Universe Expansion: How Space is Created

  • Context: High School 
  • Thread starter Thread starter decibel
  • Start date Start date
  • Tags Tags
    Expansion Universe
Click For Summary

Discussion Overview

The discussion revolves around the concept of the universe's expansion and the nature of space creation. Participants explore theoretical implications, conceptual challenges, and the relationship between time and space, with a focus on the boundaries of the universe and the idea of infinity.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses confusion about the concept of an infinite universe and questions whether there is an endpoint or a "wall" to the universe.
  • Another participant uses the analogy of a balloon to illustrate how space expands, suggesting that if one travels in a straight line, they might eventually return to their starting point.
  • A different viewpoint suggests that the universe's size is tied to the passage of time since the Big Bang, questioning the existence of a "wall" that time runs into.
  • Some participants argue against the idea of a physical wall, stating that it raises further questions about what lies beyond and suggesting that observational data may indicate an infinite universe.
  • One participant discusses the implications of causality in relation to the origins of spacetime, proposing that the nature of spacetime inherently involves expansion.
  • Another participant mentions the limitations of current physics theories in addressing the universe's early states and suggests that alternative theories may be necessary to understand these concepts.

Areas of Agreement / Disagreement

Participants express a range of views on the nature of the universe's expansion and the concept of infinity. There is no consensus on whether the universe is finite or infinite, and the discussion remains unresolved regarding the implications of causality and the limits of current physics theories.

Contextual Notes

Participants highlight the limitations of current theories such as Quantum Field Theory (QFT) and General Relativity (GR) in explaining the universe's early conditions, indicating a need for further exploration of alternative models like String Theory or Loop Quantum Gravity (LQG).

decibel
Messages
107
Reaction score
1
i know that the universe is expanding...but i don't understand how

how can space be created...like...i know the universe is HUGE...but it has to end somewhere it can't just keep going...like if say hypothetically that we can keep flying thru space and kept going...would in the end hit a wall or something lol...i just can't picture infinite ..., there HAS to be an end somewhere!
 
Astronomy news on Phys.org
Picture a balloon with little galaxies on it. Than blow it up. Space expands, universes recede. If you fly in one direction you would eventually end up where you started. Its commonly believed that the universe is as such.
 
Because the size of the universe is related to how much time has passed since the Big Bang,just think of time passing - there is no reason why time can't keep passing.What is the wall that time runs into?
 
I doubt anyone can imagine the totality of Infinity. But a physical wall makes no sense especially since it begs the question as to what would be on the other side. Observational data suggests that the universe is infinite in extent. But, if space is not infinite, then it curves back on itself somewhat like Parth Dave described.
 
decibel said:
i know that the universe is expanding...but i don't understand how

how can space be created...like...i know the universe is HUGE...but it has to end somewhere it can't just keep going...like if say hypothetically that we can keep flying thru space and kept going...would in the end hit a wall or something lol...i just can't picture infinite ..., there HAS to be an end somewhere!
At what scale does logic no longer apply? If causality is essential at all scales, then it applies even to the point where spacetime first came into existence, even before there were any particles. If applies to the most fundamental level, then causality would require that the very first point of spacetime should be the cause of another. If this is the definition of spacetime itself, then it is the very nature of spacetime to expand.
 
Mike2 said:
At what scale does logic no longer apply? If causality is essential at all scales, then it applies even to the point where spacetime first came into existence, even before there were any particles. If applies to the most fundamental level, then causality would require that the very first point of spacetime should be the cause of another. If this is the definition of spacetime itself, then it is the very nature of spacetime to expand.
[nitpick]the limits of our current, best physics theories - QFT and GR - are ~Planck time and size; only String/M Theory and/or LQG can help us with the universe at earlier times, and we have *no* indication as to whether which, or any, of these matches reality.[/nitpick]
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 24 ·
Replies
24
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 17 ·
Replies
17
Views
3K