Thought Experiments


A Guide to Different Kinds of Parallel Universes

These days it often seems that if a theory has loose ends, its dangling threads are surreptitiously tied together out of view within the hidden fabric of a parallel universe. While some researchers recoil from introducing unseen aspects to a theory, others find that the invisible knots create an irresistibly pretty package.

Depending on one’s taste, there are so many types of parallel universes to choose from—alternative cosmos galore. If extra dimensions are not your thing, maybe bifurcating timelines would work. If an endless array of gigantic bubble universes seems intimidating, then perhaps a nursery of baby universes is more endearing. While there is not yet a GPS device or app to navigate through the cartography of scientifically sanctioned parallel possibilities, perhaps this guide to all things alternative will help.


Detlev van Ravenswaay / Photo Researchers, Inc

Let’s start with the oldest, most basic idea and work our way toward newer, more complex models:

What if? Here is the simplest way to transport yourself to a parallel universe: Just imagine all the ways in which our universe might have turned out differently. Each of these might-have-been realities represents a parallel universe. The mathematician Gottfried Leibniz posited that we live in the “best of all possible worlds” (famously satirized by Voltaire in “Candide”) and that all these other, unrealized, possibilities for creation would have been less desirable. His perspective has persisted for three centuries as a way of explaining why the cosmos is the way it is. Contemporary physicists who make use of the so-called Anthropic Principle argue that if the universe’s conditions were slightly different, it couldn’t have supported intelligent life, and we wouldn’t be here today to speculate about it. For example, if the inflationary era, a fleeting period of ultra-rapid growth in the very early universe, had continued for a long enough time, the stable structures we see in the cosmos today, such as stars and galaxies, couldn’t have formed. The super-quick expansion would have ripped them apart.

Alternative realities made possible by time travel: Science fiction writers relish the intricate plots woven by introducing time travellers into a story. Einstein’s general theory of relativity does not distinguish between space and time and hence hypothetically permits travels to the past, though the mechanics of such a journey are still largely beyond us. In recent decades, backward time travel ideas have been explored in serious articles published in reputable physics journals. If journeying back in time is possible, what would happen if someone changed history? Would they launch a new timeline, and hence a new universe, in which the chain of events was different? The answer won’t be known until backward time travel is either developed or ruled out.

Sum over histories: Physicist Richard Feynman had a practical, no-nonsense approach to physics, supporting notions that are potentially testable. Yet his approach to quantum field theory introduced the startling concept of reality as a weighted sum of alternative histories. For example, according to Feynman’s formulation, if two electrons approach each other, deflect and scatter, their overall behavior from start to finish must take into account every possible intermediate path—weighted according to each path’s likelihood. It is like assessing how tired someone will be after taking a walk in the woods by assuming that they somehow split up and took every possible route from entrance to exit—assigning more weight to the shortest (and therefore likeliest) paths, but still taking all of them into account.

Many-worlds interpretation of quantum mechanics: While Feynman did not assert that the ghostly alternative histories he described represented actual parallel universes, a young graduate student, Hugh Everett III (who shared the same research advisor as Feynman, John Wheeler), made the case that they are. Everett proposed a fundamental reinterpretation of quantum mechanics in which each time that particles interact, reality bifurcates into a set of parallel streams, each representing a different possible outcome. Researchers observing the outcome of such quantum experiments would similarly split up into multiple selves—each thinking that he or she is the only one. For example, suppose a physicist named Eve wants to measure the position of an electron and there are three possible outcomes. Upon taking the measurement, she would instantly divide into three distinct selves, each recording a different result. Each version of Eve would be convinced that she was the real one—wholly unaware of her near-doppelgangers.

Copycat regions of the universe: We now turn from the exceedingly small to the incomprehensibly large. If the universe is infinite, as many cosmologists surmise, then if you travel far enough you will eventually reach regions nearly identical to ours. That’s because if you take a finite number of elements and mix them into an infinite number of combinations, eventually chance will reproduce one of the previous arrangements. It is like playing tic-tac-toe—play enough times and you are bound to repeat yourself. Hence somewhere, by pure chance, there could be a near-parallel Earth where a nearly-identical version of you is reading this article on a parchment scroll illuminated by a glowworm.

