Blue Sky Science

Blue Sky Science is a collection of Q&A videos in which scientists answer curiosity-driven questions from the public. The project is a collaboration of the Morgridge Institute for Research and the Wisconsin State Journal.

Search Blue Sky Science

  • Are there wormholes that lead to other galaxies?

    Wormholes can exist within the framework of general relativity, Albert Einstein’s theory that governs how space-time interacts with matter in our universe.

  • How do cows make milk?

    The first time you milk cows they make what’s called colostrum. We often call it liquid gold because it has lots of fat and proteins.

  • How does friction work?

    Friction is a force that resists sliding motion between contacting surfaces. A bike, for example, has many instances of friction.

  • How are video games used in research?

    Video games are used in about five different ways.

  • How do toys affect a baby’s development?

    Virtually every theory of child development says that play is crucial to development in every way. It impacts cognitive development, social and emotional development, as well as language development.

  • How do people learn to read?

    From the science, researchers know a lot about how reading works, how children learn, the kinds of obstacles children encounter, and where teachers and classroom activities can make a difference.

  • How do scientists find fossils?

    There are a number of steps that go into a researcher finding a fossil, something I spend a majority of my summer doing. First you have to figure out what kind of fossil you want to find.

  • How do hovercrafts work?

    To understand how a hovercraft works, we have to understand a few things about matter. We, and all ordinary matter, are made of little tiny things called atoms and clumps of atoms called molecules.

  • How does someone get two different-colored eyes?

    When the eye color, or iris color, is different between the two eyes, the condition is called iris heterochromia.

  • Could we use planarians to help us understand human regeneration?

    Planarians are flatworms, and they’re masters of regeneration with virtually unlimited capacity to regenerate any missing tissue or body part lost to injury or aging.

  • How do rockets get past Earth’s atmosphere?

    Rockets encounter most of the resistance when they’re near the Earth’s surface. The higher up they get, the thinner the air gets, and the resistance pushing against the rocket gets lower.

  • How many molecules are in a cubic inch?

    Molecules are formed by atoms bonding together, and there are many different types of molecules that you interact with every day. For example, water and sugar are both molecules.

  • How much does a human brain typically weigh?

    The human brain includes 100 billion neurons, or brain cells, and is an ever-changing organ.

  • How does science protect great works of art?

    Art conservators can use X-rays and infrared technology to learn more about the structure of a painting, the paint layers and what happened to a painting over time.

  • How did scientists find out about electricity?

    Electricity is a complex topic that drives the world as we know it today, from Thomas Edison’s iconic light bulb to the satellites that enable our cell phones. Fundamentally, electricity is just the presence and flow of electric charge.

  • What’s the science of leap year?

    2016 is a leap year, meaning we insert an extra day, February 29, into the calendar. We do this once every four years in order to keep our calendar aligned with the Earth’s seasons.

  • Why do clouds have water?

    Not only do clouds have water, they consist almost entirely of water. And that water comes from the earth’s surface, including the ocean, lakes and streams and even the ground.

  • Why do we have freckles?

    Freckles are composed of an ingredient called melanin, which protects against damage caused by UV light. Your body makes melanin to protect itself from sun damage.

  • How do seedless plants start?

    Plants can propagate in two ways: sexually and asexually. Sexual propagation is through seeds. Seeds develop from the sexual organs of flowers. But some plants take a very long time to be able to propagate by seeds.

  • What determines the melting or boiling point of a substance?

    Before we can answer that question, we need to know first: What is a solid? What’s a liquid? What’s a gas?

  • How long would it take a tree to grow in space?

    It’s a complicated question because, while researchers have grown spruce seedlings on the International Space Station, they haven’t grown full-size trees. Using knowledge of how trees operate on Earth, scientists can guess what’s going to happen when they’re grown in space.

  • What is a solar flare?

    A solar flare is a release of magnetic energy from the sun. The energy is stored as a magnetic field around the sun, and then it is released with energetic particles and waves coming from the solar surface.

  • How did dinosaurs go extinct?

    When it comes to dinosaur extinction, the working idea is what’s called the bolide impact. This is the hypothesis that a meteorite came to the surface of the Earth, hit the Earth, and led to the extinction of the dinosaurs.

  • How did dinosaurs evolve into birds?

