Earth’s Origin & Place In the Universe
Learn about how everything—Earth, our solar system, and even the universe itself—got started, and the fascinating objects scattered throughout the universe.
The Beginning of Everything- The Big Bang
A video by Kurzgesagt – In a Nutshell. The resources accompanying this video were created by Catriona McMahon and are shared with a CC BY-NC-SA license.
Summary
This short informative video explains the chemicals, processes, and events which led to the creation of our universe. This video discusses the ways the big bang theory was theorized by scientists, and how their theories intertwine with each other. After watching, the viewer will have a clearer understanding of how our universe came to be and what our universe is made from.
Why Watch this Video?
- Have you ever wondered how quickly the universe was created?
- Would you like to know what existed at the universe’s creation?
- Have you ever been confused by what matter makes up our universe?
Key Terms
Quarks. Tiny particles of energy that can be used to create protons and neurons, and eventually elements, like hydrogen in the big bang. Quarks are the main component in matter itself.
Matter. The very composition of everything in the universe. Everything that physically exists is made of matter.
Energy. The ability of an object to be manipulated or affected by gravity and other forces. For example, how far a ball can roll when pushed is an example of the ball’s energy.
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The Theory of Relativity
The theory of relativity is the concept of how gravity affects the universe and all its contents, which was theorized by Albert Einstein. This theory states that the laws of physics are always the same, but are relative to gravity’s direct effect on them and other objects. This theory allows us to understand how gravitational pressure was critical in the formation of the universe.
Cosmic background Radiation (CBR)
CBR The oldest form of light in the universe. CBR is the radiation remnants of the universe’s creation that acts as evidence to the big bang, and is present in the universe today. Cosmic background radiation is believed to be radiation left over from the intense heat of the big bang.
Edwin Hubble’s Discovery
Also known as “Hubble’s Law” it’s the discovery that the distance of a galaxy to the Earth is actually related to how fast it travels away from the Earth. This law explains how the universe expands during both the big bang, and our current time.
Self-Test
Try these questions to test your understanding.
References
Emspak, Jesse (2017, March 14) 8 Ways You Can See Einstein’s Theory of Relativity in Real Life. Live Science.
Lamb, Robert (30 June 2010), What does gravity have to do with the big bang? HowStuffWorks.com
Leitch, Erik. M (2001, November 1) What is the cosmic microwave background radiation? Scientific American.
National Aeronautics and Space Administration. (2016, September 5) Tests of Big Bang: The CMB. wmap.gsfc.nasa.gov.
Sloan Digital Sky Survey. The Expanding Universe.
What is the Universe Made Of? (How Atoms Form)
A video by Dennis Wildfogel for TED-Ed. The resources accompanying this video were created by Lindsey Procter and are shared with a CC BY-NC-SA license.
Summary
This video explains how the universe formed, how stars are created and destroyed, and what main elements the universe is composed of. Dennis Wildfogel narrates a thorough animation to describe the relationship between molecules and atoms and how their relationship connects to all things around us. The definition of supernovas is also included in this video and how they create elements.
Why Watch this Video?
- Have you ever wondered where our sun came from?
- Would you like to know how your body is made up of the same materials as stars?
- Have you ever been confused by the big bang theory and how the universe went from an abyss of nothing to the enormous collection of celestial bodies we know it as today?
Key Terms
Nuclear fusion. When energy is made from atoms bashing into each other so hard that their nuclei mash together. This process of fusing the nuclei releases energy that stars emit light and heat. Nuclear fusion gives the stars their shine!
Equilibrium. When the pressure of gravity pushing down on the star core is the same as the pressure pushing out from the star core.
For example, try this activity:
- Make a fist with your right hand.
- Place your left hand over your fist.
- Try to close your left hand into a fist and (at the same time) try to open your right hand!
If you do these actions with the same pressure, it would be similar to what happens to a star’s core.
Density. The measure of mass in a specific volume. For example, you are trying to fit a bag of clothes into your car. The bag of clothes has a lot of air in it, making the volume of that bag too large to fit into your car. Air has a low mass, high volume, and low density. You can expel the air out of that bag to decrease the volume so the bag can fit in the car. As you compress the air out of the bag, the bag of clothes will decrease in volume and increase in density. When your mass stays the same (clothes in the bag), and your volume gets smaller, the more dense the object, or in this case bag of clothes, will be. The tighter the clothes are packed in the bag, the higher density the clothes bag will have.
