Out In The Void

Out in the void fall ezine 2021

table of Contents Letters From The Editors

5

A Beginner’s Guide to space

6

What Happened When?

10

The Stellar Realm of space

12

A Timeline Of space exploration

16

Out Of Touch

18

Could You Be An Astronaut?

22

The foundations of the universe 24 A Universal recipe

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Letters From The EDITORS Hello! My name is William, and I’m a freshman at LASA. I’m a huge space nerd, and so I was delighted to create Out In The Void to share my love for it with everyone else. I first fell in love with space when I was seven, because I found an encyclopedia about it. I would not advise reading encyclopedias, let’s just say. I wrote my article to share my love for space without being too hard to read.

William Coury Hello, I am Alec Marintzer and I am a freshman at LASA. I am one of the producers of Out in the Void. I believe that people should learn about space and wanted to express that with my story. I was not deeply interested in space when I first started this project but as it was getting closer and closer to finishing, I found the love that others had. My hope is that others can share this love like we all have.

Alec Marintzer

Hi! My name is Ritvik and I am a freshman at LASA. I’ve always been quite fascinated by space and I was so excited when we decided to do our magazine on it. Some fun facts about me are that I enjoy playing tennis, and the violin. We worked hard on this magazine to bring everyone entertainment as well as information so I hope everyone enjoys!

Ritvik Rajesh Hello! My name is Ram Sivaraman, and I am a freshman at LASA. I am proud to be one of the authors of Out in the Void. I am passionate about physics (astrophysics is very captivating), math, and computing in general. I love learning as much as I can! When I am not studying, I like playing tennis with my friends, practicing violin, and watching YouTube. Thanks for stopping by to read our magazine!

Ram Sivaraman

A nebula, captured by the Hubble Space Telescope. Image: NASA

A beginner’s guide to space: What’s in the Universe We Live In - William Coury 6

take the light from a source like a star or a galaxy, and you split it apart with a prism. You’ll be able to see how bright the object is at specific wavelengths, and [there are] dark bands that mean the object has gas that absorbs light at that wavelength. [Each element] has a specific pattern, so you can look at it and see those are iron atoms and those are gold atoms.”

Two spiral galaxies collding, eventually forming an elliptical galaxy. Image: NASA

Space is a fascinating place, it’s where we all reside. It’s a world defined in large part by tiny particles, but also by massive galaxies. It is extremely cold and absurdly hot. Timespans and masses have to use exponents because space is both too big and too small to write out. But what is space, really?

The first thing that you need to understand about space is what stars are. They are the building blocks of astronomy, like the cell in biology. They make up the largescale structure of the universe, galaxies, clusters, and superclusters.

Stars also forged the “heavy elements”, elements that are not hydrogen or helium. This process allows planets and life to form, eventually

The way a star forms is through gas condensing on itself, which heats the gas to a point that fusion occurs and begins the process of converting hydrogen into helium by fusion, which creates energy. As stars run out of fuel, the stars cool off and expand, but the end result depends on their size. The largest stars, which are massive, short-lived

(by astronomic timescales), and blue (which means extremely hot), cool off and expand, and can fuse more elements until they form iron, which absorbs energy when it fuses, or it becomes broken apart. As a result, the star loses its sources of energy and collapses in on itself, causing an explosion.

Other stars aren’t heavy enough to fuse some of the heavy elements, so while they grow bigger (but not as big as their larger counterparts do), they instead eventually run out of fuel and become white dwarf stars.

“We don’t know how gravity works yet, and that’s unbelievably fundamental.”

Spectrums are the key tools to understanding many things about the universe, like components of a star’s atmosphere. According to an astronomy professor at UT, Dr. Steven Finkelstein, spectrums are an invaluable tool. He says “You

Spectrums also measure redshift, a way to see how far away something is, because space is expanding, causing it to move away from you, which elongates the waves. This pattern is the doppler effect. We can use this redshift to notice that the patterns have been shifted.

When we look at distant objects, though, we look back in time. Since light has a finite speed, it takes time to reach us across the vast reaches of empty space.

This means that if we see distant objects, we are seeing them as they were millions of years ago.

There is a sampling bias, because the objects are so faint that they can only be seen with a telescope and so the largest (and therefore brightest) are the only ones that can be seen. As a result, astronomers have to be careful about making generalizations about the past.