Bubble Universes and Baby Universes: In general relativity, an energy field of the right variety can trigger space to grow explosively. Researchers use this phenomenon to explain how the universe expanded so rapidly during the inflationary era. However, they’ve come to realize that if explosive expansion took place in one part of space, it probably happened elsewhere, too. Hence, myriad bubble universes could have emerged from the primordial cosmic sea of energy. We would never have access to other bubble universes, though, because they would have since moved away from us well beyond the limits of observation. Baby universes represent a related idea, in which universes would be seeded in the extreme conditions of black holes. The embryonic regions of space would then grow into successor universes in their own right.

Higher Dimensions: For this type of parallel universe, we move beyond the three dimensions of space itself and consider the possibility of a higher, unseen dimension. While such a scenario sounds a bit like “The Twilight Zone,” higher dimensions are a vital part of string theory and other attempts at unifying the natural forces. If a higher dimension exists beyond space and time, why can’t we travel through it? Theorists hypothesize that the particles of matter and light cling to our three-dimensional space, preventing us from entering or even observing the extra dimension.

While our bodies have remained in our own universe, our minds have completed an excursion through a weird assortment of parallel universe possibilities. Do any of these types of parallel universes exist? If so, how are they connected? Suggestions for testing these various hypotheses are too numerous to recount in this post. I refer the reader to several interesting proposals:

Testing Many-Worlds Quantum Theory By Measuring Pattern Convergence Rates

Testing for Large Extra Dimensions with Neutrino Oscillations

Is Our Universe Inside a Bubble? First Observational Test of the ‘Multiverse’

Go Deeper
Editor’s picks for further reading

FQXi: Philosophy of the Multiverse
In this essay, discover why many theorists are drawn to the idea that our universe is just one among many.

NOVA: Parallel Worlds, Parallel Lives
Discover web resources associated with NOVA’s “Parallel Worlds, Parallel Lives,” a film about the life and work of Hugh Everett III.

Scientific American: Parallel Universes
In this article, physicist Max Tegmark explores four “levels” of multiverses.

Tell us what you think on Twitter, Facebook, or email.


Paul Halpern

    Paul Halpern is Professor of Physics at the University of the Sciences in Philadelphia. A prolific author, he has written thirteen science books, including "Einstein's Dice and Schrödinger’s Cat: How Two Great Minds Battled Quantum Randomness to Create a Unified Theory of Physics" (Basic Books). His interests range from space, time and higher dimensions to cultural aspects of science. The recipient of a Guggenheim Fellowship, Fulbright Scholarship, and an Athenaeum Literary Award, he has appeared on the History Channel, the Discovery Channel, the PBS series "Future Quest," and "The Simpsons 20th Anniversary Special." Halpern's books include "Time Journeys," "Cosmic Wormholes," "The Cyclical Serpent," "Faraway Worlds," "The Great Beyond," "Brave New Universe," "What's Science Ever Done for Us?," "Collider," and most recently "Edge of the Universe: A Voyage to the Cosmic Horizon and Beyond" (Wiley 2012). More information about his writings can be found at

    • Ken Sharp

      I don’t think the “universes in higher dimensions” part makes any sense. They’re just other dimensions of the same Universe.

      Time travel is a PITA, theoretically speaking.

    • jayelliii

      As my reply at Twitter, these are all mambo jambo that theoretical physicists throw at us … poor ignorants.

      I, for half of my current 50 years of age, have played, in my head, everything I have heard and read in science.

      Now I am becoming a self taught physics pupil as I cannot justify sitting in a class room and wait a few years to receive a certificate.

      All these talks about multi-verses, parallel universes, bubble universes, are nothing but a justification for grants. I hope one day to speak to a large community of scientists and show my findings. Meanwhile they are just an ignorants viewpoint.

