Squishy Stars, Science, and Sirach

Posted on August 24, 2024 by Brian H. Gill
Keith Gendreau/NASA/Goddard's photo: 'NICER Optics Lead Takashi Okajima installs one of NICER's 56 X-ray concentrators, each consisting of 24 concentric foils.... The Neutron star Interior Composition Explorer (NICER) is a NASA Explorer Mission of Opportunity dedicated to studying the extraordinary environments - strong gravity, ultra-dense matter, and the most powerful magnetic fields in the universe - [of] neutron stars. An attached payload aboard the International Space Station, NICER will deploy an instrument with unique capabilities for timing and spectroscopy of fast X-ray brightness fluctuations. The embedded Station Explorer for X-ray Timing and Navigation Technology demonstration (SEXTANT) will use NICER data to validate, for the first time in space, technology that exploits pulsars as natural navigation beacons.' (July 9, 2015) via Wikipedia, used w/o permission.
Installing the NICER (Neutron star Interior Composition Explorer) X-ray concentrators.

A paper published this month doesn’t so much tell us what’s inside a neutron star, as show what’s not inside. Considering how little we know about these immensely-dense stellar objects, that’s a significant step toward understanding the things.

I’ll take a look at that, but mostly I’ll be talking about what we’ve been learning, and why I think paying attention to this wonder-packed universe is a good idea.

Even if — maybe because — this Haldane quote, written a few years before we knew about neutron stars, still reflects how God’s universe has been surprising us.

“Now, my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose….”
(“Possible Worlds and Other Essays” , p. 286, J. B. S. Haldane (1927) via Wikiquote)

Squishy (?) Stars, Strange States of Matter

A. Watts et al. illustration, showing 'a simple breakdown of a neutron star's composition. The composition of the core - that is, the nature of matter under extreme pressure - is unknown, and there are a lot of possible options.' (2016) via Sky andTelescope, used w/o permission.
Inside a neutron star: one possible arrangement.

“Neutron Stars Might Be Squishy Inside“
Monica Young, Sky & Telescope (August 6, 2024)

“New data on the brightest pulsar observed with a telescope on the International Space Station suggests neutron star interiors are ‘squishy.’

“Astronomers have found a way to peer inside neutron stars and glimpse the exotic matter hiding in their cores. By pinning down the properties of the closest and brightest neutron star yet, Devarshi Choudhury (University of Amsterdam) and colleagues have ruled out both the plainest and the strangest ideas describing the dense matter inside these exotic objects….”

The “closest and brightest neutron star” these scientists have been studying is a pulsar: PSR J0437-4715.

Pulsars and neutron stars weren’t on the old star charts. They’re too dim for anything short of really good telescopes. The supernovae that form them, that’s another matter.

Around the time folks living west of the Black Sea were making high-quality ceramics and public baths, a massive star exploded.

This isn’t the one that became PSR J0437-4715, by the way. It’s the supernova that formed the Crab nebula. Anyway —

The explosion’s wavefront reached Earth the same year that the Church stopped trying to coordinate its eastern and western regions. These days, folks speaking my language call it the Great Schism, and — when it’s mentioned at all — say that the split happened because folks in Rome and Constantinople squabbled over theological stuff.

There’s some truth to the name and claim. But I strongly suspect that we’re looking at what happens when folks let issues accumulate for a few centuries.

Besides, we didn’t have either airlines or the Internet back then. Communication between places more than a day’s walk apart wasn’t easy. Plus, the Church was going through one of its rough patches. We have those every half-millennium or so, and that’s another topic.1

Where was I? An exploding star’s wavefront reaching Earth. Right.

Supernova!

cmglee, NASA Goddard Space Flight Center's illustration: 'Stellar evolution of low-mass (left cycle) and high-mass (right cycle) stars, with examples in italics.' (2014) via Wikimedia Commons, used w/o permission.Chinese astronomers noticed a “guest star” in July of 1054. Folks living in what’s now San Juan County, New Mexico, did, too: assuming that what we call the “Supernova Pictograph” is their record of the event.

John Bevis, an English doctor, electrical researcher and astronomer, spotted a fuzzy spot where the supernova had been in 1731. French astronomer Charles Messier did the same thing in 1758, and made it the first entry in his catalog of things that look like comets but aren’t.

