Have You Seen a Space Shuttle Lift-Off?

[martix]

I've found this amazing footage of a space shuttle lift-off and I've got a question:
What is this bluish-whitish cone in the middle of the jets and why is it there?
(And holy cow, it's loud... even on video).

 

[D H]

That's hydrogen and oxygen burning. The image is from a fraction of a second after main engine startup.

 

[martix]

If that's really the answer you chose to go for, I will restate:
Why is it a different color than the rest of the jets?

 

[D H]

The solid rocket boosters don't burn hydrogen and oxygen.

 

[martix]

Another question then:
Where in the above frame do you see solid rocket booster thrust jets?

Ah... ok, let's jump ahead and skip the continuation of this little exchange of ours.

Since you seem to have misunderstood let me describe it in excruciating detail:
In the above frame, at exactly the moment it depicts, directly below each of the liquid fuel engine nozzles, in the middle of the orange hydrogen flame jets, there are those bluish-whitish cone-shaped regions.
That is what I am asking about. (let's hope now...)

 

[russ_watters]

http://en.wikipedia.org/wiki/Mach_disk

 

[martix]

Thank you.
That blackbird engine looks amazing. :)