The drawing below gives a visual representation of the explanation above, with the circle being the bag and the small diamond shapes being the clothes.
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The Big Bang Theory
The big bang theory or “the big bang” is believed to be how the universe was created. Scientists estimate, 13.8 billion years ago, a massive explosion occurred. This created all matter, energy, space, and time. Right after this huge explosion known as the big bang, the universe was extremely hot, approximately one quadrillion degrees Celsius. Since then, the universe has been cooling and expanding. The big bang was the start of everything. Without this event, humans and earth would not exist. Shortly after the big bang, the most basic elements could start to form, such as helium, lithium, and hydrogen. From these elements, our solar system could form almost 10 billion years after the big bang.
How was Earth formed?
Earth was formed about 4.5 billion years ago when gas and dust accumulated over billions of years. The bigger the Earth got, the more dust and particles were collected, creating a stronger gravitational pull. Over many millions of years, Earth became the extraordinary planet it is today, composed of a solid crust, rock mantle, and liquid core. Earth is a unique terrestrial planet because it is the only planet in our solar system with a biosphere, meaning it is the only planet that can support life.
What is an atom?
An atom is the smallest particle with a unique chemical structure. It is made up of even smaller particles called protons, neutrons, and electrons. Atoms can join together to make up molecules. H2O (water) is a molecule composed of three atoms joining together: two hydrogen atoms and one oxygen atom. Atoms are so small they cannot be seen with a microscope. Trying to see an atom with the naked eye would be like trying to see a singular speck of dust a kilometer away: impossible!
Self-Test
Try these questions to test your understanding.
References
Baer, E. M., Dr., & Wenner, J. M., Dr. (2020, June 19). How do I Calculate Density? Density and specific gravity in the geosciences. Retrieved November 12, 2020.
Center for Nuclear Science and Technology Information. (n.d.). Nuclear Fusion. Retrieved November 12, 2020.
NASA. (n.d.). Earth. In Depth. Retrieved October 09, 2020.
Pidwirny, M. (2020). Understanding Physical Geography Chapter 3, Matter, Energy, and the Universe.
Stars. (n.d.). HiRes. Retrieved November 12, 2020.
Wildfogel, D. (Educator/Narrator), Comiskey, A. (Director), TED-Ed (Producer), & Barker, A. (Animator), Davies, S. (Artist). (2014, February 25). What is the universe made of? – Dennis Wildfogel [Video file].
Solar System 101
A video by National Geographic. The resources accompanying this video were created by A. Lirondelle and are shared with a CC BY-NC-SA license.
Summary
This video uses detailed animation to show where our solar system is in the galaxy, along with a brief introduction of how it formed. Starting at the sun and working outward toward the Oort cloud, this video explains where the terrestrial and Jovian planets are situated in the galaxy. It’s different from other solar system videos because it takes you through the composition and the key characteristics of every planet and celestial object in our solar system.
Why Watch This Video?
- Have you ever wondered why humans can only live on Earth instead of other planets in our solar system?
- Would you like to know how old the solar system is and how it formed?
- Have you ever been confused about where everything is in our solar system?
Key Terms
Dwarf planet. In the video, we saw that the dwarf planet, Ceres, is about the same size as Texas, making it very small for a planet. As their name suggests, dwarf planets are too small to be considered official planets, but too large to be classified as asteroids or other objects. Aside from large size, planets must also be able to clear their orbits of space debris8, which dwarf planets are not able to do. So, by being in the asteroid belt, Ceres is a dwarf planet because its orbit is full of asteroids and debris!
Terrestrial planet. Along with being made of rocky material and having solid surfaces, terrestrial planets are also characterized by what’s at the core—or the very center of—the planet. Contrarily to Jovian planets that are just balls of ice and dust, terrestrial planets, like the planet you are standing on today, have a metal core. For example, Earth’s core is made primarily out of iron and nickel, which is divided into two parts: a solid inner core and a liquid outer core. These liquid and solid cores are then surrounded by the thick solid rock mantle and the crust, respectively, which are both made of solid silicates materials (a type of rock that is one of the most abundant on Earth4).
