ASTROVAGANT

Ep. 30 Coriolis Effect - HD and the Void

The Coriolis force is a force in physics that has profound impact on us here on Earth. Listen to hear how this apparent force has influence over the weather, tides, and even some creatures. I refuse to talk about the formulas surrounding it but I ...

We’re back in 2019 with an episode that would have been more appropriate to release during hurricane season: a discussion of the Coriolis force! This force was observed centuries ago but takes its name from the scientist who first considered it in terms of theory and physics. It has an impact on a vast range of natural phenomena, from weather patterns to ocean waves to the flights of flies and moths.

Below the cut are the glossary, transcript, a timeline of the people I mention, sources, and music credits. Send me any topic suggestions via Tumblr message (you don’t need an account to do this, just submit as anonymous). You can also tweet at me on Twitter at @HDandtheVoid, or you can ask me to my face if you know me in real life. Subscribe on iTunes to get the new episodes of my so-far-monthly-updated podcast, and please please please rate and review it. Go ahead and tell friends if you think they’d like to hear it, too!

(My thoughts on the next episode are Stephen Hawking, Hedy Lamarr, or famous comets. The next episode will go up in late February.)

Glossary

Coriolis force - a force in a rotating system that acts perpendicular to the direction of motion and to the axis of rotation. On Earth, this tends to deflect moving objects to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

Ekman transport - the net motion of fluid that results from the balance between Coriolis and turbulent drag forces.

Eötvös effect - the change in perceived gravitational force that results from eastbound or westbound movement on Earth’s surface.

Kelvin waves - an ocean wave that is trapped at the Earth’s equator and along vertical boundaries like coastlines. They move towards the equator when they have a western boundary; towards the poles when they have an eastern boundary; and make a whirlpool when they have a closed boundary, moving counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

Lagrange points -  five points where three bodies can orbit each other, yet stay in the same position relative to each other in a stable configuration. L1-L3 are in line with each other, while L4 and L5 are at the points of equilateral triangles in the configuration.

prograde - when a planet spins from east to west.

Rossby number - used to determine the relative importance of the centrifugal and Coriolis forces in maps of weather patterns. A small Rossby number indicates that a weather system is strongly affected by Coriolis forces, while a large Rossby number signifies that a system is affected by inertial and centrifugal forces.

Transcript

Timeline

Giovanni Battista Riccioli, Italian (1598-1671)

Francesco Maria Grimaldi, Italian (1618-63)

Joseph-Louis Lagrange, French (1736-1813)

Gaspard-Gustave de Coriolis, French (1792-1843)

Sir William Thompson, AKA Lord Kelvin, Scots-Irish (1824-1907)

Baron Loránd Eötvös de Vásárosnamény, Hungarian (1848-1919)

Ottokar Tumlirz, Austrian (1856-1928)

Fridtjof Nansen, Norwegian (1861-1930)

Vagn Walfrid Ekman, Swedish (1874-1954)

Carl-Gustaf Arvid Rossby, Swedish-born American (1898-1957)

Sources

Coriolis Effect via the University of Oregon

Coriolis Force via Wikipedia

Coriolis effect, two centuries before Coriolis via Physics Today (Aug 2011)

Gaspard-Gustave de Coriolis via Wikipedia

Coriolis effect via National Geographic

Hurricane, cyclone, typhoon, tornado – what’s the difference? via African Reporter (Sep 2017)

Wang, B. Kelvin Waves. University of Hawaii: Honolulu, 2002.

Ocean in Motion: Ekman Transport Background via NASA

Ekman transport via Wikipedia

What is a Geodesist? via Environmental Science

“The Second Coming” by W. B. Yeats via Poetry Foundation

Intro Music: ‘Better Times Will Come’ by No Luck Club off their album Prosperity

Filler Music: ‘Ambergris’ by Tipper off their EP Fathoms

Outro Music: ‘Fields of Russia’ by Mutefish off their album On Draught

I saw the picture and I thought it was a photo of the space between a Venetian blind and a window frame but no. No. It was a moon between the rings of Saturn.