William Parsons, 3rd Earl of Rosse, an English engineer and astronomer, observed and drew a picture of the fuzzy spot in the 1840s. He said it looked sort of like a crab. In 1848, using a bigger telescope, he observed it again, and changed his mind. But the moniker “Crab Nebula” caught on, anyway.

Fast-forward to the early 20th century. Astronomers had started using photography, and noticed that the Crab Nebula was getting bigger. I’ll skip a bunch of important names.

In 1928, Edwin Hubble said the Crab Nebula was related to the 1054 guest star. The idea didn’t line up with known physics, so it wasn’t until Nicholas Mayall used a spectrograph and considerable analysis to — okay. Bottom line, Mayall showed that Hubble was right.

In late 1933, astronomers Walter Baade and Fritz Zwicky said that neutron stars — extremely dense supernova remnants — might exist. As it turns out, they were right.

That was in the 1930s. The supernova tie-in started a search for other supernova sightings in humanity’s archives.2

Neutron Stars: Gravity, Math, and Weirdness

Hugo Spinelli's diagram: Bosons and Fermions, fundamental classes of subatomic particles; and Hadrons, which can be either. (February 10, 2013)
Hugo Spinelli’s diagram: Bosons, Hadrons, and Fermions.

Graph by A. Watts: 'mass and radius measurements for three pulsars with data from NICER. The measurements allow a range of possible values, so they are represented as oval-shape bubbles, with the darker-shaded region showing the more likely values. ... Also shown are some representative equations of state, which appear as cobra-shaped lines. The newest data, from J0437 (red), clearly rule out both the softest and stiffest states of matter, while still tending toward the squishier end of what's possible.' (2024) via Sky and Telescope, used w/o permission.Finally, and this is what I had planned on focusing on, neutron stars are what’s left when a really big star, between around 10 to 25 times our Sun’s mass, explodes.

What’s left of the star collapses until it’s a dozen kilometers across, give or take.

It’s about as dense as an atom’s nucleus: something like 100,000,000,000,000 grams per cubic centimeter.

Neutron stars are made of degenerate matter, which is a state of matter and has nothing to do with moral character.

Degenerate matter is under so much pressure that elementary particles like electrons and neutrons get squeezed together.

“…Upon the star’s collapse, the core’s atoms broke down into neutrons; only a rule that helps govern the world of the very small (the Pauli exclusion principle) prevents the neutrons from getting too friendly with one another. That pressure prevents further caving-in to gravity….”
(“Neutron Stars Might Be Squishy Inside” , Monica Young, Sky & Telescope (August 6, 2024 ))

Since making and keeping degenerate matter in laboratories isn’t practical, scientists study things like neutron stars to see how it works.

This is where things get weird, involving math that’s beyond me and phrases like “equation of state”.

An equation of state describes the state of matter in particular physical conditions.

“In physics and chemistry, an equation of state is a thermodynamic equation relating state variables, which describe the state of matter under a given set of physical conditions, such as pressure, volume, temperature, or internal energy. Most modern equations of state are formulated in the Helmholtz free energy. Equations of state are useful in describing the properties of pure substances and mixtures in liquids, gases, and solid states as well as the state of matter in the interior of stars….”
(Equation of state, Wikipedia)

That’s a useful definition.

So is this example of an equation of state’s general form: f(p, V, T)=0, “…where p is the pressure, V is the volume, and T is the temperature of the system….” Or, rather, it would be useful: if I knew more about math and its formulaic conventions.

I’m guessing that f is a number that’s the equation of state value for some substance, but I don’t know.

I was going to talk neutrons, fermions, bosons, how angular momentum applies to subatomic particles, a couple research papers using data from the NICER telescope, and what we’ve been learning about PSR J0437-4715, the closest and brightest known pulsar.

But I’m not up to digging through all that this week.

Instead, I’ve put ‘for more information’ links in the footnotes.3

“…Astronomers Still Don’t Know….”

NASA's Goddard Space Flight Center/Conceptual Image Lab's illustration: 'Scientists think neutron stars are layered, [this diagram] suggesting one, simplified view of those layers' compositions. The state of matter in their inner cores remains unknown.' (2021) via Wikipedia, used w/o permission. see https://www.nasa.gov/universe/nasas-nicer-probes-the-squeezability-of-neutron-stars/
Inside a neutron star: another possibility.

