Keeping Us Safe, Part 2: A Jewish Perspective on X-Rays, Privacy and Safety

Darla Strouse: We’re going to learn about x-rays and how advances in x-ray technology safeguard us in airports when we travel. A lot of us are traveling this coming week. Think about the enormity of ensuring that hundreds of thousands of pounds of luggage can be so quickly inspected before being loaded into planes. Now, I’m really interested in that, because of all those thousands of pounds, Jim and I are heading to California tomorrow, and I think probably a thousand of those pounds will belong to me. I can never figure out how to know a travel light.

And now I want to introduce Howard Feldmasser. Now, those of you who know Howard’s been a member here since Bet Aviv began, and you thought you knew the most important elements of Howard Feldmesser because he’s the one we depend on when something goes wrong with the speakers and the video. And if he’s in the room, he knows how to fix all this stuff. So now I’m going to tell you why he’s so good at this. Mr. Howard Feldmesser graduated from Rutgers University with a bachelor’s degree in electrical engineering. He received a master’s degree in electrical engineering from the Johns Hopkins University and is a certified clinical engineer and a certified surface mount technology process engineer. Phew. That was good.

He designed and built high-power radar transmitters and high voltage power supplies. And many of you may not know – he spent many years designing, building, purchasing, and operating medical and industrial x-ray systems, including his experience as a clinical engineering manager in the radiology department of Johns Hopkins Hospital. He is currently a member of the principal professional staff at the Johns Hopkins University Applied physics lab, and holds five US and numerous foreign patents. What do you think of that? He’s a member, too. Hello!

Linda Joseph: So, now we know what Judaism has to say, and a Jewish point of view about it. I’m going to turn it over to Howie to teach us about the technology at airports – which may be a house or a gateway or a barn, may be a place that our privacy is invaded or not, for the public good, and for us to think about how this works so we can come up with a Jewish answer to this question of is it permissible? Is it not permissible? Is it desirable? Is it not desirable?

Introduction to Howard Feldmesser

Howard Feldmesser: Okay, I guess I’m on. I must admit, when I started pulling this together after Darla invited me to be here, that I had not a clue as to how in the world we were going to put this together – Judaism and cargo screening. Pulled a rabbit out of a hat, didn’t she? Unbelievable.

So here we are. I had a little fun with the title slide, leaving out the whole thing about being safe. Should we put mezuzahs on airplanes? We sleep there, we eat there, they’re bigger than four by four cubits. We do things there we don’t want to talk about, and we put up with nasty people behind us.

So a little bit about me. That’s me glowing in the dark. It’s a joke I use constantly. I’ve been around the x-ray business since, like, 1975, so I’ve absorbed my share of x-rays. And it’s really nice. I can read my watch in the dark – built-in lights. For all you non nerds. This was a cartoon in the daily paper, Wumo – I think I actually give him credit.

Okay, so a little bit more about me. I thought I’d show you how close I am to this business.

And so this is actually a news piece that was on WRC Channel 4, back when they were channel 4. Now, I don’t have any idea where they are. Adam Tuss is a reporter. To set the stage, there is a facility at National Airport called the Transportation Security Laboratory, where I’ve done a fair amount of work. They have every known and available piece of screening machinery, and they actually have a baggage handling facility where they don’t handle real baggage, but they have a whole lot of real baggage – it’s just not anybody’s. So he did a report from there. Keep watching.

That’s me. Gives you an idea how close I am to this business. That one of me has been around the world. I wish I could have been all the places where he’s been.

Without giving anything away, we designed and built that. It’s called a “body phantom.” As Adam said, it’s coated with a material that duplicates human performance in the various screening machines. We built one during the back scanner era. We’ll talk a little bit about that. This one is actually designed for the millimeter- wave scanner – the one where you assume the position. Hopefully, you still have all your fingers. I don’t anymore. But again, I just offered that that wasn’t supposed to happen.

Okay, a bunch of necessary disclaimers that I have to make. First of all, please remember that the title of this thing is “Scientists in Synagogues.” I am a scientist – it says so somewhere in my resume.