Ep. 21 Radio Astronomy and RQZs - HD and the Void

Be brave in the face of an extremely technical episode where I tackle radio astronomy! Astronomers collect radio waves to map distant objects. To do their work they need a level of quiet that's hard to find without some help from Radio Frequency I...

I’ve gotten some feedback that episodes can be too technical. Unfortunately, that feedback came too late to save you from this week’s episode, which requires me to summarize the electromagnetic spectrum, radio astronomy, a concept called interferometry, and government regulations to talk about the topic that originally started me on this path: radio quiet zones. Please, bear with me! Pardon my mess! It was all very interesting stuff, I couldn’t resist digging into it.

Below the cut are my sources, music credits, a vocab list, a timeline of the astronomers I mention, and the transcript of this episode. I’ve bolded those sources I mention in the podcast, including the podcast that started me on this topic: The Adventure Zone! Please let me know what you think I should research next by messaging me here, tweeting at me at @HDandtheVoid, or asking me to my face if you know me. I’d love it if you would subscribe on iTunes, rate my humble little podcast and maybe review it, and tell friends if you think they’d like to hear it!

(My thoughts on the next episode are SOFIA, which you need to listen to find out what it stands for, or the pilot Chuck Yaeger. The next episode will go up February 26th.)

Glossary

aperture synthesis - the process of collecting electromagnetic radiation from a variety of separate, small telescopes and then combining this data to recreate the image at a higher resolution than would be possible with a single telescope.

frequency - the number of times a wave oscillates up and down per second.

hertz - the number of times an electromagnetic wave cycles per second. One cycle per second is 1 hertz.

interferometry - a group of techniques to extract information from superimposing electromagnetic waves to create interference. In radio astronomy, this is done by using a wide spread of receivers to look at the same distant object, then bringing that data together with a correlator that can create a larger, clearer picture than an individual radio telescope alone could.

radiation - energy that travels and spreads out as it goes.

Script/Transcript

Timeline

Joseph-Louis Lagrange, French (1736-1813)

Armand-Hippolyte-Louis Fizeau, French (1819-1896)

Edward W. Morley, American (1838-1923)

Albert A. Michelson, American (1852-1931)

Sir Martin Ryle, British (1918-1984)

Bernard Yarnton Mills, Australian (1920-2011)

Derek Vonberg, British (1922-2015)

Antony Hewish, British (1924- )

Sources

Electromagnetic spectrum via NASA

Observatories across the EM spectrum via NASA

Fermi satellite via NASA

The Neil Gehrels Swift Observatory via NASA

NuSTAR via Caltech

NuSTAR via NASA

Chandra X-Ray Observatory via Harvard

The Galaxy Evolution Explorer (GALEX) via Caltech

Kepler satellite via NASA

Hubble Space Telescope via NASA

Spitzer satellite via Caltech

Stratospheric Observatory for Infrared Astronomy (SOFIA)

Planck satellite via ESA

Spekt-R Radioastron from Russia

High Energy Stereoscopic System (HESS)

W. M. Keck Observatory on Mauna Kea

South Africa Large Telescope (SALT) in Namibia

The Combined Array for Research in Millimeter-Wave Astronomy (CARMA) via Caltech

CARMA public page (decommissioned)

Very Large Array (VLA) via NRAO

Space radio telescope (1997) via NRAO

Highly Advanced Laboratory for Communications and Astronomy (HALCA) via NASA

A timeline of the history of radio interferometry via University of Groningen (Netherlands)

Interferometers via the LIGO Laboratory

Michelson-Morley Experiment via University of Virginia

Astronomical Interferometry via Magdalena Ridge Observatory

Interferometry via XKCD

How Radio Works via How Stuff Works

Radio Spectrum Allocation via the Federal Communications Commission

Interferometry via the European Space Observatory

National Radio Quiet Zone via National Radio Astronomy Observatory

“minimize possible harmful interference to the National Radio Astronomy Observatory (NRAO) in Green Bank, WV and the radio receiving facilities for the United States Navy in Sugar Grove, WV.”

National Radio Quiet Zone via CNN

“Tucked in the Allegheny Mountains, researchers are listening to exploding galaxies at the edge of the universe – a signal that is so faint, it’s about a billionth of a billionth of a millionth of a watt.”

