Microblog Memes

Basically the sensor is interacting with the quantum particle by measuring where it is before the slit. This collapses the wave function of the particle, causing it to appear at one point in space. Since the particle is collapsed to a point before the slit, it travels through only one of the slits and impacts the screen. Since it is just a single point particle now, there is no wave to interfere with the particle and create multi-line wave pattern, so we just see two straight lines on the screen that match up with the slits.

The sensor performing the measurement is the observer in this case. No living creature is needed to observe the particle to make it collapse. It's simply just, quantum particles are just wave functions up until the point that they have to collapse to a particle because it has interacted with something (a screen or a sensor or anything). That is about the limit of my understanding at least

I'm not a physicist, so I'm unfamiliar with the particulars of how the detectors used work, but as I understand it, possible explanations like the one you suggest were initially considered as more likely than what was actually documented, but that's where replicability helps out — if one research group observes something baffling that flies in the face of what is understood to be true, then maybe that's an equipment or experimenter error. Not so much when a particular result has been demonstrated in countless different ways by many researchers, and when theories built to explain the weird stuff have predictive power for other, related phenomena.

Speaking of stuff that quantum mechanics helps us to understand, there are a few really cool examples of where quantum phenomena is relevant in my field of science (biochemistry), I'll have a look to see if I can find the thing I'm thinking of.

Yes, that's exactly what happens. Nobody has to check what it actually measured.

That's what they did with the same experiment in a closed box where they just increased the temperature. In that case air molecules just acted as the "sensor" and collapsed the wave.