# Hubble's Law enquiry

1. Jan 14, 2016

### Einstein's Cat

The recessional velocity of a galaxy can be calculated using Hubble's Law; the equation where Hubble's constant multiplied by the distance to the galaxy equals the recessional speed of that galaxy. Thus, what is the distance to a galaxy that is required so that the recessional velocity of that galaxy would be the speed of light. Any help would be very much appreciated and please correct any mistakes. Thank you.

2. Jan 14, 2016

### Simon Bridge

What do you need help with?
Hubble's law can be used to work out the kind of distance where the recession is faster than light - yes.

3. Jan 14, 2016

### Einstein's Cat

What I was asking is that what is the required distance so that the recessional velocity of the Galaxy would be exactally the speed of light?

4. Jan 14, 2016

### Simon Bridge

But you know that - you wrote it down: v = Hd where H is the hubble constant, d is the distance to the galaxy, and v is the recession speed.
So put v=c and use algebra to solve for d.