All right, what you’re about to hear is a whole lot of science. I was born a nerd. I turned into a geek. I’m back to a nerd. Whatever – I am that, and I will probably leave some of you in the dust. Some of you will say “that’s BS,” and you’ll be right. But please don’t say that out loud, because I might have made a mistake. Other things that are more necessary. I don’t represent TSA or my employer, so I am here without any sanction from either of them or any knowledge of either of them, nor did I get any material from either of them. So that’s to make the lawyers happy. All right? Looking at the one lawyer out there – you don’t work for my place, so you won’t be suing me.

All the material that I have in here was offered to me by commercial entities or I grabbed it, God help us all, off the Internet. And, of course, if it’s on the Internet, it’s true. And for those who are watching online, or who might want to watch later, yes, it’s being recorded. I will have to take the recording off because there’s some material in here that these companies don’t want on the Internet. It’s not proprietary, but they just don’t want it out there in the world wide web. So I will pull it down, I’ll blur that and I’ll put it back up. So those who want to see recordings, if you’re out there later, I will have the recording, but it will be a censored recording. Sorry, I have to do that.

I won’t be talking about magnetometers. You all know those. You don’t have to assume the position there, but your watch sets them off. Those are magnetometers. It’s technology I’m not terribly familiar with, so I’m not really fit to talk about it. And I won’t talk about trace detection technology. You saw that in the Adam Tuss piece, the little blue box where he put the bottle of liquid in there – for those of you who get your palm swabbed, that’s called trace detection. It’s an ion mobility spectrometer, for all you chemists out there, for you non-chemists… I won’t be talking about them because I am not a chemist. I don’t play one on television, so you won’t hear anything about that.

Some of the information related to cargo and baggage screening is classified. And since I don’t live at Mar-a-Lago, I don’t have any classified material (laughter). Probably shouldn’t have said that. Sorry. So I will not be presenting any of the material that is classified, or, frankly, even remotely subject to classification. We use the DoD classification process – some of the stuff, the highest stuff I’ve seen is classified secret. Clearly, none of that is in here, so don’t worry about it. You can talk about any of this. I can talk about any of this. It has been scrubbed. TSA has its own classification process called selective security information. I don’t have anything in here that crosses the boundary into that as well, so that’s the way it goes. And I’m sorry – That really does limit what I can talk about here. So I am apologizing in advance. You may ask a question that I can’t answer. Please understand.

Let’s learn a little bit about how it works. The basis of all x-ray production is quantum – thank you, Morris. He’s not here. He’s got COVID, but I’m sure he’s watching. Morris set you all up for this, and I’m going to knock you over. The technology – and I’ll branch apart from cargo screening here. The technology we use is closely related to DEXA. You may have heard of Dual-energy X-ray absorptiometry – it took me five years to learn how to pronounce that word. So many of you are already familiar with it. It’s been changed from DEXA to DXA – we left the “e” out. I don’t know why.

But I make a point here that probably all of us, especially in our demographic, should be alert to what’s going on with DXA. Take a look at the statistic there. You’ll notice that it’s for people over 50. I’m going to go out on a limb here and say we’re all in that class. For those of you who are over 50 and female, 20% of you will have bone density issues. Twenty percent? That’s a big number. Get yourself screened. It’s a lot less for men, but I am descended from men who had osteoporosis. So please keep in mind, this technology that we use for cargo screening was actually developed to cure disease, or at least diagnose it.

What’s an x-ray?

Okay, here comes the nerd stuff. So what’s an x-ray? Continuing with the nerd stuff – “apologies to Bones,” some of you will recognize who that is. Those of you who didn’t watch Star Trek have no idea what I’m talking about. “Bones,” the doc said, “I’m a doctor, not an engineer.” I’m an engineer, not a physicist. So those of you who are physicists out there, just please excuse the fact that I’m an engineer. And if you watch Big Bang Theory, you know that engineers are looked down upon by physicists and vice-versa.

So Röntgen, in 1895 (now that’s well over 100 years ago), discovered x-rays. He really had no idea what an x-ray was, which is why he called it x-ray. I’m guessing all of you have been through high school algebra – you know, X is the unknown. He called it “x-ray” because it was unknown. But he did know it was penetrating. If you look down here, do you mind pointing? No, I’m not pointing. There we go. That’s Frau Röntgen’s hand. That’s probably the most famous x-ray in the whole world. You can actually see she wore a traditional wedding ring, but her wedding ring was partially penetrated by the x-rays, as, of course, were her hands. Now, we’ve come a long way in terms of resolution and other things. He was developing x-rays in his big lab, and so they weren’t terribly well focused – not the right term. You optical guys are going to come get me for that one.

