An interesting notion about inflation.

[zeromodz]

I was thinking about how big the universe got after inflation occured. Then I thought about Hubble's parameter.

Ho = V / d (At the big bang, the distance between the two edges of the universe were zero)
Ho = V / 0
Ho = ∞ km*mpc / s

Therefore, the rate of the expansion must have been infinite once the universe started to expand. Wouldn't that mean the universe now must be infinite in size?

 

[LURCH]

If the rate of expansion is infinite, then the universe became infinitely large in zero nanoseconds, and has become infinitely larger every zero nanoseconds since.

This is the problem when we try to divide by zero, which is why the current mathematical models can't take us to the first instant of the BB (or the center of a BlackHole).

 

[Chronos]

Infinities are generally regarded as mathematical artifacts - where theory, not reality, has broken down.

 

[twofish-quant]

Therefore, the rate of the expansion must have been infinite once the universe started to expand. Wouldn't that mean the universe now must be infinite in size?

No.

Take a piece of graph paper and draw a step function. The rate of expansion is infinite at the step, but the function is finite.

You see these sorts of infinities all the time, and there are a lot of mathematical tools for detailing with them. There are also infinities that "you can deal with" and infinities that really mess things up.

 

[pmacias]

I find this notion about inflation and the expansion of the universe to be very intriguing. The concept of Hubble's parameter, which describes the rate of expansion of the universe, is an important factor to consider in understanding the size of the universe.

Based on the equations you have presented, it does seem that the universe must have been infinite in size at the moment of the big bang, as the rate of expansion was infinite. However, it is important to note that this is a theoretical calculation and may not accurately reflect the true nature of the universe.

Inflation is a complex process that is still not fully understood, and there are many theories and models that try to explain it. It is possible that the universe did not start off as infinite in size, but rather underwent a rapid expansion that eventually slowed down. This would mean that the current size of the universe may not necessarily be infinite.

Additionally, there are other factors to consider such as the curvature of space-time, which can affect the size of the universe. The concept of infinity is also a difficult one to grasp, especially in relation to the vastness of the universe.

Overall, the idea that the universe may have started off as infinite in size due to inflation is certainly thought-provoking. However, further research and evidence are needed to fully understand the true size and nature of our universe.

 

[sardar]

I find this notion about inflation and the size of the universe to be intriguing. The concept of Hubble's parameter, which relates the expansion rate of the universe to its size and distance, is a fundamental aspect of cosmology. It is true that at the time of the big bang, the distance between the two edges of the universe was zero, and therefore the value of Ho would be infinite. However, it is important to note that this calculation is based on the current understanding and measurements of the expansion rate. In reality, the expansion of the universe is not a linear process and has varied over time.

Additionally, the concept of infinity in relation to the size of the universe is a complex and debated topic in cosmology. While some theories suggest that the universe may be infinite in size, others propose that it may have a finite but unmeasurable size. Further research and advancements in technology will continue to shed light on this question.

It is also worth considering that the expansion of the universe is not the only factor that determines its overall size. The presence of dark matter and dark energy, which make up the majority of the universe, also play a significant role in its structure and size.

In conclusion, while the idea of an infinite expansion rate and an infinite universe is a fascinating concept, it is important to approach it with caution and continue to explore and gather evidence through scientific research. The true size and nature of the universe may continue to surprise and challenge us, and that is what makes the study of cosmology so exciting.