- #1
Denver Dang
- 148
- 1
Homework Statement
I've been told to calculate the age of the Universe at [itex]T = 1 \, \text{MeV}[/itex], assuming that [itex]a(t=0)=0[/itex].
Homework Equations
Now, I've already calculated the value of [itex]H[/itex] at that temperature, which was around [itex]H(1\,\text{MeV}) \approx 0.6 \,\text{s}^{-1}[/itex]. I've also shown, that in a radiation dominated Universe, which I assume much be the case at [itex]T = 1 \, \text{MeV}[/itex], that:
[tex]H = \frac{1}{2}t^{-1}[/tex]
The Attempt at a Solution
So basically, my idea was just to solve for [itex]t[/itex] in that equation, and use the value for [itex]H[/itex] I calculated, and then I end up with [itex]t = 0.85 \, \text{s}[/itex], which seems okay reasonable to me, but, my main question is the info: "assuming that [itex]a(t=0)=0[/itex]". I haven't really used that information here, so either it's just not important, or I have missed something. But what ?