So, let’s talk a little bit about spectrum. That’s what we call a spectrum of electromagnetic energy. Light is an electromagnetic energy, radio is electromagnetic energy; so are x-rays. There are two operating parameters that we talk about. I don’t want to call them theories, because we don’t believe they’re theories anymore. We’ve proven them. There’s the wave theory, where we talk about things like frequency and wavelengths, and there’s the particle theory. Morris, you out there? Particle theory is, of course, quantum mechanics. A photon, all electromagnetic energy, can be described in terms of photons. Just to impress you with big words – that’s what we engineers do. We use big words so that all you non-engineers have no idea what we’re talking about, and you think we’re really smart. (Laughter)

Photons have no mass at any speed, except the speed of light. All right, I’m sure you all captured that. That was a graduate class, and I didn’t do so well. But we can talk about wavelength, and we can talk about energy of photons, all at the same time, because all electromagnetic energy can be described in terms of waves or in terms of particles – photon particles.

For x-rays, the frequencies are so big, the wavelengths are so small, that we really have a problem just contemplating those numbers. And because of the way they behave, we always talk about them in their particle sense. We talk about [photons] as energy – little packets, quanta, of energy. What kind of ranges do they have? Well, we’ll talk about the energy range here. X-rays are in the range of 100 electron-volts to 100,000+ electron volts. That would mean if I take an electron and measure its energy after accelerating it through an electric field. So I have two plate here. This plate is 0 volts, this plate is at 100,000 volts, and I eject an electron from here – when it gets to here, it’s got a certain amount of energy in it. That’s the energy in the photon. That’s equivalent to the energy in that electron. Poorly explained, but hopefully you get a picture of that.

The reason I use the electron-to-photon analogy is because that’s how we develop x-rays. So one big note here at the bottom: the big deal is that x-rays actually cause ionization. They will hurt you, so be wary. [But it] takes it in a certain amount. So I’m not telling you, “Don’t get x-rayed.” Oh my God, no. All the dentists would go out of business, and they wouldn’t be able to diagnose your bad teeth. X-rays are necessary. You’ve got to do them. You’ve got to put up with them, but you’ve got to watch out. You don’t want too many, because although some think there’s a zero-tolerance issue, it is not the case. It is statistical. The more you get, the more chances you get for getting some problem with x-rays.

X-rays also cure disease. All right, now you’ve got a problem. Do you want to cure or kill? Pick one – we’ll go for “cure.” So we want to be careful, then. X-rays are divided into soft and hard. Soft x-rays [are] – it’s kind of qualitative, but perhaps below 10 or 15 keV. We don’t use those because all they do is get absorbed in your body and [they] don’t produce anything worthy of imaging, because none of them penetrate. So we make sure we get rid of those. Only important if you’re talking about medical stuff.

How x-rays are made

All right, so here’s the fun stuff. How do we make x-rays? They exist naturally. You are being subjected to x-rays while you’re sitting here. All right, everybody put tinfoil on your head. X-rays occur naturally. Anytime you make some change – and we’ll talk a little bit about it – you will produce photons of x-rays. We actually image them. We have satellites up there that image x-rays, and we can map a whole universe of x-rays. We make them here on Earth using an x-ray tube.

So here’s an x-ray tube. The red is a cathode. The cathode is going to emit electrons. This is an anode here in green. The important part of the anode is this black slot here. It’s generally a piece of tungsten. For mammography, we use molybdenum – not going to go into the physics of why we do that. Both of those are refractory metals – that means they melt at very high temperatures. The process we use here to make x-rays is so inefficient that more than 99% of the energy we put into the electrons leaving the cathode turns into heat.

You all remember from high school physics, right – energy is neither created nor destroyed, but it can be converted from one form to another. So I can convert kinetic energy – that’s motion – into heat energy, and that’s what I do for the most part here. So we use tungsten because it gets pretty freaking hot, so the tungsten target could get very hot.