    Not all dinosaurs were big. In fact, the smallest ones are the ones that are still alive today. The one big question is: How exactly did flight evolve?

  • Why do hurricanes form where they do? Why Florida and not Wisconsin?

    Hurricanes form near places like Florida and not further north like Wisconsin because they need some critical components to develop.

  • Could we use viruses to fight cancer?

    Cancer is, essentially, cells that have started to grow uncontrollably and stop behaving like normal cells. Viruses are an attractive treatment tool because they, by their very nature, are manipulators of cells. It may be possible to reengineer viruses in a way that could either stop cancers from growing or kill cancer cells.

  • Do trees get viruses?

    Definitely trees get viruses. There are a wide range of different plant viruses that go not only to trees but to other types of plants as well.

  • Could scientists build a virtual brain and body for research?

    To learn from a virtual body, it would need to be able to accurately simulate or predict how the body responds to internal and external changes.

  • What is gene editing?

    Gene editing involves changing the sequence of letters in the DNA. Researchers like to edit genes so they can understand the function of them, particularly genes that relate to various types of disorders that physicians have seen in the clinic. We can use this information to generate new hypotheses of how genes influence diseases.

  • How do fireworks get their color and shape?

    Fireworks, as you can tell from the name, involve fire. To get a fire you need fuel, oxygen and heat, and that’s true in fireworks also.

  • How are volcanoes formed?

    Some volcanoes, like the Cascade Volcanoes up in Washington and Oregon, are of the type called stratovolcano. These steep volcanoes sometimes erupt explosively, and other times have calmer lava flows that just spill out on the surface. The material from eruptions, like lava and ash, build up and cause these volcanoes to have a character like a layer cake.

  • Why don’t joints bend both ways?

    Structurally joints don’t bend both ways because there are physical components within their design that prevent or resist motion. This could be bone, such as the elbow joint, or it could be ligamentous restraint, such as in the knee.

  • Why does the moon have craters?

    One reason the moon has craters because it gets hit by objects, small pieces of rocks that come from outer space. These are pieces of asteroids, comets that are flying around in the solar system.

  • How do animals evolve and get new traits?

    How animals evolve and develop traits is basically the foundation of evolutionary biology. Whether it be animal or plant, bacteria or fungi, there is one organism that gave rise to all those types of life.

  • How are cells created?

    New cells are created from existing cells through a process referred to as the cell cycle. One cell can make a copy of itself and form two new daughter cells.

  • Can we use stem cells to treat brain injury or neurological disorders?

    The simple answer to the question is yes. It is possible to regenerate parts of the brain with stem cells, just like we can in other organs.

  • How many galaxies are in the universe?

    Counting the number of galaxies in the universe is tough, because we can’t see all of the galaxies in the universe. At a certain point, distant galaxies disappear from our field of view.

  • Why do chickens lay different-colored eggs?

    Genetics is the simple answer to why chickens lay different-colored eggs. Some chickens lay white shell eggs and some lay brown shell eggs, similar to the way hair color varies in people.

  • Why do cats have rough tongues?

    Cats have functional barbs or papillae on their tongue made of keratin, the same material that nails and our hair is made out of. They’re very rigid little barbs that face backwards.

  • Why is Pluto considered a dwarf planet?

    Before Pluto was discovered, it was predicted. Astronomers had observed that massive objects can affect the orbits of its neighbors, and, after seeing deviations in the orbits of Uranus and Neptune, assumed something substantial existed beyond their orbits.

  • How are waterfalls made?

    It basically it takes four things to make a waterfall.

  • Why do hissing cockroaches hiss?

    Madagascar hissing cockroaches and some of their relatives can produce an audible hissing noise that almost sounds like a cat hissing.

  • How do fireflies glow?

    When living creatures produce and emit light it’s called bioluminescence. The main reason fireflies glow is to find a mate, though they can also light up under other situations as a warning to others.

  • How does a curveball curve?

    The rule to remember for curveballs: whichever way the front face of the ball is spinning will be the direction in which it curves. The effect is more dramatic with ping pong balls and tennis balls because of their lower mass compared to baseballs.

  • How do beetles use camouflage?

    Beetles are an extremely diverse group of insects on the planet. There are about a million or more described species of insects, that we know of so far, and of those about 400,000 are beetles.

  • How do we hear?