The Quiet Zone: Where mobile phones are banned via BBC News (May 2015)

Enter The Quiet Zone: Where Cell Service, Wi-Fi Are Banned via NPR (Oct 2013)

Green Bank Observatory in West Virginia, USA

Karen O’Neil: “The types of energies we look at are less than the energy of a single snowflake falling on the Earth.”

Characteristics of radio quiet zones via International Telecommunication Union (Sept 2012)

“transmissions below 15 GHz are restricted within a certain radius around the Arecibo Observatory, located in Puerto Rico. Since no observations are carried out, nor are any expected to be carried out above that frequency in the future, no restrictions are needed on higher frequency transmissions. The reverse is not necessarily true, however. For example, some restrictions may be imposed on transmissions below 30 GHz in the neighbourhood of the large international ALMA observatory even though it is not expected to ever observe below that frequency, due to its susceptibility to interference at these lower frequencies in the signal path.”

“It is important to emphasize that a RQZ does not imply a complete absence of radio transmissions. The existence of, and coexistence with, a range of man-made devices will always be necessary. A RQZ may include options for notification of other users and for negotiation in mitigating interference. On the other hand, a RQZ does not consist entirely of mitigating techniques implemented by the radio astronomy facility; some level of control on externally-generated interference is intrinsic to a RQZ.

A RQZ is therefore a buffer zone that allows for the implementation of mechanisms to protect radio astronomy observations at a facility within the zone from detrimental radio frequency interference, through effective mitigation strategies and regulation of radio frequency transmitters.”

ALMA Observatory website

The Scientific Committee on Frequency Allocations for Radio Astronomy (IUCAF) website

Google Map of worldwide radio quiet zones (Aug 2016)

ITU-R Recommendations of Particular Importance to Radio Astronomy by A. Richard Thompson

“the necessity of maintaining the shielded zone of the Moon as an area of great potential for observations by the radio astronomy service and by passive space research, and consequently of maintaining it as free as possible from transmissions.”

The Adventure Zone: Amnesty setup episode via Maximum Fun

Intro Music: ‘Better Times Will Come’ by No Luck Club off their album Prosperity

Filler Music: ‘Junkyard Chandelier’ by Radical Face aka Ben Cooper, who primarily releases music as Radical Face but also has at least three other bands or band names he’s working with/has released music as.

Outro Music: ‘Fields of Russia’ by Mutefish off their album On Draught

Hubble Spots Two Interacting Galaxies Defying Cosmic Convention

NASA - Hubble Space Telescope patch. March 24, 2017

Some galaxies are harder to classify than others. Here, Hubble’s trusty Wide Field Camera 3 (WFC3) has captured a striking view of two interacting galaxies located some 60 million light-years away in the constellation of Leo (The Lion). The more diffuse and patchy blue glow covering the right side of the frame is known as NGC 3447 — sometimes NGC 3447B for clarity, as the name NGC 3447 can apply to the overall duo. The smaller clump to the upper left is known as NGC 3447A. Overall, we know NGC 3447 comprises a couple of interacting galaxies, but we’re unsure what each looked like before they began to tear one another apart. The two sit so close that they are strongly influenced and distorted by the gravitational forces between them, causing the galaxies to twist themselves into the unusual and unique shapes seen here. NGC 3447A appears to display the remnants of a central bar structure and some disrupted spiral arms, both properties characteristic of certain spiral galaxies. Some identify NGC 3447B as a former spiral galaxy, while others categorize it as being an irregular galaxy.

Hubble Space Telescope

For Hubble’s image of the Whirlpool Galaxy, visit:  http://hubblesite.org/ http://www.nasa.gov/hubble http://www.spacetelescope.org/ Image, Animation, Credits: ESA/Hubble & NASA/Text Credits: European Space Agency/NASA/Karl Hille. Best regards, Orbiter.ch Full article

Aboard the International Space Station, astronaut Thomas Pesquet of the European Space Agency snapped this photo and wrote, ‘The view at night recently has been simply magnificent: few clouds, intense #aurora. I can’t look away from the windows.' 

