Illusion of Time: Is the Future Already Written?

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Discussion Overview

The discussion revolves around the concept of time as presented in Brian Greene's "The Fabric of the Cosmos: Illusion of Time," particularly focusing on the implications of an alien's "now slice" in relation to Earth's past and future. Participants explore the nature of time, determinism, and whether the future is predetermined or merely a matter of perspective based on relative motion. The scope includes theoretical interpretations of time, relativity, and philosophical implications.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants propose that an alien's "now slice" changes with velocity, affecting how their future aligns with Earth's past or future.
  • Others argue that while the "now slice" changes, it does not imply practical significance since information is always received from the past light cone.
  • A participant mentions the Andromeda Paradox to illustrate the complexities of simultaneity in relativity, suggesting that different observers can perceive events differently based on their motion.
  • Some claim that in certain interpretations of the universe, the future is already written, aligning with deterministic views of spacetime.
  • Others challenge this notion, emphasizing that the laws of physics do not dictate events but arise from the structure of spacetime, leaving room for quantum uncertainty.
  • There is a discussion about whether Brian Greene's presentation implies that the future has already happened or if it merely reflects a different perspective on time.

Areas of Agreement / Disagreement

Participants express multiple competing views regarding the nature of time and determinism. There is no consensus on whether the future is predetermined or if it is merely a matter of perspective based on relative motion.

Contextual Notes

Some limitations include the dependence on interpretations of relativity and the unresolved nature of how quantum mechanics interacts with these ideas. The discussion also reflects differing opinions on the implications of time as a 4-dimensional continuum.

  • #31
I might be misreading you here, but as far as I know, the time on your wristwatch is still dependent on your reference frame. That was the whole Hafele-Keating experiment. GPS satellites have to calibrate for time dilation to match up with time on the ground. According to this, the GPS system would crash in about 2 minutes or so without adjustment for relative time.

Definitely misreading. What I refer to as wristwatch time is simply the "length" of a geodesic in GR.
 
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  • #33
TerryWalsh290 said:
According to her, the Aliens can see our future! They just can't tell us about it though, but it has been written!
Not only can they not tell us about our future, they cannot "see" it either. Any individual observer that is distant from an event,, never knows about an event before an observer local to the event, whatever their state of relative motion from the point of view of any reference frame. The Andromeda paradox and block time concept are just party tricks, with no practical application.
 
  • #34
yuiop said:
The Andromeda paradox and block time concept are just party tricks, with no practical application.

The Andromeda Paradox emphasises that the hyperplane called "now" is just a coordinate-based labelling of events. "Future" and "past" are meaningful only insofar as they refer to an observer's light cones.
 
  • #35
Interesting to see that others are also frustrated with the description by Greene. When I first read the book, I read that section three times, could not figure out what he was trying to convey, and so moved on. Haven't tried again yet and don't plan on it.

The rest of the book I also have probably read about three times...but because the rest I found extemely insightful...Starting out, I got a lot of valuable perspective from both Farbic of the Cosmos and the Elegant Universe...
 
  • #36
If it does really like that, so is the concept of time traveling becoming possible ?
since we still on the same moment even in different position just the speed of light make us to having different point of view.
 
  • #37
DevonG said:
...Imagine painting a picture - with no perspective, no angle of view. Obviously such a thing can't exist...

Really? Don't we call that 'sculpture'?
 

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