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The (Multi) Universe(s)

Tuesday, August 12, 2008 - 01:03 AM

Multi tees Multi tees (Cayusa/flickr)

Robert and Brian Greene discuss what's beyond the horizon of our universe, what you might wear in infinite universes with finite pairs of designer shoes, and why the Universe and swiss cheese have more in common than you think.

 Have you wondered if there is another you out there? Somewhere? Sitting in the same chair, reading the same blog post, wearing the same clothes and thinking the same thoughts? Well, Brian Greene says there must be one. Or two. Or lots and lots and lots and lots and... Why? You ask, well listen to Greene's argument in this week's podcast.

We are still furiously working on Season 5, so while you wait we bring you today's podcast of a conversation between Robert Krulwich and Brian Greene, physics and mathematics professor and director of the Institute of Strings, Cosmology, and Astroparticle Physics at Columbia University. The interview is part of a series called 'Giants of Science' hosted by venerable New York institution, the 92nd St Y.


PLEASE NOTE: Our apologies, there's some noise at the end of the recording, please don't be alarmed! It's us, not you.

You can see a video of Brian talking about string theory here.


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Comments [87]

john listener from Dallas

Could Robert have been any more childish in this interview? I understand his need to keep the show entertaining, but he was actually disrupting what would have otherwise been a very interesting interview with his immature comments. It would have been better if this was a presentation/talk by the expert rather than an interview.

Jan. 30 2015 10:39 AM
Hugh Harman

I don't really find the idea of parallel universes very plausible or interesting.

Jan. 07 2014 10:56 PM
ryan from New Orleans

I wish Robert wasn't so cheeky in this interview.

Oct. 02 2013 05:37 PM
william from England

how i understand it is that he describes an infinite universe but we assume that there is a finite set of rules governing that infinite universe so is that right-ish?

Jun. 18 2013 04:30 AM
Paruhang Chamling from Nepal

Robert is pretty retarded and I wouldn't mind if he was not so f**king annoying.

Jan. 24 2013 10:54 PM
Gina from New York

Instead of making me feel "haunted" by a Doppler ganger somewhere, this has actually inspired me to try to be something greater. I want to do something so great that the other one of me will feel awesome as well. Also, if I am now aware of my other self at this moment then that means my other self is now aware of me.... WOW! Instead of feeling like I am loosing a sense of self I actually have embraced it. In a way I now feel less alone knowing this other me is going through the same things as me. I now feel as though I have reached a higher level of understanding and thinking.

Dec. 06 2012 04:19 PM
James W from San Diego

If the universe is infinite, then in fact a "very large number" such as a 10 with 29 zeros after it, is not simply "very small". In fact, any number is negated by infinity. An infinite universe is ultimately stable, exhibiting no variation or change whatsoever, and is completely uniform throughout.

Jul. 31 2012 10:15 PM
Ava from New York

If the universe is like a swiss cheese, where one hole or bubble is one universe, and the other holes are other universes... Then what exactly is the meaty part of the cheese? How is it different to the bubble so that I know it is not a bubble?

Jul. 03 2012 06:55 PM
Sloppy Boggins from Toronto

A term that keeps popping up that I think is interesting is "playi out". Our perception of experience or watching things "play out" is what confuses all this. We find it difficult to see past how we experience things so we expect that infinite possibilities refers to all the things we could have done being performed by other versions of us.
If you consider that our bodies are filled with tiny living creatures who are born, eat, work, procreate, and die. Who are much less aware of us then we are of them. Then project us into their "shoes" and try to extrapolate what larger thing we are part of. Then we can start to contemplate what this infinite world might be like. Where life forms may not experience linear time as our brains do and therefore "play out" doesn't exist. It's not that you don't choose but already have like we're on "playback".
The math says infinity but we are attaching things to that idea that don't seem to belong. Apparently we see a universe of multi-coloured T-shirts when, right here on our own planet, there are things more alien.

Apr. 02 2012 09:28 PM

Just because the universe is infinite dos not mean that every possible combination of particles exists. The aleph numbers represent the cardinality of (infinite) sets. This concept encompasses the idea that “some infinities are bigger than others”. I'm not a mathematician but the gut feeling I get is that given set-1 that has a cardinality of aleph-1, and set-2 with a cardinality of aleph-2 then set-2 has an infinite number of members for each member of set 1.

If the “number of combinations of particles” has a aleph number even one higher than the “number of locations in the universe”, you will never find a duplicate.

Nov. 10 2011 02:13 PM

Wow a lot of comments about beliefs and knowing. I thought we were talking about science here? I thought science wasn't about faith or certainty but about observation? I think many people missed an important part of what he said. This idea about the multiverse comes from observation and is considered by him to be possible. He is not saying that this is the ultimate reality but simply that we have not ruled it out.
Please stop mushing religious concepts into conversations about science in this way. Please stop talking about scientific ideas in terms of Faith.
Scientist know nothing , religious people know everything and we all know what ancient Greek philosophy teaches us about what the wise man knows;)

Oct. 23 2011 05:14 AM
machtrtl from Richmond, VA

@Dan from Boston and Intrigued and Confused:

But if every configuration of particles exists in our universe (and in fact each configuration exists an infinite number of times), AND it is possible to communicate with or travel between universes (not between bubbles, but between all the galaxies in our own bubble), then it must be possible that:
a. There exists a galaxy in which there is a planet of people who have figured out how to communicate with other galaxies (in fact, there are an infinite number of these).
b. On one of these planets, someone has made the arbitrary decision to direct a communication to our galaxy, and in fact, our planet (and there are an infinite number of these someones, too, right?)
c. One of these individuals made this decision such that the communication would have arrived at our planet the moment that Brian Greene finished his talk (or in the middle of last year's superbowl, or during the series finale of Dallas). In fact, an infinite number of denizens would have made the choice to direct their communications to our planet, right?

All this is obviously ludicrous simply because the communication never showed up, which makes me think that either there are not actually an infinite number of other galaxies in our bubble, or that it's impossible fundamentally to communicate between the galaxies (which makes them basically bubbles within bubbles, right?)

As Brian said in the podcast, "infinite" is a really hard concept to get one's head around, but if we accept it, there have to be some kind of barriers to keep the infinite galaxies from getting up in each others' business all the time.

