# The Universe.

## Presentation on theme: "The Universe."— Presentation transcript:

The Universe

The universe is the sum of all matter and energy that exists, that has ever existed, or that ever will exist. There is only ONE universe. You are part of the universe, as is the Earth and everything on it.

Red Shift In 1929, Edwin Hubble observed the light being emitted by other galaxies was redder than expected. This shift toward the red end of the spectrum means the galaxies were moving away from us. The farther away they were the faster they were going. This was interpreted to mean the universe is expanding.

How do we measure distance in space?
Distance in space is hard to imagine because space is so vast. You need something bigger than miles and kilometers to measure these large distances. Units of measure must have meaning to the people who use them and be functional for the purpose they are created for.

Astronomical units An astronomical units (AU) equals 150,000,000 km (150 million)—which is the average distance the Earth is from the sun. If something is 5 AU away, it means the object is five (5) times as far away from Earth as the Earth is from the sun. Mercury is 0.38 AU; the Earth is 1 AU, and Pluto is 39 AU from the sun.

Light Years Distances between Galaxies are measured in light-years (ly). A light-year is the distance light travels in one year—approximately 9.5 trillion km (9.5 X 1015 km) Light travels so fast, it could go around the Earth seven times in one second.

The Origin of the Universe
How did the universe begin? This is a question that scientists are trying to answer by studying the stars, galaxies, and planets in our solar system. Cosmology is the study of the origin and evolution of the universe. Several theories exists about the origin of the universe.

The Big Bang Theory According to the Big Bang Theory, the universe was created 10 to 20 billion years ago with a gigantic explosion that hurled matter in all directions.

The Big Bang Theory is the dominate theory about the origin of the universe.

Big Bang Theory According to the theory, during the expansion after the explosion, it cooled the universe enough to form matter in the form of neutrons, protons, and electrons. After a million years, the universe cooled enough for hydrogen atoms to form. Since then hydrogen has been the most abundant element on Earth.

Inflationary Theory This is basically an expansion of the Big Bang Theory. This theory states that during earlier stages of development, the universe expanded at a faster rate than it is expanding today.

Steady-State Theory This theory does not propose a beginning of time.
It simply states that the universe has always existed in relatively the same state it is now and that it will remain the same forever.

How do we explore space?

The telescope The origin of the telescope is surrounded by controversy, the most likely story puts it in the shop of a Dutch spectacle maker named Hans Lippersey in 1608. The earliest known illustration of a telescope. Giovanpattista della Porta included this sketch in a letter written in August 1609

Refracting Telescope The lenses used in refracting telescopes are called concave and convex. Convex (curved outward) lenses make things bigger, but blurry. Concave (curved inward) lenses make things look clearer, but small. As you can guess, a combination of these two lenses makes things seem bigger and clearer. Refracting telescopes (or refractors) use lenses to gather and bend light making things seem larger.

What happens when you look through the telescope?
Imagine we are still outside looking at Venus with a refracting telescope. An objective, or large, lens collects light from Venus and sends it to a smaller, eyepiece lens at the back of the telescope tube. The eyepiece magnifies the little image of Venus and directs it at your eye. Wow, can you see the yellow-white disk? Now that's some planet!

Reflecting Telescope Our reflecting telescope uses mirrors to collect and magnify light. Remember that reflecting telescopes originally developed to solve the problem of color distortions caused by lenses bending light at different angles. The reflecting telescope's mirror reflects light instead of bending it so there is no color distortion.      Let's say we are still outside looking at Venus, but now we are using a reflecting telescope (or reflector).

With our reflecting telescope, light is collected by a big concave mirror. The mirror reflects light to a smaller flat mirror. This secondary mirror directs the light from Venus through the eyepiece lens at the side of the telescope. The eyepiece magnifies the image. Yep, when we look through the eyepiece, we can see Venus !

Telescope Facts The largest optical telescope in the world is in Hawaii. It's the 10-meter W. M. Keck telescope. At 4300 meters, it sits on top of Mount Mauna Kea, an extinct volcano.      Radio telescopes use a large dish to collect radio waves from space. The dish is the same shape as the mirror of a reflecting telescope. Radio telescopes are a valuable tool for astronomers since many objects in the universe do not produce enough visible light to be picked up by optical telescopes. One of the world's most powerful radio telescopes is the Very Large Array (VLA) in New Mexico. The VLA is made up of 27 linked radio telescope dishes each 25 meters in diameter.

