In this video it is literally one troll who posted dozens of times. Every other person got it and tried patiently explaining it to him.
It might have been a Thermos…it might have been Andy Griffith… 
For good or bad I’m on social media a lot. There are a tremendous number of incredibly stupid people online. It would take me ten lifetimes to correct even the dumbest, so I just don’t bother anymore.
Well done, @SenorBeef!
Also, some/a lot of people like playing dumb just for lols, so I wouldn’t take the comment section as being wholly sincere.
To be honest, I never thought about this or why it works, nor would I able to explain it (nor do I even care about the explanation.)
“What do you have in your Thermos?”
“Hot coffee, and a Popsicle!”
Good one!
Your two-mirror model really made it intuitive. Thanks for that. I remember this stuff from grade 9 or 10 science, with the various angles. But I was, TBH, having trouble with the first diagram with the dashed lines and one mirror.
In spite of the fact that I consider myself a pretty smart guy and understand optics it took me a minute or so to figure out what was going on.
I was wondering if looking at video was throwing people off so I went in the bathroom to try it with a book and a Dixie cup. I think what was happening was more obvious since I had to lean over the sink and get my head close to the mirror to get the angle right. But if you have no clue what’s happening that may not help.
I think one of the things that helps the illusion is that it photographed with a single cell phone camera that could be placed right next to the mirror. In real life you have two eyes one of which is going to have to be fairly far from the mirror so its easier to see what it going on.
I remember a time travel episode from some tv show in the 60s, where Present Day Protagonist says “You look exactly like me… except your hair is parted on the wrong side!”
Future Protagonist says “I’m you. You’re just used to seeing yourself in a mirror.”
…but less time to start a thread here with some of the most inadvertently hilarious.
You just explained my dismal failure in college physics classes.
Yup, and that’s exactly how mirrors work. They act like windows into another room with the same stuff in it.
Little kids (like, 3 years old) get this. But older students often don’t. I think this is largely because our modern world is full of things that act in some ways sort of like mirrors, but not really. On a TV or computer screen, the surface of the screen is where the image is, and so people assume that that’s how mirrors work, too. But the image from a mirror really is actually behind the mirror.
Right, what mirrors actually reverse is front and back.
I think that’s part of it, the camera and the objects are moving in a way that enhances the illusion. Doing it yourself in the mirror you can move you head and the objects side to side and catch the angle where the hidden object is being reflected in the mirror, and then tilt it back to see it disappear. Nothing can be done with the people who ignore the explanations and only watch the videos.
I do note in the OP this was not the Facebook video I am referring to when I say a lot of people don’t get it. That is just a video of the effect I found quickly on Youtube. I didn’t want to like to Facebook.
Wasn’t it The Perfect Master himself who explained that mirrors don’t reverse left to right, they reverse front to back?
Just saying that not everybody on the internet is an idiot.
What I want to do now is make a trick video using similar angles where the mirror doesn’t show the apple in the reflection.
There’s no trick, though. From an electromagnetic perspective, the virtual image really is there (assuming a perfect mirror, etc.). There’s no experiment you can perform with just photons that can distinguish a real image from a virtual mirrored image. It has nothing to do with our brains.
We all like @Chronos, but yeesh, get a room!