The dancing lights of the aurora provide stunning views, but also capture the imagination of scientists who study incoming energy and particles from the sun. Aurora are one effect of such energetic particles, which can speed out from the sun both in a steady stream called the solar wind and due to giant eruptions known as coronal mass ejections or CMEs. Credit: NASA/ESA

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Ep.17 Edmond Halley - HD and the Void

Edmond Halley was heavily involved in the establishment of modern astronomy, whether through his direct observational work or through the support he offered others in his field. Hear a quick overview of the man who's popped up so much throughout t...

I’m back! July was nuts! June was also nuts! I’ve missed this podcast, though, and have been thinking about it the entire time because I will never stop loving space. I was working my way through a very meaty book on Edmond Halley and I am here to report on my findings, and also compile some of the things I’ve already said about this cool guy and his cool contributions to science.

Below the cut are my standard glossary, transcript, timeline of people mentioned, sources, and music credits. I take topic suggestions from Tumblr messages, you can tweet at me on Twitter at @HDandtheVoid, or you can ask me to my face if you know me. Subscribe on iTunes to get the new episodes of my increasingly erratically updated podcast, and please please please rate and review it. Go ahead and tell friends if you think they’d like to hear it, too!

(My thoughts on the next episode are Stephen Hawking and his theories or famous comets. The next episode will go up in August—hopefully August 20th!)

Glossary

sidereal year—the time required for the earth to complete an orbit of the sun relative to the stars.

tropical year—the interval at which seasons repeat and the basis for the calendar year.

Script/Transcript

Timeline

Julius Caesar, Roman (100-45 BCE)

Augustus Caesar, Roman (63-14 BCE) 

Nicolaus Copernicus, Polish (1473-1543)

Pope Gregory XIII, Italian (1502-1585)

Tycho Brahe, Danish (1546-1601)

Johannes Kepler, German (1571-1630)

Johannes Hevelius, Polish (1611-1687)

Giovanni Cassini (in French, Jean-Dominique Cassini), Italian/French (1625-1712)

Queen Christina, Swedish (1626-1689)

Isaac Newton, English (1643-1727)

John Flamsteed, English (1646-1719)

Elisabeth Hevelius, Polish (1647-1693)

Edmond Halley, English (1656-1742)

John Harrison, English (1693-1776)

Sources

Morse, Stephen P. “The Julian Calendar and why we need to know about it.” The Association of Professional Genealogists Quarterly (March 2014). Accessed July 15, 2018.

Julian Date Converter via the Astronomical Applications Department of the U.S. Naval Observatory.

Hughes, David W. “Edmond Halley, Scientist.” British Astronomical Association (1985). Accessed July 27, 2018.

Cook, Alan. Edmond Halley: Charting the Heavens and the Seas. Clarendon Press: Oxford, 1998.

Intro Music: ‘Better Times Will Come’ by No Luck Club off their album Prosperity

Outro Music: ‘Fields of Russia’ by Mutefish off their album On Draught

Here’s a great example of the kinds of experiments astronauts perform on the International Space Station, just like I talked about in Episode 19! I absolutely want to high-five whoever called is ISS-CREAM.

From Frozen Antarctica to the Cold Vacuum of Space

A new experiment that will collect tiny charged particles known as galactic cosmic rays will soon be added to the International Space Station. The Cosmic Ray Energetics And Mass for the International Space Station payload, nicknamed ISS-CREAM, will soon be installed in its new home on the Station’s Japanese Experiment Module Exposed Facility. ISS-CREAM will help scientists understand more about galactic cosmic rays and the processes that produce them.

Wait, what are cosmic rays?

Cosmic rays are pieces of atoms that move through space at nearly the speed of light. Galactic cosmic rays come from beyond our solar system. 

They provide us with direct samples of matter from distant places in our galaxy.

Why do these things go so fast?

Galactic cosmic rays have been sped up by extreme processes. When massive stars die, they explode as supernovas. The explosion’s blast wave expands into space along with a cloud of debris. 

