unidentified sighting report - any ideas?

Having read a few postings, related to purported sightings, I think its time to post one of my own. My motivation is really to see if anyone has had a similar experience - I have never been able to find an explanation for what I saw, although I do have a few possibilities in mind.

I have had more than one experience over the years, but the one I am interested in relating at this time occurred about 5/6 years ago -2002, possibly 2003. It was early summer, June or July, and took place between approximately 10 and 11pm.
Sorry the dating is vague, there was a lot going on in my life at that time and I was rather distracted.

Location was in my back yard, which is in the south east of England.
I was sitting out; stargazing and watching air traffic come and go, with my (now ex) wife. We used to do this a lot when the weather was fine. The evening was quite clear, but (as usual) there was a certain amount of light pollution from the sodium street lighting that lines the main roads around the edge of the housing estate. I'm about 1/4 mile from a fairly big river, and I think that because of this there is always a slight 'haze' in warm weather, which tends to refract the orange light back down. It’s a pain, as I have a telescope, and it makes summer viewing difficult toward the horizon.
However, on this occasion, that haze was very important. I think it must have been sitting at the boundary layer (around 1000 feet), as there was no ground level mist, due to a very slight breeze.

As we sat staring up my ex, D, suddenly pointed and said 'look at that!'. I followed her direction, almost vertical, and caught sight of, well, nothing, except a wake, showing in the mist. There was no light, no sign of anything solid, just this distinct bow wave effect. It travelled across the sky quite quickly, from east to west, in probably two seconds - I was lucky to see it at all. It had the shape of, well, a disc, displacing air around it as it travelled. The apparent size would have been the diameter of a tennis ball at arms length, and it became clearer near the rooftop horizon, where the light source was stronger. There was no audible indication of any kind from the phenomena.

That was it, really. We were surprised, and discussed it, inconclusively, and then, around twenty minutes later, we saw exactly the same thing, again! The trajectory was similar, although this time a little further south, but I would guess hundreds, rather than, thousands of yards. Apparent altitude was the same, and airspeed was similar too (the sighting lasted longer, as we spotted it earlier - maybe 4 or 5 seconds).

I have wracked my brains over this - nothing solid to view, no lights - no sound. I couldn’t even see any residual turbulence in its path. It was almost as if it unzipped the atmosphere and slid between it, rather than passing through it.

Interpretations.
I wonder if it may have been a Stealth aircraft? (Hard to believe it possible, but...)
Could it have been meteorological phenomena? Certainly not one I have ever heard of.
Possibly some kind of energy beam / scalar ray projected from an orbital or high altitude source?
(Aside.... I have wondered about plasma weapons and crop circles - same principals?)
Some form of non-human technology?
Paranormal phenomena?
'
I don't expect anyone to be able to furnish a definitive answer to all this, but if you’ve had a similar experience, or have an idea you would like to throw in the mix, please be my guest.

And hey, and thanks for reading!

That's a really interesting sighting - thanks for sharing it with us. I'm not sure what conventional explanation could be found for it, but I've had some ideas about the technology for saucer propulsion, if that's what it was. The O'Hare incident got me thinking about it again.

It could be some vehicle (either ours or "theirs") using an Alcubierre drive. That's another word for Warp Drive. It's the theoretical method of propulsion where the ship creates a warp bubble around it to allow it to travel at faster-than-light speeds, without running into the whole special relativity constraints or g-force problems. Your perception that it "unzipped the atmosphere and slid between it, rather than passing through it" brought this to mind.

Here's a wikipedia article about it:

Alcubierre Drive

Thanks Nightowl, good link, and an interesting idea. I couldn't begin to understand the algebra, but the words suggest a possibility.

Big problem is when they talk about warp drive, and I start getting trekkiphobia! :0)