Space debris. In the video, as we saw in the asteroid belt, rocky objects are ranging in size from dust particles to asteroids to dwarf planets. These objects are commonly referred to as space debris or the debris of the cosmic construction site that created planets and their moons2. However, space debris encompasses both natural and man-made particles. The man-made, or artificial, particles are parts of space crafts, mission-related debris, and other fragments3, which are primarily found within Earth’s orbit. The natural debris is found everywhere, like in the Oort cloud, which is a collection of icy space debris.
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Was the whole solar system created solely by the instantaneous collapse of a solar nebula?
No. Though the video makes it seem like the solar nebula collapsed into itself in the blink of an eye to make all the planets in the solar system, this process did not happen overnight. In fact, it took 4.6 billion years to get to where Earth is today. First, one small part of the nebula, which is a cloud of gas and dust, starts to collapse in on itself. This triggers the entire nebula to collapse and start condensing the majority of its material into a star at its center. However, some material remains and settles to make a disc of gas and dust rotating around the star (much like the rings that rotate around Saturn!). Next, portions of this disc start to bond together as they move around the central star. As they gather materials, they form bigger and bigger objects over the next billion years, eventually turning into planets. This process is called accretion7, a very competitive game in which all the planets are striving to be the biggest!
Why are rocky planets near the sun, and planets made of gas and ice further away?
This arrangement did not happen by chance! The terrestrial planets are closer to the sun because of the materials that make them up. Closer to the sun, the temperatures were much higher and only allowed for some matter (in this case, the rocky and metallic materials making up the terrestrial planets) to solidify. This is why the gas and ice giants come after the terrestrial planets: the water and gases could not freeze until they were a certain distance from the sun. In fact, this required distance is marked by what is the frost line7, which separates the terrestrial and Jovian planets due to their materials’ individual freezing temperatures.
15% of stars in the Milky Way Galaxy host planetary systems
Our solar system is one of many in the galaxy! Our Sun is one of the 15% of stars known to host planetary systems. Planets that rotate outside of these stars (not including our own) are given the name exoplanets6. We are still discovering new exoplanets and their characteristics, but we can use properties of our own to approximate what the exoplanets are like. One of the main properties we use when trying to find out a planet’s composition is density (which is the weight of an object for how much space it occupies). We translate density from our own planets to approximate the materials that form exoplanets.
Self-Test
Try these questions to test your understanding.
References
1. Chapman, C. R. Basic astronomical data. Accessed Nov 10, 2020.
2. European Space Agency. Debris of the Solar System: Asteroids. Accessed Nov 10, 2020.
3. Garcia, M. Space Debris and Human Spacecraft. Accessed Nov 10, 2020.
4. Klein, C. Silicates. Accessed Nov 10, 2020.
5. NASA. In Depth: Venus. https://solarsystem.nasa.gov/planets/venus/in-depth/ Accessed Nov 10, 2020.
6. Panchuk, K. M. (2019). Are There Other Earths? . Physical Geology, 1st USask Edition. https://openpress.usask.ca/physicalgeology/
7. Panchuk, K. M. (2019). How to Build a Solar System . Physical Geology, 1st USask Edition. https://openpress.usask.ca/physicalgeology/
8. Space.com Staff. Dwarf Planets: Science & Facts About the Solar System’s Smaller Worlds. Accessed Nov 10, 2020.
Black Holes Explained – From Birth to Death
A video by Kurzgesagt – In a Nutshell. The resources accompanying this video were created by VDC and are shared with a CC BY license.
Summary
This video gives an overview of the life cycle of a black hole, from its formation to when it radiates away. It guides you from the creation of stars by nuclear fusion and how this process converts them into black holes, to the basic layout of a black hole. Finally, it describes how a black hole eventually evaporates due to the Hawking Radiation process.
Why Watch This Video?
- Have you ever wondered what would happen when our sun completes its cycle?
- Would you like to know what happens if you fall into a black hole?
- Have you ever been confused by what is needed to create a black hole?
