# TRON: Legacy - How can the light jets do a Hammerhead Stall? Is there an atmosphere in The Grid?

Just finished watching TRON: Legacy for the third time and the same question persists: If these are digital creations then "air" and "atmosphere" would only be concepts like in the Matrix ("is that air you're breathing?"). How then do the white and orange Light Jets stall-out in the air at the end of the movie when Quorra takes them straight up vertically into what is known as a "Hammerhead Stall" which is a direct function of atmosphere? I assumed the activity of "flight" was more a digital representation of movement, that wind represented fast moving data, etc, but this suggests actual Bernoulli principles in operation (why real aircraft fly)...??? Is there actual air, actual atmosphere in The Grid??

• You could have a Hammerhead Stall in a vacuum, if the thrust was not quite enough to counter the weight. You'd have a lot of forward momentum built up from lateral movement, which bleeds off incrementally when you go vertical, and then - hammerhead stall. Jul 20, 2012 at 20:11
• I'm pretty sure that a hammerhead stall is not a direct function of atmosphere. It occurs where vertical thrust can no longer counteract gravity. You might be better off asking why the jets need wings
– user11154
Dec 7, 2012 at 13:55

In the grid, everything is function of the model Flynn programmed for it. Physic are well simulated, but some feat like the light cycle's 90 degree turns are just unrealistic.

As for Light jet, they are, or are running on, a flight simulation program. If the simulation is made to simulate a stall, It may be just because Flynn wanted to implement a maximum altitude to his jets program and the stall was an intuitive way to do it. An invisible ceiling would be another, although less elegant, way to force this limitation. It could be because he does not want to deal with overflow altitude values or another reason. However, the reason behind a stall in real life (air density) don't need to be implemented to properly simulate it.

• Very good answer. Ironically I found the math of the Light Cycle's 90 degrees turns to be more palatable in a hard-logic kind of way, i.e. an if-then of the [user/program]'s "hand" input on a measure of varying degrees. In other words, I could let go of gravity and inertia in a world of math easier than I can let go of implied atmosphere! LOL :D But thank you for your thoughtful answer anyway. Let me chew on this one a bit and get back to you. :) May 15, 2012 at 4:15