Sep. 13 2011 09:26 AM
Dan from Boston

@ Intrigued and confused: there very well could be a universe where the people in that universe have developed the technology to traverse thru other universes, but given an infinite amount of multiverses, there's also the very likely chance that they might never reach OUR universe. if in fact our universe even exists, and isn't just the elaborate daydream of a giant extra-dimensional space beetle.

Jun. 30 2011 02:41 PM

ok so after listening to this i was left in awe. the argument made here was rather convincing as far as possibility. but after a while awe was replaced by speculation and i came to the conclusion that this entire argument was basses off of some impractical assumptions. first off, this man apparently did not take into consideration that not only the universe is infinite.. but that time is infinite. i think this could lead us tho believe that even if these universes did exist who says they'd exists in our speck of time? and the second theory i came up with was that then there must have been a variety of big bangs. and this is assuming that matter is infinite. and i do not believe this is true. just a thought.

Dec. 21 2010 12:17 AM
Zac from Jerusalem

Easily my favorite show yet. PLEASE DO A SHOW ABOUT DARK MATTER!!

Oct. 03 2010 06:46 AM
Jonathan Elliot

I had to laugh with this :) "Brian, do you realize how creationist your idea is?"

Oh noes! A new insult! (I'm not a creationist)

Jun. 21 2010 03:44 AM


Apr. 28 2010 02:00 AM
Intrigued and confused

I'm very intrigued by this theory, but if this theory were truth and every possibility in the universe MUST play out. Would it not be likely that there is some universe out there in which the beings who were so intelligent as to be able to discover a way to travel from universe to universe and teach the laws of the universe and universal travel to the beings of each and every other universe?

Feb. 04 2010 01:09 AM

this idea is nonsense. the universe is not infinite in the way he has presented it, precluding the existence of identical copies as he conceptualizes them. if the universe is infinite in the sense that it is a finite ball that expands and collapses forever, and has always forever prior been expanding and collapsing, then we have all existed in this configuration an infinte number of times in previous iterations of the universe, and will exist again as these exact configurations after some other big crunch and re-bang.

Jan. 23 2010 03:42 PM
Dan Warren

I know I'm way late to this, but I just listened to this podcast a couple of weeks ago and loved it. I had a weird thought, though, and I thought I'd post it here on the off chance that someone (best of all Brian Greene) would read it. I'm a scientist myself, which is probably why my brain went in this direction. I'm a biologist, though, so pardon me if I say something stupid about physics. This is all just silly handwaving anyway.

We know that a lot of the things we consider to be concrete, reliable physical laws are in fact statements about the average behavior of large collections of small objects that are each behaving somewhat erratically. To use an example that I've read somewhere (but can't remember where), it's entirely possible for all of the oxygen molecules in a room to collect in one corner rather than being more or less evenly distributed about the room, it's just so phenomenally unlikely that we expect never to observe it. Similarly, the relative solidity of two objects is really just a matter of probability - there is some infinitesimal but nonzero probability that the laptop computer I'm typing on will suddenly sink through the table it's perched on. Anyway, the general point is just that things we treat as certainties are really only things that are highly, highly probable.

Well, given a truly infinite universe, these highly improbable things must be happening somewhere, right? And it's not just that they're happening on occasion in isolated bits of space; given a truly infinite universe, there must be areas of space where, by complete chance, these things must be happening all the time. Further, there would even be areas of space where things that completely violate our expectations of reality are not only happening all the time, they are happening all the time in a manner that is, once again by sheer chance, apparently predictable. Something like, for instance, all of the oxygen in the room retreats to the northeast corner suddenly whenever someone says the words "Thomas Jefferson", but air behaves normally otherwise. Or coffee tables are only reliably solid on Wednesdays. I know it sounds asinine, but the problem with a truly infinite universe is that this sort of thing is actually going to happen.

So here's the brain-bender: if you accept the idea that there are regions of the universe where sheer chance will produce reliable behavior that is counter to the expectation under the true physical laws governing the universe, what happens to science? It means that there are regions of space in which the process of science will be reliably misleading - you're going to have to come up with laws that attempt to incorporate the fact that oxygen acts weird when you say Thomas Jefferson, or that Wednesday is unreliable table day, because those are observable facts that everybody knows. The upshot of this is that in those areas of the universe, the scientific process is incapable of revealing the true nature of the universe. Even more confusing - if such areas of the universe exist, how do you know that you're not in one? The odds are against it, but in a truly infinite universe it's guaranteed that someone's going to draw the short straw.

You would even expect that there would be regions of the universe in which the physical laws appear to change suddenly just due to the temporal and spatial clustering of highly improbable occurrences. What a disturbing thought. It honestly makes me hope that the universe is not truly infinite in that sense.

Dec. 18 2009 01:11 AM

I think Dr. Greene has been reading Jorge Luis Borges's story "La biblioteca de Babel" (The Library of Babel)from 1941:
If he hasn't then he should. Borges pretty much goes through Dr. Greene's points in his narrative, as is evident from the very first line of the story: "The universe (which others call the Library) is composed of an indefinite and perhaps infinite number of hexagonal galleries, with vast air shafts between, surrounded by very low railings."

Dec. 05 2009 12:27 PM
B L Bennett

If there is infinite space containing one universe or many, that does not mean that space is truly infinite. But, if space IS infinite, then the possibilities ARE endless. So, the discussiion was interesting, imaginative, insiteful from Greene's perspective, entertaining, and eye opening for many in the audience. But, nothing new is proved or theorized with or without the accompanying math. In other words this was all speculation or hypothysis.

Nov. 27 2009 02:39 PM

I love Dr. Greene's belief. I find a certain immediate and comforting elegance in it. But I have to ask - isn't there another assumption being made, namely, that an infinite amount of matter is available? Because if there isn't, the only way I could reckon it would be to include a law of recurrence. If I have missed or misunderstood something, please feel free to straighten me out.

Nov. 21 2009 06:50 AM

James Cates: Are you trying to twist Brian Greene's arguments to make it sound as if he is supporting the idea of a God? Let me remind you that earlier in the podcast he mentions that he clearly thinks the idea of God has no place in these theories, because it's just not necessary.

Also, you're appealing to emotion - just because it feels absurd, it doesn't mean it is absurd or impossible.

The "why" you chose to wear green or black shoes today as opposed to anything else, and "why" that other "you" chose to wear another colour is explained by probabilities, as he also mentioned in the podcast. If I toss a coin, it may come heads or tails - does that mean to imply that the coin has consciousness and free will to make any choice it wants with regards to landing heads or tails? Can we say the coin is choosing to land heads or tails?

