How Close Are We to Understanding Time and Space?

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Discussion Overview

The discussion centers around the concepts of time and space, particularly how they relate to perception and the behavior of objects moving towards each other. Participants explore questions about the nature of "now," the implications of distance on time perception, and hypothetical scenarios involving objects in motion and size changes.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant questions the relationship between distance and time, suggesting that closer objects may be perceived as being closer to "now."
  • Another participant references Zeno's First Paradox in relation to two spheres moving towards each other while decreasing in size, implying a philosophical inquiry into motion and meeting points.
  • A participant challenges the vagueness of the statement regarding distance and time, asking for clarification on the concept of "old light" from distant objects.
  • One participant asserts that two point particles traveling towards each other will meet if their velocities are equal and opposite, suggesting a simplification of the original spheres problem.
  • Another participant presents hypothetical scenarios involving the passage of time and the nature of information transfer, questioning whether receiving information implies being in the past.
  • A participant expresses uncertainty about the implications of measuring light distance from distant galaxies and its relation to the age of the universe, raising further questions about the nature of time as the universe changes.

Areas of Agreement / Disagreement

Participants express various viewpoints on the nature of time and space, with no clear consensus reached. Multiple competing views remain regarding the implications of distance on time perception and the outcomes of hypothetical scenarios involving motion.

Contextual Notes

Some discussions rely on assumptions about the nature of time and light, and the implications of hypothetical scenarios may not be fully resolved. The exploration of Zeno's Paradox introduces additional complexity to the conversation.

UnBoxedCat
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When is now?

The further away an object is, the further back in time it appears to be. So does this mean the closer an object is, the more closer it is to now?

Which brought up another question, as i lapsed between dreamland and the noise of the dogs barking and running around with squeeky toys! If there are 2 objects of equal size traveling towards each other at equal velocity (i imagined 2 spheres), and at the same time decreasing in size, at the same rate... would they ever meet?

As you probably guess by the simplicity and probably ignorant questions... I'm new to physics (as in, I've never studied or read anything about the subject). But I just had to ask these questions before they fried my brain. This seems to be the best place to ask.

Scott
 
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about those spheres, just assume some radius and velocity and calculate urself if they will reach each-other...
 
UnBoxedCat said:
When is now?

The further away an object is, the further back in time it appears to be. So does this mean the closer an object is, the more closer it is to now?

Which brought up another question, as i lapsed between dreamland and the noise of the dogs barking and running around with squeeky toys! If there are 2 objects of equal size traveling towards each other at equal velocity (i imagined 2 spheres), and at the same time decreasing in size, at the same rate... would they ever meet?

As you probably guess by the simplicity and probably ignorant questions... I'm new to physics (as in, I've never studied or read anything about the subject). But I just had to ask these questions before they fried my brain. This seems to be the best place to ask.

Scott

For your first question, both time and distance are considered to be dimensions, but distance has two directions whereas time only has one (i. e., "time's arrow").

For your second question, this appears to be a variation on Zeno's First Paradox. Google on it for some interesting discussions.

By the way, questions like these will not fry your brain. They will stretch it!
 
The further away an object is, the further back in time it appears to be.

A bit vague. Are you referring to the fact that light that reaches you from far away is "old light" in the sense that is was sent off a time of [itex]\frac{\textrm{distance}}{\textrm{speed of light}}[/itex] seconds ago?
 
For the spheres problem, they will meet. Just replace either of sphere with a point particle. Two point particles traveling head on towards each other will meet if their velocities are equal, opposite in direction and constant.

The reason I am considering point particles here is that if the spheres keeps decreasing, they will eventually approach the size of a point particle.
 
Last edited:
Consider these two points;

-I've I post a letter to you and you receive it three days later am I three days in the past?
-Two balloons are blown up then released without having a knot tied in them. They are propelled towards each other expanding air as they go. What will happen?
 
All news is old news. It takes time for all information to travel from A to B so, whatever you find out about what's happening somewhere, it's really information about how things were some while ago. Even for a spacing of 1m, there is a delay of about 3ns.
Take that Supernova that 'we' observed last week. IS it happening as we watch? One could say so - the same as when we watch a feature film. The action we see on the film is 'happening' now, for us.
 
Some interesting and mind boggling stuff to consider. Thank you. I'm still not sure if I'm further from, or nearer to the answers.
When we measure the light distance from the furthest galaxies... is this the measure of how old the universe is?
If the universe were to shrink, at what point would everything become nearest the point of now? At the point of were galaxies are the size of particles?
 

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