The World We Live In… What is the Universe? How old is it? How big is it? What is it made of? What laws of nature govern it? What was happening to it in the past? What will happen to it in the future? Assembled by Sergei Zverev

What is the Universe? The universe is defined as everything that physically exists: the entirety of space and time, all forms of matter, energy, and the physical laws and constants that govern them.

How old is it? Our Universe (which means the space, time, matter and energy) was born in a Big Bang 13.7 billion (13,700,000,000) years ago from a singularity, a point in space-time in which gravitational forces cause matter to have an infinite density and zero volume. Before the Big Bang time and space did not exist. Right after the Big Bang all matter and energy were concentrated in an extremely small volume of space. The Universe was expanding since the Big Bang, and the rate of expanding as well as it’s properties were dramatically changing.

Demonstration which shows that our Universe is not thought to be a set of objects moving in a space away from a certain point at which the explosion occurred Our Universe is three-dimensional but you can picture a universe that consists only of the surface of a balloon (get a balloon, prepare it in advance: inflate it and draw the galaxies on the surface; make sure you have plenty of galaxies; let the air out). You inflate the balloon just a little bit and note the galaxies on the surface of the balloon. Then start inflating the balloon more and more. You will see that, while the balloon is inflating, the galaxies are moving farther away from each other and, if you measure the distance between the galaxies before and after the inflation of the balloon, you will see that more distant galaxies will appear to move apart faster.

In this model it is easy to see that every galaxy will observe the same effect, and no one galaxy is in a special location. Then you can ask yourself if you can find the center of expansion on the surface of the balloon, and you will not find it. This will help you make a conclusion that there is no location on the surface of the balloon that can be identified as the "center" of the universe or a point of the Big Bang “explosion.”

How big is it? Our Universe is approximately 96 billion light years across (96,000,000,000 light years). One light year = distance traveled by light in free space in one year = 9.4605284 × 1015 meters, which is approximately 1013 kilometers. The Universe is approximately 9.6 × 1023 kilometers wide or 6 × 1023 miles wide: 600,000,000,000,000,000,000,000 miles

FROM MACRO to MEGA to MICRO COSMOS ZOOM FROM MACRO to MEGA to MICRO COSMOS

This is a trip at high speed, jumping distances by a factor of 10. We will start with 100 (equivalent to 1 meter), and will increase the size of observable area by a factor of 10, or 101 (10 meters), 102 (10x10 = 100 meters), 103 (10x10x10 = 1,000 meters), 104 (10x10x10x10 = 10,000 meters), so on, until we get close to the limit of our imagination in the direction of the mega cosmos. Later we will return, a little faster, back to the point where we started and continue our trip in the opposite direction reducing observable distances by factors of 10 into the micro cosmos. We will see how much the human race still needs to learn...

100 1 meter Distance to a bunch of leaves in the garden

101 10 meters Starting our trip upwards .... We can see the foliage

102 100 meters At this distance we can see the limits of the forest and the edifications

103 1 km We will pass from meters to kilometers... Now it is possible to jump with a parachute

104 10 km The city could be observed but we really can’t see the houses

105 100 km At this height, the state of Florida is just coming into view...

106 1,000 km Typical sight from a satellite

107 10,000 km The northern hemisphere of Earth, and part of South America

108 100,000 km The Earth starts looking small...

109 1 million km The Earth and the Moon’s orbit in white...

1010 10 million km Part of the Earth’s Orbit in blue

1011 100 million km Orbits of Venus and Earth...

1012 1 billion km Orbits of Mercury, Venus, Earth, Mars and Jupiter

1013 10 billion km At this height of our trip, we could observe the Solar System and the orbits of the planets

1014 100 billion km The Solar System starts looking small...

1015 1 trillion km The Sun now is a small star in the middle of thousands of stars...

1016 1 light-year At one light-year the little Sun star is very small

1017 10 light-years Here we will see just stars in the infinity... a light-year is the distance that light travels in a vacuum in one year at a speed of 3.0 x 108 m/s or 190,000 mi/s

1018 100 light-years A lot of stars and Nebulae...

