Listener Mail Jubilee

me some direction about where to go. Sometimes you guys are asking for stuff that we've covered on previous episodes, but that always gives me the chance to update those episodes. And sometimes you ask for stuff that I honestly never would have thought about on my own, and it really helps when I'm putting the show together. Now, in this case, we've got a few different listener mail messages, none of which really warrant a full length episode all by themselves.

Some can be answered more quickly than others, so I thought I would group them together as another listener male grab bag and address them and thank the people who wrote in. So first we have Chris I said this was all about three D printing, and when they talked about the possibility of of stores having three D printers to produce on demand as opposed to having warehouses full of inventory. Chris says there's a store that opened up in my area that the guy wants to be the

first Kinko's like storefront for three D printing. He doesn't plan on this being the primary role of the business to start out, because the demand is not there right yet, but he wants to work with inventors, designers, and mostly work with people in schools to teach people about the technology. Now, Chris did not mention, uh, the name of this particular business, but I'm going to take a wild guess, and I

could be wrong. Chris, please right in and tell me if I'm completely off track here, But I'm guessing that it might be Things Smiths and in Arbor, Michigan, and thinks Smith's is a pretty cool organization. I looked into

it online. I'm also hoping to to at some point interview someone from Things Smith's to talk more about what they do and how they conduct business, because I think it'd be really interesting to look at something that is often referred to as an incredibly disruptive technology, disruptive to

the manufacturing industry in particular. So Thinks Smith's is a shop that offers up three D printing to customers for a set price per cubic centimeter, And it depends upon what type of material and which process you want to use. So your choices are a bs P L, a p ET nylon or UH and those are all using fused

deposition modeling or methacry late plastic through stereolithography. All right, So now you're like, well, I don't know what that means necessarily, so fused deposition modeling is what a typical three D printer on the market does. So if you've ever seen one of these, you you're pretty familiar. But just in case you haven't, once you have is an extruder which ends up heating up some sort of material, uh, typically some kind of plastic to a level where it

is moldible and and you can actually extrude it. It's there are extruders that print out tiny, thin layers of this stuff, almost like a glue gun. If you've ever used a glue gun, it's kind of like that, but much smaller and more precise. Um. The level of precision depends upon the type of three D printer you're using, and what it does is it lays down layer after layer of this stuff fusing each new layer to the layers below it. And often there's some sort of chemical

within the plastic itself that allows you to do this fusing. Um. Typically you want it to cool down so that it really solidifies in the final shape that you had intended and uh it you know, it's very important for this fusing and hardening process to go smoothly, or else the material, the object would collapse in on itself and you just

end up with a lumpy, gooey mess. Now, we've used three D printers here at the office and they used this particular method, the fust deposition modeling, and it's pretty interesting stuff. I mean, you have to be a little you know, depending on the model, you have to be

a little tricksy with it. We've had somewhere the plastic was sticking to the platform, the printing platform, and that was a problem because instead of it uh, flowing properly when it would get to a point, it would start to peel off for slide instead of sticking the right way, uh, and you would end up with a deformed plastic monstrosity as opposed to that nice whistle you we wanted to print out. But that's one method. The other one, stereolithography,

is entirely print and it's super awesome. It's still additive manufacturing additive meaning that you are building this thing piece by piece, as opposed to carving away stuff to get at what you want. That would be subtractive. So in other words, sculpting is subtractive, but this is additive, where you're you're adding material until you have built the thing you want. Uh. Stereo lithography builds in a layer by layer basis that uses a laser to change the nature

of material to make it hardened. So you have a liquid material, some sort of liquid plastic for example, and imagine that you've got it in a vat. So you've got this vat of liquid material. Uh, you have submerged just under the surface of this liquid plastic a porous um platform. So I think of it like a like a grill almost. It's it's like that, but very narrow gaps between the bars and allows the plastic to come up through the bars and it's just submerged just under

the surface of that liquid plastic. On top of this vat, you have a device that is able to direct a laser an ultra violet laser. Let's say, at this liquid material which has this photoreactive nature to it, so that when it's hit by this ultra violet laser, the liquid plastic hardens into a solid. So by tracing the shape that you want to print on this liquid plastic that's on top of this platform, it turns that liquid into solid, and you have your first layer of whatever it is

you're playing on. Building to build again, the platform goes down just a little bit so that the hardened surface is now submerged just under the surface of that liquid plastic, and you do it again. The laser traces and the liquid plastic on top of the hard plastic hardens and fuses together with the layer below it, and you do this over and over again, so that platform very slowly descends as the laser traces and hardens this liquid plastic, and it allows for much greater precision than the fuse

deposition modeling. You can get to um pretty decent resolution. Now resolution and three D printers is will really what we talk about when you want to avoid those jagged edges. So it's pretty awesome and thinks Smith's uses both methods, and depending upon which method you want the price is gonna vary also depending on again which material you're using. Uh, and it's price per cubic centimeter. So uh, that is

