Tim Maudlin and Avshalom Elitzur on the Nature and Flow of Time

Dr. Tim Maudlin is an internationally-renowned physicist and philosopher of science at New York University. He is known for the clarity of his thought, above all in the foundations of physics. Maudlin has undergraduate degrees in physics and philosophy from Yale University and a PhD from the Univ. of Pittsburgh. His books, released by the world’s most respected publishing houses, include "Quantum Non-Locality and Relativity", "Truth and Paradox", "The Metaphysics Within Physics", and two volumes of "Philosophy of Physics". In addition, his "New Foundations for Physical Geometry" has received wide acclaim as a novel mathematical approach to a better understanding of space-time.

Dr. Maudlin is a member of the International Academy of the Philosophy of the Sciences and the Foundational Questions Institute (FQXi). He has been a Guggenheim Fellow, taught at Rutgers for many years and has been a visiting lecturer at Harvard. He is also founder and director of the John Bell Institute for the Foundation of Physics.

Please contribute to Maudlin's fight for the foundations of physics by visiting the following:

Dr. Avshalom Cyrus Elitzur (Hebrew: אבשלום כורש אליצור; born 30 May 1957) is an Israeli physicist, philosopher and professor at Chapman University. He is also the founder of the Israeli Institute for Advanced Physics. He obtained his PhD under Yakir Aharanov. Elitzur became a household name among physicists for his collaboration with Lev Vaidman in formulating the “bomb-testing problem” in quantum mechanics, which has been validaded by two Nobel-prize-winning physicists. Elitzur’s work has sparked extensive discussions about the foundations of quantum mechanics and its interpretations, including the Copenhagen interpretation, many-worlds interpretation, and objective collapse models. His contributions have had a profound impact on both physics and philosophy, influencing debates about measurement, the role of observers, and the ontology of quantum states. Elitzur has also engaged in discussions about consciousness, the arrow of time, and other foundational topics, including a recent breakthrough in bio-thermodynamics and the “ski-lift” pathway.

Timeline:

0:00:28 - Introduction
0:04:35 - Maudlin opening statement on time
0:16:33 - Elitzur begins his first presentation on classical time
0:50:33 - Maudlin responds to Elitzur's first presentation
1:00:43 - Maudlin invokes Hugh Price and expounds on the block universe
1:12:25 - Elitzur explains his early work with Yakir Aharanov and the two-state approach
1:16:26 - Elitzur starts his second presentation on the quantum aspects of time
1:38:19 - Maudlin and Elitzuer discuss Elitzur's latest quantum results related to time
1:52:08 - Razo elaborates on the pragmatic approach to interpretation in physics
2:02:40 - Razo on the importance of Maudlin's efforts to study the foundations of physics.
2:03:45 - Elitzur and Maudlin agree to return for a follow-up discussion.

[eismscience]

Timeline:

0:00:28 - Introduction
0:04:35 - Maudlin opening statement on time
0:16:33 - Elitzur begins his first presentation on classical time
0:50:33 - Maudlin responds to Elitzur's first presentation
1:00:43 - Maudlin invokes Hugh Price and expounds on the block universe
1:12:25 - Elitzur explains his early work with Yakir Aharanov and the two-state approach
1:16:26 - Elitzur starts his second presentation on the quantum aspects of time
1:38:19 - Maudlin and Elitzuer discuss Elitzur's latest quantum results related to time
1:52:08 - Razo elaborates on the pragmatic approach to interpretation in physics
2:02:40 - Razo on the importance of Maudlin's efforts to study the foundations of physics.
2:03:45 - Elitzur and Maudlin agree to return for a follow-up discussion.

[XRPE]

What an interesting and eloquently projected discussion. I'm eager to see the follow-up. Thank you.

[AvnerSenderowicz]

I've watched every lecture of both Elitzur and Maudlin - having both of them together is a real treat.

[whywouldidisplaymyname]

Thank you for this, lovely to see that both of them had enough time to really expound on their positions

[francescoangeli]

In relation to the first part, before they get into quantum mechanics:

Maudlin is right in defending the common sensical view of time as flowing and having directionality (asymmetry between past and future) and in stressing that - even within the conceptual framework of general relativity (which is just a model of reality, not reality itself, by the way) - time is different from space and we should not confuse spatialised representations of time with time itself (on this last point, Bergson had already shed light quite well). He is also right in highlighting the indexical nature of "here" and "now".

He is right again in saying that (from a non-perspectival, non-situated point of view) past, present and future are "equally real" (the past was really real, the present is really real, the future will be really real).

What the present, the now, is is an indexical matter: it depends on "when" you are "situated".

On the other end, Elitzur is right in saying that the present is special. But he is implicitly talking from a situated point of view, I would say almost from a phenomenological point of you. From this perspective, we are always in the present, a "moving present" which is where agency "always" and "only" is. In this sense, I believe, he rightly sees the present as "really real" in a way that past and future aren't.

I think they actually agree on more than they realise they do, it's only that they're looking at the question of time from two different perspectives: Maudlin is describing time from a non-situated point of view. Elitzur is describing it from a situated point of view (situated in the present) and is struggling to get the nuances of Maudlin's position, because he's taking the "block universe" view as a purely frozen model, which is not how Maudlin interprets it (that's why Maudlin stresses that he agrees with that model only insofar as you retain the flowing and directionality of time).

When he abandons his situated perspective and tries to interpret Maudlin's view, Ekitzur "looks at" the block universe "from outside" and finds it an implausible lifeless crystalised block, where the special nature of the present is missing.

Whereas Maudlin thinks that "looking at the block universe from outside" doesn't make sense. There's no "outside" the universe. And if you're in it, you're in time and time flows, time passes by.