Another important category of astronomical objects are nebulae (singular: nebula), gigantic clouds of gas and dust that are the source of many beautiful photos from the Hubble space telescope. Some nebulae,

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A nebula, a region of gas and dust that can form stars. Image: NASA

planetary nebula, are formed by stars becoming white dwarfs. Others are formed by supernova remnants, and others are precursors to stars.

Most nebulae have star-forming regions inside them.

Stars and nebulae make up galaxies, massive spiral or oval collections of stars. Some are primordial and irregular, but most galaxies have evolved into spiral galaxies. Dr. Karl Gebhardt, a professor at UT, says “galaxies merge all the time, galaxies merge”. This merging drives formation.

Another professor at UT I interviewed, Dr. Mike Boylan-Kolchin, and he said that “galaxies tend to be spiral if they form slowly…. If

the formation process is fast and chaotic, then there’s no preferred direction for the gas to pile up and rotate, and the result is an elliptical galaxy.”

The direction of the rotation is important because it determines whether a galaxy is “alive” or not.

As Dr. Finkelstein says,“ We like to think that forming stars is life, and not forming stars is death.” Further, Dr. Finkelstein notes that one of the main differences between spiral and elliptical galaxies is that “spiral galaxies form stars, and ellipticals don’t.” Part of his research is to figure out why galaxies stop forming stars, and to do that, he looks at the past.

Dr. Finklestein works

with theoretical physicists a lot, and some of his work is tied to investigating the past by looking for distant galaxies that do not form stars. He says “I’m trying to find the most distant galaxy that is shut down in star formation.

Because some of the mechanisms that people [suspect are used in the formation of] elliptical galaxies need 10 billion years to take place.

And that happens [now’ because you have that much time. But if I find a galaxy that’s [an elliptical galaxy] only a billion years from the Big Bang, that mechanism didn’t have enough time to work.” These mechanisms are important because they guide stellar evolution today, and allow us to learn more about future star-forming regions.

An important discovery of telescope “time travel”, Active Galactic Nuclei (AGNs), discovered in 1943, are galaxies that are characterized by unusually strong emissions on broad frequencies.

These AGNs were later discovered to be a phase in a galaxy’s past where the cores of galaxies emitted a strong amount of light, due to a supermassive black hole in the center.

As the name implies, black holes are voids in space where nothing can escape, not even light.

There are different types of black holes, but the ones important to galaxies are supermassive black holes, extremely massive black holes that dwell in the center of galaxies and serve as engines to AGNs. As galaxies merge, their black holes will start to orbit each other, but they won’t merge themselves.

If there are already two black holes dancing around each other, the third one will destabilize the system and eject one of them. Dr. Gebhardt tries to track these rogue supermassive black holes, using a method where 8

he looks for the gas that the black hole steals as it leaves.

“[The] way… I’m looking for is that when that black hole gets ejected, it will be able to hold on to some of its material. It won’t be completely naked, just scantily clad. I’ll be able to see a little bit of material around the black hole. And for maybe a few hundred thousand years, maybe a half a billion years, that material will create a little bit of light. And so you might be able to pick it up. You’ll find… features that are indicative of the black hole, but no galaxy around it.”

One of the greatest discoveries in astrophysics was the 1968 discovery that galaxies rotated at the same rate toward the edges of the galaxies as at the center.

This was the exact opposite of what the discoverer, Dr. Vera Rubin, expected. As previously discussed, spiral galaxies rotate, but in theory the arms (the spokes of a spiral galaxy) should trail behind the center, because gravity operates at an inverse-square law (which is the reason for Kepler’s second law, a modified version we can use here), so the galaxy will have slower moving arms. However, Dr. Rubin found much more speed in the arms than would be expected based on the visible matter. The leading theory that causes this change is dark matter.

Dark matter is a material of some kind that is massive enough to manipulate galaxies and to keep them together, but does not emit light. Dark matter is such a fundamental part of the universe that most major models of galaxy formation predict that without dark matter, the universe wouldn’t have the slight mass concentrations that

A spiral galaxy, with star-forming regions in blue. Image: NASA

later form into galaxies. While I appreciate galaxies existing, dark matter not reflecting any light at all is problematic for astronomers because the only observations they can take is with light. Understanding dark matter is important for understanding the universe because dark matter is almost 21% of the “energy budget” of the universe. This makes understanding the universe particularly hard. Also, in case you were wondering, only about 5% of the energy budget of the universe is visible matter. The other thing that takes up the energy budget is dark energy.

