How This Hologram* Breaks Physics

0:02 This is a fully 3D hologram complete with video games,

0:06 3D models, and this really freaky Marquez.

0:10 Except it's not a hologram.

0:12 And in order to understand why it isn't, we have to start by understanding.

0:16 Yo, what even is a hologram?

0:19 Okay, look.

0:20 Holograms are tricky.

0:21 There's like the dictionary technical definition of what a hologram is,

0:25 and then there's the idea of a hologram that we all have in our head.

0:28 And I mean, look at this thing.

0:30 Just look at it.

0:30 That is a hologram.

0:33 But technically, it's not a hologram.

0:36 Everything that you think is a hologram actually isn't a hologram.

0:42 Miku at Meikufest, that was just rear projection on a transparent screen.

0:45 Pac at Coachella, that's Pepper Ghost transparent screen.

0:48 That Razer Waifu thing at CES, I don't exactly know how that works.

0:52 I'm pretty sure it's like a transparent OLED or miniLEDD screen inside a tube.

0:55 Not only are none of these actually holograms, they're all not even 3D.

1:00 Those are all 2D images just on transparency.

1:03 If you looked at it from the side, it would be flat as a board.

1:06 Yeah, but I I've been to CES.

1:08 Like, I feel like I must have seen a hologram.

1:11 I wish that were true.

1:12 Marquez, none of the things you've seen

1:14 so far in this video are actually holograms.

1:17 And that's because a hologram is less of a specific device

1:20 and much more of a technique we can use to record 3D information.

1:24 If you were to ask a trad holographer,

1:27 they would say that something like this is your breadandbut hologram.

1:31 There's no screen.

1:32 There's no projectors.

1:33 It's just a way you can make a flat surface look kind of like a window.

1:37 You'll get some perspective shift as you move side to side,

1:40 but you're not going to see any Japanese singing,

1:42 dancing, vocaloid sensations on it.

1:44 The way real holograms work is actually really interesting.

1:48 And it all comes down to capturing depth information

1:51 and then recording it using these things called interference patterns.

1:55 So when you take a normal photograph,

1:57 effectively what you're doing is recording brightness information.

2:01 But to take a 3D photograph, you also need to capture depth information.

2:05 Well, how do you do that?

2:07 Lucky for us, light moves at a really constant speed.

2:11 Which means in order to find out how far away something is,

2:14 all we have to do is time how long it takes for the light to reach us.

2:18 But what do you do since light moves really really fast,

2:21 if you don't have a clock fast enough to time that light?

2:25 Well, the holographic answer is to take a laser

2:28 and to split it into two identical beams.

2:31 One of those beams is going to bounce off the object you're making

2:34 a hologram of, and the other is going to go straight to your holographic film.

2:38 where those two beams kiss, they mess with each other.

2:42 And the exact timing of that return beam,

2:44 the one that's bouncing off the object you're scanning,

2:47 that's going to dictate what that mess looks like.

2:49 And that mess is the interference pattern.

2:53 So then we take that interference pattern and we stamp it into a piece of metal.

2:57 And all of a sudden,

2:58 we have a flat piece of metal with these little ridges poking up.

3:01 Those ridges are going to reflect ambient light in the exact

3:05 same pattern that the original object reflected light off of it.

3:08 That means when you shine light onto your little

3:10 card and you tilt it side to side,

3:12 you're going to get the same parallax light 3D effect

3:15 you would as if you were running around that object.

3:18 I just smoothbrained the heck out of a really complicated scientific thing.

3:22 If you want to get like the full physics explanation,

3:25 go watch this video by three blue one brown.

3:28 But the point is that real holograms are actually kind of underwhelming.

3:32 They're just these flat things that sort of create this fake window effect.

3:36 But what if what if that Princess Leia digital campfire 3D apparation was real?

3:44 It's just not a hologram.

3:47 I'm supposed to be talking about holograms.

3:49 What am I doing here?

3:50 Miles, what is that?

3:52 What do you mean what is this?

3:53 We're here today to talk about the real

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4:59 But now back to the video at hand.

5:01 What if we had a hologram that wasn't technically a hologram,

5:05 but really felt like a hologram?

5:09 Ah, that makes sense.

5:10 A display with volume.

5:12 Exactly.

5:12 volume, depth, the big Z.

5:15 Technically, this is a swept volume display,

5:18 which uses a trick called persistence of vision

5:21 to create this sort of 3D effect.

5:24 Now, what is persistence of vision, you may say?

5:26 Yeah.

5:27 Look at this picture of a horse.

5:29 Now look at this picture of a horse.

5:31 Now look at this picture of a horse.

5:32 Now look at this picture of a horse.

5:33 Now look at this picture.

5:34 Now look at this picture of a horse.

5:36 Look at this picture of a horse.

5:37 Now look at this picture of a horse.

5:39 Now look at this picture.

5:40 Do this picture of a horse.

5:41 If I make the horse picks fly by fast enough,

5:44 you stop perceiving individual horse pickicss and start perceiving moving horse.

5:50 Your brain is piecing all of these images

5:52 together into one sort of continuous visual experience.

5:55 Look at this spinning LED fan display we got on Amazon for $30.