I think pretty awesome. The company also offers three D scanning and design services, so you could bring something in to scan and have them print a cop be of that thing. Theoretically you could scan yourself and have a figurine of yourself printed up. Or if you had an idea for something but you didn't have anything to scan and you didn't have the capability of designing it yourself, you can hire them to do that for you, which

is pretty awesome. Now, Chris, why don't you write me back let me know if I have the the same business that you had in mind, or if there was something else. Remember that address tech Stuff at how stuff works dot com. I'd love to hear from you either way. I really hope I can speak with someone from Things Smith's in a future episode, just to kind of talk more about the business model and and really what the future is for three D printing in this kind of way. Alright,

our next message comes from Felonious. Now, Felonious says, dear Mr Strickland, so formal, I have been a listener to tech stuff and forward thinking for many years. I recently downloaded an iPod full of back episode of those casts to listen to an extended bus trip. But about the fourth or fifth day something struck me that I want to ask you about. Does it always have to be a form factor and not just a form? And did the word shape do something nasty to you as a

small child, just wondering felonious to shape? Felonious? Um, why do I use the term form factor so much instead of just form or shape. Well, for one thing, form factor and computers means a little bit more than just the physical form or shape. There's a little bit extra implied with that particular term. Form factor refers to how these things are shaped, plus how the shape effects and

are affected by the use of that device. So, in other words, the form factor of a desktop is different from a laptop, and the use of those two things changes as a result. The form factor of a smartphone is such that you have to build that in to your design of apps for that smartphone. You know that you have a limited amount of screen space that you

can use. You know that the inputs are limited, You know that the battery life is limited because of the form factor, the the all the things that go into making that particular type of device work the way it does. So it's a little bit more than just form or shape,

and it's an industry standard. That being said, I probably could vary my vocabulary a little bit and not make you guys go crazy and create the text stuff drinking game where words like convergence and form factor and disruptive all become means to you know, take a another shot of your favorite frosty beverage um At any rate, thank you very much. The loneous but yes, form factor is a little more specific than either form or shape in the in the text of computers and electronics, which is

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Don't wait, go to stamps dot com and before you do anything else, click on the microphone at the top of the home page and type in tech stuff. Alright. Our next one comes from Chase from Washington State, who says, Hello, I was listening to your episode recently with listener mail. Hey, it's another one of those I haven't listened to the most recent episodes, so forgive me if you've already addressed this.

You were talking about the programming of a car as to how it would choose to act in either going on a sidewalk or bracing for impact. This is the trolley problem we were talking about. If cars are able to communicate with each other, wouldn't it be possible for your car to basically warn other cars that it was going to have to slam on its brakes and also allow them to do the same as to avoid either a hard impact or a crash altogether. Just a thought I had and figured I would pose that idea to

the problem. Thanks for all the amazing episodes you guys really make my long nights at work. More bearable. Well, thank you, Chase. So what Chase proposes here is fantastic. I mean, it is kind of a solution to the trolley problem. In all but the most extreme cases, this sort of communication would very often prevent these accidents from ever happening. In fact, we might prevent them to the point where you wouldn't even be aware that such an

accident was even possible. That's the ideal that, however, is a few years away. In the meantime, we have a world in which we've got a lot of manually driven cars. In fact, nearly all of them are manually driven. There are very few autonomous cars out there. But we have all these manually driven cars, and many of them are different. You know, We've got all these different years and models and makes out there on the road. Some of them predate all the cool systems that have been hitting you know,

standard ours for the last few years. So stuff that you might find standard today, like things like lane assist or or even um, you know, parking assists. That kind of stuff that's starting to become more and more common in cars just a few years ago was completely unheard of or was only found in the most high luxury vehicles out there. So with that in mind, we get to a point where we have this autonomous car that

is going to encounter an oncoming car. That the scenario, in case you forgot, was that, let's say you've got an autonomous car. You are sitting in an autonomous car, and there's an oncoming car that's veering into your lane, and the autonomous car really only has two options. One option will result in the autonomous car getting into an accident where you could potentially be hurt, you the passenger.

The other option has the autonomous car behaving in such a way that somebody else is going to be put into danger, they're going to be injured. And those are

the only two options. What what do you or what does the the designer of the autonomous car, what do they build into the car to make that decision knowing that one of the two options has to happen, there's no third option, and that that's the philosophical problem that's still going to be a problem for a while, simply because we're not going to reach a point where spontaneously everyone has a vehicle capable of communicating with other vehicles.

One day, hopefully we will reach that, whether the car is autonomously controlled or manually controlled, so that there is a better understanding on an electronic level of what is going on, so that we can have safety features built in to prevent these kind of accidents from happening. And while this is all kind of a thought exercise in the short term, it does have actual real world implications.