Dark energy is a rather dramatically titled force that is expanding the acceleration of

the universe. The Big Bang started a process of expansion of the universe, but after the extremely brief inflationary period, there was a slow decrease in the expansion rate. At the beginning of time, right after the Big Bang, there was a brief period (from 10^-36 seconds to 10^-32 seconds after the Big Bang) where the universe expanded at an unbelievably fast rate. After that, there was a 9.8 billion year slowdown in expansion rates, where gravity was slowly pulling together the universe. That was not to last, however, as dark energy took back over. Dr Gebhardt finds the existance of dark energy fascinating and a draw to the field of astronomy, because it means that “we don’t understand how gravity works, and that’s unbelievably fundamental”.

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The Big Bang

what happe A timeline of - William

The Big Bang was how the universe started, with all the matter in the universe expanding from a single point. At the time, it was too hot for the universe to be anything other than particles.

13.8 Billion Years Ago

AGN P

Around this time, a an Active Galactic has high energy ou black hole.

10 Billion

13.3 Billion Years Ago In around 500 million years, though, matter cooled down enough to create gas clouds and then into stars. The stars helped “clear out” the gas, allowing light to travel unhindered REIONIZATION

10

ened when? the universe m Coury

PHASE

NOW

almost every galaxy had Nucleus (AGN). An AGN utput and is powered by a

The universe is still accelerating the expansion of space. Now, there are humans, who are able to figure out how space works

Years Ago 4 Billion Years Ago Around this time, the universe, which was still expanding from the Big Bang, started to accelerate the expansion.

The cause for this is a force called dark energy Acceleration

Credit: NASA 11

Image of a White Dwarf star that was being measured by astronomers

Image: Courtasy of NASA

The Stellar Realm of Space by: Ritvk Rajesh

A deep dive into the wonders of stars and their significance in space.

12

H

eres a challenge. Take a moment and walk outside at night and find a place with a clear sky and observe the glistening sparkles of the millions of stars illuminating it.

Have you ever wondered what they really are and why they behave in a certain way?

Stars have been one of the astronomers’ main focuses for as long as we can remember.

Since Galileo, we have been analyzing and gathering info to try and understand the form and function of these massive spherical objects that illuminate our night sky. Without stars, the astronomical world and society would not be what it is today and neither would space exploration.

“Stars represent the building blocks of the universe, and that’s

why I think understanding stars, how they evolve, and what their properties are, is crucial for understanding the universe as a whole,” says Mike Montgomery, a professor from the Astronomy Department at the University of Texas at Austin. The first thing we see in the sky during the day is the Sun, a main-sequence star. At night, you usually see the moon glowing but that is only because the light from the sun reflects off of the moon’s surface, and in places where light pollution is at a minimum, you can see small bright dots filling the night sky. These dots are stars. If you decide to take a closer look at what lies beyond the atmosphere, you may see more stars, some planets, and if your telescope is powerful enough, possibly galaxies. Galaxies too are filled with stars, which further explains

and proves this point.

Much like planets, in order to understand stars, we need to dive deeper into their structure and make-up. A field of research that has helped us understand what the inside of stars looks like is asteroseismology.

“Asteroseismology is the idea of using vibrations of stars to try to do something similar(Similar to the seismology of Earth, which is measuring speed and direction, working out the density profile, etc) to tell what the interior structure of the stars is”, says Professor Montgomery. This is much like the seismology of planets which allows us to understand the internal components that makeup planets like Earth, the professor elaborated. Asteroseismology has helped us learn about and

Two binary stars being ejected from a galaxy

Image: Courtasy of NASA

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Depiction of neutron stars colliding

Image: Courtasy of NASA

understand what goes on below the surface of stars.

Certain things, like the temperature, the luminosity, etc., can be determined without special methods and tools. What goes on inside, like the nuclear fusion processes, cannot be determined so easily, and that’s where asteroseismology comes in.

Asteroseismology is not the only way to figure out what processes are happening within a star.

Another way is by its stage. From proton stars to main-sequence stars to red supergiants, and depending on the star, eventually a supernova or a white dwarf.

The stage of a star can determine more than people think, mainly the age of the star and the elements it is burning during the process of nuclear fusion.

