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# Science

[INTRO ♪] Back in the ‘70s and ‘80s, a man known
as the ‘Golden State killer’ terrorized California, committing a string of more than 100 burglaries,
45 rapes, and a dozen murders. Definitely a bad dude. Even though the police had DNA evidence from
crime scenes, it never matched any DNA records on file,
so the case went cold … Until last week. By this point, you’ve probably heard about
this man’s capture. But you might not realize that the science
used to crack the case is totally different from standard DNA forensics. So by understanding how DNA analysis is typically
done for crime scenes, we can dive into why the Golden State killer
case is so special. Usually, forensic scientists process DNA with
a method called short tandem repeat, or STR, analysis. The basic idea is that little stretches of
short repeated sequences, like TAGA, are scattered throughout your genome, in specific places on specific chromosomes. Because the number of repeats at each location
tends to vary from person to person, counting them can be useful. Like, they can help match the semen in a rape
kit to a suspect. For instance, you might have 6 TAGA repeats
on a chromosome that you got from one parent, and 10 repeats
from your other parent, while I might have 12 and 15. Now, if the number of repeats at one spot
in someone’s DNA happens to match evidence from a crime scene, that doesn’t necessarily mean much. But if you look at a bunch of repeats and
they all match, you might be onto something. In the US, forensic scientists have traditionally
tested for repeats at 13 different spots in the genome, although
recently they upped it to 20. That’s what’s happening when you hear
about hits in CODIS, the FBI’s database of DNA records. A match is all about probability, and there
are a lot of factors to consider, like how common certain STRs are in a given
population. But if your suspect’s DNA repeats in the
same 13 ways as a sample from the crime scene, the odds that the suspect isn’t the source
are typically about one in a billion. In other words, combined with other evidence, you can be pretty confident that you’ve
got the right person. Of course, DNA analysis isn’t perfect. Contamination is a concern, and there’s
room for doubt in cases where there’s a small amount of
DNA, or the DNA is degraded. These days, standard STR analysis uses a process
called PCR to amplify the DNA sections the police are
interested in. But that can lead to errors, and they might
not get solid data for all 20 repeat locations. Another challenge is that many samples include
DNA from multiple people, like both a victim and the criminal, making
the analysis more complicated. And any positive match still needs to be interpreted. After all, an innocent person might have scraped
their finger and left a few drops of blood behind at a
future crime scene. So that’s how standard forensic DNA testing
works. And if it’s all done right, it can be really
persuasive, as you probably know from shows like CSI. But with the Golden State killer, the cold
case heated up because of a different approach to DNA— one that’s a lot closer to spitting in a
tube to find out your ancestry. Detectives had some DNA evidence that was
collected from a double murder in 1980 and frozen, so
it was especially well-preserved. We don’t know the specifics of what they
did next, but they eventually uploaded data from that
sample onto an open-source genealogy website called
GEDmatch. While GEDmatch isn’t a power player in the
commercial DNA industry like 23andMe or Ancestry.com, it runs on the
same kind of information. So someone might use one of those services
to get raw genome data, then submit it to GEDmatch to help find long-lost
relatives and piece together their family trees. The FBI created the DNA profile of the Golden
State killer in their own labs, from that well-preserved sample. And they probably generated the same kind
of data, by looking for single nucleotide polymorphisms,
or SNPs. These are individual As, Ts, Gs, and Cs throughout
the genome that we know vary between people and can be
passed down from parents to kids—and because of that,
they’re useful biological markers. In a way, SNP analysis is similar to STR analysis, except it’s cheap and easy to test for tens
of thousands of these puppies at once. So that’s what’s going on when you mail
in your DNA. Most companies aren’t directly sequencing
your DNA for a whole bunch of SNPs. Most importantly for detectives, because there
are so many SNPs, and they change less over time from mutation, SNP testing is much better than STR analysis when it comes to identifying far-flung relatives. So, once the detectives on the Golden State
killer case uploaded the genetic profile of their suspect, they looked for similarities among GEDmatch’s
but some of his distant relatives— like, third and fourth cousins—had. These are people who would share about 2%
of their DNA with him at most. But it was enough of a lead to build potential
family trees—some 25 in all. Within 4 months of getting some initial hits
on the genealogy site, police officers had painstakingly narrowed
their focus from thousands of relatives to one man. He was the right age, and had lived in California
during the crime spree. To confirm that he was the Golden State killer, they needed some of his DNA to test for a