Similarly, as whether you will choose to wear one thing or another is a matter of probabilities (of all the particles in your body and everything interacting with these particles being in the right time, the right place, moving in the right direction etc), then it is merely a matter of probabilities which colour you will choose. And given enough instances of "you" in that dillema, you will choose any number of colours.

These concepts are very very hard to grasp, but I personally find them infinitely more interesting than any pseudoscientific or quasi-religious beliefs. The idea that the whole universe is just a dance of instances and probabilities, that nothing can really be predicted, that matter in sub-atomic realms becomes energy at will and vice-versa, that particles just pop out of thin air and disappear into the thin air they came from - all that is a great intellectual and spiritual (in the mystical sense, not the "soul"-religious one) achievement of ourselves.

Fantastic talk, and I would give sell my soul to an anti-baryon in exchange to trying some Universe cheese any time!

Nov. 08 2009 05:27 PM

Let there be light, or at least, be "lightening" up mi is just a radio wasn't attempting to change your religion/beliefs/understanding &/or science of the physical world.

It is surprising how slowly we get there. (Make progress in this regard)

And for everyone who progresses, there are innumerable s who shall rail against such progress.

Enjoy the radio program, which I'm sure you do. But it is not anyone's Bible/koran or scrolls of Monctezuma.

Admit-ably Mr. Greene could do a better job, but he has done better than most.
Even if we don't agree with what he has to share. At least he is sharing.

Make Peace and enjoy the Peace in Others!!!

For a challenge, carry out the divisions and simple minuses and share the answer if you can. Most of us are too busy with the day to day to even attempt this exercise.

Have a Lovely Day !

Nov. 08 2009 06:29 AM

I wish Jad had done this podcast. I feel Robert makes jokes about the subjects he represents, and it can be offensive to the presentor or the listener.

He also lets his religious veiws block the presented information. Not all the time, but some times, and for the Silence podcast, that was ridiculous. I listen to radiolab for new thought and Ideas, not a bible lesson.

Jad is more open minded to new age thinking, and doesn't discredit the information with sarcastic jokes. That is why I think he would have made this podcast better.

By the way, I love radiolab. I listen to it everyday. Thank you for making these broadcast public.

Nov. 02 2009 12:33 PM
William Alexander

Hi - I did not read every comment, so this may have been mentioned. I think it's interesting to imagine that in the infinite universes in which all things are possible, it is completely possible, even likely, that in one universe the reality there includes a supernatural god who created a world with people in it, and that may or may not be this universe. Free will is a fascinating topic to consider, and this interview has given me an enormous amount of fuel for thought and conversation with my atheist, theist, and otherwise philosophical friends. Thanks for an excellent show and a thought provoking podcast!

Oct. 14 2009 08:15 PM
John Beeson

This was a very interesting show to say the least. I was wondering if anyone thought of the "membranes" suggested as the cause of clumping of astral bodies and possible the "big bang" itself could also see the irregular shapes of our universe in the 11th dimension as the answer to why black holes exist. Couldn't the black holes be the point where the weak gravity is leaking into our universe from an adjacent one?

Sep. 30 2009 08:06 PM
Robert Morrison

Those strings do in fact look like computer language . Does Brian Greene know Douglas Hofstadter? I would suggest collaboration.

Sep. 05 2009 06:57 PM
John Petrina

I just had to put in my two cents, and this was the only place I could think to do it:

I found some basic (and admittedly less educated) logical contradictions to Brian Greene's findings based on determinism:

In these bubble universes, where all sorts of different versions of physics can exist, there is likely to be one, that has created an entity that is capable of breaking through repulsive gravity (or reacts to it differently), therefore could travel (hypothetically) to our universe, and alter the makeup of what we consider to be the physics we understand, in a specified location, and our physics can still exist traditionally in another specific location. Therefore in any one action (decision) where there is at least a binary possibility (choice), it seems there could be any possible number of reasons one course of action could be chosen, over another, outside our universe's meta-understanding of itself. This implies the possibility of true randomness, and validates the idea of a choice. This constant alteration could indeed lead to the agency in options (or arguably complete randomness); when approached with different iterations of what we understand as physics we are lead, in essence, to limitless possibilities.

Aug. 20 2009 07:04 PM
Paul S

If he's right, then "time" travel is theoretically possible. We just have to be able to find one of the other solar systems with its particles assembled exactly as ours were in the past.

Aug. 16 2009 12:34 AM

I find the notion of limited possibilities to be troubling. For example, if I shoot a gun, are there not an infinite number of directions in which the bullet can travel? I am interested in hearing why Brian Green does not believe this to be so. Anyone know of an information source that demonstrates this thought experiment to be incorrect?

May. 22 2009 08:25 PM

very interesting discussion! I am pleased to hear that in spite of Dr Greene's immense erudition on the multiverse theory he is, if I may say so, slightly naive when it comes to the philosophy of free will, or even Chaos Theory's implications for the concept of free will (c.f. the Butterfly Effect). Also, luckily, there are still as yet unappreciated physical insights that the ancient sages like Dogen Zenjii or the I Ching discerned that are of value to us in fully understanding where modern physics is pointing, e.g Synchronicity. However, the act of metanoia is left to the student as an excercise! "What is not forbidden is mandatory!" "Yesterday's time and today's time do not go away, they are both in the moment when you directly enter the mountains and see thousands and myriads of peaks."

May. 18 2009 06:46 PM

This is an interesting Waxing on about "Possibilities" but his Physics Focus denies many other sciences that we know of, not the lease of which is Evolution. If there is no choice, no randomness, then evolution would not work, everything that ever happened to every organism on this planet would have "had" to have happened that way in order for us to arrive at the location that we are at right now, every killer; every "accidental death" would have had to happen.

Hog Wash, Chaos exists and we pea brained creatures try to make sense of the maelstrom. the laws of physics do not dictate creativity or even thought, he is over simplyfying and over complexitizing thing at the same time.

Apr. 09 2009 10:43 AM
Steve Madere

I have a big problem with Dr. Greene's assertion that the universe is predictable if enough detail is known.

As I understand it, quantum mechanics limits the resolution of *knowability*.
Therefore, it is in fact *impossible* to predict the outcome of interactions on a sufficiently small scale.

This would seem to create an enormous hole for the possibility of "free will" in that subatomic scale interactions which are truly random can have far reaching affects on highly non-linear chemical reactions like those that occur in a brain.

