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Einstein didn't think time was an illusion

Relativity doesn't imply a block universe

28th November 2022
| Professor of Philosophy at New York University and author of Philosophy of Physics
1,941 words
Read time: approx. 10 mins

In a famous letter to a bereaved family friend, Einstein wrote: “For those of us who believe in physics, the distinction between past, present and future is only a stubbornly persistent illusion". This has been widely interpreted to mean that Einstein’s theory of relativity itself implies that the passage of time is an illusion and that time, like space, has no direction, a position often referred to as “the block universe”. But despite Einstein revolutionizing our understanding of time, nothing in his theory of relativity suggests that the distinction between past, present, and future is an illusion, argues Tim Maudlin.

 

Albert Einstein had the double-edged gift of writing striking aperçus. Instead of saying “Quantum mechanics is on the right track, but I am not convinced that the laws of physics are indeterministic”, he wrote to his friend Max Born: “The theory provides much, but it doesn’t bring us closer to the mystery of the Old One. In any case, I am convinced that he doesn’t roll dice”. The quotability of “God doesn’t play dice with the universe” has resulted in it being widely accepted as Einstein’s primary complaint about quantum mechanics, which is not the case. It was rather the non-locality—the “spooky action-at-a-distance” in his pungent phrase—that he really found unacceptable.

Time min SUGGESTED READING Einstein and why the block universe is a mistake By Dean Buonomano

Another extremely widely cited Einstein text, also written as a personal note, has caused similar confusion. When his dear friend Michele Besso died in 1955, preceding Einstein himself by only a month, Einstein wrote a letter of condolence to Besso’s family. In it, he said “Now he has departed from this strange world a little ahead of me. That signifies nothing. For those of us who believe in physics, the distinction between past, present and future is only a stubbornly persistent illusion". Since one might reasonably say that time itself is the foundation of the distinction between past, present and future—it is the temporal relation of earlier/later between events that underpins these concepts—this passage has largely been taken to suggest that time itself is, in some sense, illusory. This quote has been the basis of what has come to be known as “the block universe”, which supposedly implies that the passage of time is an illusion, and that time is just like space, another dimension with no inherent fundamental direction. However, there is nothing in Einstein’s theory of relativity to support any of these claims.

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In truth, I think that Einstein never regarded time as an illusion.

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To begin with, if one of the discoveries of physics were that time is an illusion, it would be hard to even imagine a more momentous achievement. But it ought to immediately strike one as peculiar that if Einstein had really thought his theory of relativity implied that time is an illusion, he would only include this claim in a private note of condolence that he had no reason to expect ever to be made public.

Tim Maudlin
28th November 2022

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Bud Rapanault 26 August 2023

This statement is clearly false:

"There is no “objective now” in the sense of some moment of time that all tokens of “now” refer to. But so what? Nobody ever thought differently."

As your article points out Newton believed there was a universal "now" and so too does every cosmologist who is allowed to draw a paycheck, all of whom are happy to inform you that "the Universe is 13.8 billion years old", an assertion of a universal simultaneity. That such a belief stands in direct contradiction to Relativity Theory (on which the standard model allegedly rests) is just one of the many absurdities attendant on the Big Bang fairy tale.

As to this:

"Temporal structure is fundamentally different from spatial structure."

Neither space, time, nor spacetime are observed phenomena. They are not physical things. There is no evidence supporting the widespread belief that they are physical things rather than merely relational concepts. Space and time do not have structure any more than "distance" has structure. Time is not an illusion but the belief that it is a causally interacting entity that makes physical processes "flow" is delusional.

Xinhang Shen 3 December 2022

Time is what a clock tells. Nobody in the world has problems in using clocks and arranges their activities according to time, regardless what philosophers and physicists say as they take time as a kind of playdough that can be stretched and pressed according their willing. In order to facilitate his postulate that the speed of light is constant relative to all inertial reference frames, Einstein redefined time with Lorentz Transformation, while time has already been defined by clocks and there is no freedom to redefine it. Thus, the only consequence is that the time defined by Lorenz Transformation is not the time defined by clocks. Actually we can easily see their difference: according to Lorentz Transformation, the relativistic time of the inertial reference frame moving relative to the observer becomes shorter than the relativistic time of the inertial reference frame of the observer, the period of the moving clock as an interval of the relativistic time of the moving frame becomes shorter too, which makes the frequency of the moving clock as the reciprocal of the period becomes faster rather than slower. Thinking the moving clock will tick more slowly than the stationary clock is totally wrong. Therefore, the relativistic time of the moving frame is not the clock time of the moving clock, but a new variable without physical meaning. Based on such a fake time, special relativity is wrong and so are all relativistic spacetime based physics theories are wrong.

Matthew Huddleston 30 November 2022

As a fan of Maudlin's previous writing, I am amazed at the number of misunderstandings he displays here, in physics, history, and philosophy. As a physicist, I'll stick to identifying two glaring errors in that realm.

First he writes, "There is no 'objective now' in the sense of some moment of time that all tokens of 'now' refer to. But so what? Nobody ever thought differently."

Lots of people have thought differently! Lee Smolin, for example, has spent the last few decades trying to convince other physicists that "now" has a unique quality to it that may unlock future discoveries into a deeper understanding of quantum mechanics.

Secondly, Maudlin uses circular reasoning to equate sequence with flow. He asserts that time is different than space because it has direction, and thus, flow. But, as innumerable physicists have written, although there is a difference between past and future, the *direction* of that difference does not appear in physics. The only reason we think of a sequence of events as flowing towards the future and not towards the past is because we have a sense of time flowing.

We could easily imagine a preferred direction to a spatial dimension that would allow things along that dimension to be placed in an ordered sequence. That would in no way imply that space "flowed" in any particular direction.

Please, Dr. Maudlin, read up on the numerous people who have written on this subject (including your history of Einstein and philosophers who have defended true presentism) before publishing articles on this topic.

Gabriel Vacariu 1 30 November 2022

Einstein's relativity presupposes "time" (spacetime), but his personal belief was "time" did not have an ontological status...