But what happens – and we’ll talk a little bit more – when I decelerate the electrons – slow them down – so all these electrons leaving the cathode, when they get to the anode, they interact with the cathode atoms (we’ll talk about it in the next slide), [and] they slow down. In the process of slowing them down, we have to conserve the energy, right? We can’t create or destroy it, we just convert it. So that energy that was in the electron gets converted, in part, to a photon of x-rays. So don’t stand near the x-ray, too. The biggest damage – you’re going to burn yourself.

Okay, so let’s delve into the physics hard here again. Excuse me, physicists. This is the Bohr model of the atom. And why do I have that one? Because it’s the only one I understand. The rest of them that have come out since Neils Bohr – when did he come up with that? The 30s, 40s? [1913]. Everyone after that is “huh?”

So here’s a picture of an electron coming in from outside, and it gets near the nucleus here, and it bends. When it bends like that, it also slows down. So its path bends, it slows down. When it slows down, it’s losing some energy. And here comes that energy as an x-ray photon coming out. So we have all of these electrons coming out of the cathode, hitting the anode, burrowing into the atom structure of the anode, and some of them will produce photons of x-rays. That’s how we make x-rays.

The good and the bad of that – and here’s a graph called a “spectrum.” I showed you a spectrum before, including light, where you go from red to violet. That’s across a spectrum – “spectrum” just meaning the width of something. So you see here that I’m producing x-rays predominantly at lower energies, but I also produce [them] all the way up to high energies.

Here’s where the engineers get to us. We engineers will talk about kilovolt peak, meaning that’s the peak energy of any photon coming off of the anode; the physicist will just talk about kV. So pardon me as I switch units and go back and forth here. They’re pretty much the same thing, just we’re a little more precise than the physicists (laughter) – annoying them all.

So to give you an idea, the x-ray energies that we’re going to use in the rest of this range anywhere from maybe 10 or 15 keV per photon, all the way up to mega electron volts per photon. Light is in the area of 1-3 eV. Photons at that energy will cause no damage. I don’t give a damn what these people tell you about holding your cell phone to your ear. It’s not going to do anything to you, except maybe warm you up a little bit, all right? Energy from the microwave oven is not going to hurt you in that sense. It’s not going to destroy your DNA, it’s not going to cause cancer in you. It is going to warm you up. It’s going to cause cataracts, but it’s not going to do any real damage like cause cancer. So let’s try and – I’ll get off my soapbox here.

So how do we make a radiograph? What I’ve got here is an x-ray source, and it’s just blasting a pile of x-rays out here in what we call a cone beam. We generate them from a real small point, as small as we can possibly get, on an x-ray tube, and that’s just going to radiate out in a big cone-like thing. So when you go to the dentist and you’ve got an x-ray tube humming over here, it’s actually producing an x-ray beam. We call it a beam, but it’s not really. It’s just a whole lot of rays going out in all directions, but generally confined to a cone.

Back here, we put a detector – [it] used to be a piece of film. Many of you have probably seen x-ray films thrown up on the viewbox. We’re modern now. We use electronic detectors. We convert x-rays to light, we measure the light, we measure them in little cells called pixels. You all know about pixels because that’s how many you have on your screen, on your computer screen, how many I have on this screen.

I put something in the x-ray beam here. What I’ve got is a thick object and a thin object. And you see a green line across here. (I hope you can see it. I’m slightly red-green colorblind, so I have trouble seeing that.) And if I plot the x-ray intensity along that line – you see this here? You notice that the thin object is also small, so it doesn’t attenuate the x-rays as much as the thick object, which also happens to be big, so I can tell them apart.

You’re probably more familiar with an x-ray that looks like this. Now, I need an orthopedist or a radiologist here to tell me, but I don’t think there’s anything wrong with that guy’s knee. I think this is actually a healthy knee – good for him. Mine don’t look that good, and probably yours don’t either.

But up here is an x-ray tube. It’s producing a big cone of x-rays. We call this a collimator. What it does is it just limits the x-ray field. Here’s our patient. Below that is a detector, and here’s what the x-ray pattern is on that detector. So you can see the higher attenuation here – so, lesser x-rays. The cortical bone, the trabecular bone here is thinner, absorbs less x-rays, so more of them come out. And here, when you get to the tibia, it’s thicker, so it absorbs more.