Key Terms
Nuclear fusion. It is the process of atoms’ nuclei reacting together to form heavier elements. The Big Bang is known to have created hydrogen atoms, which then reacted together to form helium, and so on. This process goes on until iron, the heavier element that can be fused within a star, is created. Iron builds up at the centre of the star until it breaks the balance of radiation and gravity. When the core collapses and the star implodes, a black hole is formed.
Event horizon and singularity. The event horizon is the boundary of a black hole, even if it is not a physical surface. Anything can go in, but nothing can come out due to its immense gravity. Therefore, it is also known as the “point of no return”, where gravity becomes so strong that nothing can escape, including light. The Singularity is a hypothetical place at the centre of a black hole that occupies no space. Like it was mentioned in the video, we do not know for sure what a singularity is and what happens inside it. All we know is that it has an infinite density (because the mass of the entire star compresses into a single point), with a radius of zero (or infinite value).
Empty space. It is important to note that empty space is not empty. ‘Quarks’, the particles that are the base of protons and neutrons (even though there are no protons or neutrons in empty space), interact with each other through ‘gluons’. They disappear when they interact with each other, in a process called annihilation. These “gluon field fluctuations” are what is found in empty space. For more information on empty space, you can watch a four-minute video here.
Loose Ends
Do all stars eventually turn into black holes?
No. The fate of a star is determined by the amount of matter that forms it (in other words, the amount of hydrogen it must burn). Two examples of what could happen to stars that fill their cycle apart from black holes are white dwarfs and neutron stars. As nuclear fusion creates heavier elements and reaches iron, the star will collapse.
If the star has a low mass, this will leave an Earth-sized core that will gradually cool, so it is no longer able to continue with nuclear fusion. Therefore, the star will contract even more until it becomes a white dwarf (a “star corpse”).
However, if the star has an intermediate mass, it will collapse into a supernova. This event exudes so much energy that it will release elements even heavier than iron. What is left after this reaction is a neutron star; a ball of neutrons stuck together.
Only stars with a much higher mass will create black holes.
What will happen to our solar system once the sun completes its cycle?
Our sun is not big enough to turn into a black hole once it ends its cycle. Instead, it will expand until it becomes a red giant (a larger star, in its last stages of life), which will eventually swallow the planets closest to it (including Earth). Therefore, planets and moons with frozen liquids will melt. This will go on until the sun inevitably collapses, leaving behind a white dwarf. Once the sun becomes a white dwarf, it will begin to cool down, and the solar system will freeze again.
What is Hawking radiation?
Empty space is an important process to keep in mind to understand the Hawking radiation. These are virtual particles that interact with each other and disappear. However, if one of those particles is inside the event horizon, it will be lost (since it is the point of no return). The other particle escapes as lost radiation, which will cause the black hole to lose energy as well as its mass. As this process repeats, the black hole slowly evaporates, until it completely disappears. Additionally, bigger black holes, since they have a larger mass, will take longer to evaporate than smaller black holes. For more information on the Hawking radiation, you can watch a three-minute video here.
Self-Test
Try these questions to test your understanding.
References
Conn, Robert W. (2019). Nuclear Fusion. Encyclopaedia Britannica, inc. Retrieved October 11th, 2020.
Core Explore. (2018, April 12). Death of black holes – Hawking radiation Explained [Video]. YouTube.
Best0fScience. (2009, April 29). Black Holes, Event Horizon And Gravitational Waves [Video]. YouTube.
Dreksler Astral. (2017, March 3). Solar System During the Death of Our Sun [Video]. YouTube.
The Editors of Encyclopaedia Britannica. (2019). Event Horizon. Encyclopaedia Britannica, inc. Retrieved October 11th, 2020.
Eternally Curious by Federico Pistono. (2017, February 9) What is a Singularity? | Eternally Curious #11 [Video]. YouTube.
Oxford. (n.d). Singularity. Oxford Learner’s Dictionary. Retrieved October 11th, 2020.
Professor Dave explains. (2018, August 28). The Life and Death of Stars: White Dwarfs, Supernovae, Neutron Stars, and Black Holes [Video]. YouTube.
Veritasium. (2013, April 30). Empty Space is NOT Empty [Video]. YouTube.