      Voyager (I or II) is just reaching the boundaries of the Solar System …. after 35 years since it was launched into space.

      The viewable Universe (by super high tech telescopes) is 16 billion light years which gives us that the Universe is 16 billion years old (?????). Hey, wait a second: this is just the visible Universe. How about beyond? It doesn’t count?

      Back to Voyager: it took 35 years of traveling in space to be just reaching the boundaries of the Solar System. We cannot, today, even reach Mars (the closest planet to Earth) with a man mission. We cannot even see details of the nearest Star (at 4.7 light years away or so). We cannot, with certainty, come up with any data from Begeujice (that no longer possible exo-planet).

      We barely know much in science. The minuscule wave we can measure is microwaves at, if my memory serves me well, is 10 at -13 m.

      There is so much we don’t know about even our surroundings and we try to confuse everyone around us with “what-if’s”.

      Let’s concentrate on … here I go: for over 15 years I am telling my confidents that the only way we can get out of this vicious circle is to throw away every science book at start new ones. Maybe even discount star physics of the past even like Albert Einstein.

      Einstein said (I believe that is what I read or heard): “you can visualize the past; but not travel into it”.

      No ones, that I know or head of, ever thought of if being just an analogy.

      You can VISUALIZE THE PAST through records (books, fossils, ancient documents, audio tapes, video tapes, etc).

      You can only VISUALIZE THE PAST as a whole for the recorded past; not for individual pasts. For example, YOU cannot travel INTO MY PAST. Only I, through my memories, can travel into my past.

      I go further: TIMESLICE does not exist. There is only the NOW. Every new now, like there is a new now during each character I type which encompasses EVERY NOW before this new one as a flat two-dimensional now or a flat single frame in a movie (a static picture) which is constantly being updated.

      You cannot see your immediate past; you can remember it. But, however, you can predict your immediate future like … I am going to write that word next by typing the needed characters …

      You can even predict an immediate collective future but as time (as a relative quantity) stretches into the future, you can no longer predict with 100% assurance that it will happen because many factors or variables can and will change meanwhile.

      Physics is complicated but we are relying on theories (and well proved ones) that are 100, 200, 300, … 700, thousands of years old and not really adding to them. Just trying to still accept them as you hear the Physics of the world say “as so and so said …”.

      My history professor (I did start a 4 year Economic Sciences but dropped out on the 5th semester) used to say, that history is a vicious circle: it goes forward, rewinds, modifies it, and go forward again.

      I just finished watching a documentary about cars (How We Invented the World: Cars) where, basically, we are, now, trying to make electric cars …. which were produced as the very first car or right there.

      Economies of the world dictate Physics. We only develop what can be sold. We only research what is paid for. No one can any longer be a researcher just for the fun of it as life has become very costly.

      • Paul Halpern

        Thanks for sharing your thoughts. In my opinion, there is always room for speculation in science, as long as the major focus is on testable hypotheses. When Dirac suggested antimatter, it must have sounded like science fiction. Yet when the positron was discovered, an abstract idea turned out to be real. Science must maintain a healthy mixture of the practical and the speculative.

        • jayelliii

          I do … accept the speculative side of physics and physicists. Antimatter, as a -mater- of fact, was produced in tiny quantity in a laboratory. TANGIBLE!!!; right here, right now, and “embraceable”. When it comes to multiverse, parallel universe, bubble universe, none of those can, even fictionally, be conceavable.

          Granted none of us, or at least myself, don’t have the necessary Degrees to either try to prove or disprove the speculations on this artcle and many like it.

          Why don,t the physicists (finally correct) stick to tangible physics?

          • Paul Halpern

            As I mentioned at the end of my post, physicists are trying to test some of these hypotheses.

        • jayelliii

          BTW: Nicholas Tesla also encountered barriers by the Scientific Societ by not having any degrees under his belt.

