Verified answer

if we weren't any good at hiding our craft, then we probably wouldn't be using any kind of chaff. we'd be spotted because we wouldn't know how to hide.

but, to try to answer, I guess we would have to know what they where using to "see" with, like radar or what type of technology.

Knowing how they actually see see with their eyes or whatever would help. We might be able to scramble their "eyes" with radio waves or something simple.

heres a group that is actually working on some projection "cloaking" device/fabric

http://www.star.t.u-tokyo.ac.jp/projects/rpt/movie...

Then theres REAL DEAL light warping cloaking device... but it still needs some beefing up.

http://www.youtube.com/watch?v=Ja_fuZyHDuk&feature...

Depends on the definition of primitive. If they had really advanced radar and sensory equipment and things, then the best bet would be to send out some sort of electromagnetic waves (gamma rays would probably fry the machines.... and the aliens too... -.-) to disrupt the signals bouncing back and forth. Or go with good ol' metal thrown out the side door (or through the air-seal-uber-space-walking-hatch-thingy); however, that would prabably only make them think that there are more intruders. You could also try sending out an EMP (electromagnetic pulse); that would render all electronic machines useless... ohe wait... I forgot, we're a thousand feet high in the air in an electronic (partly) machine.... ><

Well maybe you could concentrate the pulse in one direction, make a spaceship out of non-elctronic components, or launch an ICBM at them and fly a way real fast (nukes send out EMPs).

Now, if they're detecting old school (aka their eyes), then you might want to use some sort of cloaking device (like Star Wars) or a projection that looks like their sky. Or just kill them. Or fly reeeeeally high. There are some studies in materials that are able to bend light around and object and place it back in its original trajectory, thus preventing reflections and thus eliminating visibility. However, so far such inventions have only been compatible with microwaves and such. Creating material able to bend visible light entirely would be very difficult; one has to take into account all of the different frequencies of the visible spectrum, each of which requires a different composition of material.

The third option is to stay away in the first place, as us humans would probably get owned by the other life forms. It could turn out like a version of War of the Worlds with us as the guys in the big tripods and laser beams. And all those invasion stories end with the invaders getting their butts kicked.

The best way to hide in plain sight would to be to construct an aircraft that looked just like one of theirs. If YOU looked up and saw a 737 jet flying over that was full of alien scientists you wouldn't look twice at it.

Holograms, projected images into the clouds, maybe, maybe visuals and sound both. Fireworks displays.

It all depends on the level of development of the primitives and whether they were enough like us to allow humans to mingle.