The immensity of space primarily stems from an incredibly rapid expansion of the universe in its earliest moments.
The Role of Inflation
The prevailing theory, known as inflation theory, suggests that the universe underwent a period of extremely rapid expansion called the inflationary epoch. This period occurred about 10-32 of a second after the Big Bang. During this fraction of a second:
- Dramatic Expansion: The universe's volume increased by a factor of at least 1078. This is an almost unfathomable amount of expansion, equivalent to a linear expansion of at least 1026 in each of the three dimensions.
- Rapid Stretching: This expansion wasn't like an object moving through space; it was space itself stretching.
Understanding the Scale
To put this in perspective:
- Imagine a tiny balloon. In the inflationary epoch, that balloon would have expanded at a rate much faster than even the speed of light.
- This rapid stretching caused an incredibly large universe.
- The distances between objects grew exponentially, leaving vast emptiness in its wake.
Summary of the Universe's Expansion
| Event | Time After Big Bang | Volume Expansion | Distance Expansion (per dimension) |
|---|---|---|---|
| Inflationary Epoch | ~10-32 s | At least 1078 | At least 1026 |
Consequences of Inflation
The inflationary epoch explains why:
- Space is so vast.
- The universe appears so uniform.
- The density fluctuations which led to the formation of galaxies are so small.
Conclusion
The immense size of space is largely a result of the inflationary epoch, a period of incredibly rapid expansion of space itself very early in the universe's history. This expansion vastly increased the distances between objects, contributing to the vastness we observe today.