    Sounds reach our ears from different locations and first travel through the ear into the ear canal. Then tiny bones inside the middle ear end up vibrating and pushing on a small window. This then gets a special membrane inside our ear to vibrate.

  • What can your center of gravity help you with?

    Gravity is this invisible force that pulls objects toward one another. And one of the things that gravity does is pull us toward the earth. So it’s important to know that’s what gravity is. And then center of gravity is sort of this middle point where all of a body’s weight or an object’s weight is.

  • How does thunder form?

    Thunder is formed by the intense heating produced by lightning. The thunder you hear is made up of vibrations that travel as sound waves through the air until they reach your ear.

  • Can all mosquitos transmit viruses like Zika?

    Not all mosquitos can transmit the Zika virus, and that’s the case with any mosquito-borne pathogen. There are about 3,000 species of mosquitos in the world and only a handful—about 150—are considered vectors of pathogens, capable of spreading viruses.

  • How does our immune system recognize bad from good?

    Important cells for distinguishing between good and bad are T cells, and it’s estimated that there are approximately a trillion T cells in our body.

  • How do planes fly?

    Imagine this: Stick your hand out of the window of a car that travels at around 60 mph, and you will notice how lift is being produced as you twist your hand up and down. As the car accelerates, you will notice that no matter how you shape your hand, lift is always being produced.

  • Why do the northern and southern lights only appear near the poles?

    The formation of the northern and southern lights—known as aurora borealis and aurora australis—begins with solar flares from the sun. The solar flares eject groups of electrons from the sun that act as a wind and flow toward the Earth.

  • Why do some logs float and some sink?

    Whether an object floats or sinks in water is determined by the ratio of its weight compared to its volume. If an object of a certain volume weighs more than an equal volume of water, it sinks because the water can’t hold it up. If an object weighs less than an equal volume of water, it floats because the water can support its weight.

  • Why is the sky blue?

    Light from the sun comes in many different colors including colors we can see and some colors we can’t see. And just like sound waves or waves on the water, light travels in waves as well.

  • Why do leaves change color in the fall?

    September and October are the peak months for admiring fall foliage, the orange, yellow and red leaves. To understand why leaves change color, you have to start with the process of photosynthesis. All plants, including trees, have green leaves because of a compound called chlorophyll.

  • Is the biofuel process a complete cycle?

    The production of biofuels starts by growing plants out in a field or forest. All of the biomass represented in those plants essentially comes through photosynthesis.

  • Why (and for how long) do butterflies stay in a cocoon?

    Caterpillars start out as very small, tiny creatures. In the beginning they eat lots of food—just like the book “The Very Hungry Caterpillar”—and get bigger and bigger.

  • Why are snowflakes individually unique?

    Two important factors influence the shape of snowflakes. One is the ambient temperature, and the other is humidity. A snowflake needs to grow under the condition of a super saturated environment.

  • Why can dogs hear a dog whistle but people can’t?

    Humans can hear sounds in a range from about 20 hertz to 23 kilohertz at the upper range of their hearing ability. The hearing range of dogs is almost double that.

  • How are crystals formed?

    The word “crystal” comes from the Greek “krystallos,” meaning clear ice. A crystal is defined as a solid material consisting of a three-dimensional periodic ordering of atoms, molecules or ions. Crystals form by a process called crystallization that signifies a transition from chaos to perfection.

  • How does virtual reality work?

    A broad definition says virtual reality is the idea of combining the physical world and the artificial world in such a way that the two are indistinguishable. How could technology provide all of the sensory sensations or different ways that people see, feel and hear the world such that the artificial and physical are blended together?

  • When will a human trip to Mars be possible?

    We could send humans to Mars whenever we want to. We have the technology to do it today, though we would need to build new rockets that use that technology.

  • How and why do our teeth fall out?

    It’s normal and natural for baby teeth to fall out. Usually kids start to get loose teeth between ages 5 and 7. The new permanent tooth begins eating the root of the baby tooth away, that baby tooth becomes loose, and then the permanent tooth eventually pushes it out and erupts into its place.

  • How does electricity move through wires?

    It’s a complicated process, but there are charges inside wires and these charges can be acted on by an electric field. They can move through the wire in something that’s called an electric current.

  • What is pain tolerance and how does it work?

    Pain is subjective and is different for every person who experiences it. There’s also different dimensions of pain including sensory, emotional and behavioral components.