6:00 You take a bunch of LEDs,

6:01 you spin them around real fast where they're lit up, you get a circle.

6:04 But if you pulse those LEDs so they're on in the exact same place each rotation,

6:08 you'll get a dot floating in space.

6:10 sort of like a pixel.

6:13 Okay.

6:13 So, I mean then that's kind of like what that is,

6:16 but maybe they stack a bunch of those spinning fans

6:18 on top of each other and you get some depth.

6:21 That was pretty easy to pull off.

6:25 The VX2 is the perfect example of a piece of tech that is so simple in theory,

6:31 but as soon as you want to turn it into a functional consumer product,

6:34 it gets astronomically difficult.

6:35 This thing spins at 900 RPM.

6:39 That's like 15 times a second.

6:41 That's That's as fast as your car's wheel on the freeway.

6:44 Yeah.

6:44 See, the way this thing works is it takes a 3D object

6:47 and it turns it into a bunch of these vertical slices, right?

6:50 And then as the LED panels spin around,

6:53 it displays each one of those 2D slices at exactly the right point.

6:58 Let's do some quick napkin math here.

7:00 If it rotates at 15 times a second and loads about 480 slices into a rotation,

7:07 that means in order to play a 3D

7:08 video at 30 frames per second, God's frame rate.

7:12 You need to update the panels on this thing over 7,200 times per second.

7:17 And moving that fast complicates things even more, right?

7:20 Because if a single one of those slices is shown at the wrong time,

7:24 your image starts to flicker and get jumbled

7:26 and it just becomes really hard to look at.

7:28 And on top of all this, you still need enough processing power to do

7:32 error correction because the motor is never going to spin it at exactly 900 RPM.

7:36 This thing is only connected to the PC with a single USB 3.0 cable.

7:41 There's there's no Thunderbolt.

7:42 There's no HDMI.

7:43 It's USB 3.0 delivering all of this data,

7:46 which means you need one hell of an efficient graphics engine.

7:50 in order to get a graphics engine so

7:53 efficient that you could pull all of this off.

7:55 The guy who wrote it wrote a lot of like Duke

7:57 the Duke Nukem graphics engine from the '90s which was like

8:01 a really ahead of its time first person shooter graphics engine

8:04 that let you run 3D graphics on a old '90s computer.

8:08 Here's another thing you didn't consider, right?

8:10 How do you get data and power to something that is spinning that fast?

8:15 If you just ran a normal cable to those panels in there,

8:19 you'd get instant cable tangle.

8:21 The whole it would just turn into wire

8:22 spaghetti inside that little dome, you know.

8:25 And so Voxon actually developed a wireless technology.

8:28 They're getting power to their to the panels via induction.

8:31 They're getting all the data transferred wirelessly, too.

8:34 So on top of all the crazy hardware and software

8:36 Foxcon had to develop to make this thing exist,

8:39 they also then had to beat the literal laws of physics.

8:43 Because when you spin an LED panel at 900 RPM, it really wants to flex.

8:48 And what happens when it flexes?

8:50 Those individual LEDs will be at a slightly

8:52 different place than they're supposed to be,

8:53 and your image gets warped and jumbled again.

8:56 So to defeat this flexing, they came up with two clever solutions.

9:00 The first is an aluminum frame between those two

9:03 LED panels that keeps everything nice and rigid.

9:06 And the second they build a super elegant solution where the air

9:09 in there actually moves in laminer flow with the display spinning.

9:14 There is no turbulence in there.

9:16 It's smooth.

9:17 It's smooth.

9:18 Marquez, it's so much work.

9:20 But Ellis, what does it actually do?

9:25 Okay.

9:25 What does it actually do?

9:29 You would never ask a car manufacturer what

9:32 a car could do in a world with no roads.

9:36 I believe Confucious said that.

9:38 Is it the highest resolution display that's ever existed?

9:41 No.

9:41 Does it have the most color accuracy of any display in the studio?

9:45 No.

9:45 Does it flicker a little bit when you're in front of it in person?

9:48 Yes.

9:49 However, this thing is simultaneously the future because

9:53 this is really the invention of the digital campfire.

9:56 the first narrative experiential display that people can stand around

10:01 and see each other and see the content from 360 degrees.

10:05 It's a blast from the past because it's made

10:08 by a group of tinkerers who started in a garage.

10:10 It's like Apple or Compact.

10:12 It's it's something you don't see that often in tech anymore.

10:16 Yeah, having Having the display before the content is an interesting conundrum.

10:20 As a reviewer, it's funny.

10:21 It's like if someone invented mechanically

10:23 complex McLaren P1 before we had roads,

10:27 it would be a bad take to say that the car is useless.

10:32 But you know, you are totally wrong though.

10:34 No, exactly.

10:34 Like if you were trying to explain it to a technologist, you'd be like,

10:37 "This is great." If you were trying

10:38 to convince someone to buy it, you'd be like, "Yeah." Yeah.

10:42 So, what does it actually do?

10:45 Skibby toilet.

10:47 can click right here to hear me talk about speakers,

10:50 other weird experimental new consumer tech stuff.

10:53 Um, but I got to go.

10:54 I got a hot date tonight.

10:56 So, uh, make sure to subscribe to the studio channel.

11:00 Peace.