[fusion event]What is Time

This topic will be a repeat from 3 years ago.

Time is a concept and feature of the world we deal with continually, but we have a shockingly poor understanding of it,

For most of history, time has effectively been treated as a logic feature-- things tend to happen in state sequences, and time is basically just the ordering of state sequences. When one then adds the concepts of choice and experience to this, then one point in state sequencing stands out, the present. The Presentism model of time postulates the only things that actually exist are the things of the universe, and they only exist in their "present" state -- hence "presentism". "Time" doesn't really exist -- it is an invented concept by us to refer to the history of state sequences, and to project future state sequences -- time is a nominalist concept. Presentism works well for our experiences, and the logic of event sequencing, but has some flaws when engineers and physicists are modeling the past and future, and when logistics planners need to construct supply line plans.

Which leads to the Block model of time. This model treats time as a dimension of a 4-D Space-time continuum. This is Einstein's model behind General Relativity. In Block Time -- the past, present, and future all have the same status -- there is no special feature to the present. And the future is already set. Block time works great for calculating when to set out in a spacecraft to get to Mars, how long it will took to drain a bathtub, and how soon one needs to head to the airport to catch a flight.

Historians, and photo album assemblers, however, tend to think there is a fundamental difference between past and future, and generally use Growing time as their model. In Growing time, the past is a Block, and the Block of past is time. The present is the growing edge of time, and the future is just speculations.

Here are three recent physics books advocating for each of these time models:
https://www.amazon.com/Now-Physics-Time-Richard-Muller/dp/0393354814/ref=sr_1_21?qid=1554052463&s=books&sr=1-21

https://www.amazon.com/Singular-Universe-Reality-Time-Philosophy/dp/1107074061/ref=pd_sim_14_3/142-1644542-8390269?_encoding=UTF8&pd_rd_i=1107074061&pd_rd_r=e0f49f8f-53d8-11e9-b6b9-cd59af5e4b95&pd_rd_w=C6bGd&pd_rd_wg=435Rj&pf_rd_p=90485860-83e9-4fd9-b838-b28a9b7fda30&pf_rd_r=A4MCG724N1CV7NYNAZE6&psc=1&refRID=A4MCG724N1CV7NYNAZE6
https://www.amazon.com/Brief-History-Time-Black-Holes/dp/0816147736/ref=sr_1_2?keywords=a+brief+history+of+time&qid=1554052738&s=books&sr=1-2

These books criticize each other's models.

• Block time provides no explanation of our sense of the present -- leaving out a key feature of time.
• Block time is in conflict with indeterministic models of Quantum Mechanics (all but Bohmian Mechanics).
• Presentism's (and Growing Time's) infinitesimal approach to time's extent -- moments are all that there is -- cannot explain the duration of processes.
• Presentism is in conflict with the "no common reference time" of general relativity (Smolin and Unger's book proposed a fix for this)
• In growing time the present is SECONDARY to the past. But the present seems to be far more important than the past.

In application, we then to jump between these three models. Presentism is used in pretty much all decision-making and thinking about causation. While growing time is how pretty much all formal studies of the past and informal reminiscences tend to operate. And Block Time is used for all problems that project a future state.

Questions:
These three models treat time as significantly different in nature. what does it say about our understanding of time, that such radically different models are being claimed to be "true" about it?
These three are exclusive of each other, but in application people tend to jump from one to another. What do you folks think of the "exclusively true" claims by the three advocates cited? Is it possible NONE of these are exclusively true? Note, this is often the case in empirical science where models are only locally valid, and one must jump from one modeling approach to another for a different aspect of a problem.
If "none of the above" were true, what alternate approach to time might be fruitful to consider?

We meet in person and online. In person will be on the upper level of Wegmans in Columbia. Online will be: https://teams.live.com/meet/93583191724730?p=hY3jxVvnOciVl2aRn5
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-----------------------------------------------------------------------------------------------------------------------------PS -- Wegman's has made an exception to their "no meetings" rule for us. They ask us to be non-disruptive, and for most of us to purchase food or drink. If someone asks, we have been given permission to meet by Ayana Douglas.