  • Do you think there’s life on other planets?

    The short answer to the question is that we don’t know. The closest planets to Earth are located millions of miles away, so it’s very difficult to go off and find evidence directly.

  • What’s the difference between types of 3D printer filaments?

    3D printing is the process by which we make a piece layer by layer, and the various forms of 3D printing differ in how they make each layer. Extrusion-based printing, or fused deposition modeling, uses filaments. It takes a raw material and extrudes it through a die to create a long strand That’s what a filament is.

  • Why can people eat the same diet or take the same medication and have different outcomes?

    This is a question scientists are still trying to figure out. We know that it has to do with the specific genetic makeup, and everyone has slight differences in metabolism.

  • What precautions are recommended in regards to Zika virus and pregnancy?

    Many people travel to areas that have active, ongoing transmission of Zika virus disease.

  • How did animals evolve from water to land?

    Water to land evolution is a complex question, and one that is still actively researched today.

  • What is water scarcity?

    Water scarcity is essentially when there’s not enough water in the right place at the right time. Even in places that seem water-rich, it may not be clean enough for its intended purposes.

  • How were the Madison lakes formed?

    Before the last glaciation, which started about 30,000 years ago, there was a deep river valley that ran under where Lake Mendota and the other Madison lakes are now. A glacier moved into this area and slowly filled up the valley.

  • Is it possible to bring back extinct animals?

    De-extinction, as it’s been termed, hasn’t happened in over 3 billion years of life on earth, so it will be an epic event if and when it happens.

  • What are bacteria?

    Bacteria are amazing single-celled, simple organisms. They’re found everywhere on the planet in all sorts of environments from your gut to the soil to the Arctic and Antarctic.

  • Can brain injuries sustained while playing sports be fully recovered from?

    A concussion is defined as a traumatic blow to the head coupled with some kind of altered consciousness. Some people refer to it as seeing stars, getting your bell rung. People may feel disoriented for a period of time.

  • How is a gummy bear made?

    Gelatin is the basis of what makes a gummy bear a gummy bear, but we first start with sugar, corn syrup and water. Gelatin is thermoreversible, meaning that heat can turn it back into a liquid.

  • What’s going on in the brain when people sleepwalk?

    When we sleep we go through different types of sleep stages. You have slow-wave sleep, which is like your deep sleep, and then there’s dream sleep, which is called REM sleep.

  • Why do some animals go extinct while other species regenerate their populations?

    Much depends on the circumstances in which the animals have become rare in the first place. It could be a big environmental change in the habitat, something affecting food, water, shelter or cover.

  • How are stars (like the sun) formed?

    A star is considered a sun if it’s in the center of a system with planets orbiting around it. Stars are formed in very large dark clouds. These dark clouds are made primarily of hydrogen and carbon monoxide.

  • Why can eye color vary between siblings?

    We all have genes in our body, and our genes carry DNA. Siblings can inherit various genes from their parents and they don’t always get the same ones.

  • Could we harness energy in space for use on Earth?

    When thinking about collecting energy from a source in space, the natural answer is the sun.

  • How does the moon affect the tides?

    The tides are the result of the moon exerting its gravitational force on the ocean and bulging it both toward and away from the moon. The tide is higher, the ocean is higher, at the location closest to the moon and on the opposite side of the Earth.

  • How does a 3D printer make color?

    3D printing involves making an object layer by layer. There are many 3D printing techniques, and they all differ in how each layer is constructed. Each type of printer has a different opportunity or mechanism for adding color.

  • Why do beavers, rabbits have the same kind of teeth?

    Squirrels, beavers, chipmunks and rabbits all have similarly-shaped teeth, because all of those animals have teeth that continually grow throughout their lives.

  • Why do fresh cheese curds squeak?

    When cheese is manufactured, the milk is clotted and some of the water removed. You end up with a curd, a tough structure where the proteins in the cheese form a mesh.

  • Could we make a living creature using only stem cells?

    Stem cells are special cells inside your body that can multiply indefinitely, or make copies of themselves. They can also differentiate, meaning they can become every cell type that’s present in your body.

  • Do plants produce nectar every day?

    Not all plants produce nectar, only plants that are visited by animal-type pollinators. Plants that are wind pollinated, for example, will not produce nectar.

  • How do temperature and wind affect traffic noise?

