# Total energy at Planck time?

1. Jan 31, 2016

### big_bounce

Amount of Planck energy is 1.956 * 10^9 J.
Was this total energy of universe at plank time at big bang cosmology model?
It's clear this amount of energy is not enough for making our solar system, even it's not enough for making mass of me ( 60 kg ).
Should we postulate energy increase in the universe after Planck time?

If yes, how could? by means quantum tunneling? inflation?

2. Jan 31, 2016

### Drakkith

Staff Emeritus
No, it's just the unit of energy you get when you set the constants G, ћ and c to 1.
https://en.wikipedia.org/wiki/Planck_energy

3. Jan 31, 2016

### big_bounce

4. Jan 31, 2016

### Drakkith

Staff Emeritus
Why not?

5. Jan 31, 2016

### big_bounce

Because c and k are constant in this formula.

6. Jan 31, 2016

### Chronos

How does that compare to the planck temperature? A leading question, I admit.

7. Jan 31, 2016

### Drakkith

Staff Emeritus
And how does that tell us that the mass of the universe at planck time couldn't be more than the planck mass?

8. Jan 31, 2016

### big_bounce

If i put my mass (60 kg) at this formula we don't get 1032K.

9. Jan 31, 2016

### big_bounce

10. Jan 31, 2016

### Drakkith

Staff Emeritus
Of course you don't. That's not how you use the equation. Unfortunately you'll have to look into how temperature is defined in order to see why the equation is set up the way it is (or wait for someone with more knowledge than myself to explain it).

11. Jan 31, 2016

### Staff: Mentor

Temperature is not the total energy; it's the average energy per particle. If you have 60 kg worth of particles each one of which has the Planck energy, then the temperature of the whole system is the Planck temperature.

Last edited: Jan 31, 2016
12. Jan 31, 2016

### bcrowell

Staff Emeritus
13. Feb 2, 2016

### newjerseyrunner

My understanding of the early universe is that most of the energy of the universe was created by Hawking Radiation during inflation, not the instant of creation.

14. Feb 2, 2016

### bcrowell

Staff Emeritus
This sounds wrong to me for a variety of reasons. Energy is locally (but not globally) conserved, so we don't have processes that create energy. There is no "instant of creation," since GR doesn't describe a singularity as a point on the spacetime manifold.

15. Feb 2, 2016

### Staff: Mentor

No, this is not correct, for at least two reasons. First, what happened at the end of inflation was not "creation of energy"; it was just a transfer of energy from the inflaton field to the fields described by the Standard Model of particle physics (quarks, electrons, neutrinos, etc.), caused by the inflaton field changing state from the "false vacuum" state it had during inflation, to the "true vacuum" state it has had ever since. Second, this energy transfer process (which is called "reheating" in cosmology, something of a misnomer since there was no previous "heating" of anything) was not Hawking radiation and bears no resemblance to it.