[peristar]

Hello everyone....i have a really big problem so i was wondering if anyone here can help me...well...i need to find out if there is any gas that can change the color under outside influence( electromagnetic field, temperature, preasure or whatever)? pls if anyone have clue or links let me know....thanks...

[Borek]

Short answer: no.

Longer answer: whatever exists, is toxic.

Detailed answer: search the forums, this question is posted every few weeks.

[intrepid_nerd]

read about JJ Thompson's experiment. if you can have an anode and a cathode, then yes!  make some plasma! WEEE!!!!  umm....this could be interesting if you put the anode and cathode outside of your cathode ray tube (i guess then it wouldn't be a cathode ray tube), perhaps design some new-age tube?  just be careful about exploding glass.  you'd still be penetrating into the sample though and this is probably against your stipulation.  umm... i'd bet this is possible. it's all in the design of the shape of your glass containing your sample.  remember the old tornado experiment with two 2L coca-cola bottles?  maybe if you designed something like that, put two types of gasses in there, separated them into opposite sides somehow and then increase pressure (temp?).  who knows, chemistry is all guesswork anyway.  read children's picture books, the most simple/practical answers are in them, i swear to it.