No Boundary Condition Universe: Stephen Hawking

In summary, the conversation discusses Stephen Hawking's no boundary condition universe proposal and how it is similar to the structure of Earth. It also brings up the possibility of a closed universe dominated by dark energy that would continue to expand forever. The question is posed whether the existence of dark energy would affect the origin of space-time, to which the response is that it does not falsify Hawking's proposal nor have any specific implications for the origin of space-time.
  • #1
us40
29
0
Hello,
According to Stephen Hawking no boundary condition universe does not have any boundary in space time.If it is so then it is like earth.You can not go north to north pole.Earth does not have any edge or boundary.So universe is like closed structure like earth.Means after some times it collapse on its own and expansion stops.But acceleration of expanding universe suggest that universe may be expand for forever and that is open universe.So does it imply that universe had in past(before plank epoch) boundaries for space and time?
 
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  • #2
us40 said:
Hello,
Means after some times it collapse on its own and expansion stops.
How does this follow from the premises of the proposal?
 
  • #3
bapowell said:
How does this follow from the premises of the proposal?

http://web.uvic.ca/~jtwong/Hartle-Hawking.htm
 
  • #4
Aha. There is an additional assumption here that there is no dark energy in the Hartle-Hawking universe. There is nothing wrong, however, with a closed universe dominated by vacuum energy (dark energy) that goes on expanding forever. In other words, it is incorrect to conclude an open universe from the fact that it is accelerating now, or indefinitely into the future.
 
  • #5
bapowell said:
Aha. There is an additional assumption here that there is no dark energy in the Hartle-Hawking universe. There is nothing wrong, however, with a closed universe dominated by vacuum energy (dark energy) that goes on expanding forever. In other words, it is incorrect to conclude an open universe from the fact that it is accelerating now, or indefinitely into the future.

Thanks for reply..
But what my question is that if Hartle-Hawking model is wrong or finding of dark energy after that model does it has any effect on "origin of space-time"?
 
  • #6
us40 said:
Thanks for reply..
But what my question is that if Hartle-Hawking model is wrong or finding of dark energy after that model does it has any effect on "origin of space-time"?
No. AFAIK the presence of dark energy does not falsify Hartle-Hawking nor does it have any specific implications for the origin of spacetime.
 

1. What is the No Boundary Condition Universe theory proposed by Stephen Hawking?

The No Boundary Condition Universe theory is a cosmological model proposed by physicist Stephen Hawking in the 1980s. It suggests that the universe has no beginning or end and is a closed, self-contained entity with no boundaries or edges.

2. How does the No Boundary Condition Universe theory differ from the Big Bang theory?

The Big Bang theory suggests that the universe began as a singularity and has been expanding ever since. In contrast, the No Boundary Condition Universe theory proposes that the universe has always existed and does not have a specific starting point.

3. What evidence supports the No Boundary Condition Universe theory?

One of the main pieces of evidence for the No Boundary Condition Universe theory is the cosmic microwave background radiation, which is the leftover radiation from the early stages of the universe. This radiation is consistent with a universe that has no boundaries or edges.

4. How does the No Boundary Condition Universe theory explain the origin of the universe?

The theory suggests that the universe arose from a quantum fluctuation, which is a random and temporary fluctuation in the energy levels of empty space. This fluctuation caused the universe to expand and evolve in the way that we observe it today.

5. What are some potential implications of the No Boundary Condition Universe theory?

If the theory is proven correct, it would significantly change our understanding of the origins and nature of the universe. It would also have implications for the concept of time and the laws of physics, as well as potential applications in fields such as quantum mechanics and cosmology.

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