“The old saying, live fast, die young, and it’s true for stars.

The more energy they produce, the more massive they are.

They spend their energy like

drunken sailors, and the quicker they run out of energy, the quicker they die,” explains Don Winget, another professor at the University of Texas at Austin from the Astronomy Department.

Color is a major defining factor of stars as well because it allows us to easily understand what temperature the surface is. Our sun is yellow, meaning it is reasonably hot and red stars are slightly less hot. The hottest stars are in the blue color, like Rigel, a blue supergiant star in the constellation Orion.

White Dwarfs also exist at the temperatures of blue stars. They look white as the name suggests and their temperatures exceed 10,000 degrees Kelvin.

There are proton stars, which essentially are the first stage of stellar evolution. Next, there is the Main Sequence which is where our Sun is present. Then, there are Red Giant stars, which are stars with very hot cores but are puffed up on the outside making them very large in size, David Guszejnov

explained, a researcher at the University of Texas at Austin who specializes in the phenomena of star formation. After the Red Giant stage is the Red Supergiant stage, which is when the star is really nearing the end of its life.

Afterward, and depending on the size of the star, the supergiant could become a supernova, neutron star, or white dwarf star.

“They (Stars) spend their energy like drunken sailors, and the quicker they run out of energy, the quicker they die.”

Our sun is not and will not be large enough to become a supernova, therefore it will become a white dwarf. Stars that are large enough to become 14

“core-collapsed supernovas”, which is when the core of a star collapses and becomes a supernova, could leave behind a Black Hole which is a region of space-time that has such an immensely powerful gravitational pull, that nothing at all can escape it.

Researchers are working on discovering new things that challenge our current knowledge of stars, namely the creation of matter in labs. When trying to understand the opacity of matter, researchers find out that its ability to block radiation(for the safety of astronauts and such, since radiation can be harmful) was wrong, explains Professor Montgomery.

“Galaxy evolution, galaxy formation is actually all a house of cards based on what we understand about fundamental physics and then stars is the first chance on that sort of scale, the solar system, objects, and then stars themselves, and we

find out our understanding of stars themselves is not correct and needs significant revisions of what we call the constitutive physics that govern them,” says Professor Montgomery. What we know of stars, and the universe for that matter, cannot be proven to be 100% true because there may always be something that could prove a fact wrong. It is important that we continue our research so that at some point, we will be able to confidently say without a shadow of a doubt that something is true while something else is not.

Did you know that stars don’t only exist alone with planets revolving around them?

There are instances where stars exist closely with other stars in star systems known as “stellar binaries”. The two stars are always moving relative to each other. “If the mass of the two objects were similar, then it would be more of a dance of the two objects and so stellar binaries are closer to that. It’s

very rare for a Star to have a companion that has less than 10% of its mass, so most of them have similar mass ratios. So just for reference, I think the Sun is like a million times heavier than Earth, so that’s separate,” explains Dr. Guszejnov. This just shows how vast of a place space really is and can be.

“[Stars] are a fundamental building block of the universe. It’s stars, and the nuclear processes that go on with them are the only reason we are talking for several reasons…”, says Dr. Guszejnov. Without stars, we would not exist. Earth would be a cold rock in the middle of space that would not be able to support life.

We owe almost everything to stars. For example, the carbon we humans are made up of comes from red giant stars, Dr. Guszejnov informs.

These facts merely scratch the surface of the vast ocean of space and specifically the significance of stars in our universe. There are so many more mysteries to be uncovered, and astronomers are hustling to do just that.

It is important to understand objects like stars because, without them, we would not exist.

Closeup of a supernova remnant

Image: Courtasy of NASA

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A Timeline of Space Exploration by: ritvik Rajesh

For thousands of years, astronomers have been trying to decipher the mysteries of space. Thanks to advancements in technology, we have physically been able to travel in space to get a better look at how are universe works. From first being able to go outside of Earth’s atmosphere, to getting ready to go to Mars.

Let’s take a closer look at some of the most notable advancements that have shaped what space exploration is today.

1969

Neil Armstrong becomes the first ever person to set foot on the moon apart of NASA’s Apollo 11 mission.

This feat was something space agencies from all over the world had tried to accomplish and this alone has helped us understand more about our planet and our surroundings than ever before.