According to the principles of quantum mechanics (which as I recall are rather firmly supported by experimental evidence) this randomness below the Heisenberg uncertainty scale is not possible to predict. It is supposedly
truly random. Is Dr. Greene proposing
that QM interactions are actually mediated by a
pseudo-random generator rather than
true randomness?

Apr. 06 2009 02:42 PM
Nanda Kumar

I just heard this podcast. There is a catch-22 here.
How do we prove that there is another me in the other universe. If i manage to go there, i wont find him there..he would be here right. So lack of my existence in the parallel universe proves my existence or disproves it.

Dec. 24 2008 10:20 PM
chris welch

Wait a second!! This is where reductionism goes full circle and runs smack dab into it's supposed opposite -metaphysics. If there are literally an infinite amount of universes then everything can likely be explained by chance. The laws of physics might well be a confluence of random events. Instead of gravity it is just coincidence that the planets seem to be rotating and the stars coalesce into orbs. On some universe they are rectangular or shaped like Stars of David. Why not? Infinity is Maxwell's invisible demons run amok.

How can we prove a law when infinity strips us of the basic tenants of experimentation and observation?

Dec. 24 2008 03:29 PM
Torbjörn Källström

One thing that I'm thinking about infinity is that people say, "with an infinite amount of possibilities everything will have happened." I don't think that's the case. Even if you have an infinite amount of bananas, no banana will become an apple. Infinite amount of space doesn't necessarily mean an infinite amount of possibilities.

Flipping a coin an infinite amount of time doesn't even mean you'll get a single heads because the result of a coin toss isn't really defined by how many times you throw it but how you toss it.

Nov. 15 2008 08:40 AM

Delightful interview Robert! I've studied Buddhism for a few years and as others have discovered in recent years it seems to have a lot of parallels with the understanding of Physics. The "field" & "cheese" discussion about 20 minutes in was the ringer for me, as it could equally apply as an explanation of the emergence of Dharmakaya, Sambhogakaya, and Nirmanakaya from infinite Space (or cheese), which is one of the ways that Buddhism explains the structure of "reality" or experience of all phenomena. To explain this further would take more skill than I have here. I'm glad to have this further illumination - which like most of your episodes (the Space episode particularly comes to mind) tickles my curiousity about the world and my perceptions of it.

Oct. 04 2008 10:21 PM

Just another attempt to deny our true maker and savior Jesus Christ.

Sep. 26 2008 01:39 PM

Philip i believe in what you question. If we can't know either way, theories are not answers. So, do i believe a human sound/scream can travel throughout space indefinitely. Why not?! Sound would not end. Light would not end, in one direction or another. AH, but yes. The theory is, probably not, because of barriers. So the barrier from infinity presents the "end" theory. I not believe space goes on and on. I believe in an end, just as i believe GOD intended. Size is relative my friends but infinity is not.

SueB, you seem angry at the notion people are searching for wisdom. You may believe this is because some men are looking for significance, because of worldly insecurities, but for the most part we are just curious about our existence AND other existence's!

Sep. 24 2008 10:15 AM

I think this theory is similar to "the earth revolves around the sun" theory that drove men to feel insignificant.

What kind of egos do we as humans develop to HAVE to be special? Is the raccoon raiding your garbage can special? Only when your kids give it a name, right?

Get over yourselves humans! You are insignificant and if that makes you scream you should get off your damn pedestal.

I find peace from the thinking about how incomprehensible the universe is, but I am agitated by so many myopic people who can't see beyond their own property lines. It seems to hurts their head. Hang on to your ego!

NOTE: The audio at the end is obscenely distorted i could not listen to the conclusion.

Sep. 11 2008 11:21 AM

After listening to Dr. Greene's theory, it seems to me that his basic premise is that anything is possible and every possibility exists in some form or another, whether in this universe or another universe or many other universes.

With that in mind, there is something I would like to hear explained: if any possibility can and does exist somewhere, then in one of these other universes there must exist the possibility that there is only one universe, and that ours is this only universe, and other "multiverses" are only ideas. And if Dr. Greene's theory is applied, then this idea of a singular universe must be as accurate as his idea of many universes. So the notion that there is only one universe must be as likely as the idea that there are many. Right?

Aug. 27 2008 05:47 PM

Not sure whether Robert or anyone will respond to this, but is there a book someone would suggest not only about the different ways to arrive at the Multiverse(s) conclusion, but also the alternative brought up in the lecture about why a single universe solution is more likely. I am thinking something along the lines of how other authors have done great jobs of describing very detailed concepts in a not completely dumbed down manner (i.e. John McPhee). So any advice would be great.

Aug. 26 2008 08:22 PM

I admit I don't have an extensive background in science, especially physics. But I don't understand why Greene says that physics doesn't suggest the universe is infinitely complex in the number of possible configurations of matter. Barbara Montero was critical of the materialist philosophy of functionalism in that it asserts that science has determined the nature of all matter, when this is highly unlikely, as we have no way of determining what we don't yet know about matter. Quantum physics studies the smallest KNOWN particles of matter, but this does not mean that matter cannot become smaller than what we can observe. If matter is infinitely divisible, then the number of possible configurations is infinitely complex, so there is no finite variables to be infinitely repeated. And how do we draw statistics out of the unknown? For example, how can we claim the odds that space is infinite when we don't have a view of infinity?

Aug. 26 2008 11:51 AM

hi! i look forward to listening to this.

i was wondering, though. could y'all maybe come up with a convention for the tags you put on your podcasts and stick to it? my player organizes podcasts by their tags, and y'alls' keep changing. so, when i went to play this one, i couldn't find it at first, but i see that's because the artist tag is "Jad Abumrad & Robert Krulwich."

i mean, that's accurate, they are artists--but that's never been the tag before! (usually it's radiolab. or radio lab. or wnyc. or pro tools. you get the idea.)

thanks for considering my request.


Aug. 26 2008 10:04 AM

>>Well, if this parallel universe thing is true, than there are millions of little space capsules floating around in the universe, and if if we are all in the same universe, than there are lots of chances that we find one of the space capsules sent by the parallel planet. Will they, at the same moment find one too? Will all the parallel universes at the same moment find one?>>

I was just thinking along these same lines, i.e. trying to prove the existence of an exact copy of Earth by contact. To take your example, we probably wouldn't know if the capsule that had reached us was our own or sent by some duplicate Earth. How could we know? The contents would be the same, and perhaps the effect on the capsule of traveling through space would be the same for both ours and the duplicate Earth's. Tests run on the capsule itself might only tell us that it travelled a very long way, not that it came from an exact twin of ourselves or that it was our own having doubled back on its path. Along the lines of proving the existence of our twins, the test results would be inconclusive: neither affirming or denying either possibility.

