Quick and Easy Explanation of the Kuiper Belt

An artist’s impression of a Kuiper Belt object (KBO), located on the outer rim of our solar system at a staggering distance of 4 billion miles from the sun. Image Credit: NASA, ESA, and G. Bacon (STScI).

Kuiper Belt–a donut-shaped collection of asteroids beyond the orbit of Neptune

Where is the Kuiper Belt located?

The Kuiper Belt orbits around the sun just beyond the orbit of Neptune. It covers a vast region of space starting about 2.7 billion miles (4.4 billion kilometers) from the sun. It stretches to about 9.3 billion miles (14.9 billion kilometers) away from the sun.

Here’s another way of thinking about it. The distance from the sun to the Earth is described as 1 atomic unit (AU). The Kuiper Belt stretches from 30 AU to 100 AU from the sun. That means the distance from the inside edge of the Kuiper Belt to its outside edge is much wider than the region inside the Kuiper Belt, the region from the sun to Neptune! (Compare that to the Asteroid Belt, which is only 140 million miles wide.)

If you have ever seen a model of the solar system, you know the eight planets all travel in the same plane around the sun. Their orbits–the paths they take–look like a disc (or flat plate) of rings around the sun. The Main Asteroid Belt also orbits around the sun, between the orbits of Mars and Jupiter, along this same plane. The Main Asteroid Belt is flat.

Artist’s concept showing the exploration of the Kuiper Belt so far. New Horizons became the first spacecraft to explore a Kuiper Belt Object—dwarf planet Pluto—up close in 2015. Image grab from Solarsystem.nasa.gov.

Unlike the Main Asteroid Belt, the Kuiper Belt is not flat. It is donut-shaped with icy bodies orbiting the sun above and below the plane or disc formed by the orbits of the planets.

[Compare the orbits of planets and the orbits of electrons in atoms!]

What can be found in the Kuiper Belt?

The largest object in the Kuiper Belt is the dwarf planet Pluto. Astronomers once called Pluto a planet, but in 2006 it was reclassified as a dwarf planet. Like other planets, it orbits the sun and it has enough mass to have formed a round shape, instead of the bumpy, irregular shape of an asteroid. But Pluto’s gravity has not cleared a path through Pluto’s orbit of asteroids and other bodies.

Most of the objects floating in the Kuiper Belt are small clumps of rock and ice. These are ancient remnants left over from the formation of our Solar System.

Asteroids in the Kuiper Belt and the Main Asteroid Belt come in many shapes and sizes. There is even a snowman-shaped asteroid in the Kuiper Belt named Arrokoth.

Image of the asteroid Arrokoth, which appears as two round lumps joined together, one lump slightly larger than the other.
Here is a photo of Arrokoth taken by the New Horizons spacecraft. Image grabbed from NASA’s website.

NASA has a great interactive web page dedicated to the Kuiper Belt.

Colonize the Kuiper Belt!

You finally have the ships, the fuel and your team in place to colonize this cold, distant part of the Solar System. What will you do there? How will you make a living?

  • Mine for metals?
  • Collect ice water for other space colonies?
  • Act as a guide for adventurous vacationers?

Please post your comments below.

Be stellar!

Matthew Cross

A quick review of the unusual history of quarks

Image: Large Hadron Collider at CERN. Text: QUARKS--Tiny particles that comprise protons and neutrons. Learn the secret of this unusual word.

Today is Wednesday, so it’s time for our regular feature What is that? Here’s today’s term:

Quark–a tiny particle found in protons and neutrons

A quark is a tiny particle that can be found in any atom. Protons and neutrons, which make up the nucleus of an atom, are made of quarks.

[Read more about atoms and how they were once thought to be the smallest objects in the universe.]

What are the six “flavors” of quarks?

There are 6 types of quarks: up quarks, down quarks, top quarks, bottom quarks, strange quarks, and charm quarks. Some physicists also used to call top quark “truth” and the bottom quark “beauty” but that has apparently fallen out of style, which seems a shame. I like the whimsical names of strange, charm, truth and beauty.

Physicists refer to the different types of quarks as “flavors.” Maybe some of those physicists grew up working in an ice cream shop. (When I use “flavor” to describe something, I’m usually referring to the particular feel or mood I get when I’m reading a particular book.)

As I understand it, the names of the “flavors” don’t really mean anything. They are just tags that physicists placed on different types of quarks to tell them apart. I don’t mean that physicists literally put tags on quarks. Quarks are far too small for that. They are so small that even scientists can’t see them with microscopes. In fact, for decades, physicists just theorized that quarks existed.

Photo of the Globe of Science and Innovation at CERN headquarters.
Here at CERN headquarters near Geneva, physicists use particle accelerators to study subatomic particles like quarks. Photo by Faith Tucker.

In 1964, physicists Murray Gell-Mann and George Zweig, working separately and coming to their own conclusions, proposed the existence of quarks. At the time, they were just describing neutrons, protons, and other rarer particles made of quarks. Back then, there was not much evidence that quarks actually existed.