U S A

1961

Yuri Gagarin of the Soviet Union become the first person ever to go to space. This was a ground breaking feat that caused an astronomical exploration boom where countries from all over the world joined the race.

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The Future...

Companies, noteably SpaceX by Elon Musk hope to go to Mars by 2024 and bring people along in the 2030’s. This is the next step in getting to know our surroundings in space which can help us understand the unverise as a whole better.

U S A

2019

A picture of a real blackhole was taken by the Event Horizon Telescope. The blackhole was found at the center of a galaxy called Messier 87(M87). Astronomers couldn’t confirm the existance of blackholes but this helped us understand that the universe is a vast place and there is so much more to learn.

1971

The launch of the first spacestation named Skylab. This technological advancement helped pave the way for the International Space Station which is still in use today.

U S A

1970

The first softlanding on Venus. This event has helped pave the way for the exploration of our Solar System and the planets around us.

1998

The International Space Station(ISS) was built in union with the ESA(Europe), FKA(Russia), Japan (JAXA), and Canada(CSA). This advanced spacestation has helped space research accelerate faster than ever. The ISS may be seeing retirement around the year 2030. NASA hopes that commerical labs will replace the space station in orbit opening more job opportunities and research capabilities.

Information from ESA, History, Space, CNBC, and NASA.

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Image of the Milky Way. -From NASA

OUt of touch 16

Distances of our universe 16

By: Alec Marintzer 18

This is a picture of sudents practicing their scouts practices like NASA would. -From NASA The universe, filled with up about 17 football fields back lightyear, or 5.9 trillion miles. wonderful worlds and trillions to back, that would create a mile. of galaxies which contains us, There is a measurement for the There are actually larger humans. We have conquered distance that light travels in one measurements than just a our planet, made it into space, year, which is called a lightyear. lightyear. Take a parsec for and even survived diseases This measurement is based on example. A parsec is roughly 3 threatening our lives. times bigger than Soon we might even a lightyear. Even a travel beyond what “Have patience. Don‘t be in a rush. parsec is not the is possible, into the biggest measurement.

It‘s good to have good successes in impossible, into the There are kiloparsecs unknown. But first, we three months, it is more important to and megaparsecs that need to know what the really help to have steady successes throughout will universe is. define the size of our your life, even if it takes longer to universe. A kiloparsec The size of the (kpc) is 3,260 light get to each one of them.“ universe is almost years. With this, the impossible to size of our galaxy, comprehend. It is the biggest two things, the speed of light The Milky Way, is about 30 kpc. A thing that we know of. It is 613 and the time in one year. The megaparsec (mpc) is even bigger mpcs (megaparsecs) wide. To speed of light is about17186,000 than a kiloparsec and a parsec by know how big that is, we have miles per second and there are 10 and 100 times respectively. to start from the smallest figure 31,536,000 seconds in a year. By In the metric system, units we can. Think of a football field, multiplying the speed of light by are found by multiplying the 100 yards in length. If you lined the seconds in a year, we get a previous number by 10 or adding 19

Image of the sun in our solar system.

-From NASA

an extra 0. The imperial system side of the universe. The place (the system US countries use that you were calling me would today) is based on the imperials be destroyed from the universe that decided that their foot was before the signal got to me. Not 12 inches and thus was the foot to mention that we would both standard that some countries use be dead long before either of us today. I talked about both the got the call. That’s 11.7 sextillion metric system and the imperial miles or one hundred ninety nine system earlier but they shouldn’t sextillion, two hundred seventy be together normally. Getting two quintillion, one hundred back to the measurements, our twenty two quadrillion, seven galaxy, The Milky Way is about hundred thirty two trillion, one 30 kpc. This means that we are hundred sixty billion football getting closer to the actual size fields to reach from one corner of of the universe. A megaparsec is the universe to the other. This is even bigger than a kiloparsec by insane and it’s still getting bigger 1000. This means that the size of The Milky Way is .03 megaparsec The nearest star from Earth is (mpc). Scientists believe that the Proxima Centauri, and it might universe never be is 613 explored.

