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?

Why is the Solar System Flat?

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

Our Sun and the Earth, and all the planets and moons and dwarf planets and asteroids and 1____ - the solar system, in short, formed about 4.6 billion years ago from a nebulous cloud of swirling gas and dust which coalesced thanks to the irresistibly attractive force of 2____. However, this nebula started off more or less as a big 3____ blob. So how did our solar system end up with all the planets and their moons 4____ in a flat disk? I mean, we’ve all seen the planetary model of the atom, which is definitely wrong when applied to atoms, but it also kind of suggests that 5____ might revolve around the sun every which way. So is our solar system somehow special in its flatness? Or is the 6____ model of the atom doubly wrong? Well, our solar system definitely isn’t alone, many exoplanets’ star systems are 7___, a lot of galaxies are flat, black hole accretion disks are flat, Saturn’s 8___ are flat etc. So why, when there’s all of 3D space to fill, does the universe have this preference for flatness? The answer has to do with two things: 9___ and the fact that we live in three dimensions. Bear with me. Anytime a bunch of objects held together by 10___ are zooming and circling around, their individual paths are nearly impossible to 11____, and yet, collected together they have a 12____ total amount that they spin about their center of mass. It may be hard to figure out exactly what direction that rotation is in, but the 13____ implies there must be some plane in which the cloud taken as a whole  spins. Now, in two dimensions a cloud of particles rotating in a plane is flat by definition, it’s in two 14____. But in three dimensions, even though the rotation of the cloud is given by one plane, 15____ can whiz around far up and down from that plane. As the particles 16____ into each other, all the up and down motion tends to cancel out, its energy lost in crashing and clumping. Yet the whole mass must continue spinning 17____, because in our universe the total amount of 18____ in any isolated system always stays the same. So over time through collisions and crashes, the cloud loses its loft and flattens into a spinning, roughly 2 dimensional 19____ shape, like a solar system or a spiral galaxy. However, in four spatial dimensions, the math works out such that there can be two separate and 20____ planes of rotation which is both really, really hard for our 3D-thinking brains to 21____ and also means there’s no up and down direction in which particles lose energy by collisions. So a cloud of particles can continue being just that... a 22____. And thus, only in three dimensions can a nebula or infant galaxy start out not flat and end up flat which is 23_____ a good thing because we need all that matter to clump together in order for stars and planets to form, and for us, even those of us who think atoms look like this, to 24_____.
	shapeless
	planets
	comets
	planetary
	orbiting
	gravity
	gravity
	single
	rings
	mathematics
	collisions
	flat
	predict
	bump
	inexorably
	dimensions
	disk
	spinning
	particles
	cloud
	definitely
	complementary
	exist
	picture

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.     The solar system is flat.

2.     There aren’t any other planets beyond our solar system.

3.     It’s easy to predict the way of a particle in a system of many particles.

4.     The total amount of spinning in any isolated system always stays the same.

5.     It’s possible for the solar system and us to exist because of the phenomenon of flatness in three-dimensional space.

6.     The rules of mathematics are the same in three- and four- dimensional space.

4 Answer the Questions.

1.     When was the solar system formed?

2.     What objects in our universe are flat?

3.     What motion tends to cancel out in the spinning cloud of particles?

4.     What characteristic of isolated spinning system of particles always stay the same?

5.     Why is flatness of nebulas and systems of particles in general so important in our universe?

Physics. What if the Earth was hollow?

