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  • As we gaze up into the vastness of outer space, we are reminded of just how small we are in

  • the grand scheme of the universe.

  • We've only explored just a small fraction of the universe, and even physicists know

  • that there's more that we don't understand about outer space than what we've figured

  • out.

  • A new paper that was published in the Journal of High-Energy Physics in March twenty-twenty,

  • calledNothing Really Matters” - great title - is why scientists are freaking out

  • overbubbles of nothingthat eat spacetime.

  • Marjorie Schillo is one of the authors of this amazing new study.

  • She is a researcher at Sweden's Uppsala University in their Department of Physics

  • and Astronomy where she studies theoretical physics.

  • Physics is the study of matter, energy and the interactions between them, but it's

  • a much more exciting science than that description makes it sound.

  • Physicists try to answer big questions likeHow did the universe begin?” orWhat

  • are the basic building blocks of the universe”, or evenHow will the universe end?”

  • Theoretical physics and math may not sound very cool, but some of the biggest rock stars

  • of science have come out of this field.

  • Isaac Newton invented calculus and discovered gravitation; Albert Einstein came up with

  • the Theory of Relativity, among many other important discoveries, and Stephen Hawking

  • was one of the most recognizable scientists of all time.

  • Many physicists use experiments to test their theories, but theoretical physics is different

  • in that they use math to attempt to answer these big questions in areas where scientists

  • can't yet perform experiments.

  • Marjorie Schillo and her colleagues have spent years studying the phenomenon ofspacetime

  • decay”, trying to answer the big questions about how the universe might end.

  • This newest paper explores one possible answer - a bubble of nothing that eats spacetime.

  • As she explains it: “A bubble of nothing describes a possible channel for universe

  • destruction; in that the bubble of nothing expands and can 'eat' all of spacetime,

  • converting it into 'nothing'.”

  • Umm...OK.

  • Translated fromscienceto plain English, what she and her team of researchers at the

  • University of Uppsala in Sweden are saying is that a bubble of nothing that eats spacetime

  • is just one of the theoretically possible ways that our universe could be destroyed.

  • To be honest, that doesn't sound much better...

  • There's plenty of things in the universe worth freaking out about - black holes, supernovas,

  • even rogue asteroids.

  • But could a bubble of nothingness really eat all of space and time, devouring the universe

  • and ending life as we know it?

  • Is the universe really eating itself from the inside out?

  • The idea of a “bubble of nothingnessin space isn't a new one.

  • In nineteen-eighty-two, theoretical physicist Edward Witten first posited that the universe

  • could be devouring itself when he wrote about a hole thatspontaneously forms in space

  • and rapidly expands to infinity, pushing to infinity anything it may meet.”

  • To understand these bubbles of nothing, we need to wrap our heads around vacuums.

  • No, not that kind of vacuumIn physics, a vacuum is an empty space devoid of all matter.

  • In Quantum Field Theory, the theory that connects quantum physics with spacetime, a vacuum is

  • the lowest possible energy state.

  • More 'excited' or higher-energy quantum states tend to decay very quickly into lower

  • energy states as they give off energy.

  • Since a vacuum doesn't have a lower energy state to decay to, vacuums are relatively

  • stable.

  • It's commonly accepted that outer space is a vacuum, so the universe should be pretty

  • stable, right?

  • Well, it's not quite that simple.

  • Outer space certainly isn't devoid of matter - it's full of stars, planets, particles

  • and, umm ... people!

  • It's the extremely low density of the matter that's important - between the planets in

  • our solar system there is an average of five atoms per cubic centimeter.

  • In interstellar space - between the stars and molecular clouds - there is only one atom

  • per cubic centimeter, and in intergalactic space - between galaxies - there's one-hundred

  • times less matter per cubic centimeter than in interstellar space.

  • This extremely low density of matter, combined with the incredibly low pressure in space,

  • creates an almost perfect vacuum ... but not quite.

  • Quantum theory actually suggests that a perfect vacuum is impossible, since energy fluctuations,

  • known as 'virtual particles' happen even in empty space.

  • In the nineteen-seventies, some Russian physicists were the first to suggest that there could

  • be a middle ground between a stable vacuum and an unstable non-vacuum.

  • These 'false vacuums' stay in a metastable, or semi-stable, state for an incredibly long

  • time before decaying, giving them the illusion of being a stable vacuum when in fact they

  • are not.

  • The quantum force field that pervades the universe and gives all matter its mass is

  • called the Higgs Field, and it was first detected by the Large Hadron Collider at CERN.

  • It would take a whole other video to even begin to explain the Higgs field, but as far

  • as understanding bubbles of nothing is concerned, here's why it matters: Recent research into

  • the Higgs Field suggests that we may actually be living in a false vacuum after all.

  • If that's true, our university is not the safe and stable place we once thought - it's

  • actually unstable, and this is where the bubbles of nothing have their opportunity.

  • A bubble of nothing is one of the ways that a false vacuum could theoretically decay to

  • a more stable energy state.

  • If a bubble of nothing were to form within the apparently false vacuum that is our universe,

  • it would start out as a small hole in the fabric of our reality.

  • The tiny space of emptiness would then quickly begin to expand outward, picking up speed

  • as it expands until it's growing at the speed of light.

  • As it grows, the bubble of nothing would eat all of the matter it encounters, gobbling

  • up everything in its path and converting all matter into nothingness until the universe

  • is erased completely.

