There was a mall near where I lived that had a giant concave mirror. You could walk into it and actually pass through your own reflection. They also had a life-sized concrete hippopotamus, but that's a story for another time.
I was having a mental breakdown earlier from trying to imagine a concave mirror using only some text, and now i understand it all perfectly. Thank you for this demonstration.
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
I think you're correct with the effect you suggest for this situation . However for a flat mirror there is a head scratch conundrum to pose :-" if a mirror reverses left and right then why not also top and bottom ".
@@charlesdickens6706 Well that's just semantics depending on how you define "reversing". But saying a flat mirror reverses an image left to right but not top to bottom doesn't make sense. Imagine if you lie down on you right side facing into a flat mirror. Now will think the mirror is reversing the image top to bottom (because your left side is now the top)? I'd say a flat mirror is not reversing it left to right nor top to bottom. If you could grab your reflection from the mirror's perceived 3D space and superimpose it over your physical self in actual 3D space, the face of the mirror you would be poking out the back of your head but your left arm would still be intersecting with its reflected self. So the image is being reversed front to back.
what I find more fascinating(sort of...it's really kinda of the same thing...but try and follow lol) than the ball switching, is the fact that the mirror can have both types of reflections simultaneously e.g. when the ball is close to the mirror it is "correctly" reflected, but the chairs and cameras further off are upside down.
I can't stop watching this video, the more I watch, the more I get to understand the sketches in my textbook. Sir, I thank God I found a teacher like you!
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
Very informative demonstration. A possibly useful supplement would be to have a series of graphics plotting the path that the light takes at the different points in the movement of the ball, as it might help students understand why the reflection inverts. Thanks for posting.
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
What i find interesting about this demonstration is that this is a great example of what a 4th or 5th dimensional object would look like passing through our 3rd dimension
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
Yeah, it's weird. We used to live in a world where we'd comment that the CGI was "looking almost real". Now we comment that our reality "looks almost CGI". We're losin' it, a little more every day. 😬☹️
@DogMan Haha.. I was going to throw a flat earth comment in as well.. But... I saw this and thought I'd just laugh instead (and write a short comment that actually got progressively longer as I decided to explain myself)
This confused me bc the mirror is 360’ What about the effect on the left and right? This must also switch, but the ball is only divided 180’. I would like to se this demo with four color patterns divided in fourths. My imagination tells me that the ball’ reflection will appear to spin?
Would be interesting to see, don't think you'd get a spinning effect though, might even be if you imagine every line you could draw from the centre of a circle to the edge (cross section of the ball), every line might actually be effectively mirrored in a perpendicular plane that passes through the centre of the circle, so on a clock face the 1 and 7 would switch places, and 10 would swap with 4 etc, due to all the spherical curvature going on with the mirror and ball, in this case all the imaginary lines in the top half of the circle get mirrored across the centre into the bottom and vice versa causing an apparent vertical mirroring effect, when it's actually a circular mirroring across all angles which as I write this I realise would give the same end result of a simple horizontal+vertical mirroring. But what ever would happen I think it would still happen suddenly as it passed back and forth through that middle point rather than looking like it is spinning. After thinking about it that much I definitely want to see it also
You get reflection symmetry through a _point._ Looking head-on, each point on the edge of the ball gets reflected to a point on the opposite side of the ball. (Technically, you get reflection symmetry through the point at the center of the disk defined by looking at the ball head-on, which is the same as saying "the image of the ball _projected_ onto a 2D plane normal to our line of sight.) So to answer your question: No, you wouldn't see spinning. Imagine a ball with 4 colors: red, yellow, green, blue, say, going clockwise, starting with red on the top right of the ball. In the reflection when the ball is far from the concave mirror, you'd see green, blue, red, yellow. Fun fact: it turns out reflection through a point in a 2D plane is equivalent to two reflections across orthogonal lines (e.g., reflecting across the x-axis and then y-axis, in either order). Fun fact 2: reflection through a point in a 2D plane is equivalent to a 180° rotation. *Note*, however, that you wouldn't see _any spinning,_ as this "rotation" is just the operation that you imagine to map the colors on the ball to the location of the colors in the reflection. In some sense, the "rotation" happens the instant the ball crosses the focal point and the image switches instantly to its "rotated" version. Hope this helps. Sorry if the words are confusing-I tried to keep everything clear.
i studied optic for like 10 times but never get to see it in reality. dude thats like magic and its facinating. i never understood the consept of "virtual and real" image. once i saw this it started to makes sense. while the ball swings it looks like the ball coming from behind of the mirror and after a point (f point) it looks like the image switches dimensions and actually swing toward you. its crazy to me.
Saw an amazing effect on an observatory mirror at Herstmonceaux, Sussex, UK. Much bigger than this one with a longer focal point, and a holographic effect was the amazing thing.
Another physics demo is conservation of energy where you hold the ball right next to the mirror and release it and it swings back and will never hit it.
If u mess this one up, u could just use that as your inelastic collision demo, as the mirror steals all the ball's energy when it shatters. Then just rewrite your lectures a bit to work some Newtonian physics into your optics class and ur set.
This demo has all to do with the tangent function. It's part of how the thin lens equation is derived. Similar triangles and all that. The image goes to and fro infinity. Negative infinity too. It's amazing.
