brought so much time zone confusion. Today, we take an in-depth look at that choice that someone made and brought so much regret.
[Dr. Pamela Gay]
We also have mind-melting science that includes cloud-melting science, as 196 lasers take on the task of replicating a galaxy core. And we have some theories on measuring icy worlds oceans and on melding gravity and quantum mechanics.
[Eric Mattis]
All of this and more is coming at you right here on Daily Space.
[Dr. Pamela Gay]
I am your host, Dr. Pamela Gay.
[Eric Mattis]
And I’m your host, Eric Mattis.
[Dr. Pamela Gay]
And we’re here to put science in your brain. Today’s first story is one that literally had me just shaking my head as I read it. According to the press release title, 196 lasers help scientists recreate the conditions inside a gigantic galaxy cluster.
I don’t know exactly how this research got started, but I feel like a couple of researchers were in a cafe and one lamented to the other that modeling galaxy clusters in a computer just isn’t accurate enough. And the other was like, I’ve got some lasers. Let’s just replicate a cluster after lunch tomorrow.
Again, I don’t know exactly how this research got started, but that’s going to be my new head canon. Here’s the problem. When we observe a cluster of galaxies, we see superheated gas.
10 million Kelvin levels of superheated gas of just protons and electrons that are too hot to form atoms. Exactly how gas this hot comes to exist and stay this hot is something we couldn’t explain. And uncovering the details of how hot gas magnetic fields and time interact hasn’t been an easy process.
So researchers focused 196 lasers at the National Ignition Facility in California on a tiny target and heated that target to white hot plasma with powerful magnetic fields. And in this short lived blob, they observe temperature variations that indicate that in this kind of an intense environment, electrons don’t transfer energy the way they normally do. Instead of colliding regularly and radiating heat, these tangled magnetic fields cause electrons to spiral through the fields.
This directed motion stops the normal dispersion of energy. In this experiment, the suppressed conduction of energy was suppressed by a factor of 100. According to researcher Don Lamb, this is an incredibly exciting result because we’ve been able to show that what astrophysicists have proposed is on the right track.
Colleague Petros Tavakis adds, the simulations were key to untangling the physics at play in the turbulent magnetized plasma. But the level of thermal transport suppression was beyond what we expected. And in addition to these needed results, they got to blast a small sample to smithereens with 196 lasers for science.
Who doesn’t love that? According to a release on this work, more questions remain about the physics of galaxy clusters, however. Though the hot and cold spots are solid evidence for the impact of magnetic fields on the cooling of hot gas and galaxy clusters, further experiments are needed to understand exactly what is happening.
The group is planning its next round of experiments at the National Ignition Facility later this year. For now, this work appears in Science Advances and was led by Principal Investigator Gianluca Grigori. Science makes progress in weird ways.
Our understanding of how baseballs arc and moons orbit requires calculus to fully understand. An entire field of math had to be developed to make the same calculations our brains do automagically every time we catch something. Understanding quantum mechanics required Derek to invent yet more maths, and with relativity, field theories entered regions they had never entered before.
When researchers try to understand complex problems, there is almost always this underlying, for me, fear, or for others excitement, or both, that new math is going to be required. As Daniel Pearson puts it, we strive to understand the laws of nature and the language in which these are written in mathematics. When we seek answers to questions in physics, we are often led to new discoveries in mathematics too.
This interaction is particularly prominent in the search for quantum gravity, where it is extremely difficult to perform experiments. Quantum gravity is that just-out-of-reach concept that unifies quantum mechanics and gravitation, with all its relativistic twists and turns. Robert Beerman explains, the challenge is to describe how gravity arises as an emergent phenomenon, not just as everyday phenomena, such as the flow of liquid emerges from the chaotic movements of individual droplets.
We want to describe how gravity emerges from the quantum mechanical system at the microscopic level. And Beerman and his colleagues just might have succeeded. Maybe.