So what I can get out of this detector is – in this case, it’s one line at a time, but we can take one line at a time and stack them on top of each other, and suddenly we have an entire area that’s full of a pattern right here that – is somebody’s knee! So, this is a medical x-ray. You’ve seen these, I’m sure. I wish you hadn’t, because generally, if you’re seeing them, that means you’re thinking there’s something wrong with you, and perhaps there is. Hopefully, there’s nothing. But that’s x-rays.

Harnessing x-ray energy

Now, let’s get more into the physics. Again – you’re paying me as a scientist, so here I am. (You’re not paying me. It only took donuts.) So, here’s a little bit about the attenuation of x-rays. What I’ve got here – this is a graph of x-ray energy, photon energy, here, versus absorption here. And I’ve got a bunch of different materials, which I can’t read from here, because I really do need new glasses, don’t I? But I’ve got a bunch of different materials. The most important ones for what I’ve been talking about might be bone right here. That graph is right here.

So what this is telling me is I can treat x-ray energies like colors. I showed you “Roy G. Biv” earlier, and we went from red to violet. I can actually separate the x-ray spectrum out and get several colors of x-rays. And I use the color analogy because we’re going to need it.

Let’s try it with light, so maybe you can understand, hopefully a little better. So we’re just going to try and do an explanation here. So I have a piece of the spectrum here – it’s taken from out here. So it’s kind of purplish, and another piece of the spectrum here, kind of orangish. [I’m] using qualitative terms deliberately, because we do take broad spectrums, we don’t get single colors. We tried that with DEXA and it didn’t work because it took forever to make an image. So we do this.

Now, I take a pair of filters – a blue and a red, and a blue and a red. And you notice that under the purplish light, the blue filter lets in a lot. The red filter, not so much. With the orangeish light, the red filter lets in a lot. The blue filter, not so much. Darn, if I look at that, I can tell you that one of those is red and one of those is blue.

All right, that seems pretty easy, but now I’m trying to extend this process to x-ray. So what I do now, and what I’ve done is taken hunks of that original chart.

So, here’s absorption, and here’s the piece right around 16 keV. And here’s the piece around 60 keV. And I use those advisory because those are the energies used for DEXA. And if I look at bone here, and if I look at not bone – fat and muscle – here, I can see that (well, I guess I can used water) if I look at the ratio of absorption, (again, we’re getting a little algebra here. So you mathematics folks are going to yell at me that I’m not doing that right).

If I look at the ratio of absorptions at 15 and 60 keV, bone has a ratio of 33; water has a ratio of 7.5. So if I measure the radiation without the water and with the water, without the bone, with the bone, and I see the differences, I can tell you that that’s bone and that’s water. So that’s DEXA. I can also measure density of bone, which we’re not going to do here.

So how do we do this? And let’s get off the physics and let’s get on to real-world stuff. Yay, engineers. So here’s an image of what’s called a test box. This one is the ASTM F792-08 phantom. I had nothing to do with this except for buying a few of them, and they’re expensive. And we use this for testing all of our x-ray systems.

I point out a bunch of things here. Here’s a list of all the tests that are in there. Who cares? If you’re testing the machines, you do care. I am not allowed to tell you what the limits are. I can’t tell you how fine we can see. Obviously you can see something here, but this has been doctored, so you can’t tell from here what the limits are because the limits are classified.

But here are some tests. What’s the fine resolution? Copper wire is important to us. What do you make bombs out of? Generally, copper wire. You might think about using aluminum wire. Ah, we can see aluminum, too, so we can see those. We have tests that are just simple resolution –  this one is a penetration test to see how thick a hunk of steel I can actually see through. That’s important to us. We’ll talk about that a little bit more on some other stuff. The important thing to know from all of this is: take a look at the different colors. You see green here? That’s aluminum. How do I know it’s aluminum? Because I went through that process of sorting out, how much does it attenuate, low energy versus high energy. If it’s in a certain range, it’s got to be aluminum. How much does it attenuate here if it’s low versus high energy? If it’s colored blue, it’s steel, or metals like steel. If it’s colored orange – and you’ll see most of this is orange – it’s going to be polymers which tend to be low atomic numbers, water. Now, the problem is, and I will share you this, I can’t tell water from gasoline in this process. I don’t have that kind of precision. Thus, you can’t carry gasoline. You also can’t carry water. That’s why the agent is telling you that water bottle cannot fly in your hand, carry or in your pocket. Very hard to tell the difference. So we have to ignore or eliminate all of our liquids. Polymers are going to show up. We’re going to live with those. So we’ll figure out what to do with that.

