The Big Bang and Stars

Everything was condensed in one infinitely small spot​.

• Only one force

• Infinitely hot

• Infinetly dense

• No space or time

Before the big bang

The Big Bang Theory says that everything in the universe once fit into an incredibly small area. Because this area was very hot, a powerful expansion of energy was created. Everything that was densely packed in the small area went flying out in all directions. In a blink of an eye, this microscopic area expanded into something larger than the Milky Way galaxy.

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​Within seconds, everything began to cool down. Still expanding, the building blocks of the universe began to form. After millions of years, the universe’s temperature was cool enough to allow galaxies and stars to form. To this very day, the universe is still cooling and expanding.

​Doppler Effect: Imagine An ambulance getting near you. What do you think it sounds like?
What if it gets farther away?

​The frequency is higher when an object is getting nearer, but lower when it's getting farther away.

What is the Doppler effect?

Multiple Choice

What is the doppler effect?

• It is the reason why objects appear larger or smaller as they move.

• Increase or decrease in wavelength of a wave as the source or the observer move closer or farther apart.

• It is the bending of light around an object.

• It explains why objects accelerate as they approach an observer.

Multiple Choice

Which Observer is receiving more energy,

the left or right observer?

• Left Observer because the wavelengths are longer.

• They are both receiving the same amount of energy because they both receive 5 wavelengths.

• Right Observer because more wavelengths are packed into the same area equaling more energy.

• Right Observer because the source is moving towards them.

Multiple Choice

The Big Bang Theory suggests that our universe formed as the result of a huge explosion that sent all existing matter flying outward from a single point. The Big Bang Theory is supported by which of these observations?

• All matter in the universe is composed of the same atoms.

• All galaxies appear to be moving away from all other galaxies.

• All stars in the universe are approximately the same age.

• The universe is relatively the same temperature in all locations.

Multiple Choice

According to the video, what was discovered by accident in 1964?

• The identification of quasars

• The observation of gravitational waves

• The mapping of the Andromeda galaxy

• Cosmic Microwave Background Radiation

Multiple Choice

According to the video, what had to happen in the universe right after the Big Bang in order for atoms to form?

• The universe had to cool down.

• The universe had to heat up.

• The universe had to create antimatter.

• The universe had to split all the quarks.

Multiple Choice

What were the first two elements to form once the Universe expanded and cooled?

• Hydrogen and oxygen

• Carbon and helium

• Helium and oxygen

• Hydrogen and helium

Multiple Choice

According to the video, when did stars and galaxies form?

• Stars formed after all the elements were created and after galaxies were formed.

• Stars and galaxies formed immediately after the quarks clumped together.

• Stars and galaxies formed when the hydrogen gas clumped together.

• Galaxies formed first after the big bang and then stars started shining a hundred thousand years later.

Multiple Choice

Which one of the following quotes comes from the video?

• "The universe is under no obligation to make sense to you."

• "Since we ourselves are made of dead stars, we are not separate from the Universe, we are part of it."

• "Not only is the universe stranger than we imagine, it is stranger than we can imagine."

• "Astronomy compels the soul to look upward, and leads us from this world to another."

Blue - Blueshift- means more frequency which means more energy!

Red- Redshift- means less frequency and less energy!


THINK ALSO ABOUT FIRE: Which is hotter, blue or red fire?

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Which color shows more energy?

Hotspot

Which one has more energy? Is the hottest?

Multiple Choice

What does it mean if a galaxy gives off light which has been shifted toward the red end of the electromagnetic spectrum?

• The galaxy is much older than Earth.

• The galaxy is moving away from Earth.

• The galaxy is very hot and has not cooled down yet.

• The remnants of an explosion are between the galaxy and Earth.

​The Big Bang Theory is not the only theory that tries to explain the creation of the universe. However, it the most popular current theory. Scientists have discovered that galaxies are traveling away from Earth. Scientists know this by studying the color of light that the galaxies give off. Light from each galaxy appears to be shifted toward the red end of the electromagnetic spectrum. This means they are traveling away from Earth. This supports the idea of a

great expansion from the Big Bang.

Multiple Choice

Hubble's Law is an equation where V = HD.

V = velocity, D = distance, and H = Hubble's constant or 74.3

If you measured a redshifted galaxy 200 megaparsecs away, how fast would it's velocity be?

• 14860 km/s moving away

• 2.69 km/s moving closer

• 3715 km/s moving away

• 274.3 km/s moving closer

Multiple Choice

What is Hubble's law and its relation to the universe's expansion?

• Hubble's law calculates the universe's age, not related to its expansion.

• Hubble's law relates a galaxy's size and color, indicating a shrinking universe.

• Hubble's law relates a galaxy's distance and velocity, indicating an expanding universe.

• Hubble's law is about black holes formation, unrelated to universe's expansion.

Electroweak force separated into weak nuclear and electromagnetic, allowing quarks to form

​Quarks form

​Quarks combine to form protons and neutrons

​​Protons and Neutrons form

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The first elements appear. Predominately H, with some He

Hydrogen and Helium​

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​As the universe expanded....... It cooled down

Multiple Choice

What is happening to the Universe to this day?

• The universe is getting smaller and hotter.

• The universe is staying the same.

• The universe is getting cooler and bigger.