Particles caught up in this blast wave can bounce around in it and slowly pick up speed. Eventually they move so fast they can escape the blast wave and race away as a cosmic ray.

Where can we catch cosmic rays?

Cosmic rays are constantly zipping through space at these super-fast speeds, running into whatever is in their path – including Earth.  

But Earth’s atmosphere is a great shield, protecting us from 99.9 percent of the radiation coming from space, including most cosmic rays.  This is good news for life on Earth, but bad news for scientists studying cosmic rays.  

So… how do you deal with that?

Because Earth has such an effective shield against cosmic rays, the best place for scientists to study them is above our atmosphere – in space.  Since the 1920s, scientists have tried to get their instruments as close to space as possible. One of the simplest ways to do this is to send these instruments up on balloons the size of football stadiums. These balloons are so large because they have to be able to both lift their own weight and that of their cargo, which can be heavier than a car. Scientific balloons fly to 120,000 feet or more above the ground – that’s at least three times higher than you might fly in a commercial airplane!  

Credit: Isaac Mognet (Pennsylvania State University)

Earlier versions of ISS-CREAM’s instruments were launched on these giant balloons from McMurdo Station in Antarctica seven times, starting in 2004, for a total of 191 days near the top of the atmosphere.  Each of these flights helped the team test their hardware and work towards sending a cutting-edge cosmic ray detector into space!  

How is going to space different than flying balloons?

Balloon flights allowed the team to collect a lot of cosmic rays, but even at 120,000 feet, a lot of the particles are still blocked. Scientists at the University of Maryland, College Park, who operate ISS-CREAM, expect to get about 10 times as much data from their new home on the International Space Station. 

That’s because it will be both above the atmosphere and fly far longer than is possible with a balloon. As you might imagine, there are large differences between flying something on a balloon and launching it into space. The science instruments and other systems had to be changed so ISS-CREAM could safely launch on a rocket and work in space.

What will ISS-CREAM do?

While on the space station, ISS-CREAM will collect millions of cosmic rays – electrons, protons and atomic nuclei representing the elements found in the solar system. These results will help us understand why cosmic rays reach the wicked-fast speeds they do and, most important, what limits those speeds.

ISS-CREAM launches to the International Space Station aboard the latest SpaceX Dragon spacecraft, targeted to launch August 14. Want to learn more about ISS-CREAM and some of our scientific balloons? Check out our recent feature, NASA’s Scientific Balloon Program Reaches New Heights.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Biggest Scientific Breakthroughs of 2013

From intergalactic neutrinos and invisible brains, to the creation of miniature human “organoids”, 2013 was an remarkable year for scientific discovery. Here are some of the biggest scientific breakthroughs, innovations and advances of 2013.

Voyager I Leaves the Solar System

Escaping the solar system is no mean feat. For 36 years, NASA’s Voyager 1 spacecraft has putting distance between itself and the Sun at speeds approaching 11 miles per second. At a pace like that, scientists knew Voyager was approaching the fringes of the heliosphere that surrounds and defines our solar neighborhood – but when would it break that barrier? When would it make the leap to interstellar space? After months of uncertainty, NASA finally made the news official this September. “Voyager 1 is the first human-made object to make it into interstellar space” said Don Gurnett, lead author of the paper announcing Voyager’s departure; “we’re actually out there.”

The Milky Way is Brimming with Habitable Worlds

Planet-hunting scientists announced in November that 22% of sunlike stars in the Milky Way are orbited by potentially habitable, Earth-size worlds. This remarkable finding suggests there could be as many as two-billion planets in our galaxy suitable for life — and that the nearest such planet may be only 12 light-years away. Is Earth 2.0 out there? With figures like that, it’s hard to imagine otherwise. Who knows – with all the Kepler data we’ve got to sift through, there’s a chance we’ve already found it. 

Curiosity Confirms Mars Was Once Capable of Harboring Life

In March, NASA scientists released perhaps the most compelling evidence to date that the Red Planet was once capable of harboring life. Earlier this year, Curiosity drilled some samples out of a sedimentary rock near an old river bed in Gale Crater. This geological area used to feature a series of stream channels, leaving behind finely grained bedrock indicative of previously wet conditions. Using the rover’s onboard instrumentation, NASA scientists analyzed these samples to detect some of the critical elements required for life, including sulfur, nitrogen, hydrogen, oxygen, phosphorus, and carbon. The rover is currently on a trek to its primary scientific target – a three-mile-high peak at the center of Gale Crater named Mount Sharp – where it will attempt to further reinforce its findings.

