Chapter 6 - Parallel Quantum Universes

This chapter was my favourite chapter to read because it explained a theory revolving on the fact that we can never know for sure where an electron is. Meaning that until you see a certain tree, for example, you can never know for sure if it’s falling or standing up, but you can calculate the possibility that it’s falling or standing up.

According to the quantum theory, there is small but calculable probability that you can suddenly dissolve and reappear on the other side of a wall! This is because electrons have the ability to dematerialize and rematerialize on the other side of wall. If electrons could not be in two places at once, we could not exist (Because of this fact electrons form a cloud around the nucleus allowing for atoms to bind).

I really like this chapter because I have always believed in parallel universes/worlds. This chapter explains there the possibility of parallel worlds is almost certain, and there is even a (extremely small) chance that we could slip between these two universes.

To calculate this probability we must use the infamous wave function created by Schrödinger.

Unfortunately, this leads to the “cat problem.” Say there is a cat in a box, then it is impossible to tell if it is dead or alive so we can say that cat is 50% dead and 50% alive at the same time. But, how can a cat be dead and alive at the same time just because we haven’t looked at it yet?

At this point, Hugh Everett III discussed that maybe the cat is both dead and alive at the same time but in different universes. So, when you finally open the box, the cat may be alive in your universe, but in a different one, the cat will be dead.

The many worlds theory has been my favourite theory so far because it confirms that anything is possible. For example, there must exist a world where dinosaurs never became extinct so they are currently living on the same planet we are. Or, there is even a universe where Jurassic Park actually happened and dinosaurs came back to life. There is only a small chance that this would happen in our lifetime, but in an infinite number of universes, this is very likely to happen at least once. The only problem is that our wave functions are different so we can’t interact with the other universes.

Our universe seems like the only universe, but it’s really just the only universe we can interact with. So, our reality simply depends on our specific wave function, and remember for every decision that you make, there is another you who made the opposite decision, and is living out the life you chose not to live...

Chapter 5 - Dimensional Portals and Time Travel

In this chapter, Kaku discussed two theories that intrigued me. The first described “a universe in your bedroom” and the other “time paradoxes.” Both deal with time travel, and the second more specifically about the problems with time travel.

The first theory, is a simplified universe created by Charles Misner. In this universe, for example, your room would become an entire universe. The right and left wall of your bedroom would be identical, so as you tried to walk through the wall on your left, you would end up reappearing into the room from the wall on the right. This concept is also applied to the ceiling, floor, front and back of the room. In this way, you cannot escape from your room making it an entire universe.

In this case, all four walls would be transparent and you would notice that there would be exact carbon copies of yourself beside you, in front of you and behind you. There would be a infinite series of you, but you could never see your own face because if you were to look right, all the copies of you would be looking right and therefore you could only see the back of your head. It would also be advised not to point a gun at the clone in front of you because you will soon notice that the clone behind you will also be pointing one at your head.

In a Misner universe, we’ll say that the right wall is moving in at a speed of 2 m/s. So, if you leave through the left wall, you will reappear through the right but have your speed boosted by 2 m/s. If you continue to go through the loop, you can reach speeds close to the speed of light causing you to go back in time, or visit any point in space-time.

Hawking analyzed this scenario and compared it to two mouths of a wormhole, where both mouths of the wormhole would be identical. So, if we were to find a wormhole that moving in, we would be able to time-travel.

This universe is not stable so it has not gotten us much closer to time-travel, but created lively discussions in the physics world.

These discussions lead to time paradoxes. There are four main paradoxes which render time travel very complicated:

-The grandfather paradox where you alter your past, for example, killing an ancestor so you would not exist, and therefore not be able to go back in time to kill your ancestor.

- The information paradox where information comes from the future and so it has no origin in the present. So if someone from the future were to tell you how to make a time machine, your idea would not have an origin since you did not create the machine.

- Bilker’s paradox where a person knows the future, but does something in the present that makes the future impossible. For example, if you knew went into the future to find out who you’re going to marry, and then go back to the present to kill that person, your future cannot exist.

- The sexual paradox where you go back in time and father yourself, which is biologically impossible.

Having so many paradoxes means there are many theories explaining how to get around the paradoxes. Like the “many worlds theory” where all possible quantum worlds would exist, and so in one world you may have killed your parents and you would not exist, but in the other, nothing would have changed and life would continue normally.

Finally, time travel also stumbles upon free will. If we don’t have free will, and somehow, something is constraining us to “act properly” so we can’t kill our parents, we could eliminate certain paradoxes. So, I’m wondering, do you think time travel is possible? And, do you think we actually have free will?

Chapter 3 - The Big Bang

While studying the Big Bang and the aftermath, scientists soon discovered that most of the universe was not made up of familiar atoms but mostly substance called “dark matter.” Dark matter weighs approximately10x more than normal matter.

In the 1930s, a Swiss astronomer, Fritz Zwicky, noticed that the Coma cluster of galaxies were not moving according to Newtonian gravity. He saw that the galaxy was spinning so fast it should fly apart and dissolve. He suggested that the only the cluster was not being ripped apart was if it had hundreds of times more matter than what was seen by the telescope. In 1930, either Newtonian laws were incorrect or there was a huge amount of invisible matter in this cluster holding it together.