How x-rays are used for travel security

Okay, so what do these images look like? You’ve probably seen the hand baggage screening systems. If you’ve been to an airport, you can’t go by without them. All your stuff is going to be there. You may have also seen some check bag systems. Some of the airports actually have check bag systems right there at the terminal place. Generally, they’re pretty sophisticated ones. The cargo systems look like what you’ve seen on steroids. So we’ll give you an idea what they look like in just a minute.

Cargo systems are divided into three different categories. There’s a “small” category, 60 by 60 centimeters. Not a whole lot different than the hand carry system. In fact, many of the systems used for hand baggage are used for small pieces of cargo. There are the big ones. They’re up to a meter by a meter, pretty sizable – for large cartons and other things.

And then there’s humongous, up to 2 by 2 meters. Three or four families can live there. If somebody sleeps there, you’ve got to put mezuzahs on it. (Laughter) And then there are the really big ones, and I’ll show you a couple of those, too. All the modern systems provide at least two views. At least two generally right angles like this. Some of the ones you’ve seen, if any of you are cruisers, you get aboard ship. They’re much less expensive. They’re single view systems. I think that’s security theater. We put on a show that says we’re being secure. They’re kind of useless as warts on a frog. I won’t go into why, because that’s not allowed.

So here’s a medium-sized unit, and there’s me at full size next to it. [I want to] point out that this is a two-view system. So there’s an x-ray tube sitting in this section here that points this way, there’s an x-ray tube in this section here that points that way. I have deliberately removed the manufacturer’s name from here – you should know who this is. This is open material, but I don’t want to give them either credit or blame for anything.

So you get an idea how big these are. This one can actually process 100 parcels an hour. It’s faster than one a minute. That doesn’t give the screener a whole lot of time. So in terms of the parapet on the roof, this is the parapet, but somebody has to inspect it. We do a whole lot of tricks, and the color-coding is the most important part of that trick to make this go by on a screen pretty quickly and still see it.

So here’s a bigger system. Same guy, still had his fingers then – he lost a few of them today – but scaled appropriately. This one is 1.8 by 1.8 meters. Still just a two-view system. I said coupled to a conveyor system, but actually, this one is a roller-based system because this is going to handle up to 1,000 pounds. So this is getting big stuff. You can put a whole pallet full of gear on this.

Analyzing x-ray images

Now let’s look at an image. All right, Rich [Richard Madonna], you’ll probably understand what that is. Those are bicycles. All right, interesting about these bikes, you can find a whole lot of stuff. First question is, can you spot the anomaly? And I’m betting no. All right, let me start pointing some stuff out here. All right, this is aluminum. So part of these bikes are made out of aluminum. This is the chain ring, and it’s steel, as are the brakes – disc brakes on these bikes. These are probably pretty sophisticated mountain bikes. There’s single suspension here. So here you can see the suspension mechanism.

Interesting things about this package: those are polymers. Those are tires. You can see that they’re mountain-bike kind of tires. They have little grips on them, studs, if you will. We’ve got a chain ring out here. There are only two tires. That will cause somebody to say “what?” We’ll ask a question. Now, the manifest may say two tires, five bikes. Okay, we’re good. We know our two wheels This frame right here – carbon fiber frame. You see, it’s orange – plastic. So there’s a lot of material. What you probably didn’t see is right there – metal shot, as in lead balls. The hell’s that doing there? That will cause somebody some attention.

Now, this is a multi-view system. This particular system actually has seven views. So you can get a whole lot of going around. And the screener needs that to be able to see things. Something that might be hidden in one view is not going to be hidden in another view. So we get multiple views and you get all – these are actually pretty good bikes. I don’t have any this good.

So we’ve got an even bigger system. You notice that mini-me here just barely fits into that system. This one’s for cars – drive through with your car. Going to have these at ports, ferries, other things like that, so we can screen a car. We’ve designed this so that the dose to the passenger is so low, the passenger can go through it. Many places now are towing the cars through or putting a conveyor of some sort, so nobody gets any x-rays. But I can tell you that you’re going to get more dose flying cross-country than you will get from this x-ray system.

