Is this a parallel universe? Take the quiz!


Modern science tells us that somewhere out there, in another fabric of time, there could be entire worlds that look very much like our own. Take our Parallel Universe Theory Quiz to see what you know about these unknown worlds.

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Question 1 of 20

What is the name of the idea that there are countless parallel worlds that share the same time and space?

the Xanadu quantum hypothesis
the space-time continuum theory
the many-worlds interpretation of quantum mechanics

... The many-worlds interpretation theorizes that a countless number of parallel worlds are created to accommodate all possible outcomes of any quantum experiment.


Question 2 of 20

Who introduced the many-worlds interpretation of quantum mechanics?

Harvard physics professor Lisa Randall debuted the theory at a conference in 1998.
A then-graduate student at Princeton named Hugh Everett published a paper on the subject in 1957.
Quantum theory founder Max Planck introduced it in a paper called "Quantum Selection" in 1948.

... Hugh Everett made public the idea that any event with multiple possible outcomes splits the universe. Each new universe reflects one of the possible outcomes of the experiment.


Question 3 of 20

What is the name of the theory that parallel universes spring from a "parent" universe?

quantum cosmos theory
chaotic inflation theory
the never-ending bang theory

... Physicist Andrei Linde's work with chaotic inflation theory proposes that universes can grow out of a "parent" universe. Linde even believes we could invent an entire new universe in a laboratory.


Question 4 of 20

Both the many-worlds interpretation and string theory seem to support the idea of parallel universes. How do these parallel universes interact with each other?

According to string theory, the parallel worlds can come into contact with each other. According to the many-worlds interpretation, they can't.
Both theories agree that these parallel universes have no influence on one another.
According to both string theory and the many-worlds interpretation, gravity from one universe can affect matter in another.

... Both theories support the existence of parallel universes, but string theory proposes that these separate worlds have some causal interaction.


Question 5 of 20

What is the term for a theoretical stucture that contains multiple universes?

total quantum field

... "Mulitverse" means, essentially, a universe full of universes. It is the proposed complex in which multiple parallel universes live.


Question 6 of 20

The newly discovered and unexplained "dark flow" demonstrates that our universe is being pulled along by another force. Which theory of the universe does this provide evidence for?

the many-worlds interpretation
the Copenhagen interpretation
string theory

... Dark flow does not prove string theory's take on the existence of parallel universes, but it does provide evidence for it.


Question 7 of 20

What is the scenario proposed by the "grandfather paradox"?

You travel back in time to kill your own grandfather, making your birth impossible.
You travel back in time to meet your grandfather, causing a rip in the space-time continuum.
You travel forward in time to meet your unborn grandchildren, seeing the results of your actions before you perform them.

... The idea of time travel is complicated by paradoxes like this. If you were to go back and kill your own grandfather when he was a baby, how could you have ever been born? But if you weren't born, who killed him?


Question 8 of 20

Physicist Niels Bohr suggested that an unobserved quantum particle exists in all of its possible states at once. What is this theory called?

the Copenhagen interpretation
Bohr's particle gamble
quantum turbulence

... The Copenhagen interpretation theorized that an unobserved quantum particle exists in all of its states at once -- it's only when we observe the particle that it chooses a position.


Question 9 of 20

What was the name of the story mathematician Edwin A. Abbott wrote depicting geometric figures living in a two-dimensional world?

<em>When Two Becomes Three</em>

... Abbott wrote Flatland in 1884 to explain the possibility of dimensions beyond those with which we were familiar. In the book, the narrator, A. Square, is perplexed and alarmed when introduced to the third dimension.


Question 10 of 20

In Phillip Pullman's His Dark Materials series, what artifact does protagonist Will Parry use to cut his way into parallel universes?

a frozen bolt of lightning
a hatchet
a knife

... Will Parry uses a one-of-a-kind knife to cut openings that allow him to travel between universes.


Question 11 of 20

What is the common name of Erwin Schrödinger's famous thought experiment that challenged Niels Bohr's Copenhagen interpretation?

Schrödinger's machine
Schrödinger's owl
Schrödinger's cat

... "Schrödinger's cat" supposed that an unopened box contained a cat and a vial of fatal toxin that had a 50-percent chance of rupturing. According to Schrödinger, if we were to treat the cat the same way we treat a quantum particle, we would have to believe the cat to be both alive and dead until we open the box to look at it.


Question 12 of 20

Which of the following is not a type of quark?


... Quarks, which are subatomic particles that join to make larger subatomic particles, have six different types, known as "flavors." "Swan" is not one of them.


Question 13 of 20

There may be parts of the physical universe that you could never reach, even if you traveled at the speed of light forever. Why is this?

Traveling at the speed of light for longer than several seconds freezes you in time.
Parts of the universe are expanding away from us at a rate faster than the speed of light.
They are blocked off by a "quantum barrier" made of entangled bosons.

... While matter supposedly cannot travel faster than the speed of light, the empty space of the universe can expand faster than the speed of light. Some things are so far away, and moving farther away so fast, we could never hope to reach them.


Question 14 of 20

If there are multiple universes and they have collided in the past, where might evidence of this be found?

the core of a star
the strata of Earth's crust
cosmic microwave background

... Associate Professor Anthony Aguirre from the University of California at Santa Cruz believes past collision of universes may have left visible indications on the cosmic microwave background.


Question 15 of 20

Particles that exist on a quantum level have a quirky habit of being altered by observation. What is this known as?

string theory
the Heisenberg Uncertainty Principle
the dynamic quark principle

... The Heisenberg Uncertainty Principle refers to the fact that you alter a quantum particle when you observe it.


Question 16 of 20

Cosmologists speculate that the laws of physics may be quite different in parallel universes than they are in our own. What do they speculate the presence of such universes can explain?

why protons are heavier than electrons
whether there is an after-life
the nature of time

... Cosmologists hope that the laws of physics in parallel universes might explain certain aspects of our own universe, like the fundamental nature of time.


Question 17 of 20

According to many interpretations of string theory, of how many dimensions is our universe composed?

10 or more
112 or more
829 or more

... Different versions of string theory posit different numbers of dimensions, but we generally haven't broken three figures yet. One popular strain of string theory proposes that there are 11 dimensions over which all matter in our universe is composed.


Question 18 of 20

What is the name for the area of the universe outside which objects move away from the observer faster than the speed of light?

Hubble volume
the illuminated universe
Planck scale

... Outside of the Hubble volume, there could be many undetectable worlds.


Question 19 of 20

In H.G. Wells' novel The Time Machine, which dimension does the Time Traveler travel through to reach the future?

the violet dimension
the flat dimension
the fourth dimension

... The Time Traveler builds a machine that he explains travels through the fourth dimension to reach a strange future populated by the descendents of humanity.


Question 20 of 20

Which of the following would necessarily imply parallel universes and other Earths?

a finite universe with no boundary
the heat death of the universe
an infinite universe

... If the universe were truly infinite, there would be infinite space, infinite expansion, and the possibility of infinite worlds, infinitely similar to and different from our own. This is one reason it's hard to imagine such a thing as an infinite universe.


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