The True Science of Parallel Universes

1 Watch the video   and put the words into the gaps in the text.

Everyone loves the idea of parallel universes - maybe it’s the appeal of an ideal 1____ where you have second chances and things turn out differently - an alternate reality where you do get into Hogwarts and the Star Wars prequels aren’t made and you finally plug in your asymmetric computer cord correctly on the first try... But is there really a place in science for such wistful speculation? I mean, if «the universe» is everything that there is, you can’t have two 2____ of it, right? Otherwise the pair would really be everything and what you started off calling the universe, wouldn’t it? The problem here is terminology: 3_____ speaking informally often say «universe» when they really mean «4_____ universe» - that is, the part of the whole universe that we’ve so far been able to see. And it’s perfectly fine to talk about multiple different observable universes. For example, an 5____ near the edge of OUR observable universe will see parts of the Whole Universe that we cannot yet see. But that’s a well-understood question and not what physicists normally talk about when they discuss 6____ observable universes, or «multi-verses».      So let’s cut to the chase: in physics, the word «multiverse» normally refers to one of three distinct and largely unrelated proposed physical models for the universe - none of which has been tested or confirmed by experiment, by the way. The three «multiverse» models are:       Type 1: bubble universes or baby 7____ hole universes. This is the most 8_____ kind of multiverse. The basic idea is that perhaps there are other parts of the universe which are so far away that we will never see them (or are inside black holes so similarly we will never see them). This kind of model was created as an attempt to explain why our universe is so good at making stars and 9_____ and black holes and life. As the argument goes, if each of these separate mutually un-seeable «bubbles» in the universe had slightly different 10____ of physics, then by definition we could only exist in one that had the right physical laws to allow us to 11____. If you’re not convinced by this logic, don’t worry too much: there’s not yet any experimental 12_____ for this kind of multiverse.       Multiverse type 2: membranes and extra dimensions. Inspired in part by the inability of the 13_____ of string theory to 14_____ the right number of dimensions for the universe in which we live, string theorists proposed the idea that perhaps what we think of as our universe is actually just a 15______ surface embedded within a larger super-universe with 9 spatial dimensions. Kind of like how each page of a newspaper is its own two-dimensional surface 16_____ within our three-dimensional world. And of course, if space had 9 dimensions rather than three, there’d be plenty of space for other three-dimensional 17_____ that appeared, like ours, to be universes in their own right, but, like the pages of a newspaper, were actually part of a bigger whole. These kinds of surfaces are called «18_____» or «branes» for short. And as a reminder, there is not yet any experimental evidence for this kind of multiverse.     Multiverse type 3: the many-worlds picture of 19_____ mechanics. Surprisingly, physicists still don’t fully understand how the collapse of the wavefunction in quantum mechanics happens, and the many-worlds 20_____ makes an attempt at explanation by proposing that every possible alternate 21_____ for the universe is real and they all happen in an ever-larger, ever-branching way. Like, a universal choose-your-own-adventure where every possible story happens! If this were the case, we might not realize it because we’d be stuck living out just one of the infinitely many possible lives available to us. In some ways, “many-worlds” is similar to the “bubble multiverse” model by proposing «maybe anything that can happen, does. And we just happen to exist in the series of happenings that were necessary for us to exist». If you’re still not convinced by this 22____, don’t worry: there is not yet any experimental evidence for this kind of multiverse.      Of course if you want to get imaginative, you could also combine several of these models together into a multi-multiverse. A new super-23_____ model based, itself, on speculative and experimentally unconfirmed models. But that’s not to say we couldn’t test these multiverse 24_____. For example, if our observable universe were really just one of many disconnected bubbles or membranes and if it happened to 25____ with another bubble or membrane some time in the past, then that collision would certainly have had some sort of 26_____ on what we see when we look up at the night sky. On the other hand, the many-worlds interpretation might be 27_____ fairly soon since experimentalists are becoming increasingly able to 28______ and control ever-larger quantum mechanical systems in their labs - systems that 29_____ the line between the quantum realm and our everyday experience. So as always, we must remember that 30_____ is science, not philosophy; and in our attempts to explain the universe that we observe, we have to make 31_____ that can in principle be tested - and then test them!
	multiple
	observable
	versions
	physicists
	alien
	world
	straightforward
	laws
	exist
	galaxies
	black
	evidence
	membranes
	surfaces
	predict
	embedded
	three-dimensional
	mathematics
	hypothesis
	quantum
	logic
	timeline
	collide
	hypotheses
	tested
	effect
	speculative
	approach
	claims
	manipulate
	physics

2 Vocabulary focus. Study the words and  word combinations, practise their translation, spelling. Check your knowledge in the test. Play vocabulary game and set your own vocabulary game record.

3 Mark the following statements as True or False.

1 String theorists proposed the idea that our universe is a three-dimensional surface.

2 Baby black holes and bubble universe models have been proved using scientific evidence.

3 Physics can describe how the collapse of wave function in quantum mechanics happens.

4 There are four models of multiverse.

5 In physics the term “force” means the same as “observable force”.

 4 Answer the Questions.

1 How many universes exist?

2 What is the most straightforward kind of multiverse?

3 What cannot physicists understand?

4 What is the second type of multiverse?

5 What would happen if our universe collided with another universe? 

6 What evidence proves the multiverse theory?