Additionally, we could only track our own capsule so far into the universe. At some point we would lose contact. Then, presumably, we would regain contact. Question is: what have we gained contact with, our capsule or a duplicate? You couldn't know if everything created on the Earth's exact twin were themselves exact twins. The tracking signal would be the same.

Suppose that we could travel to our doppelganger planet. If you did, how would you know if you didn't just arrive back at your own home? There would be know way of determining which was which. You might have just passed, like Brian Greene mentions, through some passage like you find in PacMan. You'd never know if you found a duplicate Earth. You'd never find yourself there to ask because your twin would also be travelling and most likely be roaming the Earth trying to determine if it was his or not. Everyone you asked would confirm you left Earth on some fool's mission to prove some other Earth existed. How would they know that you weren't the person they said goodbye to? How would you, yourself, know that you weren't?

I wonder if you could ever prove the existence of an exact duplicate Earth. Could you contact them remotely, like on some super-spacephone? That's a little facetious, maybe. My point is, since everything is duplicated between the two planets how would we ever know if any signal, ship or vessel that we sent out wasn't ours returning when we received one just like it? There would always be an equally likely hypothesis as to why it was our own, instead of someone else's, and why there was only one Earth. We could never be sure.

I suppose there's a possibility of running into yourself if you could travel from one Earth to another. I doubt, though, that we could ever experience a duplicate Earth and be satisfied knowing that it was indeed a twin. We could most probably only experience it as a mathematical possibility. One whose probability would be enhanced by the discovery of near-twins, similar but not exact. But that's assuming a lot.

The question I have is, how much would have to duplicated in our solar system or even our galaxy for another Earth to be an exact twin our own? The entire geography of the universe would repeat numerous times. Wouldn't it seem, if we stepped back far enough, that our universe was made up of nothing but repetition? But I guess, maybe, that's what's being proposed. I don't know.

Aug. 22 2008 04:21 PM
Listened a second time

Thanks very much RadioLab and thank you Brian Greene! I thought that was a great piece of radio. Really interesting and thought-provoking. Took some very difficult stuff and made it as clear as possible to a lay radio audience with a limited amount of time. Great stuff.

Of course the big question is whether the universe is infinite or finite. And as Greene himself pointed out several times, that is still an open question, even if some of the current data points to it being infinite.

I look forward to further advances in cosmology and Radio Lab's being there to explain them to us.

Aug. 22 2008 12:21 AM

Ok, I have nothing against this Greene guy, but there is one thing that confuses me. Remember that Space episode (the one with Carl Sagan)? They were talking about that time capsule that they sent into space.

Well, if this parallel universe thing is true, than there are millions of little space capsules floating around in the universe, and if if we are all in the same universe, than there are lots of chances that we find one of the space capsules sent by the parallel planet. Will they, at the same moment find one too? Will all the parallel universes at the same moment find one?

Will we then know for sure that there are parallel universes/galaxies/planets? And granted, some of them may be the same, considering some of those universes are supposed to be the same, but didn't Mr. Greene say that there were some that are slightly different? So if we did find a space capsule and it was slightly different, what would that mean?

If we tried to contact them, would we say the smae things? HOW WOuLD IT WORK???!?!?!!? It is driving me nuts!

Aug. 21 2008 06:51 PM
Tim Coulter

Okay, so we've got a finite array of things to arrange and infinite space-time in which to arrange them. But what happens when we run out of things to arrange? Or is matter infinite, as space-time is?

Put another way, say I've got three kinds of yarn and infinite time and space to knit things. At some point I will run out of new patterns, but won't I also run out of yarn?

See also the discussion on AskMetafilter:

Aug. 20 2008 06:41 PM
Frank Glover

It would be interesting to bring together any two versions of identical individuals like this. In each other's presence, it seems they would *have* to behave differently in some manner.

And it's not asking that terribly much. If any possible variation must exist somewhere, then there's an infinitesmal but non-zero chance that there are two *adjacent* but identical galaxies, right down to identical Earths. They don't all *have* to bebeyond the red-shift limit from each other, however much more probable that is...

Aug. 20 2008 05:23 PM

My comment is along the same lines as Clever Human's post. Let's assume there is infinite universes and infinite space and the rules that govern this universe also rule all other ones. Can one also assume that all of the particle movements that went into the creation of this planet from the outset also approaches infinity? If that is true does his idea of duplicates fall to the wayside?

Aug. 20 2008 02:22 PM

nice, definitely

Aug. 19 2008 10:50 AM
Paul Kotta

Some scientists get attention through actual achievements, others by coming up with far-fetched theories. Get a real job, Brian.

Aug. 18 2008 03:46 PM

This guy is absolutely wrong about the "finite configurations" part.

It would be true if every atom had to fit into a fixed grid of possible locations. But thats not true. In fact, if you look at just two neighboring atoms within a nanometer apart, there is still an infinite number of distances they can be from each other.

Imagine those two atoms are in a neuron in ones brain. Say the distance between them affects the strength of the neuron. A very small difference in their distance apart could yield two slightly different thoughts, leading to different actions, etc.

THERE! At 25 minutes, he even says "infinitesimely small". So he understands that there are infinite possibilities within the small ranges. The guy is a fool if he actually believes that the world has a finite number of configurations.

Aug. 16 2008 04:11 PM
Ken Luallen

Perhaps you could demonstrate specifically your justification for these conclusions. Specifically what are these constant dead giveaways of God’s existence? On what basis have you dismissed all infinity based theories?


Science holds that matter cannot be created or destroyed. In answer to the question 'where did it come from?' science's answer is 'it just is'. Utterly and wholly unscientific, delivered by countless accomplished scientists with straight faces.

That's the irony of scientific atheism.

At its very foundation science insists on defining things, and for good reason -- this is what makes the discoveries of science reliable and believable. This is great for understanding our physical world. But on the question of the origin of matter, the scientific community should simply admit that they cannot possibly reach an answer because science limits itself to matter that already exists. It can go no further.