    In terms of temperature, sound waves move faster in warm air and slower in cold air. So as sound moves through the atmosphere, some parts of the wave will be moving faster than the rest.

  • What is machine learning?

    Machine learning is an area of computer science that focuses on building computer programs that help machines learn by example. This is similar to the way young children learn about the world around them.

  • What is the Kuiper belt?

    The Kuiper belt, named after astronomer Gerard Kuiper, is a massive, icy region of our solar system that exists just beyond the planets. Actually shaped more like a donut than a flat belt, the Kuiper belt is best known as home of the dwarf planet Pluto.

  • What is the purpose of the appendix?

    For decades, scientists and physicians have believed that the appendix really doesn’t have a function in human beings. It may have had a purpose in some living thing tens of thousands of years ago, but that purpose never persisted in humans.

  • How do we identify new species from fossils?

    When we try to identify different species in nature today, we usually think of that question in terms of interbreeding. We look at different populations, whether they look different or the same, and ask, do they ever interbreed with each other or encounter each other in nature?

  • What is cedar-apple rust disease?

    Cedar-apple rust is one of several plant diseases that are all caused by different species of a fungus called gymnosporangium. All of these diseases are referred to as gymnosporangium rust diseases.

  • How do bees make honey?

    Most bee species do not make honey, but those that do—as you might guess—are specifically called honey bees.

  • How do plants grow if there’s no sunlight?

    Plants need sunlight for a process that we call photosynthesis. Plants are what we call autotrophs, meaning they create their own food or energy to grow.

  • How do we make robots?

    Imagine building a robot in three stages.

  • How do the sun and rain make rainbows?

    Rainbows are really cool because they’re a blend between art and science. It required a number of scientists to actually explain how they form, including Isaac Newton.

  • What is 3-D printing?

    3-D printing refers to a kind of manufacturing where a part is built up layer by layer. With a typical machine, you take a block of material and subtract away. With additive manufacturing, or 3-D printing, you start with nothing and you add layer by layer until you have a final part.

  • How do you identify edible mushrooms?

    There’s not one rule that applies to mushrooms. You have to know your biodiversity to know which species are edible and which species are not edible.

  • How does the epiglottis distinguish between water, food and air?

    Swallowing is one of the most obvious functions the epiglottis serves, because it hoods over the airway, or larynx, when you eat and drink. When you swallow, the muscles in your throat respond by pulling the voice box up and underneath the tongue, and the epiglottis is pulled to cover over the larynx.

  • How are robots and humans similar?

    Robots can be similar to people, but they aren’t necessarily so. People create the robots and can choose what aspects of functionality and design are important, but there are some benefits you get out of similarity.

  • How does your brain form memories?

    The first step in forming a memory is called encoding, and encoding starts with perception. If you remember back to the first time you met your best friend, you encoded or perceived a lot of information about them.

  • How can we use stem cells to build tissues and organs?

    There are two major properties of a stem cell, and the first one is its potency. By that we mean its ability to give rise to specialized cells.

  • How many species of snakes are there?

    There are more than 3,400 species of snakes worldwide, and they exist on every continent except Antarctica. We have about 50 snake species in the United States and 21 different snake species in the state of Wisconsin.

  • Does an earthquake ever form a new tectonic plate?

    Most earthquakes occur when a geological fault, fractures within the earth’s crust, slip and release energy. Individual faults, some of which form the tectonic plate boundaries, build up strain over decades and centuries to eventually break in large earthquakes.

  • Why do we have wisdom teeth?

    Wisdom teeth are the third set of permanent molars that typically come in between the ages of 17 and 25. Some people don’t form them anymore, and a lot of people that do need to have wisdom teeth taken out.

  • Why is light faster than sound?

    Light and sound are very different. Sound is actually a mechanical disturbance through air or another medium. Sound always needs a medium to travel through and the type of medium determines its speed.

  • What is beyond Pluto?

    There are many, many objects beyond Pluto, but where they came from and when they formed is a whole other question.

  • How does cancer form and is there a cure?

    Cancer occurs when one of the tissues in our body decides to grow uncontrollably, and our immune system is not able to recognize and destroy it. So the tissue continues to grow and can eventually break off into pieces and attach to other parts of the body and affect our health.

  • How does the brain get the heart to constantly beat?