      • No Name

        I really don’t see your logic in the throwing away every science book and starting new ones. Reinventing the wheel isn’t going to change it. Isn’t science built in layers on the testing of new hypotheses? If you think something is wrong, posit a new one and test it. It would be a tremendous waste to redo hundreds of years of progress just for the sake of starting fresh.

        • Jay Ell III

          By “throw away current books and start new ones” I meant that what we have come to, so far, has not allowed us to develop further.

          We need to rethink, revisit those “laws” and improve on them and,I am 100% believer, most should be thrown away.

          Let’s take a few points here:

          a) With “bare hands” the Egyptians built structures that, today, with all the technology available, cannot be replicated; and

          b) Up to 1915 (Einstein), the physicists; astrophysicists; astronomers; and the likes, contributed to science with bare hands, paper, and pencils. Today, even with multi-billion Dollars Hedron Colider, we have not made any contribution to science besides infuse a gazzilion mambo-jambo with theories that cannot be fundamented.

          Bare in mind that many of the physics scenarios is “let’s assume ….”.

    • DrSheldonCooper

      Oy. It appears your self-education efforts are falling short when it comes to written composition. /Perhaps you should re-enroll in some elementary writing courses and leave the physics to the professionals?

      Ps. while its true many scientists of the past were ‘self-taught’, it was chiefly because there wasn’t as much real ‘science’ at the time, so it was possible for someone to be an expert on ‘all there was to know’ (ie. think Liebnitz). Comparing the depth of knowledge in physics or chemistry or any branch of science in the 18th century to today is laughable at best.

      You aren’t being dismissed because you are self-taught, mind you, but because you are woefully ignorant and, in the end, incorrect in the extreme.

      This isnt a political forum where opinion matters. Everyone’s viewpoints aren’t as valid as everyone else’s. Its physics. If you know your stuff, please made your informed argument. if not, please STFU.

      • Jay Ell III

        That’s where we stand: STFU. You, the so called “Dr”, want us just to accept whatever you write or throw at us at face value. You (“theoretical physicists”), apparently, GODs of science, can’t be confronted. Laughable!

        Hey, wait a second: you are hiding behind a fictitious tv character. What a waste of my time ……

    • Julia

      I can’t begin to visualise the immensity of this universe, the idea of many many more (to infinity) is mind boggling – but it didn’t stop me from enjoying this post. Especially the image of my near dopple-ganger reading a similar article on a parchment scroll by glow-worm.

      BTW, Dr Sheldon Cooper: I’m sure you won’t mind me pointing out: “It’s physics” as you’re shortening the phrase from “It is physics”. Your basic elementary writing course teacher would tell you to throw an apostrophe in there, just for giggles and stuff.

      • Andrew

        Good call, Julia!

      • Paul Halpern

        Thanks Julia! Glad you enjoyed the post!

    • Yatin Dhareshwar

      Excellent post – the simplicity is very refreshing and makes it comprehensible by ordinary humans.

      • Paul Halpern

        Thank you very much! I like your mp3 player analogy.

    • Yatin Dhareshwar

      Time travel is not possible – or so I believe.

      I can best explain this through an every day example. Imagine you have an mp3 player with shuffle mode on. When you choose “Forward”, you have no idea which song will play next. Likewise, if you were to choose “Previous”, then too, you will have no idea which song will play.

      Switch off shuffle mode, then you get total predictability on which song
      will play and in which sequence. No matter which way you navigate, you will always have the songs playing in the exact same sequence.

      So if we expect to go back in time and find things exactly as we saw
      them while there, then we are in shuffle-off mode and hence we should have a completely predictable future, i.e. some one some where has already written a complete script and we just enact it without an iota of control.

      But, if anything we know for certain it is that uncertainty is the hallmark of our Universe. We have no idea how life will turn out, much less what the next moment holds for us. There is no shuffle-off mode. So even if we were able to travel back in time, whatever that means, there is no way we can expect things to be what they were when we experienced them.