“If you’re interested in mpc. This Proxima pursuing, if you know what means Centauri that if we your career is, try and learn is 4.246 were to lightyears as much as you can about it fit 20,433 away Milky Ways as fast as You can, because from us. into our To show a maybe you won’t like it.” universe, it would fill it up. That’s enormous and it is comparison, the farthest that any still getting bigger! space probe has gone is about 14.5 billion miles, with Voyager There are 613,000 kpc in the 1 and Voyager 2. Voyager 1 and universe, or 1,998,380,000 Voyager 2 were launched 16 days light years, or almost 2 billion apart in 1977 and have traveled light years! That is enormous! almost 14.5 billion miles. That is This means that there are 63 less than 0.06% of the distance quadrillion light seconds. This from Earth to Proxima Centauri means that if a star blew up on or must travel almost 1700 one side of the universe, it would times farther from us to get to take 63 quadrillion seconds or Proxima Centauri. The voyagers almost 2 billion years for light were launched for the purpose of to travel to the other side of reaching farther into the universe the universe. Phones take much than anything has ever been and longer to send and receive to research all about the areas information than light but just that it passes through. Also, the imagine if you were on one voyagers were used to contact side of the universe and tried life outside of earth. On the to call me, whos on the other voyagers, there is a disk called 20

the golden record, that carries the sounds, cultures, and diversity of earth.

Have you ever wondered why making rockets and spacecraft takes so long? It’s because sending a spacecraft into space can be extremely costly, and if not done properly, could lead to a loss of money and time. The rockets cost around 1 billion dollars and all the scientific instruments which could go up to hundreds of thousands of dollars. “If your robot breaks, you can reach over and fix it. If our robot breaks, we’re done,” says Ross Beyer, a NASA scientist.

This is why space travel could be difficult. If one bolt is not screwed in or a circuit board malfunctions, that could lead to a catastrophic end. In addition, the technology on the spacecraft is very precise. Because of this, scientists spend extra time measuring and checking every

Ross Beyer interviewee

http://rossbeyer.net/science/

little thing inside the spacecraft before launching it into space where it can’t be reached or changed by humans.

Places like NASA and the University of Texas are training people to become astronauts and teaching about space. It is important to trust these people because they will make the world a better place. Space programs advancing in space technology are,“not day to day” states Ross Beyer but will definitely help in the future. Advancements in science could lead to better medical and better living standards. Who knows, we may even be living in space in a couple of years from now. By then, the most important thing is what the scientists researched about.

Youth development is also a big topic concerning astronauts and space development. The youth

Margaret Baguio

https://smdepo.org/user/204

are our next generation and will run the world while we are gone.

If we teach them information about space, they can go on and continue researching and learning like we have. Margret Baguio, an employer passionate about youth development at NASA’s Texas space grant says, “You and your classmates will be the ones that are finding how to develop the new rover and developing the gateway that’s going around the moon and landing astronauts on the moon and then on to Mars.” This goes back to the bigger picture that the youth are going to be incontrol in the years to come.

The development of crucial sciences is key to the discovery of planets or behaviors in space, but if no one is there to use it and understand it, it won’t be as useful as it would be if the younger generations are better educated.

Srinivas Bettadpur

https://www.jsg.utexas.edu/researcher/ srinivas_bettadpur/

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Could You be an astronaut?

By: Alec Marintzer

Becoming an astronaut is very difficult. They have to go through rigorous test and regulations as well as giving up important things like connections with family. You also have to be very persistent because it is almost gaurenteed that you won’t be let in on your first try. You must be between 62 and 75 inches tall and have 20/20 vision. Becoming an astronaut is challenging but it is highly worth it in the end.

Are you interested in space travel or scientific research?

YES

NO

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Do you want to do something great with your life and honor the people you love?

YES

Do you have a degree in STEM programs such as engineering, sciences of mathematics, biological studies, or technical sciences like computer science?

NO

NO

NO

YES

Do you have 20/20 vision and are in perfect physical shape (AKA best shape of your life)?

YES Under pressure, can you think of a solution to a difficult problem? Can you hold your breath or think strait for an extended period of time?

NO

YES

You are someone who is well educated and is ready to become an astronaut. You are willing to do what it takes to become one and are very interested in space. You can withstaind many things like physical and mental tests.

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You are a regular person, not obsessed with science like some are or you are someone who isn’t willing/able to become an astronaut.

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Observing dark matter in distant galaxies Image credit: NASA/ESA

The Foundations of the Universe How dark matter could potentially be at the nexus of our understanding of the Universe

by Ram Sivaraman

24

T

The Universe is a vast, mindboggling collection of everything we know and don’t know yet. To understand the Universe, we need to look deeper. We can ask ourselves many philosophical questions about why the Universe is the way it is - Why does the Universe behave as it does today? Where did all of the matter we know come from?