Any honest inquiry into 'where did it come from' forces you to look beyond the material world as we know it - and thus beyond the realm of science.

Any problems with my logic in this?

I don't believe I dismissed infinity theories except to the extent that they can ever provide an explanation of our existence. I'm all for math. 'Infinity' is the word we use for our human inability to comprehend the boundary of something, be it space or an equation. But we know everything has a boundary -- it's a very scientific principle except when trying to answer the greater questions of origin and space, at which point science starts referring to 'the void'.

I could accept the existence of a void/infinity and call it a day or I could keep searching for an answer to what was before time and what existed before matter. My curiosity leads me to choose the latter. I just wish science would admit that there logically must be something bigger than science. (Even if it's not the God I believe in.)

None of this is at odds with a theory of multiple universes.

(By the way I don't think you took the low road, which would be name calling and arguing a point without attempting to support it. There's nothing wrong with disagreeing.)

Aug. 16 2008 01:18 AM
lisa Emmons

I get the idea of the redundant universe - and I believe the opportunity is out there - but there is also the 'random' science - the same science that lets a drop of water choose to go off to the left then go down again - rather than drop like a very heavy rock.
Yes, if you studied them there is usually some minor partical in the drops' way -but that is not always the case and even you can not account for them all

Aug. 16 2008 12:06 AM
Max L

If there are infinite universes / infinite space, there are still rules that govern on a more macro scale, like entropy, or for biology, evolution. Universes are not giant cocktail shakers - they are particles that follow rules, and I find if unlikely that every single possible configuration of particles could happen to exist. There could be an imaginable animal which could never actually happen because the conditions which would make it evolve that way would, say, destroy the world.

Are there no debates about Greene's "cocktail shaker" model?

Aug. 15 2008 11:50 PM
Rob Palmer

There are different classes of many-world ideas. The versions that Brian Greene is discussing doesn't necessarily have anything to do with quantum mechanics. If you are keen, Max Tegmark lays out the many worlds landscape in an academic lecture:

As to quantum mechanics, there is simply no question about it. It has been experimentally confirmed to a far greater precision than perhaps any other mode of knowledge.

It is, however, extremely difficult to explain using classical terms. If you really want to understand, the math is unavoidable. Leonard Susskind offers a free online course that can be followed using high school level math:

So anyone trying to explain QM using classical objects such as dice or coins is drawing an analogy that is necessarily flawed.

The most straightforward method of explanation I know of is the double-slit experiment:

Essentially, classical statistical mechanics sensibly predicts that the probability of quantum particles passing through two slits should be the sum of the probability of each slit. Experimentation does not yield that result however and QM is required to explain the interference pattern that we actually obtain.

Ultimately, classical physics fails us.

As per the discussion above, Heisenberg makes probability fundamental to the universe whether as an actual quality (as in the strong interpretation) or even if only as an unavoidable byproduct of the measurement problem (weak interpretation.)

Aug. 15 2008 11:47 PM
Audita Sum

And I haven't believed in free will for quite some time. Hee hee.

Because, you know, I'm the sum of my atoms.

Aug. 15 2008 05:08 PM
Audita Sum

When I read a booklet on parallel universes by Scientific American, I thought it was totally stupid. Mostly because if one takes any of the quantum theory examples-- flipping a coin or rolling a die, for instance, there is no real chance. That coin is 'fated' to land on a certain side or that die is 'fated' to land on a certain number because of the way you threw it, the surfaces surrounding it, etcetera. The way you threw it has its own subconscious reasons too, and isn't the result of some probability. In my mind, probability is just our guessing and ascribing percent symbols.

Listening to this podcast, though, I found myself being pulled in. If atom arrangement really is random and has no actual causes, then sure. Maybe quantum theory is a possibility. And then, maybe multiple universes are a possibility.

Still, I don't see why we have to complicate it to multiple universes. Can't we just have one universe, with an infinite number of Earth-duplicates floating around in it? How can equations lead to the knowledge that our universe could be a bubble within a bubble? Seriously. I'd like to know this stuff.

Aug. 15 2008 05:06 PM

Ridiculous. Math is a tool to represent reality, not the other way around. Physicists live so much in the world of math they think the rest of the world has to conform to math rather than make math conform tot he rest of the world. Silly kitties!

Still, there is value in running around and talking this kind of thing up. It helps get grant money. Study particles dancing around? *yawn* Study Kewl Froopy Multiverses?? Wow, let's pay for that! Amazing how easy it is to dupe even the top 1% of society into scarfing up such nonsense.

Aug. 15 2008 04:42 PM
Clever Human

There seems to be a flaw here.

At the beginning of the podcast an analogy was used about flipping coins. It stated that with an infinite number of flips, even the most unlikely combination would occur -- 1,000 heads in a row was the example used.

But there are some examples that would never show up in an infinite number of flips -- all heads or all tails. Because if those two showed up, then none of the other really unlikely chances would happen (you can't have 1,000 heads in a row if you are flipping all tails.)

And then the rest of the podcast goes on to talk about infinite heads showing up (if the analogy is that heads is an exact duplicate of an atom in this universe, and tales is a difference in that atom).

The one combination that cannot show up again is the one that leads to exact duplication of everything.

Does this make sense, or am I missing something.

I know analogies != physics.

Aug. 15 2008 04:07 PM

@ Dave Kliman

Given infinity, there is no proof required, as eventually everything will repeat as there only a finite, though exceedingly large, number of possibilities so long as there remains a finite number of particles.

Aug. 15 2008 02:10 PM

As discussed in the podcast, if I start travelling in one direction.... and keep travelling... and travelling... until I reach a parallel universe, why would I find another me? Wouldn't THAT another me be travelling and reaching another parallel universe at the same time? Since the other me will make the same thoughts and actions at the same time as me?

Aug. 15 2008 09:33 AM

Wait! Wait! Wait!


Aug. 15 2008 08:59 AM

I think some people here are missing the point; alternative universes mean that everything has happened. Because anything can be traced back to a single point, albeit sometimes way back. By definition, alternative universes dictates that you have already developed the cure for cancer in the bathroom, while simultaneously inventing the flux capacitor and destroying exactly 58/42th of the universe in exactly 8.9352+(5/pi)^7 seconds, infinite times.

Aug. 15 2008 12:49 AM

Just like monkeys writing Hamlet.

If Brian Greene is right, I guess there are lots of Hamlets, lots of Shakespeares and lots and lots and lots of monkeys.