That is kind of redundant saying. They don't need to be from infinity. You can get parallel rays by having, let's say, an array of laser pointers. The point is, when you have a normal source of light (bulb, candle,...) at non-infinity, the rays go from its center in all directions. If you have a distant source (like the Sun), it still goes in all directions from the Sun, but the rays hitting your location are almost parallel. If the source is in infinity, it would be truly parallel...
The thing is, it works also in the opposite way - parallel rays converge to the focal point (that is how the parabolic antenna works, the dish focuses the signal to the small receiver), but if the light source IS in the focal point, the reflected rays will be parallel (that is how some car lights work)
Yes, of course. Sure for the optics portion of physics we did convex n concave mirrors and lenses but we may have overlooked this little detail or some of us . Here's something else :- I'm longsighted so I don't need specs for driving but a decade ago I noticed that to see objects clearly in my convex rear vision side mirror I needed to wear the reading spectacles , not immediately but eventually the penny dropped , it's cos I was viewing a virtual image rather than a reflection in the manner we are used to with flat mirrors. The virtual image being equivalent to two feet from my eyes instead of a hundred metres away say for the actual object. There's a phantom image position that can be traced somewhere behind mirror by following the convergence of light rays . Another optics phenomenon is with polarising filters . It's more a paradox that occurs when messing with three filters. There may be one or two good videos about it . John Gribbin in his book Schrödinger's Kittens leads into quantum theory from the paradox .
@@physicsdemos Hello sir, I have a question. I don't have a double sided mirror at home. But is the front side of the mirror concave and its opposite a convex? Or its front a plane mirror while its opposite side a concave?
@@xyz-vl8ri Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
If you own a Movado watch with the museum face then you have one of these at 12 o'clock. A perfectly polished little concave mirror that is amazing under high magnification.
British Gas once had a demonstration of a large concave mirror with a white hot limestone ball floating on a powerful gas flame. You viewed it from one spot and saw a vast (virtual) white hot 'Sun' slowly rotating, filling your field of view. (The roaring gas torch added to the drama!)
Woah! Do you know where I can view this? Is there footage online? That seems like something I'd pay to see in person. MOSI the Museum Of Science and Industry has some really cool demos like that, such as a huge indoor tornado simulator and a massive fire vortex, but nothing like what you described.
@@DanteYewToob I have looked for it without success. I think it was an exhibit in a Hultons Boys & Girls Exhibition in Olympia London in the 50s or 60s (I am in my 70s) These were created to encourage interest in Science & Technology (worked for me!)
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
Crazy how you can have a single reflection on a concave surface but multiple different objects in the reflection which are different orientations. When the ball is close enough to the inside of the mirror, it is upright while the background is inverted.
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
The intensity of the light to an observer from a source is inversely proportional to the square of the distance from the observer to the source. This shows that as the distance from a light source increases, the intensity of light is equal to a value multiplied by 1/d2.
Thanks a lot sir for explaining it in a very interesting way. But I have one question that I do not understand for a long time. As far as I know we can not see real image until we project them on a screen. Also we know concave mirrors produce real image when object is placed more than focal point. So how we are able to see the image within the mirror without projecting it on a screen ?
I was hoping to see if the ball were swung side to side or parallel to the mirror if you would achieve the same or different effect. Thomas M. Dutkiewicz
Interesting - do the red and blue areas when the ball is at the focal point reveal anything about deviations in the mirror's shape? Kind of thinking about the Foucault method of grinding parabolic reflectors for telescopes.
I wonder what would happen in a hypothetical perfect mirror. I imagine it would get bigger and bigger until it reaches a infinitely small point before switching ?
@@danilooliveira6580 The image is still a one to one representation. It appears bigger because the entire area of the mirror is reflecting a smaller section of the ball but is not enlarging any one section of the ball!
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
@@XMostaxX Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
@@nickryan6787 Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
A very good demo... Is the inverted image formed inside the mirror real or virtual. real images are formed when reflected rays from the mirror actually meet and virtual images are formed when reflected light rays appear to meet ..So the can the inverted image be got on the screen kept infront ?
Nitin K raised another question: Can we see the real image at different angles, or we can see it only straight in front of the mirror? Answer: When forming a real image on a screen, the image will be in a certain location on the screen. If the object is centered in front of the mirror, the real image will be centered on the screen. If the object is not centered, the image will not be centered either.
So a blackhole bends the light and what you can see on the edge just before the light gets devoured is actually on the opposite site and curved? And what does this in mean in comparison to the camera obscura?? I’ve got allot more questions know…
So, the image is real between the pole and just ahead of the focus and virtually behind the focus? Also, what is infinity in mirrors? Thanks for the videos by the way, very helpful. -Asmi
Asmi, I'm glad the videos are useful to you. The image is virtual when the object is inside of the focal point, and real when the object is outside of the focal point. Through the mirror, you can see both real and virtual images, as shown in the video. The difference is that when the object is outside of the focal point, you could also see the image on a screen, that is, you could put a screen in the image plane and see the image, if the object is bright enough.
Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
@@boydedwards5475 Hi, If anyone is interested, I published a book called "Making Technique for Large Diameter Concave Mirror, Convex Mirror, and Thin-Sided Lens" on Rakuten Kobo E-Book platform. In the book, molding silicone, clear epoxy (or clear plastic resin), polyurethane, air pumping tool, air vacuum tool, wood chips, acetate paper, etc. I mentioned the methods that will allow you to produce meters of diameter using. In this way, you will have the knowledge and experience that you can carry out your projects for astronomy and solar energy in a practical way. Have a nice day.