      The text above is an extract from the full article I have posted on my blog. Interested reader may find it at:

      Paul Halpern: BTW, i owe you a thank you for inspiring the post…

      • DoktorJones

        To borrow your mp3 player metaphor… what’s to say the universe *isn’t* in shuffle-off mode? Perhaps it’s just that some stranger we’ve never met loaded in the songs, and we don’t know how to look at the screen yet to see what’s coming. The songs yet to come are certainly unknown to us, but that doesn’t necessarily mean they aren’t a definite set of songs in a definite order.

    • Daniel Uffner

      This just blew my mind several times over

      • Paul Halpern

        Science is amazing, isn’t it!

      • Frank Gomez

        same brother, im still thinking

    • Essam Munir

      Prof. can i translate your articles to arabic ? i love your writings , awesome thing ^^

      • Paul Halpern

        Thanks for your comment! Regarding any content on this site, you would need to contact NOVA for permission.

        • Essam Munir

          ok thank you prof.

    • Diana DiGioia

      Thanks for breaking it down for us. An endlessly fascinating subject. The Nova piece on Everett and his son is great – and very sad. He died an isolated, lonely, uncommunicative alcoholic mess at an early age, and nobody gave his theories credence while he was alive. (From what I can recall seeing it a few years ago). That’s what I remember most ! Like being an artist; a tough lonely profession that requires lots of self-sustainment to hang in.

      And, of course, Brian Greene’s Fabric Of The Cosmos is an excellent discourse on the subject.

      • Paul Halpern

        Glad you enjoyed it. I agree that the NOVA segment Parallel Worlds/Parallel Lives is excellent!

    • Paul Halpern

      Just to let readers know that I will be hosting a live, interactive discussion on Shindig about my new book Edge of the Universe on Thursday, Dec. 6 at 3:00. I’d be glad to answer any questions about parallel universes.

      • Paul Halpern

        To clarify, the discussion will start at 3:00 PM EST.

    • Dr Moebius

      You missed the idea that the Mobius Toroid which has always existed, and always will. One thing infinite (and in the time domain, eternity) implies is that there is no beginning, and no end – the Ouroboros. This is the most difficult concept for most people to comprehend – no starting point. And the Big Bang? And as you describe above, this may be a localized phenomenon, with many more to come. And then there is the Breath of Brahman, which the Hindus conceived of 10,000 years ago – an expanding and contracting universe, moving forward and backward in time.

      Both of these models resonate for me, and in the end, it may be a culmination, or something else entirely – there’s no way for us to ever really ‘gnow’ (as in the Gnostic knowing). Perhaps we are just the manifestation of God’s dreams, but whatever it is, one thing’s for sure: We are all going to die. It’s what happens next that some believe never will. Personally, if there is no afterlife, and the mind dissolves back into the cosmos, for our brief flash of life, well, thanks for the ride. But for too many of us, it’s a lousy one (ride..). So it all comes back to sharing as much love as you can, and making the most of the ride as you can. Mentally masturbating about ‘what’s out there’ is good fun, but until we start building the Prometheus and actually go exploring (which means we have to find another way forward than the greedy oil barons who control the government), it’s all conjecture. Your move, Mr. Spock?

    • Bill Bodge

      Is there anything in this space-time universe smaller than a system? If not, than point particles are only half or part a of system. The simplest system should be a binary system. This would lead me to believe that motion of particles is not continuous, but discontinuous or digital.

      Particles click on and off as they travel.
      Where do they go when they click off or disappear in space-time? I would say the particles are entering a parallel dimension or universe that has no time and infinite possibility. Quantum probability gates governed by the Uncertainty Principle would exist at the boundry between the two. When the particle enters space-time again it’s position and momentum are decided by a probabilistic set.

      Take Bell’s Theorem as an example. When you send two quantum entangled particles off in opposite directions and the and change a characteristic called spin, the other entangled particle instantly changes it’s spin to match. That’s information traveling faster than light and breaks the laws of General Relativity. Now let’s take a look if motion of particles is discontinous and the particles are clicking on and off. One entangled particle is sent off and the spin is changed. The other particle clicks off and is instantly informed of the change in spin of it’s paired particle (Remember in the parallel universe to ours time does not exist).