1019 1,000 light-years At this distance we are travelling in the Milky Way, our galaxy

1020 10,000 light-years We continue our travel inside the Milky Way

1021 100,000 light-years We begin reaching the periphery of the Milky Way

1022 1 million light-years At this tremendous distance we can see the entire Milky Way and other galaxies as well

1023 - 10 million light-years From this distance, all the galaxies look small with immense empty spaces in between The same laws are ruling all bodies of the Universe We could continue traveling upwards (up to 100 billion light years) with our imagination, but now let’s return home

1022

1021

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1019

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1016

1015

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1011

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109

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102 In this trip “upwards” we went to the power of 23 of 10

101 Now we are going to dig inside of matter in a reverse trip...

100 1 meter 10 centimeters or 4 inches We arrive at our starting point. We could touch it with our hands...

10-1 10 centimeters Getting closer at 10 cm ... We can delineate the leaves

10-2 1 centimeter At this distance it is possible to observe the structure of the leaf

10-3 1 millimeter The cellular structures begin to show...

10-4 100 microns The cells can be delineated You can see the union between them

10-5 10 microns Starting our trip inside the cell...

10-6 1 micron The nucleus of the cell is visible.

10-7 100 nanometers Again we changed the measuring unit to adapt to the miniscule size You can see the chromosomes

10-8 10 nanometers In this micro universe the DNA chain is visible

10-9 1 nanometer ...the chromosome blocks can be observed.

10-10 1 Angstrom It appears like clouds of electrons... These are carbon atoms, one of the organic components Is there some resemblance of the micro cosmos with the mega cosmos? cosmos ...

10-11 10 picometers In this miniature world we can observe the electron cloud

10-12 1 picometer You can see a small nucleus in the middle of the atom and an empty space between the nucleus and the electron orbits

10-13 100 femtometers At this incredible and minuscule size we could observe the nucleus of the atom

10-14 10 femtometers Now we can observe the nucleus of the carbon atom: 6 protons and 6 neutrons

10-15 1 femtometer Here we are in the field of the scientific imagination, face to face with a proton

10-16 100 attometers Examine the proton in the nucleus There is nowhere further to go... We are at the limits of current scientific knowledge

What is the contents of the Universe? There are approximately 100 billion galaxies in the universe, including approximately 3,000 visible galaxies. The diameter of a typical galaxy is 30,000 light-years, it contains between 100 - 400 billion stars, and the typical distance between two neighboring galaxies is 3 million light-years. In the center of many galaxies there are compact objects of very large mass, black holes. Gravitational attraction of a black hole is so powerful that nothing, not even electromagnetic radiation (for example visible light), can escape its pull. It makes the hole's interior invisible, and indistinguishable from the black space around it.

What is the contents of the Universe?

What is the contents of the Universe?

What is the contents of the Universe?

What is the contents of the Universe?

What laws of nature govern it? Laws of nature are observable and measurable. Physical laws are scientific generalizations based on measurements and observations of physical behavior of our environment. They describe observable laws, and they are typically conclusions based on repeated scientific experiments and observations, over many years, and which have become accepted within the scientific community. The production of descriptions in the form of such laws is a fundamental objective of science. Examples of laws of nature include Classical (Newtonian) Mechanics, Quantum Mechanics, Einstein's Theory of Relativity and Standard Model of elementary particles.

What was happening to the Universe after the Big Bang? A period of "inflation" produced a burst of exponential growth in the universe. For the next several billion years, the expansion of the universe gradually slowed down as the matter in the universe pulled on itself via gravity. More recently, the expansion has begun to speed up again as the repulsive effects of dark energy have come to dominate the expansion of the universe. A representation of the evolution of the Universe over 13.7 billion years.

What was happening to the Universe after the Big Bang? Observations suggest that the universe as we know it began around 13.7 billion years ago. Since then, the evolution of the universe has passed through three phases: 1. The very early universe was the split second in which the universe was so hot that particles had energies higher than those currently accessible in particle accelerators on Earth (particles had no mass, only one force existed). 2. Following this period, in the early universe, the evolution of the universe proceeded according to known high energy physics. This is when the particle acquired mass, one force split in four, first protons, electrons and neutrons formed, then nuclei and finally atoms. 3. With the formation of neutral hydrogen, the cosmic microwave background was emitted. Then matter started to aggregate into the first stars and ultimately galaxies, quasars, and clusters of galaxies formed.

