Possible Positions on the Passage of Time

By Bryan 2 February 2009 philosophy of physics

Presentism

The present exists; the past and the future do not.

Block

The past, present and future all exist.

Growing Block

The past and present exist; the future is coming into existence.

Shrinking Block

The future and the present exist; the past is destroyed as we go.

Growing and Shrinking Block

The future is coming into existence; the past is being destroyed.

Anti-presentism:

The past and future exist; the present does not.

Anti-block

The past, present, and future do not exist.

Random Block

A surprise combination of existence, growth and destruction.

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10 thoughts on “Possible Positions on the Passage of Time”

Mike J. 2 February 2009 at 11:33 pm

That’s terrific.
Anonymous 3 February 2009 at 2:32 am

Isn’t presentism a limiting case of the growing and shrinking block model? (in which the block that exists is reduced to a surface really). Well, this is so, if presentism is okay with saying that future will come into existence.
Bryan 3 February 2009 at 9:24 pm

It’s been suggested (thanks JDN) that we add some possibilities, by taking each of the cases above, and restricting attention to the causal past/future of an observer (or set of observers). This kind of thing was first suggested by Stein (1991).

So instead of a growing block, we would have a growing cone, etc.
Jim Bowery 3 February 2009 at 9:59 pm

Try dynamic rather than kinematic Markov processes.
Jim Bowery 3 February 2009 at 10:00 pm

Sorry, here’s the URL:

http://boundaryinstitute.org/articles/Dynamical_Markov_files/v3_document.htm
Brad 4 February 2009 at 2:43 am

I endorse random block, but only when it takes the depicted form, namely, containing a series of love-heart-shaped cross sections.
Seamus 5 February 2009 at 12:48 pm

I advocate the view that spacetime is shaped like the Menger sponge.
wolfgang 7 February 2009 at 7:23 am

I think the anti-block is the most convincing.
Bryan 7 February 2009 at 10:29 pm

The Menger sponge spacetime is a cool idea. It’s a compact spacetime! However, it’s ridiculously discontinuous. This is weird, but I think the idea is worth taking seriously. It certainly seems unlikely that there could ever be an experiment establishing the continuity (let alone the analyticity!) of spacetime.
Anonymous 27 May 2012 at 4:09 pm

Comprehensive list, but after Shrinking Block, you sort of lost me LOL.

–Alfred