There are real world engineers working on this kind of problem and trying to determine and what's the best way to cause the least amount of harm in these extreme circumstances, knowing that under regular operating and conditions, an autonomous car is likely always going to be more safe than a

manually driven car. Keeping in mind things like the Google car story about how uh, in the entire history of the autonomous cars that Google has been running, there have only been a couple of accidents, and they've all been due to human drivers, not the autonomous driver. So maybe Chase in the future will get to a point where cars, whether they're autonomously controlled or manually controlled, are communicating with one another well in advance, so that these kinds of

situations can be headed off before they become dangerous. That would be wonderful. I hope that that's the future that we see. I expect that we will get there. I just don't know what the timeline is yet, but I'm hoping sooner rather than later. And of course it will all depend upon the rate at which older cars are removed from the roads and newer cars are replacing them. Even if that never reaches a point where you know,

we don't have a mandate. Let's say, let's say that we never pass a law that says you have to have a car from X year or later, or you have to convert your vehicle to have these systems in it, or else you can't drive it. Let's say that never happens. Even if that never happens, we just have to have enough cars with these systems to really make a huge

difference in in passenger and pedestrian safety. We've seen some studies have suggested that as few as twenty of vehicles would need these in order to make massive changes to everything from traffic jams to again passenger of pedestrian safety. So that's really encouraging to know that we don't have to have a world where everybody's in one of these vehicles. We just have to have enough of them to make it different. It's moving on. This next request came from Twitter.

This is from Jerry who says, uh podcast episode Idea was wondering if you could explain what goes on during the sound of a dial up modem. Yes, that well, Jerry. Just in case our younger listeners have not experienced this or have heard it and not known what it is. Let's first hear the sound of a dial up modem connecting. Beautiful, isn't It Just really brings a tear to your eye. So that sound, if you are not familiar with it, it probably sounds horrific. But for most of us that

was the sound. Not for most of us, for the older set of us, that was the sound of connecting to the Internet specifically, not even just the Internet. That was the sound of one computer connecting to another computer using dial up modems. So dial up modems use the tele own lines in order to make data connections. So we were making we were making use of the existing infrastructure to do something new. Instead of it being voice communication,

now it's specifically computer data communication. And that sound is essentially a handshake. It's just not the type you would do with your hands. It's a modem handshake between two modems, and that's what facilitated the communication between one computer and another computer. So here's what's going on. If you listen to that noise, you're going to hear a series of sounds. And this is the order of those sounds and what

they mean. So the first early tones, once you get past the dial tone and the dialing, which is typical for any telephone call, not just dial up modems. Uh, the earliest tones established the modem speeds of the two modems in question. So modems come at different speeds. Um, dial up modems come at different speeds, and you can only really transmit data as quickly as the slowest modem.

You can't go any faster than the slowest one. Kind of like, uh, if you've got a slow car moving down a one lane road, it doesn't matter how fast the vehicle is behind it, it's limited by the car that's in front of it. So let's say that you're using a you know, you're you're you're a bleeding edge adopter back in the day, and you've got a nice six D BOWD modem and most folks are still using BOD modem. You would be stuck at a slower speed.

Whenever acting, you know, communicating with a slower modem. By the way, in case you're wondering, modem would transmit a blistering two point four a kilobits per second would be nine point six kilobits per second. So that's uh, that's incredibly low data transfer speeds compared to what we see today.

That's why whenever you hear people talk about the old dial up modem days, you would, you know, try and view a picture that someone had pasted online, and you would just start that the process of getting the picture, and then you would walk away from your computer for like forty five minutes and come back to see if it was done yet. It's because we're talking about super slow data transmission speeds or data rate transfers. I guess

you should I should say. Now, the next series of tones you would hear represents the sin act handshake, which sets up other parameters that guide the interaction, like parody. So parody is meant to make sure that communication is proceeding without errors. This parity P A R I T Y not parody, which is hilarious. So essentially parody helps modems guarantee that they are actually sending and receiving the

information properly. It's it's a means of making certain that communication is not being dropped in any way, because otherwise you would just be getting lots of corrupt files and errors and problems like that. The next series of sounds you would hear is when the modems would go through what was called rate negotiation, which is the actual speed of communication that will take place, as opposed to whatever the maximum possible speed is between the two modems. This

would be the actual communication speed. The next series of sounds is a point in which the modems are preparing for simultaneous communication with each other, so we're finally getting to the point where they can really have this exchange of information going on at the same time. After that, the sound indicates that there is a connection that has

been accepted and the two modems are in communication. And the final little noise that you hear before the modem goes to silent represents data actually moving between those two modems. So there you go. There's the demystification of that modem dial up sound. It's really just the establishment of a connection and the you know, making sure that everything is working properly before you start trying to send files or or uh ask for files or any other kind of

computer computer communication through a dial up access point. So there you go. I hope that that answers your question. It was fun to look at, and that wraps up our listener mail Jubilee. I want to thank all the listeners who sent in listener mail. There's tons more where that came from, so I'm sure I will do more episodes like this. If you have any questions or comments

or suggestions, please send them to me. Whether it's something that could be a full episode all in its own, or something like this where I take a few different questions and then just kind of make a grab bag episode. I like doing both, so let me know what you want and I will make episodes. Send me that email, though I need to know what you think first, so it could be a full episode. Maybe it's an interview, maybe there's a guest host that you really want to

have back on the show. Send me that message. The email is tech Stuff at how stuffworks dot com, or drop me a line on Facebook, Twitter, or Tumblr. The handle at all three of those is tech Stuff h s W and I'll talk to you again for more on This and thousands of other topics is a how stuff Works dot Com