What was happening to the Universe after the Big Bang? The Planck epoch - up to 10–43 seconds after the Big Bang: only one fundamental force exists. The grand unification epoch - 10–43 - 10–36 seconds, gravity separates from the fundamental force. The electroweak epoch - between 10–36 seconds and 10–12 seconds: strong force separates from the electroweak force. The inflationary epoch - between 10–36 seconds and 10–32 seconds: inflation (rapid exponential expansion) occurs. In the end the universe is filled with a quark-gluon plasma. The quark epoch - between 10–12 seconds and 10–6 seconds: particles acquire a mass, fundamental interactions of gravitation, electromagnetism, the strong interaction and the weak interaction have taken their present forms. The hadron epoch - between 10–6 seconds and 1 second: The quark-gluon plasma cools, protons and neutrons and other hadrons form, neutrinos decouple and begin traveling freely through space. The lepton epoch - between 1 second and 3 minutes: The majority of hadrons and anti-hadrons annihilate each other, leptons and anti-leptons dominating the mass of the universe, then most leptons and anti-leptons annihilate leaving a small residue of leptons. The photon epoch - between 3 minutes and 380,000 years: universe is dominated by photons. These photons are still interacting frequently with charged protons, electrons and later with the nuclei, and continue to do so for the next 300,000 years. After 17 minutes the nuclear fusion stops. In the end of the epoch most of the atoms in the universe become neutral, and the photons can now travel freely: the universe has become transparent for radiation. Dark ages - 380,000 – 500 million years: the universe is filled with neutral hydrogen and helium and is relatively opaque at certain wavelengths, and does not emit radiation. Structure formation: after 150 million years: first stars and quasars formed, large volumes of matter form galaxies. Reionization - 150 million to 1 billion years: intense quasar radiation re-ionizes the surrounding universe. From this point on, most of the universe is composed of plasma and is transparent. 5.4 billion years after the Big Bang – the Milky Way formed. 8.5 billion years after the Big Bang – the Solar System formed. 13.7 billion years after the Big Bang - you were born. Expansion of the Universe is accelerating.

What was happening to the Universe after the Big Bang?

What will happen to the Universe in the future?

What will happen to the Universe in the future?

What will happen to the Universe in the future? Big freeze: 1014 years (100,000,000,000,000 = 100,000 billion = 100 trillion) and beyond. This scenario is generally considered to be the most likely, as it occurs if the universe continues expanding as it has been. 1. Over a time scale on the order of 100 trillion years or less, existing stars burn out, new stars cease to be created, and the universe goes dark; 2. Over a much longer time scale in the eras following this, the galaxy evaporates as the stellar remnants comprising it escape into space, and black holes evaporate via Hawking radiation; 3. In some grand unified theories, proton decay will convert the remaining interstellar gas and stellar remnants into leptons (such as positrons and electrons) and photons. Some positrons and electrons will then recombine into photons. In this case, the universe has reached a maximum-entropy state consisting of a bath of particles and low-energy radiation at thermodynamic equilibrium. 4. No changes after that.

What will happen to the Universe in the future? Big rip: 200+ billion years This scenario is possible only if the energy density of dark energy actually increases without limit over time. Such dark energy is called phantom energy and is unlike any known kind of energy. In this case, the expansion rate of the universe will increase without limit. Gravitationally bound systems, such as clusters of galaxies, galaxies, and ultimately the solar system will be torn apart. Eventually the expansion will be so rapid as to overcome the electromagnetic forces holding molecules and atoms together. Finally even atomic nuclei will be torn apart and the universe as we know it will end in an unusual kind of gravitational singularity. In other words, the universe will expand so much that the electromagnetic force holding things together will fall to this expansion, making things fall apart.

Trivia Questions 1. What is the Universe? Space, time, matter, energy and laws of nature 2. How old is our Universe? 13.7 billion (13,700,000,000) years old 3. How big is our Universe? 96 billion light years wide 4. What is it made of? Atoms and radiation, dark matter and dark energy 5. What is the largest object in our Universe? Super clusters of galaxies up to 500 million light years (or 5x1024 meters) in size and containing up to 10,000 galaxies 6. What is the smallest object in our Universe? A quark and an electron – both are less than 10-18 meters in size 5. What was happening to the Universe after the Big Bang? It was expanding from a tiny dot, it is expanding now, and will keep expanding in the future

And now ... Note that going downwards we could only go to the power of minus 16 of 10 to reach the known limits of matter... and upwards we went to the power of 23 of 10 but we could have continued our trip up to the size of our universe – 1027 meters (power of 27 of 10) then ... What is behind those limits? Are there any limits? What initiated the Big Bang? What are the dark matter and dark energy? Why zillions of elementary particles of the same kind (for example electrons) in the universe are absolutely identical? Are we alone in the universe or there is life in other solar systems and galaxies? How long can the mankind survive on Earth? – etc., etc., etc. Do you want to find answers to these questions?

I hope that one day you will say YES!