Who knows if it's true, but it's fun to think about so many monkeys.

I'm surprised by the comments that dismiss what is essentially an easy argument. Finite possible arrangments distributed over infinite space (two big assumptions), lead to inevitable duplication.

And more monkeys.

Aug. 14 2008 07:44 PM

When ideas are divorced from facts - when they are accepted arbitrarily - fantasy is the result. Whether the person who does this calls himself a professor or a voodoo priest doesn't change the fact that their ideas are pure non-sense (literally).

Rationalism (in its 'secular' or religious form) is an intellectual dead-end.

Aug. 14 2008 07:28 PM
Rob Palmer

Ken Luallen:

I guess I'll take the low road.

I see nothing in physics that suggests existence must be created and ordered by something that does not obey the laws of physics much less am I constantly confronted by such.

The phrase 'beyond infinity' sure sounds nice. But it is void of actual content. Definitionally, it is about as sensible as the playground invective of infinity plus one.

Perhaps you could demonstrate specifically your justification for these conclusions. Specifically what are these constant dead giveaways of God's existence? On what basis have you dismissed all infinity based theories?

Many mathematical theories are infinity based. Perhaps you can show me how math suffers from this and becomes less conclusive or indicative of anything.

Aug. 14 2008 06:04 PM

One more comment, sorry . . . I don't believe that because 23 other people decided to go to Pineapple Express last Monday night, that none of had free will.

Aug. 14 2008 05:36 PM

In order from things to repeat themselves, doesn't there need to be multiple closed systems (universes)with the same particles in each system (universe) for this to work? In one universe isn't every particle having an effect on every other particle?

Aug. 14 2008 05:31 PM
Ken Luallen

First I am a bit surprised by the vehement reactions to Brian Greene's belief that there really isn't any free will. His theories are perfectly logical and quite well-articulated. Why can't you respect that? If you truly believe in free will (as I do) someone's reasonable alternate belief should not bother you. I am quite glad Brian and Robert were able to discuss and challenge his ideas without any hint of hostility or sarcasm. Taking the high road serves all sides of a debate.

The problem with any infinity-based theory is that it scales infinitely and only grows less conclusive and less indicative of anything. This is the great irony with scientists -- the ever-expanding scope of a world defined by physics constantly suggests that all existence simply must be created and ordered by something that does not obey the laws of physics.

That said, physics and God are not in conflict at all, they exist on completely different levels. I am amazed that some scientists are willing to extend their minds through the extraordinary distances of infinity but so deeply unwilling to go a step further into what must be beyond infinity.

I always appreciate the fact that Robert very subtly poses this dilemma in every interview. (His subjects duck it every time.)

Great job once again.

Aug. 14 2008 04:30 PM
Rob Palmer

There are various approaches to free will. Greene believes in the block universe/multiverse implied by Einstein.

That is not a position that 'science' has settled on but rather an interpretation to which some scientists adhere. It is based on the ideas of causality and determinism. If your actions are perfectly determined in advance, then free will is an illusion much as Greene claims. If your actions are only probabilistically determined then there is still some wiggle room for free will. (At least this version of it, leaving aside Ramachandran's post hoc rationalization.)

It all basically comes down to how you interpret Heisenberg. A strong interpretation is that knowing a quantum object's position makes its momentum indeterminate and leads to a conclusion that the future is open ended. A weak interpretation sees this phenomenon as merely a product of measurement, that the momentum is still determined but we cannot discover what it is. That position postulates that there are hidden variables at work that we have yet to find which would allow for an absolutely determined universe in which free will is an illusion.

Myself, I think hidden variable theories are tremendously hopeful. The Everettian many-worlds interpretation is one such theory but postulates a different version of the many worlds than is discussed in this thread. In the Everett MWI the other worlds are not spatially distant as we have been discussing but produced so that every possibility is actualized. So there really is a world in which I chose chocolate rather than vanilla.

The problem is that Heisenberg is not going to go away. MWI or even Bohmian QM may try to explain it ontologically, but they are not going to get around it: Uncertainty has been experimentally demonstrated to great precision.

And while the absolute determinists make bold promises about being able to perfectly predict the flight of a bird in the golden future, probabilistic determinists such as Iain Couzin are producing stunningly accurate models of entire flocks of birds in the here and now.

The elephant in the room is actually time itself. We don't really have a handle on it. Even as we do accept that space and time are unified, spacetime, our metaphysics is entirely constructed on the basis that space is one thing and time is another.

Aug. 14 2008 03:52 PM

Free will/no free will, I think most of the posters completely missed the point. It is not the job of science to explain the "why" of things but the "how." Dr. Greene is simply explaining the mathematical model of how things could work given the information that we have today. What is wonderful about science and Dr. Greene mentions this several times, that if something new is found, science is more than happy to revise itself to fit the new data. There are still plenty of unanswered questions that people can fit into the notions of free will if they find that comforting. We don't know why the 'energy field' the 'cheese' in the story folds down in such a way to create our bubble universe and not another type, etc etc etc. We don't know why the you that is you is in this area of the universe and not in another area, all that stuff still adds up to some wonderful mysteries out there.

Aug. 14 2008 01:31 PM
Amanda Black

Did any Lost fans find familiar themes here? I sure did!

Aug. 14 2008 11:19 AM
Rob Palmer

If the particles in our universe have an infinite time-like quality then we [are] actually dividing an infinite number into the infinite multiverse and the result is that the multiverse is under no obligation to repeat itself.

Aug. 13 2008 06:21 PM
Rob Palmer

Fortunately, Heisenberg does not scale up. In the classical realm I can know both an object's position and momentum with sufficient precision for predictability.

Or, perhaps better put, the uncertainty of classical objects is so tiny as to be negligible. The fuzziness of cannonballs does not diminish their effectiveness.

It is usually not productive to question scientists' calculations. The mathematics are generally widely agreed. Their assumptions and interpretations are fair game however. I don't think there is much question that dividing infinity by a finite number will offer endless repetitions.

One approach, to question whether infinity is an appropriate description of the multiverse is certainly valid and has been mentioned previously.

But there is another way to question the assumptions of this particular multiverse theory. In the calculations particles are described as space-like objects (a finite calculation) divided into a multiverse of infinite space and presumably infinite time.

If we are to take Einstein seriously, we have done some significant damage to our conceptualization of particles by stripping out their time-like qualities. Welding time-like qualities back into our calculations of the particles yields a very different result.