Cover of The Quark and the Jaguar: Adventures in the Simple and the Complex by Murray Gell-Mann
The Quark and the Jaguar: Adventures in the Simple and the Complex by Murray Gell-Mann

It took until 1968 for an experiment at the Stanford Linear Accelerator Center to provide some real evidence of quarks. And it took until 1995 for physicists to discover real-world evidence of the final quark flavor, the top quark.

The Quark has a literary heritage

Where did the name “quark” come from?

Physicists suggested different names for these tiny particles. It was Gell-Mann’s name–“quark”–that caught on. When thinking up a name, he first decided on the sound he wanted–“kwork.” Later, he ran across the word “quark” in Finnegans Wake by James Joyce and chose that spelling.

I’ve heard the word originally was a German word for curd cheese, and I’ve also read that it can mean “rubbish.” The use in Finnegans Wake might mean curd cheese, or it might mean something entirely different, like a cheer (or “croak”) made at a drinking establishment (a bar) or just a sound a bird might make.

Here’s the quote from Finnegans Wake:

Three quarks for Muster Mark!

Sure he has not got much of a bark

And sure any he has it’s all beside the mark.

Finnegans Wake by James Joyce

I find the source of the word and its original meaning to be as mysterious as the particle itself.

Discover and name your own particle!

Imagine you are a physicist. You discover an unknown particle!

  • What do you name it?
  • Why do you choose that name?
  • What does the particle do?

Please post your comments below.

Be stellar!

Matthew Cross

What is that?–ANDROID-a robot made in human form

Image of silver android. What is that?--Android-a robot made in human form

Today is Wednesday, so it’s time for our regular feature What is that? Here’s today’s term:

Android – a robot made in human form or with a human appearance

Robots can come in any shape or size. An android is a robot with a human shape.

Robot playing piano
Photo by Franck V. (unsplash.com/@franckinjapan).
Open hand of an android
Photo by Franck V. (unsplash.com/@franckinjapan).

Scientists, engineers and Sci Fi writers realize that human-shaped robots can be especially useful.  For example, if you want to build a robot that can drive a standard car, the ideal robot is shaped like a human.  It will have feet to push the pedals, two hands to turn the steering wheel and shift gears and it will fit easily in the car seat.  A robot with human-shaped hands can also use all the tools made for humans.

That means a well-made android can do anything a human can do.  And that is much more useful than a round disc-shaped robot that can only sweep the floor.

What is the difference between a cyborg and an android?

Sometimes I still confuse the terms cyborg and android. In last Wednesday’s What is that?, I wrote about cyborgs, which are humans comprised of both natural, organic parts and mechanical parts. In comparison, an android is a robot–usually made of entirely mechanical and electronic parts–but shaped like a human.

You can cover an android with human-like skin and hair, but if the “brain” is still a computer, it’s still an android.

I think about it like this. If a creature starts as human and you add mechanical parts, it’s a cyborg. If a an object is a robot–a machine–and you shape it like a human, it’s an android.

I think that a cyborg–which starts human–remains a cyborg as long as it still has a human brain. I also think an android, which starts as a machine, also remains an android no matter how many human or human-like parts you add, as long as it has a computer operating system at its core. So you can cover an android with human-like skin and hair, but if the “brain” is still a computer, it’s still an android.

Scif Fi novel Cinder compares cyborgs and androids side-by-side

Cinder, by Marissa Meyer, is filled with cyborgs and androids. The title character, Linh Cinder, is a cyborg with a mechanical hand and foot and “optiobionics” in her head that show lights and words across her vision. Cinder, a licensed mechanic, repairs androids and other machines in her marketplace stall.

Cover of Cinder by Marissa Meyer

The book begins with Cinder, surrounded by android parts, removing her own mechanical foot, which she has outgrown. Her android, Iko, finds her a replacement foot.

“She tightened the last screw and stretched out her leg, rolling her ankle forward, back, wiggling the toes. It was a little stiff, and the nerve sensors would need a few days to harmonize with the updated wiring, but at least she wouldn’t have to limp around off-kilter anymore.”

In the same chapter, Prince Kai visits Cinder’s marketplace stall. He brings her an android, a robot that served as his childhood tutor, for Cinder to repair.

“Cinder reached for the android and pulled it to her side of the table. ‘What seems to be wrong with the android, Your Highness?’

“The android looked like it had just stepped off the conveyer belt, but Cinder could tell from the mock-feminine shape that it was an outdated model. The design was sleek, though, with a spherical head atop a pear-shaped body and a glossy white finish.”

. . . .

White android with white bob and camera eyes
Photo by Maximal Focus (unsplash.com/@maximalfocus).

“‘Tutor8.6 model,’ she said, reading the faintly lit panel inside the plastic cranium. The android was nearly twenty years old. Ancient for an android. ‘She looks to be in pristine condition.’

“Raising her fist, she thunked the android hard on the side of its head, barely catching it before it toppled over onto the table. The prince jumped.

“Cinder set the android back on its treads and jabbed the power button but nothing happened. ‘You’d be surprised how often that works.'”

Design your android!

If you built an android, what features would you include?

  • Would you build it in the exact shape of a human or give it treads, like the androids in Cinder?
  • Would you allow its mechanical parts to show or cover it in a synthetic skin?
  • Would you hide secret tools inside or give it only human-like parts and features?