The Importance of Light
Most of what we know about the Universe comes from information that has been carried to us by light. But we have seen that visible light is only a small part of the electromagnetic spectrum. In recent years the remainder of the electromagnetic spectrum has revealed extensive information about our Universe.

Radio waves have the longest wavelengths in the electromagnetic spectrum. These waves can be longer than a football field or as short as a football. Radio waves do more than just bring music to your radio. They also carry signals for your television and cellular phones.

Radio Telescopes Detect radio signals emitted by distant objects. Some of the oldest, most distant objects in the solar system have been detected by radio telescopes. Radio waves from those objects were emitted almost 15 billion years ago.

How do we "see" using Radio Waves?
Objects in space, such as planets and comets, giant clouds of gas and dust, and stars and galaxies, emit light at many different wavelengths. Some of the light they emit has very large wavelengths - sometimes as long as a mile!. These long waves are in the radio region of the electromagnetic spectrum. Because radio waves are larger than optical waves, radio telescopes work differently than telescopes that we use for visible > light (optical telescopes). Radio telescopes are dishes made out of conducting metal that reflect radio waves to a focus point. Because the wavelengths of radio light are so large, a radio telescope must be physically larger than an optical telescope to be able to make images of comparable clarity. For example,

The Parkes radio telescope, which has a dish 64 meters wide, cannot give us any clearer an image than a small backyard telescope! In order to make better and more clear (or higher resolution) radio images, radio astronomers often combine several smaller telescopes, or receiving dishes, into an array. Together, the dishes can act as one large telescope whose size equals the total area occupied by the array. Time-lapse view of Parkes radio telescope at night in New South Wales, Australia

The Hubble Telescope Named for Edwin Hubble, the Hubble Space Telescope now probes the depths of the universe from it’s orbit high above the Earth’s atmosphere.

Hubble Space Telescope

Space Flights

Sputnik Sputnik was the first man-made satellite.
Many consider October 4, 1957 to be the beginning of the Space Age. On this date, Sputnik — a basketball-sized, Soviet-made satellite — orbited our planet. Due to cold-war tension between the world’s superpowers — the United States and the Soviet Union (now Russia) — the Sputnik launch fueled the space race between the two countries.

BIRTH OF A SATELLITE Sputnik I's vital statistics
Launch date: Oct. 4, 1957 Diameter: 23 inches Weight: 183 pounds Material: Aluminum alloy Life span: About 22 days, ending when transmitter batteries expired Name: Translates to "fellow traveler" or "traveling companion" in English Function: Gathered data on the atmosphere, emitted beeps, tested radio transmission Impact on pop culture: Amid concerns about what Sputnik meant regarding the Soviets' space and military capabilities, Americans began to riff on the Sputnik theme. Bars offered vodka-based Sputnik cocktails; restaurants named sandwiches after the satellite. There were Sputnik toys and bubble gum, and satellite-shaped ceiling lamps, earrings and Christmas ornaments. Several musicians penned Space Age songs, such as one by Al Barkle with the Tri-Tones that began with Barkle imitating the satellite's beeping. Sources: NASA; Russian space writer Anatoly Zak; After Sputnik: 50 Years of the Spage Age

Space Race Milestones Wide-open spaces: An astronaut enjoys a spacewalk. Image courtesy of NASA Intense research and development ensued over the following decades. Successes by both nations are marked by important milestones: First person in space — The Russian astronaut Yuri Gagarin achieved this on April 12, 1961. First person in space — First person to orbit Earth – American John Glen orbited Earth on Feb. 20, 1962. First person in space — First moon walk – Neil Armstrong and Buzz Aldrin were the first people to set foot on the Moon on July 20, 1969, answering the challenge of former U.S. President John F. Kennedy.

On the Horizon Currently, both nations maintain active space programs. Other countries, such as France, Japan, and China now have space programs as well. Current space exploration endeavors include: Deployment of reusable spacecraft, called space shuttles International Space Station Orbiting space telescope (Hubble Space Telescope) Unmanned missions to explore Mars The future of space exploration may include bold projects such as a lunar colony and manned missions to Mars. Many technological challenges must be overcome to succeed in these missions. However, that’s never stopped us before . . . An artist's concept of a Mars rover - a remotely controlled vehicle that traverse the Martian surface and send data to scientists on Earth. Image courtesy of NASA