In order to achieve a finite number that can be divided into an infinite multiverse we must arbitrarily limit time in some way. If the particles in our universe have an infinite time-like quality then we actually dividing an infinite number into the infinite multiverse and the result is that the multiverse is under no obligation to repeat itself.

Aug. 13 2008 05:45 PM
Alex Grigg

From Dave Kliman "what is to say each and every possibility MUST play out?"

There is less to say that every possibility MUST play out, although if we assume an infinite universe with infinite variations of the laws of physics it does seem likely. The fact that something does happen once, though, suggests that it is possible and therefor in an infinite universe where many worlds are similar to our own some of them will be exactly the same. If your "infinity" is big enough then there will be infinite worlds where exactly the same thing happens.

alexandre van de sande says there is a contradiction between a clockwork, no free will, universe and the universe of infinite variations.

The water does get a little muddy here and I don't think Brian had sufficient time to adequately explain the no free will theory. Quantum physics and uncertainty principles are hard enough to understand that I don't think I can explain the lack of contradiction, especially since I'm not sure I have a firm grasp on them in the first place. What is important, though, is that physics cannot explain free will. You can say the position of an electron is as uncertain as you like, but we don't choose where that electron is and what it's speed is, or whatever the actual particles are that we're unable to exactly describe.

Aug. 13 2008 02:37 PM
Dave Lockwood

The elephant in the room is the whole idea of calling the universe infinite. If you take that one concept out of the argument the irrational aspects go up in a puff of logic. Perhaps, despite scientists' assumptions, the universe is not infinite and what we have is reality expanding into nothing. In other words, reality and the laws of physics are generated as we go along. Since that is what we observe that must be the case. As soon as we observe something different let me know and I'll reconsider.
I have the utmost respect for Dr. Greene and feel this was a setup. Without a firm grasp of the concept of infinity this all sounds like nonsense. This looks to be to be hatchet job by the interviewer who constantly played to the incredulity of the audience at the expense of Dr. Greene.

Aug. 13 2008 02:09 PM
Lola Rogers

I keep going round and round about the probability thing, and I end up with the same question Dave Kilman asks above: the fact that something can happen doesn't mean it will.

The idea in your discussion is that, given enough time and space, infinite time and space, everything that can happen will happen. But is that how probability really works?

What about the gambler who sits at the roulette table for hours and hours, calculating that if he sits there long enough, probability dictates that he will eventually win. The problem is that he's no more likely to win the millionth time the wheel goes around than he was the first time.

Can anybody point out what I'm missing here?

Aug. 13 2008 11:54 AM

Does this mean that somewhere in the universe movie-physics might apply? People can jump out of the way of explosions, bullets ricochet until they hit their intended targets, and cars are indestructible?

More seriously, how far ahead of engineering is this science? In other words, how long (if ever) until there is application of these theories to human life? Is it already happening and, if so, in what fields? Communications? Computing? Energy?

I had little patience for similar conversations about the other spectrum of modern physics (atomic science) until I met an electrical engineer taking advantage of electron spin in his circuit designs. Impressive. Humbling.

Aug. 13 2008 11:27 AM
alexandre van de sande

I believe Brian Greene contradicts himself when he tell us that modern science has disproved the "clockwork" universe newton described but then Brian describe a very "clockwork-like" bird when he states that we could in theory know where the live bird in a canon would fall.

He is certainly wrong, probably because he is letting his personal relaxed opinion on free-will contaminate a very scientific talk.

The error consist in the idea that one could possibly know everything about a bird so to be able to know where it would land after shot by a cannon. We physically can't.

First, the Heisenberg Uncertainty Principle he himself states makes it clear that we can at best determine the chance of a certain eletron in the brain of the bird being in a certain place. When taken in account every atom that makes up the bird that uncertainity scales up very quickly.

Secondly the study of chaos theory also shows that those small bits of uncertainity can result in radically different and unpredictable results.

Therefore according to modern, non-newtonian physics, the best a modern physics expert could tell you is that given a live bird is shot in the air there's a high probability he will die of heart attack, but there's also a chance he will fly the hell away from those crazy scientists and land in a far away tree where there is some shade.

Aug. 13 2008 11:16 AM
Dave Kliman

I have to disagree with Dr. Greene on the idea that just because there may be infinite space for finite configurations of atoms, who is to say imelda marcos will EVER wear those red shoes in the corner?

what is to say each and every possibility MUST play out?

I have been exploring the mandelbrot fractal for years. there are an infinite number of possible images in there, but i just do not think one will ever be able to find the equivalent of every photo ever taken.

the same applies to things like kotch snowflakes. you can have i suppose what amounts to a finite number of possible kotch snowflakes, but there will never be one that looks like the script for hamlet. ever.

Does Dr. Greene have some kind of proof that every single possibility MUST play out?

Aug. 13 2008 02:14 AM

Freewill is given to mankind to make mistakes and learn from them. Life is a long journey of learning. Don't even get me started on reincarnation and karma. Peace

Aug. 12 2008 05:26 PM
James Cates

Have you ever had the feeling that you just avoided something disastrous?

Maybe in one reality I choose A and cause mayhem, while in another I choose B and things turn out better and closer to "the script".

Maybe we do have free-will with the realm of each reality, each choice and outcome is weighed and the one closest to "the script" is made the central reality. Maybe there are these multiple realities between which we can instantly shift and we are constantly being swapped around by a controller algorithm as described...

Why is THAT not a possibility? Brian, I find your particular solution to be extremely pessimistic and limited.

Aug. 12 2008 12:11 PM
James Cates

The prospect that we do not have free-will is absurd to me. Surely, there are multiple possibilities in any given situation. Brian never explains why "I" in one "place" does not choose option A while in another "place" "I" choose B.

I find it totally absurd to suggest that free-will is just a useful, comforting and necessary component that helps us get through the day. In that case, has Brian suddenly discovered the Red pill? In that case, he is more or less also suggesting that everything is pre-defined according to some cosmic formula which leads to a pretty divine suggestion.

Brian, do you realize how creationist your idea is? You are handing over all creation and logic to a single, unknown entity.

So, you maybe you are exposing the matrix and its maker(s), eh?

You realize, of course, that it is sort of pointless for you to TRY to discover any of this since you are by your own suggestion pre-disposed to do so and can't do a thing to change that. (grin) Really?

Aug. 12 2008 12:06 PM

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