Really big security x-ray machines

Anybody own a Tesla? That’s the inside of a Tesla, I can tell you that. The man driving there has no broken legs. You can actually see his femurs show up pretty nicely right here. He’s got a six pack here in the front trunk. Very interesting. You can see motors here and here. No problem there. This one might be a little suspicious – it’s actually a toolkit, so if you’re used to Teslas, you’re going to let that one go.

So this car has no anomalies in it that are of real interest. I bring it up here to show you – these, incidentally, are battery stacks. The batteries in a Tesla form the floor, so most of the weight in the car is batteries. You can drop that entire battery pack out and put it in. You can see all the wiring in here, all a lot of fun stuff inside a Tesla.

So we get up to “humongous.” That’s an engineering term. This one actually happened to be on our property. This one does trucks. It’s kind of interesting in that this generator up here points down and is dual-energy. We have one here that points left-to-right, one here that points right-to-left. We’ll do something special with that.

They are single energy systems. All of these are driven by linear accelerators and generate photon energies in the megavolt range. Why do we have megavolt-level front? Because we’re penetrating a ton of steel here, so we need very energetic photons to go through. We can still make images off of here – and here’s the image off of that, oddly enough.

And clearly, this wasn’t designed by engineers. These are called forward-scatter images. They’re transmission images. They like to call them “forward-scatter” because we’re also using a technology here called “back-scatter.” Back-scatter was what we used to use for passenger screening. We went away from it not because we were worried about the x-rays on passengers, because it was very, very low. We couldn’t find a system that would do what’s called automatic target detection, automatic target recognition, ATR. And so the screener had to look at you without your clothes on. And for privacy reasons, we had to drop that. So we don’t use back-scatter for passenger screening anymore.

Back-scatter, however, is very useful [for baggage screening]. If you look right here, you see this little white thing sticking out – it’s a bag of heroin. It turns out that the bad folks love to put the drugs in tires and inside doors. Or other powders. If we see something that’s powdered, lightweight, it lights up brightly in back-scatter – not going to go into the physics of back-scatter. That’s a several-hour course, but lights up very nicely, and we can find it. So back-scatter’s real good for cars and trucks going through border crossings or the like, because we can get the contraband.

Now, what you can also see here, what you can’t see here – you see something here, whatever it is. But here, in what they call forward-scatter and transition image, it’s a rifle. So this system actually tells us a whole lot. Yeah, the shapes look a little funny because somebody drove through a little fast or perhaps a little slow. In this case, I think it was slow. But these systems do a great job of picking up contraband as well as explosives or weapons or other things like that with the dual technology.

Here’s another system. You’ve actually got to look at the doors closing on this system. This is in the “humongous” category. This one goes a little beyond two views. It actually uses… 63 views, and produces CT scans. Why are CT scans good? Because we just uncover everything. You can’t hide anything from a CT scan. It’s very hard to hide things in even the 2D. It’s even harder to hide it from a CT scan.

In 2D, I think I forgot to mention, when we see something that’s dark in the image – that’s black – we’re going to do two things to it. First thing we’re going to do is turn on what we call high-penetration mode with the standard system. That takes away the color screening and cuts through the black of the steel, or lead, if it can, and sees what’s inside, mechanically. In general, if a screener sees this block of dark, that screener is going to stop and hand- examine that. We’re going to swab it, we’re going to take it apart, or we’re going to drag you over to the secondary screening and say, “Take it out.”

Quick story. I was in Denver, working with TSA, standing behind the lines – oh, you people are terrible (laughs) – and watching the x-ray images screen across there. And I about browned my underwear, because what came through on that image? Hand grenade. I looked at the screener and said, “That’s an (expletive deleted) hand grenade!” At which point he says to me, “Sure looks like one, doesn’t it?” He said, “Yeah, it’s not,” and pointed out a couple of things. It was all orange. Hand grenade would show up as steel. It showed up as plastic. He says, “Still, yeah, we’ve got to do that.”

You should know that every airport has an EOD (explosive ordinance disposal) technician, if you want to call him or her that, on duty at all times. The EOD tech was called in, woman had to open her suitcase, and out comes a $900 bottle of perfume, which she had to throw away. Don’t carry perfume. It’s liquid. You can’t do that. Don’t carry perfume that looks like a hand grenade – with or without the expletive, right?