      Why is the expansion of the universe accelerating? Take a look at the internet. Information builds on itself exponentially. In this binary system of two parallel universes, everything could be looked at as information. The universe is computing and Uncertainty Principle tempers and guides the outcomes.

    • Stephen A. Halkovic III

      Good day Paul Halpern,

      I’m Stephen A. Halkovic III and I had left the field of astrophysics during the eighties for numerous reasons because of the Big Bang theorists’ lack of ethical, moral, and scientific integrity. Actually one of the oldest theories is contained in the first book of Moses. “In the beginning God created the heaven and the earth. And the earth was without form and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.” Genesis 1;1-2 This is for sure older than the ideas that you have put forward. It falls in the last category of a spatial dimension (or two) beyond the three dimensional existence we see. The idea of multiple universes an ancient one and has been discussed in innumerable ‘metaphysical’ books for many centuries before Jesus Christ. These theories consist of various levels of heaven and hell.

      The other categories of theories concerning multiple universes fall apart under critical thinking. For instance the idea of bubble universes. It’s really just sloppy thinking not realizing that the share universe of the ‘elsewhere in space’ is the point of reference and that this bubble in space is related directly to the elsewhere bubble as the original relationships are related and really no different than the difference of this galaxy and any other one that you might point towards in the sky.

      The other examples are merely subjective interpretations of this three dimensional space. My sister and I certainly have differences of opinions of what happened when we were kids growing up and what is going on in the world today but we are from the same universe. If you actually apply vector analysis to the hypothesized concepts of derived universes diverging from this one then it is seen that there should be an influence on this universe and there is no such evidence.

      Getting back to the metaphysical disclosures of heavens and hells and then the Judaic-Christian construction of a higher dimension “Kingdom of God” it is almost impossible to disprove and the only proof is to experience it. Go ahead, pray, meditate, go forth and do good deeds. You may travel through heaven and hell. Why not? You may even see God.

      May God bless you that you may know the Perfect Peace Profound,


    • Batman

      I’m Batman

    • Karla Feldstein

      When thinking of parallel universes, my first thought always goes to the traditional science fiction theory or the “what if” theory. However, I found some of these rather interesting and quite plausible. I found the copycat theory to be the most intriguing as far as theories go. With the amount of choices that have gone on over the years and an infinite number of realities, there is bound to be a reality that is almost identical to ours, which, to me, seems highly likely. Higher dimensions would also make sense if we could in fact prove there are higher dimensions. All of the theories seem possible to me, but the bigger problem is how to test them.

    • Kristie Sparks

      Scientists have been searching for ways to test the hypothesis of multiple universes. One physicist, Brian Greene, uses string theory to explain the possibility of multiple universes in his book “The Hidden Reality.” In the book he says that the universe can be thought of as small vibrating strings that connect unseen dimensions, and that each dimension can be thought of as two-dimensional membranes moving on the surface of the strings. If his theory is correct then slamming particles together using a Large Hadron Collider debris would be ejected to another membrane (another dimension). According to the to law of conservation of energy, energy cannot be created or destroyed, which means that the energy of the particles before they collide and the energy after the collision should be the same. If the energy levels were slightly lower after the collision then the string theory hypothesis of multiple dimensions would be supported. To learn more about Brian Greene’s hypothesis and tests visit:

    • alex forselius

      My mother is dead in breast cancer but Im sure she is well in an another dimension where her suffering is away and be well. Our lives is a expedition at Earth only to grow spiritual knowledge of the physics realm to the higher realms after death.