How did humans affect this timeline?.

If we delve into the depths of these questions, where do we end, and what is our final answer?

As we dive into these little questions, a reality emerges. Particles smaller than atoms themselves, the subatomic particles, are the building blocks of the complex Universe we know today. They have existed for as long as we know - since the beginning of the timeline of our Universe. All of the matter we see today is made of these subatomic particles. All of these subatomic particles are only a small percentage of the Universe. All that is remaining is just void! One question remains unanswered, though: What is the remaining black, void-like part of the Universe made of? Is it really a void? Could it be that this will define the Universe? This void of blackness is filled with what particle physicists like to call dark matter, an unknown substance that some scientists think could help generalize and understand the Universe as a whole.

Before we understand dark matter, we need to understand the fundamental subatomic particles and their behavior.

Dr. Can Kilic, a particle physicist working at the University of Texas at Austin, has worked in the field of collider physics at various particle accelerators. His research on the Standard Model of Particle Physics provides us with some insights. The

Standard Model is an organized collection of the fundamental particles we know. To understand the basics of particle physics, there are a couple of key ideas that we need to wrap our heads around. First is the Standard Model, and the second is quantum field theory.

Realm” in Avengers: Endgame, which Ant-Man, Doctor Strange, and The Wasp accessed only through shrinking to a very tiny scale. There were no other ways to get there. One could consider the Standard Model as the set of rules that predict what happens in this Quantum Realm!

“Quantum field theory tells us basically the general rules, or what particles are, how they interact with each other, and how they exchange energy,” Dr. Kilic said. “Basically, it comes down to a set of rigid rules, which are pretty mathematical, but the intuitive way to think about it is … there are a bunch of particles [in space], there are [strict]

There are many things that the Standard Model can describe, Dr. Kilic explained. All of the particles we know exist, and the fundamental forces, except gravity, are described by the Standard Model. These include the electromagnetic force (transmitting electric/magnetic waves), the weak nuclear force (responsible for particle decay), and the strong nuclear force (holds atomic nuclei together). These three forces are transferred through the bosons (nicknamed the “force carriers” in our Universe) of the Standard Model. There are four bosons: the photons, the W and Z bosons, and the gluons. There is also one remaining boson, the Higgs boson, which gives other particles mass.

“Thinking is not the same as proving.

Right now, there is no [definitive] evidence.” rules for who can exchange energy with whom, and that forms a quantum field theory. So, the Standard Model is a quantum field theory. Quantum field theory describes all possible worlds, and the Standard Model describes the one that we happen to live in, with the particles that we know and the forces that we are aware of.”

This is almost like the “Quantum

Remember the Quantum Realm? Well, as The Wasp learned, getting out of the realm was a matter of its own!

Likewise, in the real world, we see that gravity (a fundamental force) is not included in the Standard Model, as it does not fit nicely with other force equations. There is a separate understanding required for gravity.

Scientists do not know how to represent gravity using mathematical equations. Gravity is always present; it is dynamic and changing with space and time. However, quantum mechanics is rigid in space and time.

Dr. Kilic explained that trying to mathematically represent gravity in quantum mechanics often resulted in inexplicable infinites in the 25

equations. String theory, he noted, was a promising method of explaining gravity using quantum mechanics to a certain extent. It may not give particle physicists a full mathematical understanding of gravity but promises to combine all forces into a single, unified theory.

Jacques Distler, a professor of physics at the University of Texas at Austin, has worked extensively on string theory.

Dr. Distler generalizes string theory to higher-dimensional theories. He said we only see four dimensions: the x, y, z dimensions in space and the time dimension. However, there is a possibility of dimensions beyond these four (thus the name “higher

dimensional theories”) that are curled up behind each other in a manner that does not allow us to observe them with the energies given to us.

“One analogy … is an ant crawling on a … very thin drinking straw,” Dr. Distler said. “So that is really two-dimensional, but if you’re large compared to the diameter of the straw, then you really only see the one dimension along the length of the straw and not the circular direction orthogonal to that.”

