2 pointsWhat up! I know I am about 16 years late but, I just wanted to point out that (like others have) @Tesseract was incorrect in saying that salt and vinegar makes hydrochloric acid. I dislike the spread of misinformation. Next time make sure something is correct before you post it to the internet. Also I made this account to post this. But I'm sure nobody will ever see this. I put so much time and effort into doing something so utterly pointless.
1 pointWhat makes the question even more complex is the tachyon wavefunctions must be subliminal. There is a particular rule for this though I would have to dig for it as I can't recall the name atm. If I recall correctly Beaz mentions it in one his tachyon articles. Edit I was right it's Paley Weiner theorem http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/tachyons.html
1 point@John Cuthber and other experts For this experiment, I confirmed again. My guy said that he could observe the movement of the spot without adding the vacuum tube. He didn't make a very careful comparison. So sorry. Now I prefer to believe that Einstein's idea that the speed of light is constant is believable. Thank you very much for your attention and suggestions on this topic.