As Beerman puts it, using techniques from the mathematics that I have researched before, we managed to formulate an explanation for how gravity emerges by the holographic principle in a more precise way than has previously been done. The holographic principle is part of string theory, and it explains that any higher dimension volume can be described on a lower dimension surface. As Larry Suskind put it, the three-dimensional world of ordinary experience, the universe filled with galaxies, stars, planets, houses, boulders, and people, is a hologram, an image of reality, sighted on a distant two-dimensional surface.
Basically, according to the holographic principle, all of reality really is just shadows on a wall, as Plato suspected. If this math proves to not only match reality, but also to have testable, predictive qualities, then this team is destined to win a Nobel Prize. But experiments will be needed.
This is a watch this space kind of result. String theory has never been proven. It is a lot of really ugly math that can be tuned to match what we see, but it hasn’t made unique predictions that make it clear it is more than just math, like Ptolemy’s epicycles, that seems to work if you fuss hard enough with it.
So, watch this space. Maybe gravity and quantum mechanics can be unified, or maybe not. Time and testable predictions will tell.
I, for one, sit firmly in the let’s do experiments camp, and gladly now switch topics to look at things we can measure, magnetic fields in ocean worlds, in our own Earth’s continental ancestral crust. As much as I love experimental and observational data more than I love theory and all the mathematical models theory builds on, I have to admit that sometimes doing a lot of modeling ahead of time makes it possible for experiments to be done much more effectively. Consider the question, how do we know if an icy moon actually has liquid water on the inside?
Sometimes we get lucky and the moons spray water at our spacecraft, but we can’t exactly count on that. In planning a flyby of Neptune’s moon Triton, researchers realized they’d have about 12 minutes to acquire as much data as they could to determine if the moon does or doesn’t have subsurface water. In the absence of geysers, researchers have to turn to things like magnetic fields.
Large worlds like Neptune have large magnetic fields that can be measurably affected by passage through salty seas and moons and by an atmosphere that also happens to be present. Since both atmosphere and internal oceans can affect magnetic fields, and since neither of them affects the magnetic fields a lot, mission planners realized it was going to be imperative that they figure out exactly what to measure and focus on measuring just that. Enter the modelers.
Researchers programmed software to run 13,000 models of magnetic field interacting with a moon that had variable amounts of atmosphere and ocean and look to see what measurable features changed and to isolate collections of things that changed the most. This is called principal components analysis and it allows researchers to figure out if we measure these three things, we will know this one thing really well. And now this team has a bunch of software that is ready for that day when someone finally funds a mission to Triton.
And that software, with 12 minutes of just the right data, will be able to say ocean world or not. One thing we can say for certain is that Earth is an ocean world. But how did it end up with as much continental crust as it did?
The most prevailing thought started to look really good when scientists decided that plate tectonics was a thing. Beth wants me to say, just did for Alfred Wegener. After all, plates drive down under one another in subduction zones, causing the underlying rock to melt and rise through the crust to form volcanoes that create more crust.
And as those plates come together, others rift apart and create zones where molten rock rises up again, forms new crust. See Iceland. Of course, the flip side to the subduction zones is that the rocks that submerge and get heated are also destroyed.
So we’re not actually seeing a net gain in the continental crust there or from the rift zones. Additionally, plate tectonics hasn’t always worked this way, which really defies a basic precept of geology that what’s past is prologue, meaning we can trace back how things worked in the past by looking at how they work now. It’s just not fair when we ignore a basic principle, in my opinion, but that’s how this story goes.
So plate tectonics started gradually about three billion years ago, more than a quarter of the way through Earth’s long history. This means continents had to come from somewhere else. With all the oldest rocks being destroyed in the mantle through subduction, scientists had to turn to the tiniest crystals to get a glimpse of the past.