Using this concept of the possibility of multiple dimensions, Dr. Distler introduced string theory as a framework for other theories in nature. “Solutions” to string theory

are a certain amount of dimensions curled up in a complex manner. He explained that understanding solutions individually could help us derive and understand results we could not have reached with ordinary quantum field theories. Scientists have even observed far-away places in the Universe that obey predictions by string theory.

However, it does not give us a complete view of gravity because gravity is a classical concept understood at a macroscopic level. However, quantum theory, like string theory, is understood at a very microscopic level. This is the reason gravity is not a part of the Standard Model.

With all the basics of the Standard

Data from the Chandra X-Ray Observatory tests String Theory Image credit: NASA/CXC/Cambridge Univ./C.S. Reynolds

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The Linac4 particle accelerator Image credit and copyright: CERN

Model and quantum mechanics, we can now take a step into the research of dark matter. Dr. Don Lincoln, a particle physicist at the Fermi National Accelerator Facility, is experienced in researching particles at accelerators around the world. These particle accelerators collide different particles at very high energies, enough to simulate the early Big Bang in a tiny microscopic area. The results of the collisions are observed, and new research is built upon it.

As Dr. Lincoln explained, dark matter cannot be easily observed like other particles. We do not even know if it exists in the Universe, but the thought of dark matter arises from observations about galaxies deep in space. We observe some galaxies (not all) to rotate faster on the outside than predicted, which could indicate there is some quantity of invisible mass we

have not detected. This invisible mass is known as dark matter.

“People are going back to the drawing boards and saying, well, let’s take another look at the idea that gravity is messed up, or inertia is messed up,” Dr. Lincoln said. “Right now, it’s an open question. We simply do not know if dark matter is real or not. All I can tell you is that most astronomers think that it is. But thinking is not the same as proving. Right now, there is no [definitive] evidence.”

We can only experience or deduce that something like dark matter exists but cannot see or detect through our current tools or technologies. This brings memories of the scene from Star Trek: Enterprise. T’Pol detects a higher concentration of particles, yet all that is visible is just stars filling the black universe. Captain Archer sends

two charges at what seems to be a void. A few moments later, the charges explode, and a brilliant “dark matter nebula” is revealed. In a similar manner, we can see the effects of dark matter through galaxy rotation but do not know what the root cause is.

Dark matter, as seen through these observations, only seems to interact with gravity. We have no clue what particles it is made of, if it exists, or if there is something we do not understand about the Universe yet. This brings back the point of how hard it is to observe dark matter because particle accelerators work with quantum particles, not classical objects. Dark matter, as a result, could be at the crux of our understanding of the Universe.

It is a twist between dimensions and particles that scientists have yet to uncover.

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A Universal Recipe by: Ram Sivaraman

__________________________________________________________________________ To understand something as large as the universe, we need to look at objects at the smallest scale.

If you thought atoms are the smallest particles, there is more to learn by zooming in even further!

The smallest particles that we know of are arranged and classified under the Standard Model of particle physics. All of these particles are much smaller than an atom, but fill up outer space! The interaction between these particles are fundamental in creating the matter that we observe today.

There are three main subcategories in the Standard Model: Quarks, Leptons, and Bosons U

C

T

e

μ

τ

D

S

B

νe

νμ

ντ

Quarks are subatomic particles that come in six different flavors: up, down, charm, strange, top, and bottom. These quarks interact under the strong nuclear force. Together, they can create protons and neutrons.

G

γ

Leptons are in a sense opposite to quarks.

They don’t interact with the strong force, only the electromagnetic force, the weak nuclear force, and gravity. They can either have electric charge or stay neutral. Just like quarks, they also come in six types: electrons, muons, and taus, and their respective neutrinos.

W

Z

H

The final subcategory is the Bosons. Bosons are “force carrying particles” - they moderate the fundamental forces. Currently, we know of five: the gluon (moderates strong force), the photon (moderates, electromagnetic force), the W and Z bosons (moderate the weak nuclear force), and the gluon (moderates the strong nuclear force).

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A Brief Timeline: the Standard Model in the Universe

Larger Universe!

Starting from the tiny particles from the Big Bang, the Universe is now epanding faster than ever in the age of stars and galaxies.

Atoms Combine!

The Universe is growing in size and the subatomic particles start to form atoms, some of the building blocks of matter.

The Big Bang!

All of the subatomic particles flew out and the Universe started cooling.

This started forming the fundamental forces.

Information from ThoughtCo, CERN, and Britannica

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