Nobody believed Zwicky and so the theory of dark matter was abandoned until 1962 when astronomer Vera Rubin noticed that the Milky Way was experiencing the same problem. According to Newtonian Laws, the Milky Way was missing 90% of its mass. Since so much mass was missing, Rubin knew that there must be some other form of matter that takes up the extra mass. Unfortunately, Vera was a girl, and so she was ignored until 1978, when a man, Albert Bosma, published an analysis showing that Rubin had been right all along, and “dark matter” does exist.

Dark matter has now been mapped out over the entire universe. From the picture on the left, we can see that dark matter clumps together, and over time it is getting closer and closer together. Not shown in this picture, but has been observed by telescope is that matter tends to form it self on top of dark matter, meaning that there is more matter wherever there is more dark matter.

The theory of dark matter intrigued me because it is invisible mass. It coexists with us, but we cannot interact with us. It controls the movement of our galaxy yet we know so little about it. We don’t know what it is made of, but it has been speculated that it is made of brown dwarf stars, neutron stars and even black holes. All of these are nearly invisible to us which is why we can’t see dark matter.

Interestingly, some scientists disagree, and think that dark matter is made of a an entirely new type of matter called “cold dark matter” or “weakly interacting massive particles.”

We know very little about dark matter, but it is speculated that it accounts for 22% of the mass of the universe. Observable mass/energy, or the matter that we can see accounts for 4% of the mass leaving 74% of the mass of the universe to “dark energy” which is even more interesting than dark matter. Dark energy being the energy of nothing or the repulsive form of gravity.

By learning more and more about what our universe is made we realize that we actually know less and less about the universe. We don’t even understand what makes up 74% of the energy in our universe. We realize that we have a far way to go in understanding what really is going, and makes us wonder if we’ll ever know what is really controlling us.

To learn more about the picture, how scientists created the picture, or to learn more about dark matter, please watch this video. It is only three minutes, but it will be worth your while.

Chapter 2 - The Paradoxical Universe

When the apple fell on Newton’s head, this caused him to think to himself: “if an apple falls, does the moon also fall?

Newton, while observing Halley’s comet noticed that the force of the sun on the comet diminished as the comet got further away. Newton discovered that the comet was moving in an ellipse as a consequence of the inverse square law. After the apple incident, Newton realized that everything in the universe falls under the inverse square law. Newton also noticed that the mathematics of his time were too primitive to solve the law, he created calculus to help determine the motion of falling objects, including the moon.

Newton’s Mathematical Principles of Natural Philosophy or, Principia, described the rules of mechanics such as the inverse square law, and it raised paradoxes about the construction of the universe. After Newton’s work had been published, there were arguments debating the size of the universe and whether or not it was finite. In 1962, Richard Bentley wrote a letter to Newton concerning the finiteness of the universe. Bentley noted that since gravity was always attractive, and if the universe was finite, all the stars would collide into a fiery superstar. He also wrote that if the universe was infinite, any force tugging on the star would be infinite as well resulting in all the stars being ripped to shreds.

Newton responded saying that he preferred an infinite universe, but the force pulling the star to the right would be cancelled by the force pulling it to the left leaving us with a static infinite universe.

Since the universe is infinite, there should be an infinite number of stars glowing white, and therefore the night sky should be white. Edgar Allen Poe, a famous poet wrote that “… that there could be absolutely no point … at which would not exist a star.” He concluded that even though there is never a point in the universe where a star doesn’t exist, that the distance between us and this invisible background is so immense that the light from these stars still has not hit our eyes.

With this new idea from Poe, astronomers programmed the Hubble space telescope to take a picture of the farthest point in the universe. This photograph showed ten thousand infant galaxies 13 billion light-years from Earth. When studied, scientists noticed that there is only blackness between the galaxies and this is what causes our night sky to be black. However, they soon discovered that the blackness was actually microwave radiation from the big-bang itself. So, if we could somehow see microwave radiation in colour, our night sky would not be black at all, but the colour of microwave radiation.

Below is a time line of the creation of our universe.

Chapter 1 - Baby Pictures of the Universe

Since the beginning of human existence, we have pondered whether or not the universe is timeless or has a beginning or end. In different cultures, you’ll find different answers. Scientifically, we have found that there was beginning, but when did this beginning happen?

Scientists have been studying a new satellite known as the WMAP or the Wilkinson microwave anisotropy probe. This satellite was launched in 2001 and can paint a detailed picture of the universe when it was 380,000 years old. (Comparing the universe to an 80 year-old man, this detailed picture would show the man as a newborn less than a day old.) The WMAP can detect the radiation emitted from the original fireball that created the universe. This map measured the age of the universe to be about 13.7 billion years old and that the temperature of the universe was between 2.7249 and 2.7251degrees Kelvin.

When the Big bang originally happened, the universe had a great period of inflation. Now, scientists predict that within a fraction of a second, the universe is expanding by a factor 1050. But, what caused this inflation? It is not yet discovered what caused it, but Russian physicist has proposed that whatever caused the inflation then could still be at work randomly causing other regions of the universe to expand.

According to this theory, a part of the universe will “bud” creating a “daughter” parallel universe which will in turn bud and create another daughter universe. This theory could mean that our universe could simply be the daughter universe of another universe.

So, if our universe was simply a daughter of another universe, the chances of life in other universes are relatively high. And so, the next question is proposed: will we ever be able to leave our own universe, and how can we do this?