  • So what are these 'bubbles of nothing' exactly?

  • As you can imagine, describing 'nothing' is not exactly easy.

  • It's tempting to compare a bubble of nothing to another phenomenon of 'nothingness'

  • that we know exists in our universe - black holes - but a bubble of nothing couldn't

  • be more different from a black hole.

  • A black hole is an area of such intense gravity that it sucks anything, including light, into

  • its center.

  • A bubble of nothing, on the other hand, expands outward and devours everything in its path,

  • turning anything it encounters into more nothing.

  • If you threw something into a black hole, it would disappear forever, and we would have

  • no idea what happened to it once it passed through the black hole, since we've never

  • seen the inside of one.

  • But if you could throw an object into a bubble of nothing, it would bounce right back out

  • - for all intents and purposes, it would have hit the edge of the universe.

  • A bubble of nothing is not the only kind of bubble that might exist in space.

  • A spacetime bubble is any area of space that has different properties inside the bubble

  • than the space outside the bubble.

  • For example, some bubbles could have different strengths of dark energy inside and out.

  • Bubbles of nothing have no interior at all - they are totally empty inside.

  • As the bubble grows, it 'eats' all the regular matter it encounters and converts

  • it to 'nothing'.

  • So how could a bubble of nothing form in the first place?

  • To understand how bubbles of nothing might form, we have to dive into string theory a

  • bit.

  • Don't worry, it won't be that bad

  • String theory attempts to tie together the two most basic laws of physics: the theory

  • of general relativity, or gravity - with quantum physics, the study of the very smallest particles

  • that make up the universe.

  • String theory also attempts to unify the four forces in the universe - electromagnetic force,

  • strong nuclear force, weak nuclear force and gravity - into one model.

  • String theory may indeed turn out to be thetheory of everything”, but it's important

  • to know that String Theory relies on a lot of assumptions about particles and forces

  • that can't yet be proven.

  • Don't worry, scientists aren't just blindly guessing - these assumptions are all based

  • on solid scientific evidence and complex mathematical equations - needless to say, you'd need

  • a PhD in physics to truly understand the intricacies of String Theory.

  • The biggest problem with string theory is that it requires more than the four observable

  • dimensions to work.

  • We can easily observe the three dimensions of space and the extra dimension of time,

  • but for string theory to work there must be at least a few other dimensions that are invisible

  • to us.

  • As cool as the idea of hidden dimensions sounds, it's not the parallel universe you might

  • be picturing - you know, the one where you're you, but with money and power and good looks

  • and….*coughs* anyway

  • Physicists theorize that these extra dimensions could actually be incredibly tiny and curled

  • up below the observable scale, making them too small for us to see them.

  • Scientists can still account for these extra dimensions mathematically, but we have yet

  • to actually prove they exist.

  • For some reason, bubbles of nothing can't form in four dimensional spacetime - don't

  • ask us to explain the math behind why, it would take years!

  • But scientists believe that they can form in stringy multidimensional spacetime like

  • the spacetime described by string theory.

  • In fact, one model of stringy space time, the Kaluza-Klein model, states that across

  • infinite space the probability of a bubble of nothing destroying everything is one-hundred

  • percent.

  • So, should we be concerned about bubbles of nothing appearing in space and devouring the

  • entire universe?

  • Apparently not.

  • Most scientists believe that since the universe hasn't eaten itself in the thirteen billion

  • years since the Big Bang, it's an unlikely scenario.

  • One Czech string theorist named Lubos Motl went so far as to say that we should use the

  • idea of bubbles of nothing to rule out certain descriptions of our universe, since if it

  • was going to happen it would have happened by now.

  • That doesn't totally negate the possibility, but it's also reassuring to know that scientists

  • consider this to be something to rectify, not something to agonize over.

  • We're not sure exactly how scientists would suggest that we fix a bubble of nothing, but

  • it's nice to know that they at least think we can...right?

  • Perhaps most importantly, physicists think that studying these bubbles of nothingness

  • can give us important clues about the very beginnings of our universe.

  • The study authors think that the mathematical models used to describe a bubble of nothing

  • could also be used to model the birth and expansion of the universe.

  • Marjorie Schillo, the researcher we met at the beginning of this video, has saidIt

  • would be interesting to work out under what conditions an observer could 'ride' on

  • the bubble of nothing and see a universe that is similar to the one we live in.

  • Because the bubble expands, such an observer would see an expanding universe.”

  • Riding on a bubble of nothing may be a bit far-fetched, but this research is important

  • for helping us understand our universe, according to the researchers who authored theNothing

  • Really Matterspaper.

  • They argue that we can learn important lessons from these bubbles of nothing that might help

  • us better connect the current best theories about fundamental building blocks of the universe

  • with theories about space and time, and hopefully, finally, help us finalize String Theory - the

  • theory of everything.

  • So, what are your thoughts on the bubble of nothing that eats spacetime?

  • Do you think we should be worried about the universe eating itself from the inside out?

  • Be sure and let us know in the comments!

  • If you thought this video was interesting, be sure and check out our other videos, like

  • Astronomers Discover Mysterious Radio Signal From Another Galaxy”, or this other one

  • instead.

  • See you next time!

As we gaze up into the vastness of outer space, we are reminded of just how small we are in

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Scientists Are Freaking Out Over 'Bubbles Of Nothing' That Eat Spacetime

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    Summer posted on 2020/08/10
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