And when we say tiniest of crystals, we mean microscopic bits of zircon, which is not indestructible, left over in larger, more recently created crystals. In particular, research published last year in Nature Communications provides an analysis of microscopic zircon grains found in the archived stream sediment samples taken in a region in the west of Greenland. Using lasers and isotopic analysis, scientists learned that the zircon crystals varied widely in age from 1.8 billion to 3.9 billion years old, a much broader range than what’s typically observed in Earth’s ancient crust. This result proved to be intriguing and set the stage for further analysis of more samples from around the world to compare. And all the samples began to say the same thing. These large datasets all showed evidence of repeated injection of mantle melts into much more ancient crust.
Ancient crust seemed to be a prerequisite for growing new crust. And these injections all occurred around the same time, about 3.2 billion and 3 billion years ago, which coincides with the period when Earth’s mantle temperatures are thought to have been at their peak. So just like hot flashes happen with people, they apparently happen with planets.
And this particular hot flash provided such a huge amount of mantle melt to largely create the volume of continental crust we see today. Plate tectonics has destroyed and created lots of rocks, but it wasn’t enough to give us the current amount of rocks. And now we know.
Up next, we have a special segment on everyone’s least favorite time of year, daylight saving time. But first, Eric has a launch update.
[Eric Mattis]
Before we get to our sort of bonus history segment, we have an update on Astra’s ELANA-41 mission. This particular launch failed on February 10, 2022, shortly after the first stage cut off due to an apparent fairing separation failure. And Astra now thinks they know what happened.
The fairing separation system on Rocket 3 consists of five mechanisms that are triggered by electrical signals, which occur rapidly in series to separate the two halves of the fairing from each other and from the rocket’s first stage. The problem with LV0008’s fairing separation mechanism was that its wiring harness, which sends commands from the computer to different parts of the rocket, was designed incorrectly. This resulted in one of the separation systems being initiated in the wrong order so that the last one never got the command to fire, causing the fairing to not separate.
Astra has redesigned the harness on vehicles currently being built and has come up with a new test to catch similar errors in the future. During the failure investigation, Astra also discovered a separate software issue that prevented the upper stage from gambling its engine and recovering from the tumble due to its bad separation. The flight software sent a signal to start that system, but somewhere in between the computer and the engine, the signal got corrupted or lost, resulting in what is called packet loss.
According to the report, an unlikely combination of factors caused a failure that we didn’t predict. Astra has been able to replicate this issue on their hardware simulator and modify their systems to reduce the chances of this happening again. Astra attributed these rapid fixes to the fact that they are constantly iterating on their hardware, which is designed to be simple and cheap to produce, so it’s relatively easy to implement fixes like these.
And now let’s talk about daylight saving time, which goes to effect Sunday, March 13th here in much of North America.
[Dr. Pamela Gay]
Every year at about this time, most of North America roll their clocks forward in a vain attempt to save energy. I say vain attempt because there hasn’t been any sound evidence that adjusting the clocks to chase the sunshine has actually resulted in any reduction in the demand for energy. The story of daylight saving time goes back to 1784 when Benjamin Franklin mused about how many candles could be saved if the clocks were adjusted so that people were more in sync with the sun.
Since then, the idea reared its ugly head every few decades, but it wasn’t until the advent of standard time in the United States and Canada, led by Sanford Flemings in about 1876 and in other countries over the next few decades, that it was even possible to propose something called daylight saving time. In 1905, William Bellet, a well-known builder of houses in the United Kingdom and a fellow of the Royal Astronomical Society, came to the conclusion while out riding his horse early one morning that there were a lot of people not taking advantage of the early morning sunlight in the spring and summer. So he made it his mission to make them get up earlier in the morning by setting the clocks forward in the spring and in 1907 published a pamphlet entitled The Waste of Daylight and thus began his campaign for the adoption of daylight saving time in the UK.
Over the next few years, proposals to implement daylight saving time were made but not adopted. Until 1916, about a year and a half into World War I, the British Prime Minister of the day was asked in Parliament that given there was a need to conserve electricity, gas, and oil for the war effort, would the government propose legislation along the lines of a earlier bill to introduce daylight saving time? The Prime Minister said, no sir, I cannot introduce legislation on this contentious subject.