    • Shan

      After studying shamanism..I began to journey spontaneously. These realities were only what I can describe as like ours but different – as if the world had split at a certain point and had developed differently. Animals were different species, plant-life I didn’t recognise and alphabets/languages that were sometimes different from ours and sometimes the same. This has reoccurred many times – always beginning with a sense that I’m speeding incredible quickly through darkness. I’ve seen churches, schools and religions, read signposts, watched strange species of animals and witnessed modes of transport like ours – only different. I’ve spoken to people there and tried to gather information. I’m always very conscious and aware when there – not like a dream at all.

      I love quantum physics and neuroscience – this is such an amazing subject!!

      • Arik

        were mind altering substances involved in your journey?

    • Chris Landry

      the key to parrel universes is time and a trigger for the parrel universe and multiverse to open and chage will mean changing space and time itself which can also cause negative or positive affect on branchs of our or anyone else time/universe

    • h

      Can parallel universes be created/destroyed?

    • h



      ANSWER H!




      preetttttyyyy pleeeeeeeeaaaaaase





    • Doctor Who

      Doctor Who explores this idea in every episode. Again it maybe valid math wise? But can we ever prove it? That’s the question.

    • Concerned

      I was wondering if someone could be stuck in a parallel universe?

    • Concerned

      This subject is pretty confusing to me. Does a parallel universe have a door like a wormhole? can it be opened and closed? It’s amazing yet very scarey Please help if u can..

    • Teófilo de Jesús

      Fascinating as the multiverse hypothesis might be, testing it will be a bear. Direct proofs will be mighty difficult, for it will require us to leave our universe and go into the other and then return and file a report. Not addressed in this report are those hypothetical universes having different physical properties than our own. Can we imagine a universe where π is not equal to 3.14159265359…, where maybe it is 2.168593249? We won’t we able to even probe it using energy or particle beams from our universe, nurtured and grown with “our π” built within them. In other words, universes with different physical constants will be fire-alled from ours.

      Indirect proofs will also be difficult to ascertain, for these will depend on observable phenomena taking place in our own universe, not lacking simpler explanations of processes taking place in our own universe, not from outside influences.

      To end, the multiverse theory is analogous to “i”, the √-1. Sure, we can use such number in equations, but it is imaginary, probably as imaginary as the multiverse.

    • catmandoo

      If it can’t be objectively tested for false hypothesis, its is meta physics. Why not a place for lost souls as well?

    • Art Riechert

      What about the holographic universe theory? Many near death experiencers come back after their experience and say things that sound or are congruent with the holographic universe theory? They say they were in a universe where time and space didn’t exist, where there was an overwhelming feeling of oneness and connectedness, and that they literally felt like they were everywhere in the Universe at once.

    • orkoskey

      My question about the bifurcation theory is where does the extra mass/energy come from to power all of these bifurcations? How can my decision to both write this and not write this equal a being that is the same mass as the one who read the article and had not yet decided to write a comment?

    • Valerie King

      If life is possible, all is possible.

    • Htrag

      Buncha nonscientific BS

    • Ivy Lane

      And what about the parallel universes that already exist? In the World Wide Web and in the world of MMO’s many universes already exist and we as individuals and sometimes groups travel time and space to enter these other worlds, most often with an avatar of some sort that represents us. The avatar does not exist without our mind and spirit making it have life, or so most believe at the present time There are many 2d and 3d worlds within this internet. Some call them communities but when you consider that each has it’s own semiotics and culture they become more like worlds unto themselves.

    • scarlett

      they are not as cool as people think when they are trapped trust me.

    • Erdman West

      SciReligion!!! They are the same [there is no Deity at all] and we confuse ourselves by placing them at odds. The beautiful mystery of INFINITY is physical [measurable in discreet segments] and spiritual [cannot me measured at all in its entirety.] Paradox is the source of existence.

    • Ramiro

      with all due respect: EINSTEIN never said a time travel to past was possible.
      indeed in his studies he observed the thermodinamics laws, showing that it was impossible. saudações do brasil

    • Andrew Bennett

      In the end time Satan is going to trick humans into going to war with each other !Using dreams !

    • Andrew Bennett

      Satan The GOD of this earth ! will fight a war against The Creator God !