Please post your comments below.

Be stellar!

Matthew Cross

Orbits–Giant solar systems and tiny atoms both contain orbits. Let’s explore giant and microscopic worlds!

Old model of the solar system. Text: Orbits--Giant solar systems and tiny atoms both contain orbits. Let's explore giant and microscopic worlds!

The solar system is made of giant, orbiting bodies: planets

Eight planets orbit the sun, forming our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Asteroids also orbit the sun in the Main Asteroid Belt and the Kuiper Belt. The planets and the Main Asteroid Belt orbit the sun in a flat plane, like an invisible plate in space where the planets pass mainly through the plate. Sometimes they rise higher than the plate, sometimes they travel a little lower, but not by much.

The planets are very large objects. The sun, at the center, is the largest object in our solar system.

Tiny atoms are made of microscopic bodies that orbit each other

Cover of The Elegant Universe by Brian Greene

Next, let’s look at some of the very smallest objects in our universe: atoms. According to physicist and author Brian Greene, in his book The Elegant Universe, the ancient Greeks believed that “the stuff of the universe was made up of tiny ‘uncuttable’ ingredients that they called atoms.” The ancient Greeks thought the atom was the smallest building block of all matter. They said the atom was not made of anything smaller and could not be divided.

In the nineteenth century, scientists found that oxygen and carbon were made of the smallest pieces that could be recognized. “[F]ollowing the tradition laid down by the Greeks, they called them atoms. The name stuck,” Greene writes.

But it was later learned that oxygen and carbon atoms, and atoms of all the other elements, were made up of even smaller pieces. “Far from being the most elementary material constituent, atoms consist of a nucleus, containing protons and neutrons, that is surrounded by a swarm of orbiting electrons,” Greene writes.

Writers create new ideas by converting large to small or small to large

Sci Fi writers create fascinating creatures by turning something very small in the real world into something very large in their story. Consider the lowly worm. Frank Herbert turned the worm, a creature of a few inches, into his gigantic and fearsome sandworms of Arrakis in Dune.

Today, let’s do the reverse. Let’s take something very, very large–our solar system–and imagine it as small as an atom. If a sun were the nucleus of an atom, and if each electron orbiting around that nucleus were a planet, what kind of solar system can you imagine?

Build your mini-system!

Imagine your miniature solar system.

  • Would your planets be inhabited? Would the third planet–like Earth–support life?
  • Would travelers cross the vast distances between atoms to visit?
  • Where would your atom-sized solar system be floating? Would it be safe?

Please post your comments below.

Be stellar!

Matthew Cross

What is that?–CYBORG-a person made from natural and mechanical parts

Photo by Judeus Samson (unsplash.com/@shotbyjudeus). Model/artist: Rio Sirah.

Today is Wednesday, so it’s time for our regular feature What is that? Here’s today’s term:

Cyborg – a cybernetic organism; a person or creature comprised of both mechanical and biological parts

Clynes and Kline coined the word “cyborg” to describe modifications to astronauts

Scientists Manfred Clynes and Nathan S. Kline coined the term “cyborg,” which is merely a contraction of the words cybernetic organism. Cybernetics is a study comparing the human nervous system and systems that govern how machines operate.

Clynes and Kline created the word to use in scientific papers discussing how humans might one day be modified with machine or artificial parts so they could endure long travel times in space and survive the hardships of life in space. They even discussed how modifications might make it possible to live without breathing.

Cyberpunk explores future societies filled with cyborgs

Cover of Neuromancer by William Gibson

One of the most famous cyborgs from cyberpunk is a woman named Molly Millions, a “razorgirl” mercenary. Author William Gibson created Molly in his 1981 short story “Johnny Mnemonic.” The short story was later the inspiration for the 1995 film of the same name starring Keanu Reeves.

Molly is a cyborg with eye implants and blades built into her fingers. Here is how Gibson describes her in his cyberpunk classic, Neuromancer. (By the way, she carries a gun Gibson calls a “fletcher” that shoots flechettes or darts.)

“He realized that the glasses were surgically inset, sealing her sockets. The silver lenses seemed to grow from smooth pale skin above her cheekbones, framed by dark hair cut in a rough shag. The fingers curled around the fletcher were slender, white, tipped with polished burgundy. The nails looked artificial.

. . . .

“She wore tight black gloveleather jeans and a bulky black jacket cut from some matte fabric that seemed to absorb light.”

. . . .

“She held out her hands, palms up, the white fingers slightly spread, and with a barely audible click, ten, double-edged, four centimeter scalpel blades slid from their housings beneath the burgundy nails.

“She smiled. The blades slowly withdrew.”

Punk woman with bright red hair wearing black clothes and black surgical mask
Photo by Valery Sysoev (unsplash.com/@valerysysoev).

Become a cyborg!

If you could be a cyborg, what three cybernetic features would you add to your own body?

  • Would you add brain power with faster computing speeds or massive memory?
  • Would you improve your strength, speed, or vision?
  • Would you add wings to fly? Some other upgrade to do what no human can?

Please post your comments below.

Be stellar!

Matthew Cross