I think the common ground is that what is special is THE Present, not this present (which will pass).

From a situated perspective, this means that the "when" in which you are now is special.

From a non-situated perspective, it means that there is a real difference between past, present and future, but that what "present" means (where you position the "index") is relative, not absolute, and if you "remove the index", past, present and future stand on equal ontological footing.

Said otherwise: from the perspective of the One, the totality, the whole of time is real. From the perspective of the Many, the multiplicity, what is real is the situated now in which each of the many are.

[timjohnson]

I just read the Einstein’s response to Gödel in the “Reply to Criticisms” portion of Schlipp’s book: Albert Einstein Philosopher-Scientist. I strongly disagree with Avshalom that this is some kind of evidence that Einstein believes there is no asymmetry in the direction of time. Einstein is talking about special cases where two events happen outside a causal horizon of eachother. And the issue in these cases is that there can be no claim which event came first. Einstein said it disturbed him when developing relativity that there wasn’t an answer to this and he never resolved it. However, Einstein points out that there is asymmetry in 2 events that can be connected by a time-like line and “the assertion: ‘B is before A, ’ makes physical sense”.

The reading Avshalom recommends actually defends the idea that, in general, Einstein believes time is asymmetrical, not the other way around as Avshalom claims. And as an aside, it’s interesting that Tim’s approach to have a theory with a preferred foliation of space, would likely solve these special cases that bothered Einstein in the response to Gödel.

[mp]

I give up. Why am I watching him give Tim a powerpoint presentation. Jezus.

[EzraAChen]

There is no time!! It is only a fraction or multiplicity of distance. And look into Lorentz transformation and time can be done away. There is no time only the human poetry of false immortality.

[enterprisesoftwarearchitect]

This isn’t the first time I’ve seen Tim correct lifelong misconceptions of a physicist.

[JerryMlinarevic]

Indeed past present and future do exist again. Reality is created by small differences in iterations creating the illusion of time and space. Because consciousnesses takes relatively more iterations to create than a rock, and then can only interpret reality in arrears to the creation process we lag behind in being able to see a greater depth of field in time and space living in just a single moment.
The creation process from beginning of the universe to some unreachable future repeats with small changes until the black hole evaporates. No moment in time is the same. In the far future we may have a history without Jesus but we will not know or remember that there ever was a Jesus.
So, you can go back in time but not the past of your current present from which you departed, that past has dissolved away. The past that you go to is the future past of a future event. Hence, there are no paradoxes and you can exist in multiple copies - Nature does not care for your human perspective.
Indeed, Nature permits all possibilities, even that which you cannot imagine. So, you can create incredible technologies to explore Nature but it will always be less than Her.

[mylittleelectron]

In many mathematical representations of nature, an objects scale can be altered through numerical operations, however, this procedure often misrepresents reality. Seeing as though objects in the physical world are composed of atoms, their scale cannot be changed to arbitrary values as increasing its dimensions equates to adding atoms to its structure. I feel in some way that this is relevant to Tim maudlin's description of special relativity and the idea that objects have no fundamental length or size.

[techteampxla]

Hiya Luis Razo, Thanks for publishing this content. Great speakers and great talk!

I just visited the IESM website and I'm so tempted to take some of these courses they look amazing!

[dimitrispapadimitriou]

15:35 That convention doesn't hold in General Relativity ( e.g. in the usual Schwarzscild or Eddington/ Finkelstein etc. coordinate systems, the time coordinate in the interior
{ the trapped region } of Black Holes { that is the "radius" r, not the "t" coordinate that becomes spacelike inside } counts from r=2M ( the Horizon) until r=0 ( the future singularity).
The same in rotating Black Holes with the Boyer/ Lindquist coordinates etc...

[DocSiders]

I clocked Time recently. It elapsed at PRECISELY... 1 second/ second. Accurate locally to 1 ppb.

[winstongludovatz]

It would be more fruitful to discuss in depth if entanglement effects refute the speed of light limit on the propagation of effects decisively. In that case: why worry about relativity theory, the block universe and the relativity of simultaneity. The basic assumptions are already refuted. The question is: do the experiments stand on their own or is quantum theory needed to interpret them.

[UnMoored_]

Avshalom keeps repeating ideas such as, "They have the same degree of existence". It's fine if he wants to introduce his own ideas to explore or challenge GR but if he's teaching GR to students, he has to make the distinction very clear because he is stating things which are not supported or are irrelevant in general relativity. He should instead say that he is philosophically not satisfied with GR and discuss that as opposed to implying that there are Einstein's theory has internal contradictions. His approach is messy.
EDIT: He doesn't understand, which is the minimum requirement to be able to say, "I don't agree".

[carolmartin]

We use time to describe the supernova because humans have limitations on what they can perceive. We only use five senses. The supernova could be happening at the same time as everything else, but our eyes can't see it. Just because our eyes can't see it doesn't mean it's not happening. Using before-and-after or cause-and-effect is one way we pass on information, but which came first the chicken or the egg?

[samfawlia]

it's relieving to hear that everything isn't happening all at once

[elijaguy]

perhaps the circumstances of space and time were given to us, but the experience and perceptions of space and time emanate from us, and it is we who are the authors of these perceptions and experiences, and it is our natural native right to describe it, symbolize it, transform it, any ways that our exclusive authority on it may choose.

[josem.]

To exist means simply to be "actual". Real things exist outside of the mind as opposed to those that exist inside someone's mind. Therefore, everything that is real must be actual.
The past is no longer actual, and the future is not actual yet. Therefore, neither of them can be real. While the present, because it is actual, is real.
Can you make up a word that covers what was actual, what is, and what will be? Yes, but what would be the usefulness of that?