Is This True Quantam Experiment If You Look At it It Changes?

firstly, im a begginner, and my brother showed me a video that if you have 2 slits and you send 1 electron it will become distorted.


its a long descritoptino so ill try to shorten it.





1 electron goes through at a time it makes that 2 lines affect only when oberving it, and when you dont look it makes a distriributed afect?





is this true?





herse the video





http://www.youtube.com/watch?v=DfPeprQ7o鈥?/a>





its about 2 minutes before the endIs This True Quantam Experiment If You Look At it It Changes?
Yes, it's true. Any measurement that tells you what slit the particle went through will stop the interference pattern from forming. In fact, if you have a detector that randomly works half of the time, you will get a pattern halfway between the two-band pattern and the interference pattern.





HOWEVER, the word ';observe'; is very misleading. ';Observe'; implies that a conscious observer changes the interference pattern. Really, it is the presence of the detector that matters. No people required.Is This True Quantam Experiment If You Look At it It Changes?
It's true. Google ';young's double slit experiment'; and you'll find a couple of different interpretations. In particular, Wikipedia's article on this is pretty good, though its references are to printed books, so I don't know know how accurately the article has synthesized information from the sources.





Here's an excerpt describing why an observer interferes (HA!) with the interference.





';The detection of a photon involves a physical interaction between the photon and the detector of the sort that physically changes the detector. (If nothing changed in the detector, it would not detect anything.) If two photons of the same frequency were emitted at the same time they would be coherent. If they went through two unobstructed slits then they would remain coherent and arriving at the screen at the same time but laterally displaced from each other they would exhibit interference. However, if one or both of them were to encounter a detector, time could be required for each to interact with its detector and they would most likely fall out of step with each other鈥攖hat is, they would decohere. They would then arrive at the screen at slightly different times and could not interfere because the first to arrive would have already interacted with the screen before the second got there. If only one photon is involved, it must be detected at one or the other detector, and its continued path goes forward only from the slit where it was detected.';