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

Flying in a 747 from one side of the Earth to the exact opposite side would take about 22 hours… and while I know there’s a bit of rock in the way, that’s really going the long way round. So what if we did dig a hole all the way through the Earth, through the center, and jumped in? Well, Michael, you probably wouldn’t make it very far - that’s because of the Coriolis 1_____ (which is why a ball curves weirdly when you toss it while riding a 2_____ and why hurricanes always spin 3________ in the northern 4______). At the equator, the Earth is rotating eastwards at 1670 km/hr. As you go deeper, the bits of Earth around you are still spinning around once per day, but they don’t have as far to travel so they’re going at slower and slower 5______. If you jumped into a vertical 6_____, you’d soon be traveling east faster than the rock around you so that after falling only a few kilometers, you’d crash into the eastern wall. It might not be a 7______, but some miners near Lake Superior tried to test this by dropping cannon balls down a mile-long shaft - and the balls never reached the bottom. Ok, so what if the tunnel went from pole to pole, so the Coriolis effect didn’t 8______, and let’s also assume that there’s no air resistance, or 9______. Ok. Since the Earth’s mass is more concentrated close to the middle, 10____ would pull you down with roughly the same amount of force for the first 3000 km, or halfway to the center of the Earth - this familiar, constant force would 11 ______ you until you were falling 8 km every second, and the trip halfway to the middle of the Earth would only take 13 minutes. Soon after, you’d reach the Earth’s outer 12 ______, and this is the point in your journey where the pull of gravity would be strongest - but only slightly stronger than the force we’re used to on the 13 ______. As you continued to fall closer to the 14 ______, so much of the Earth’s mass would now be above you that it would begin to seriously cancel out the 15 ______ of the mass below, and the pull would weaken until you reached the center. Here, you’d experience no gravitational pull at all - or rather, the Earth would be pulling on you the same amount in all 16 ______, so you could 17 ______ freely around with no sense of ‘up’ or ‘down’. Except, remember, that you’d be speeding past at 22,000 miles per hour, or 6 miles a second. Once you passed the center, the whole process would 18 ______ and you’d gradually slow, pulled down weakly at first and then more strongly, until when you got to the other side, you’d stop moving and could step out on the surface, a mere 37 minutes, or one dryer cycle, later. Of course, the deepest we’ve ever been able to dig is the Kola Superdeep Borehole in Russia. But it only went down 12 km, which is only two thirds the length of Manhattan. They had to stop because it got too 19 ______: 180°C. And this is sort of the problem with digging a hole through Earth - Earth is hot, and 20 ______  in the middle. You can’t just dig a hole through it with shovels. But here is a question: wasn’t the middle of Earth wasn’t all ‘liquidy’, what if Earth was 21 ______, but weighed the same? Well, with its entire 22 ______  concentrated in a thin shell right under our feet, the Earth wouldn’t have a 23 ______  field any more, because that comes from the molten 24 ______  core. So we’d be totally 25 ______  to radiation from the solar wind and storms, and this means we’d see the 26 ______  everywhere. Look! The Northern-Southern-Eastern lights! And if you jumped inside the hollow Earth to escape the solar storm? Well, 27 ______ from the different parts of the 28 ______ Earth-shell would perfectly cancel out and you’d float freely about inside as if the Earth weren’t there at all! Of course, you’d better bring a 29 ______ suit, because there’s not nearly enough air ON Earth to fill up the entire INSIDE of Earth. But what if the entire inside of the hollow Earth were covered with mirrors? Henry, that’s ridiculous… for now. Ok, so back outside of the Earth, we wouldn’t really notice much difference from a gravitational 30 ______ - falling things would still accelerate at 9.8 m/s2, a baseball would follow the same 31 ______, and the moon would follow the same orbit around the Earth. Hey, Henry. Let’s go to outer space, right now. Bring your gun - this’ll all make sense later. C’mon.
	shaft
	merry-go-round
	disaster
	counterclockwise
	effect
	speeds
	hemisphere
	friction
	apply
	core
	attraction
	accelerate
	float
	directions
	gravity
	reverse
	surface
	center
	magnetic
	vulnerable
	hollow
	hot
	aurora
	molten
	mass
	iron
	spherical
	space
	gravity
	trajectory
	perspective

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.            The bits of Earth around you are going at slower and slower speeds. 

2.            The balls always reached the bottom, if they were dropped down a mile-long shaft.

3.            The Coriolis effect doesn’t apply to the falling objects.

4.            The Earth’s mass is more concentrated close to its middle.

5.            If the middle of the Earth had no air resistance, no friction; the result of passing through its center would be gradual acceleration.

6.            Digging Kola Superdeep was stopped because it was too cold.

7.            The Earth wouldn’t have a magnetic field anymore if Earth was hollow, but weighed the same.

8.            If the Earth was hollow people wouldn’t really notice much difference from a gravitational perspective.

9.            People wouldd be totally invulnerable to radiation from the solar wind and storms, if Earth was hollow, but weighed the same.

10.       Hurricanes always spin counterclockwise in the southern hemisphere.

4 Answer the Questions.

1.       What would happen if Coriolis effect didn’t apply and the tunnel through Earth went from pole to pole?

2.       How long would the trip halfway to the middle of the Earth take without air resistance, or friction?

3.       What is the deepest borehole?

4.       What is the problem with digging a hole through the Earth?

5.       Under what circumstances would people be able to see the aurora everywhere?