“Three Neutron Stars Reveal Inside Secrets“
Colin Stuart, Sky & Telescope (June 27, 2024)

“Astronomers surveyed dozens of neutron stars, homing in on three that challenge most ideas about what these exotic objects are made of.

“Astronomers using the XMM-Newton and Chandra space telescopes have revisited a trio of young neutron stars that are particularly cool for their age. Explaining their existence requires ruling out 75% of all neutron star models — bringing astronomers closer to identifying the correct one.

“A neutron star is among the universe’s most exotic objects, forged in the fury of a massive star’s death. The star’s core buckles under its own weight, crashing down so hard that electrons and protons are forced to merge into neutrons. The resulting neutron star material is so dense that a single spoonful would weigh more than every human on Earth put together.

“Yet astronomers still don’t know the exact structure of a neutron star, which probably includes electrons and protons in its crust and maybe quarks in its core. The key to finding out what’s really inside neutron stars is identifying the correct equation of state that describes the relationship between temperature and pressure in all neutron star interiors. There are hundreds of possibilities….”

Friedrich Graetz's political cartoon (March 5, 1883): 'An appalling attempt to muzzle the watch-dog of science', from the cover of Puck magazine. (March 14, 1883) and see https://loc.getarchive.net/media/an-appalling-attempt-to-muzzle-the-watch-dog-of-science-f-graetzI don’t see nearly as many ‘science proves that’ declarations now as I did, back when folks were still getting used to the idea that Robert Goddard was right. Apart from the usual climate doomsayers, that is, and that’s yet another topic.

Maybe it’s because I have access to better sources these days. That’s another reason I’m not upset about the Internet and other threats to the status quo.

I suspect that the old ‘Scientific Certainty Frees Us From the Shackles of Superstition, Ignorance, and (religious) Oppression’ triumphalist tone was clashing with the 20th century’s discoveries of just how much we haven’t learned yet.

And I suspect scientists, those involved with physics and related fields at any rate, have been getting a great deal less stuffy.

Sure, folks have been naming telescopes after famous scientists, like the XMM-Newton and Chandra space telescopes.

But we’re also calling one the Neutron Star Interior Composition Explorer.

I’ll grant that the full name sounds a bit pretentious: even megalomaniacal. As my oldest daughter said Tuesday, “A neutron star explorer? How are they going to get that thing close [to] a neutron star?”

Fact is, they can’t. There’s serious talk about launching interstellar probes, but technology like that is still in the early R&D stages.

I’ll probably talk about Neutron Star Interior Composition Explorer and the research it’s making possible — eventually. This week I’ll focus, very briefly, on its shorter name: NICER.

I mean to say: a telescope called NICER.

Writing about squishy stars.

Subatomic particles called quarks.

Quarks that are up, down, top, bottom, charm and strange.

And scientists who don’t even Latinize their names for research papers.4

Quite a lot has happened over the last hundred years. Take astronomy, for example.

New Views of This Universe: Radio, X-Ray, Gravitational Waves …

Virgo Collaboration's photo: aerial view of the VIRGO gravitational wave detector in Italy. (2015) via BBC news, used w/o permission.
The Virgo gravitational Wave detector in Italy. (2015)

'Dutch telescope' from 'Emblemata of zinne-werck,' Johan de Brune. (1624) Print engraved by Adriaen van de Venne.It’s been about four centuries since Galileo Galilei — and almost certainly others — turned a “Dutch perspective glass” into a “telescope”. Five decades later, someone made the first telescope with mirrors instead of lenses.

Textbooks say Isaac Newton invented reflecting telescopes, and that’s probably so.

By 1927, U.S. Navy short-wave communications researchers were launching detectors into the upper atmosphere on Goddard’s rockets.

In 1932, physicist and radio engineer Karl Jansky noticed radio noise, a “hiss”, coming from the constellation Sagittarius.

He announced what he’d learned in 1933, but the Great Depression was in progress, followed by World War II. Building another, more expensive, radio antenna/telescope wasn’t an option. Even so, I think 1932 is a reasonable choice for radio astronomy’s start.

Nicola Tesla’s signals “from another world” in 1899 had probably been transmissions from another researcher’s radio.

Either way, radio astronomy took off when amateur astronomer Grote Reber built the first parabolic radio telescope. That was in 1937, followed by more folks who had been working on wartime radar systems.