    Interestingly, in the course of the day, your heart will beat somewhere around 100,000 times and over a calendar year might beat up to 35 million times. Over the course of a lifetime then, your brain and your heart have to work together to engineer 3 billion heartbeats.

  • Why is it difficult to predict which flu vaccine will be most effective?

    A vaccine is meant to train your immune system to recognize a virus so it can fight off that virus if you ever come in contact with it.

  • What makes a mammal? Is an octopus a mammal?

    It’s a great guess, but an octopus is not a mammal. An octopus is an invertebrate animal, which means it has no spine. More specifically, an octopus is a cephalopod, like squid and cuttlefish. They’re some of the smartest invertebrates.

  • How is spider silk made?

    Spiders have silk-producing glands in their bodies, specifically in their abdomen. In these glands they have the chemical components already put together to produce silk, but it’s in a liquid form.

  • How does a hot air balloon work?

    Directionally you never know where a balloon is going to go because the wind controls it, I don’t. I can send a balloon higher or lower, but not steer it in specific directions. So before we send passengers up in a hot air balloon, we send up a small hydrogen balloon that tells us the wind speed and direction.

  • How do some plants grow without dirt?

    The principal purpose of soil is to provide mineral nutrition for the plant.

  • Why is there gravity on Earth but not in space?

    There’s actually gravity pretty much everywhere. But why do we feel gravity more here on the surface of the Earth instead of in space when astronauts appear weightless?

  • Does space go on forever?

    We really don’t know if space goes on forever. The universe is big enough that we can’t see all of it for a number of reasons. And there are ways that we could live in a space that doesn’t go on forever, but still has no actual edge to it.

  • Why do some viruses cause cancer?

    Infectious agents—both bacterial and viral—are responsible for about 25 percent of all human cancers. The virus infection does not by itself cause cancer, but can interfere with a cell’s normal maintenance of things.

  • How does autopilot work?

    An autopilot is a flight control system that allows a pilot to fly an airplane without continuous hands-on control of the airplane. It allows the pilot to focus on higher-order tasks such as navigating, communicating with air traffic control, planning for weather contingencies and rerouting associated with any kind of emergency circumstance.

  • How are moons created?

    Anything that orbits a planet is a moon, and moons can form in several different ways.

  • How long does it take a GMO product to grow?

    Genetically modified organisms, or GMOs, refer to any plant or animal that has been genetically modified by humans. For centuries, breeders have been able to do this through selective breeding practices.

  • Why do some colors make you feel emotions?

    Over the years you’ve learned to associate certain colors, certain shapes, certain things that you see with specific emotions.

  • How can milk make so many different products?

    Milk can make many products because of its complex chemistry and history. Early humans used milk and had to experiment with various means to preserve it and its nutrition content over time.

  • Why do supercomputers have to be so big?

    We need supercomputers because scientists are doing really awesome work that requires lots of computing time. For some of this work, if we weren’t using supercomputing to break up tasks and make processing faster, it would take years or decades to complete.

  • How fast could a human theoretically run?

    The current world record for running speed is held by Usain Bolt at roughly 28 miles per hour, and it’s difficult to imagine running faster.

  • How do we purify dirty water?

    What we use to purify water depends a lot on where the water’s coming from and what we want to do with it. If we’re going to drink water it needs to be very clean and very safe. There are lots of regulations that we have to meet.

  • Can people have the abilities of animals?

    This question brings up all kinds of interesting issues about who we are as humans and how we compare to other animals.

  • How does saving a file or image to a hard drive work?

    A hard disk drive contains a circular shiny silver disk, similar to a CD or DVD but much smaller. This disk is coated with a magnetic material, and information is stored by magnetizing very tiny pieces of this surface.

  • What and where is the Yahara watershed?

    The Yahara watershed is a geographic area in south central Wisconsin. It is comprised of about 370,000 people and 359 square miles home to the city of Madison, the University of Wisconsin-Madison, and this chain of lakes we refer to as the Yahara lakes.

  • How does our brain think?

    In order for your brain to think, you need nerve cells that can detect information about the outside world and can transmit that information to other nerve cells.

  • What is a neutrino?

    In high school you learn that matter is made of atoms, atoms are made of electrons and nuclei, and nuclei contain neutrons and protons. That’s a basic picture of matter, but it’s an incomplete one. Missing in that picture is a full particle called neutrinos.