My wife and I recently decided we could not, in clear conscience, make a trip to London merely to attend a wedding.  We were both sure that the cost to the planet of such whimsical continent-hopping must be unsustainable, but had no real idea just much energy it takes to move one adult from Johannesburg to London by air (approx 9000kms or a quarter of the way around the world).  We'd love an answer expressed in everyday terms like say tumble-drier-hours, or 100W lightbulbs burning, etc.

Tim Greene Johannesburg

On a long haul flight I wondered with the amount of people who now fly, and the amount of money airlines make, surely one that was as big as an Airbus yet as fast as a concorde would certainly dominate the market in which people want to use.

I am not only concerned with cost as I am sure they would make the money back, but is it possible to make such a big plane fly so fast? 

On our approach to landing at Melbourne airport just after sunrise while aboard a commercial airplane I noted moving on the clouds at the same speed as the plane a circle of light with a rim of bright light and an outer rim of red light (see photo). On occasion I saw the shadow of the airplane within this circle of light.  It seems that this circle of light was from the rays of light from the rising sun and that they were being distorted by the airplane. What was happening?