Suborbital flights picked up Solar ultraviolet radiation in 1946. The Orbiting Solar Observatory’s ultraviolet telescope gave astronomers a better look, starting in 1962.

Instruments launched from the White Sands Missile Range in New Mexico in 1949 detected X-rays from the sun in 1949. That suborbital flight used a V-2 rocket. The first rocket-born X-ray telescope imaged the Sun in 1963.

Infrared astronomy arguably started in 1800, when William Herschel put a thermometer in sunlight that had passed through a prism. Skipping ahead, better technology and radio astronomy’s success put infrared astronomy on the map in the 1960s.

Then, in 2015, the LIGO and Virgo collaborations recorded the first observations of gravitational waves.5

It’s been an eventful century.

Beauty, Wonders, and Paying Attention

ISS Expedition 7 crewmember's photo: '...Earth's horizon as the sunsets over the Pacific Ocean....' (July 21, 2003)
Psalms 98:4; and sunrise over the Pacific Ocean, seen from the ISS. (2003)

I could be a Catholic and not take a lively interest in God’s universe.

But paying attention to the beauty and wonders around me is, I think, a good idea. If I don’t, I’ll be missing a great deal of what God is ‘saying’ to us. (Catechism of the Catholic Church, 293, 299, and more)

I figure that’s partly why folks like Saints Hildegard of Bingen and Albertus Magnus helped lay the foundation of what we call science.6

NASA, ESA, Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration's image: 'Stellar Jewel Box' - 'Thousands of sparkling young stars are nestled within the giant nebula NGC 3603, one of the most massive young star clusters in the Milky Way Galaxy....' (2020) via NASA, used w/o permission.That was just under a millennium back now, but the idea of taking notice both of God’s creation and God is much older.

“God is known by natural knowledge through the images of His effects.”
(“Summa Theologica” , First Part, Question 12 – How God is known by us, Article 12 – Whether God can be known in this life by natural reason?, Reply to Objection 2; St. Thomas Aquinas (13th century, unfinished at his death in 1274) via NewAdvent.org)
[this is a very brief excerpt]

“Question the beauty of the earth, question the beauty of the sea, question the beauty of the air, amply spread around everywhere, question the beauty of the sky, question the serried ranks of the stars … question all these things. They all answer you, ‘Here we are, look; we’re beautiful.’…
“…Prayer:
“O God, You are never far from those who sincerely search for You. Accompany those who err and wander far from You. Turn their hearts towards what is right and let them see the signs of Your Presence in the beauty of created things. We ask this….”
(The beauty of the unchangeable creator is to be inferred from the beauty of the changeable creation, St. Augustine, Sermons, 241, Easter (c.411 A.D.))

Developing a sense of scale is also prudent. And remembering who’s in charge.

“By faith we understand that the universe was ordered by the word of God, so that what is visible came into being through the invisible.”
(Hebrews 11:3)

“He who lives forever created the whole universe;
the LORD alone is just.”
“Like a drop of water from the sea and a grain of sand,
so are these few years among the days of eternity.
That is why the Lord is patient with them
and pours out his mercy on them.”
(Sirach 18:1–2, 10–11)

“The heavens declare the glory of God;
the firmament proclaims the works of his hands.”
(Psalms 19:2)

If this sounds familiar, it should. I’ve talked about it before:

1 A pulsar, and a quick look at part of humanity’s story:

2 The same supernova, its remnant, and skywatchers:

3 Physics, the Crab Nebula and Pulsar again, another pulsar, and two research papers:

4 Science, scientists, subatomic particles, X-ray space telescopes, and an old custom:

5 Astronomy, from the Dutch perspective glass to X-ray telescopes, and a little history:

6 Saints and science:

How interesting or useful was this post?

Click on a star to rate it!

Average rating 0 / 5. Vote count: 0

No votes so far! Be the first to rate this post.

I am sorry that this post was not useful for you!

Let me learn why!

How could I have made this more nearly worth your time?

About Brian H. Gill

I was born in 1951. I'm a husband, father and grandfather. One of the kids graduated from college in December, 2008, and is helping her husband run businesses and raise my granddaughter; another is a cartoonist and artist; #3 daughter is a writer; my son is developing a digital game with #3 and #1 daughters. I'm also a writer and artist.
This entry was posted in Discursive Detours, Science News and tagged , , , , , . Bookmark the permalink.

Thanks for taking time to comment!