Researchers Detect Neutrinos from Another Galaxy

By drilling a 1.5 mile hole deep into an Antarctic glacier, physicists working at the IceCube South Pole Observatory this year captured 28 neutrinos, those mysterious and extremely powerful subatomic particles that can pass straight through solid matter. And here’s the real kicker: the particles likely originated from beyond our solar system – and possibly even our galaxy. "This is a landmark discovery,“ said Alexander Kusenko, a UCLA astroparticle physicist who was not involved in the investigation, "possibly a Nobel Prize in the making.”

NASA Discovers “A Previously Unknown Surprise Circling Earth”

NASA’s recently deployed Van Allen probes — a pair of robotic spacecraft launched in August 2012 to investigate Earth’s eponymous pair of radiation belts — turned out out some very unexpected findings in February, when they spotted an ephemeral third ring of radiation, previously unknown to science, surrounding our planet.

Human Cloning Becomes a Reality

A scientific milestone 17 years in the making, researchers announced in May that they had derived stem cells from cloned human embryos.The controversial technology could lead to new treatments for diseases like Parkinson’s and diabetes — while bringing us one step closer to human reproductive cloning.

Giant “Pandoravirus” Could Redefine Life as we Know it

Scientists in July announced the discovery of a pair of viruses that defy classification. Bigger and more genetically complex than any viral genus known to science, these so-called “pandoraviruses” could reignite a longstanding debate over the classification of life itself.

Brain-to-Brain Interfaces Have Arrived

Back in February, researchers announced that they had successfully established an electronic link between the brains of two rats, and demonstrated that signals from the mind of one could help the second solve basic puzzles in real time — even when those animals were separated by thousands of miles. A few months later, a similar connection was established between the brain of a human and a rat. Just one month later, researchers published the results of the first successful human-to-human brain interface. The age of the mind-meld, it seems, is near at hand.

There is Life at the End of the World

There is life in Lake Whillans. For millions of years, the small body of liquid water has lurked hundreds of meters below Antarctica’s Ross Ice Shelf, sealed off from the outside world and the scientists who would explore its subglacial depths. Earlier this year, a team of researchers led by Montana State University glaciologist John Priscu successfully bored a tunnel to Whillans and encountered life, making Priscu and his colleagues the first people in history to discover living organisms in the alien lakes at the bottom of the world.

Doctors Cure HIV in a Baby Born With the Disease

In a monumental first for medicine, doctors announced in March that a baby had been cured of an HIV infection. Dr. Deborah Persaud, who presented the child’s case at the 20th annual Conference on Retroviruses and Opportunistic Infection, called it “definitely a game-changer.”

Newly Discovered Skulls Could Prune Humans’ Evolutionary Tree

An incredibly well-preserved, 1.8-million-year-old skull from Dmanisi, Georgia suggests the evolutionary tree of the genus Homo may have fewer branches than previously believed. In a report published in October, a team led by Georgian anthropologist David Lordkipanidze writes that it is “the world’s first completely preserved hominid skull.” And what a skull it is. When considered alongside four other skulls discovered nearby, it suggests that the earliest known members of the Homo genus (H. habilis, H.rudolfensis and H. erectus) may not have been distinct, coexisting species, at all. Instead, they may have been part of a single, evolving lineage that eventually gave rise to modern humans.

Neuroscientists Turn Brains Invisible

Gaze upon the stunning effects of CLARITY, a new technique that enables scientists to turn brain matter and other tissues completely transparent. It’s been hailed as one of the most important advances for neuroanatomy in decades, and it’s not hard to see why.

[source | gifs → galaxyclusters]

Here’s the nose scratching sponge I talked about in Episode 19!

‪This is how astronauts clear our ears (and scratch our noses!) during a spacewalk. ‬

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