Naturally, the topic came up repeatedly over the course of the next few weeks. It ended up being Germany who decreed that summer daylight saving time would be instituted in Germany as a wartime measure starting at the end of April 1916 when the Germany would be set forward an hour and that it would remain in effect until the beginning of October. Companies were strongly discouraged by the government from changing their business hours by an hour to maintain the same patterns relative to the rising and setting of the sun.
The UK finally implemented daylight saving time legislation in May 1916. Of course, when it was implemented, many munitions workers in the UK that were on shifts that started at 6 a.m. the next day overslept and had their wages docked for being late. In the United States, daylight saving time was signed into law for the first time on March 19th, 1918, and two weeks later, Americans rolled their clocks forward by an hour on Sunday, March 31st.
Over the years, there have been numerous reasons given for why daylight saving time should be implemented, including it benefits the farmers. Spoiler alert! Cows don’t understand clocks and thus the farmers get even more out of sync with the rest of society.
This is also true for horses. It also, they say, saves energy, except there’s no strong evidence to support that it does and stronger evidence that suggests it actually results in increases in energy consumption. Australia even tried to use it to offset power consumption during the 2000 Olympic Games and found that demand for electricity did not decrease as a result.
But the reality is that there are significant negative consequences whenever the clocks are rolled forward in the spring or back in the fall. Perhaps the most disturbing is the fact that in the week immediately following the changing of the clocks, there is an increase in accidents because people’s sleep patterns are disrupted and there’s a 10% increase in the likelihood that you’ll experience a heart attack in the days immediately following the time change. When the U.S. changed the dates of daylight saving time and they started and ended differently because of the U.S. Energy Policy Act of 2005, the goal was to achieve a 1% reduction in energy consumption. But as far as we can tell, this was not achieved and there was reportedly lobbying for it by the convenience store industry and sporting goods manufacturers because it would mean people would be out later in the evening playing sports and buying snacks so one could ask whether the motivation to extend it was to save energy or sell soccer balls. Yet, except for a couple of states in the U.S. and the province of Saskatchewan in Canada that doesn’t change their clocks, we continue to adjust our clocks twice a year despite the fact it’s not saving energy, despite the increase in injuries, and despite the fact that neither the cows nor the horses care. If you want to learn more about the history of daylight saving time, we’d like to recommend David Peru’s book titled Seize the Daylight, The Curious and Contentious Story of Daylight Saving Time.
We’ll include a link in the show notes at dailyspace.org.
[Eric Mattis]
This has been The Daily Space.
[Speaker 4]
Today’s episode was written by Dr. Pamela Gay, Beth Johnson, and Eric Mattis. Audio engineering is provided by Allie Pelfrey and web content is produced by Beth Johnson. You can get a complete transcript, show notes, and see images related to each of our stories at our website dailyspace.org.
The Daily Space is a product of the Planetary Science Institute, a 501c3 non-profit dedicated to exploring our solar system and beyond. We are here thanks to the generous contributions of people like you. The best way you can support us is through patreon.com slash CosmoquestX. Like us? Please share us. You never know whose life you can change by adding a daily dose of science.
End of podcast:
365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by Planetary Science Institute. Audio post production by me, Richard Drumm, project management by Avivah Yamani, and hosting donated by libsyn.com. This content is released under a creative commons Attribution-NonCommercial 4.0 International license. Please share what you love but don’t sell what’s free.
This show is made possible thanks to the generous donations of people like you! Please consider supporting our show on Patreon.com/CosmoQuestX and get access to bonus content. Without your passion and contribution, we won’t be able to share the stories and inspire the worlds. We invite you to join our community of storytellers and share your voice with listeners worldwide.
As we wrap up today’s episode, we are looking forward to unravel more stories from the Universe. With every new discovery from ground-based and space-based observatories, and each milestone in space exploration, we come closer to understanding the cosmos and our place within it.
Until next time let the stars guide your curiosity!