Building on x-ray imagery: some real-world examples

So we have our ways of finding things, even if they’re all dark. We’ll get there.

So this one is a CT scanner. And here’s the image from that. There are anomalies in here as well. Now, to point out a couple of things: The screener is rotating the image multiple times, turning on different functions of the screening system. This function is black and white, just looking at density. This is white and black just looking at density. What you saw was only blue, lighting up only the steel. There it is. This one’s lighting up only the polymers, plastics, lightweight stuff, looking for water bottles and other things. All right, the anomaly turns out to be – I probably went right by it. I did go right by it. Somewhere up here that quickly went by – some wires. Something you’re going to pay attention to. Not necessarily bad, but enough to pay attention to.

Okay, I’ve got some images here. They’re not real. I can’t show you real images because real images would contain privacy issues – personally identifiable information. That is, if I showed your suitcase, that means I’m spilling the beans and I shouldn’t do that, so I can’t do that. The most interesting ones that I have seen I can’t show you here because they would tell you how good the system is, or where its limits are. Can’t do that. So these are all test images, and all but this one are based on that test object I showed you before.

So here’s one. You clearly know what that is, right? That’s a Mason jar full of dried mushrooms. Now, imagine that you were looking in this for something not allowed. What’s not allowed? It turns out that right here is not allowed – hunk of metal. It’s probably not a problem, unless you’re eating the mushrooms. You bite down on that, you’re in trouble. But that was put there deliberately to make this bottle show up. The mushrooms you get that have been screened – not a problem.

 

Okay, so here’s our test object with something bad in it. Hopefully this one you can see. I call it an easy one. This line of stuff right here, those are all shotgun shells. You can see the lead shot. Where’s my arrow? Again, the lead shot is right here. And here’s the brass cap with the primer in it. Gunpowder itself doesn’t show up terribly well because the brass cap is sort of blocking it. But you can see that. So that’s an easy one.

 

 

I call this another “easy” one. This is to give you an idea of what some of the stuff is that might be caught. Keep in mind that in Baltimore alone, at our airport, Thurgood Marshall, last year, 413 loaded weapons were found. At National, it was a little more than that. Nationwide, it was in the thousands – loaded weapons.

This right here, that’s a pipe bomb. You can see here – this is the detonator. This is a steel plunger of some sort. You’ve got a plastic housing full of plastic explosive.

You’ll probably have no trouble finding this one either. But there’s a lot of things to unpack from this image. Clearly, there’s a gun. That’s easy. In cargo, we don’t care. Put all the guns you want in cargo – so what? You can’t get your hands on them, so we don’t care about that. But there are some things besides the gun, which is pretty obvious. Right here is a problem. It’s steel, probably a telescoping steel rod, used as a whip of some kind. So we don’t want that.

Now, what you find here is that area that’s highlighted, that’s called “automatic target recognition.” The system found it and lit up the area and told the screener, “Look here.” We don’t 100% rely on that, but we certainly make things easier and better because of it.

So here’s one. These are carry-on bags. We’re highlighting, here, the polymers. This is what you don’t bring on board. That’s a water bottle. Now, it turns out that one’s empty, so you probably get away with it. All right, you can see the steel bars here – this suitcase is pretty well beat-up. Here’s a laptop. It’s a non-problem. We can tell if you’ve got something bad in a laptop. So, put a lithium ion battery in there, probably okay, up to a point. Remember, we have our limits on how much battery you can take on board. Has nothing to do with “we’re worried about you being a terrorist.” We’re worried about you burning down the airplane. That’s a separate problem.

So here’s another bag. Clearly, you can see the steel support structure here. This is seriously a problem, because I can’t see through it. So we’re going to turn on what’s called high-penetration mode, or we’re going to look at that. Here’s a laptop. This laptop is also a non-problem. We would see if there was anything in here that had the look of a bomb. There’s the problem right there – there’s your water bottle. Those are easy to find. Every screener is going to find those. Every other passenger is going to try and stick them in.

So here’s the last test. Can you find the bad one there? Well, I’ll give you a hint. It’s right there. That’s a knife, on edge. Now, the other view would show it up pretty brightly, but I didn’t want to bother you with that one, because everybody would find that one. So that’s one of the tough ones to find – we find it, all right. That’s the last of my material.