​​The universe was continuing to expand, the universe was finally cool enough for these atoms of hydrogen and helium to attract free electrons, turning them into neutral atoms. This was the moment of first light in the universe The first time that photons could rest for a second, attached as electrons to atoms.

​What does redshift, microwaves, and doppler effect tells us about the universe and the big bang?

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Lets connect the dots.

The universe as we know it today begins to take shape​

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Galaxies start to form

​Astronomers noticed that all galaxies are redshifted

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Redshift indicates moving away due to doppler effect

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The universe must be expanding​

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Hubble realized that the further the galaxy is, the greater the red shift

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Further galaxies are moving away faster​

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Cosmic Microwave Background

​Faint glow of light that fills the universe, falling on Earth from every direction with nearly uniform intensity.

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Observed through radiotelescopes.

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This is the piece of evidence that made astronomers realize that the big bang model must be correct.

Multiple Choice

At what moment did most astronomers finally decide that Big Bang cosmology was real?

• The formulation of Hubble’s law

• The calculation of the age of the Universe

• discovery of cosmic background radiation

• The uncovering of the first atoms to be formed

Multiple Choice

According to the video, the Cosmic Microwave Background Radiation is a snapshot of what?

• A picture of the Universe from when it was 380,000 years old.

• The Universe at 13.8 billion years old.

• Visible light from other galaxies in the Universe

Multiple Choice

Since the Universe began expanding, light or energy has been ________ and has become ________.

• heating up, compressed

• heating up, stretched out

• cooling, compressed

• cooling, stretched out

Multiple Select

According to the video, how do we know that the CMB is the earliest light
we can see from the early universe and not something else?

(Chose 2 correct answers.)

• If your eyes could see microwaves, you would see this type of light everywhere you look.

• The CMB has a unique color that distinguishes it from other sources.

• There would be a residual temperature that is measurable, and that it is cold within the microwave range.

• The CMB has a different speed compared to other light.

Another piece of evidence that supports the Big Bang was found when scientists

launched the Cosmic Background Explorer satellite in 1989. It precisely measured the temperature of the Cosmic Microwave Background radiation. Scientists had made temperature predictions based on starting with a hot Big Bang. The satellite found temperatures which matched with the predictions. Scientists believe this radiation is from the energy released during the first year of the Big Bang.

Multiple Choice

Cosmic Microwave Background Radiation (CMBR) is the term used to describe the residual microwave radiation observed everywhere in the universe that seems to have no single source. The observation of CMBR is used as evidence of The Big Bang Theory because it is believed to be -

• The result of collisions between neighboring galaxies.

• Particles of dust that have absorbed radioactivity.

• Radiation left over from the rapid expansion of matter.

• Light energy emitted from the source of The Big Bang.

​Scientists have estimated that the universe was formed over 13 billion years ago. In 1995,

scientists pointed the Hubble Space Telescope into an area of space that seemed empty.

The telescope collected light for 240 hours. The images that were sent back to Earth were

amazing. Many thousands of galaxies appeared in a space as small as a grain of sand.

​If there are this many galaxies spread evenly through space, there could be over 50 billion galaxies in the universe. The farthest galaxies are over 13 billion light years away. This supports the Big Bang Theory by telling scientists how old our universe is.

Multiple Choice

According to the standard model of Big Bang cosmology, approximately how old is the Universe?

• 65 million years old

• 13.8 billion years old

• 4.5 billion years old

Multiple Choice

What is the observable universe and its relation to the universe's expansion?

• The observable universe is what we can see, and it stays the same size despite the universe's expansion

• The observable universe is a small part we can see, and it doesn't relate to the universe's expansion

• The observable universe is what we can see and detect with our technology. As the universe expands, light from distant objects gets stretched, moving them further away and harder to observe.

• The observable universe is the entire universe we can see, and it shrinks as the universe expands

Multiple Choice

In which direction are nearly all galaxies moving?

• toward each other

• away from each other

• colliding into one another

• in the direction of Earth

Multiple Choice

What are two important pieces of evidence we have for the Big Bang?

• Ptolemy’s work on epicycles and Hubble’s law (the expansion of the Universe)

• Hubble’s law (the expansion of the Universe) and cosmic background radiation

• The fact that we have multiple Universes to compare and study and cosmic background radiation (CBR)

• The abundance of hydrogen, helium, and lithium found in the Universe and Ptolemy’s work on epicycles

Multiple Choice

As part of The Big Bang Theory of the formation of the Universe, scientists believe that over time, the universe is continually changing in what characteristic?

• From more dense to less dense.

• From rotating to stationary.

• From cooler to hotter.

• From very large to very small.

Multiple Select

Which pieces of evidence support the Big Bang Theory?

(choose all that apply)

• Analysis of Spectra showing that the Universe is mostly made of Hydrogen and Helium

• Cosmic Background Radiation that is evidence of an explosion

• Most of the galaxies are redshifted, and moving away from each other.

• More distant galaxies are moving at a higher velocity than closer galaxies.

The universe’s creation is still a mystery to scientists. The Big Bang is just one theory that tries to explain the origins of the universe. Exactly how big is the universe? Where is it expanding to? These questions continue to fascinate scientists and non-scientists alike.

STEMSCOPES - 2013 Rice University.