match. So they put him under surveillance and grabbed
his trash. They used something with some of his cells
on it: maybe a straw, soda can, or used Kleenex—we
don’t know what exactly. And then they did a DNA test, probably STR
analysis, and got a match. Just to be sure, they checked again. Another garbage item, another test—and another
match. After 44 years, they had identified
the Golden State killer. He was a former cop named Joseph James DeAngelo, now age 72, living in a suburb of Sacramento, California. Now, this case isn’t the only time DNA has
been used like this, but it’s one of the highest profile cases. And it’s likely to have people talking for
a while, especially about data privacy issues. We won’t get into that here, but it’s
definitely something people are thinking more about, as investigators
realize how many ways they might be able to use DNA. Even if it involves way more work than TV
crime dramas ever show. Thanks for watching this episode of SciShow News! If you want to learn more about forensics, you can check out our episode that dives into
a lot more crime scene science. And if you just want to keep thinking about
the world more complexly with us, you can go to youtube/scishow and subscribe. [OUTRO ♪]

I made a thing. It lights up mostly sometimes. Since leaving the
lab, I’ve really missed the physicality
of doing science. I’ve missed working
with my hands. And so I decided to
take on a project that would combine genetics,
embroidery, circuitry, and coding. I decided to
embroider a DNA helix and use little LEDs
as the base pairs. Step 1 to doing this
was to design my pattern because there was
absolutely no way that I was going to do this freehand. DNA is a double-stranded
molecule. Each strand is comprised of
a sugar-phosphate backbone and then the four
molecular bases– A, T, C, and G– that comprise the genetic code. The two strands come
together to form this beautiful
helical structure. And while I wasn’t
going to be embroidering every individual
molecule of the backbone, there were still some
important properties that I thought it was
important to stay true to. The first is the
handedness of DNA. A DNA helix can be either
left or right handed. It’s going to look backwards
to you, but this is my left, and this is my right. The most common DNA structure
in solution in our bodies is B-DNA. And this is right handed. What I think about in my
head what works for me is to look at a helix
and imagine it in 3D, and imagine running my hand
around the outside of it up the strand. And so the fingers
of my right hand curve up and around that helix. So it’s a right-handed helix. This is a left-handed helix. This is a right-handed helix. Typically, when we’re
right-handed helices. The other thing I really
wanted to get right was the spacing
of the base pairs. There are just about 10
base pairs per turn of DNA. And the width of the helix
3.4 nanometers long, so I tried to get those
ratios correct as well. Once I had this basic
structure drawn, I started to think about how
I was going to actually add the circuits to this helix. And for this video, all
of my circuitry supplies are from Adafruit. and I’m going to put
a list of everything I used in the description below. This video is not
supplies that I needed and some great tutorials
to help me get started, so they get a thumbs up from me. When we think about
electric circuits, the most basic circuits
consist of a power source, the conducting
path, and the load. Here, our power source
is a battery pack, the path is some
well as a Gemma M0 electronics board, which will later let
me program what the LEDs do. So I’d really hoped that I
could stitch all of these LCD in series just because it would
make the actual stitching a lot easier, but when
I prototyped this, I found that when I placed even
just two LCD sequins in series, it significantly reduced
their brightness. So instead of my
series circuit, I came up with a
parallel-circuit design. Next, I had to decide which base
pairs to place into my helix, and this is the first coding
section of this video. DNA– is made up of 4 base pairs
A, T, C, and G. As bind to Ts, and Cs bind to Gs. The order of those bases
in your genes codes for the order of amino acids
in a resulting protein. Your DNA is
transcribed into RNA, and then that RNA is
translated into protein. That is the central dogma
of molecular biology. The way that it works is that
the protein-producing machinery in your cells looks at the
RNA three bases at a time. Those three bases,
called codons, tell it which amino acid
to add to a protein. The process starts at a start
codon, most often, ATG in DNA, or AUG once it’s been
transcribed into RNA because their Us replace Ts. And then each
three-base-pair codon after that encodes the
information for the amino acids needed for the protein. So GCA would be an amino
acid called alanine, GGU would be a glycine,
et cetera, et cetera. So I decided to start
with a start codon on and then go from there. Now, because it’s a
very short sequence, there isn’t a real
protein encoded in here, but I decided to have
a little fun with it. Each three-base-pair codon
denotes an amino acid. And each amino
acid can be denoted by a single-letter code. Using that single-letter
amino-acid code, I tried to spell out “stars,”
but it’s a little hard to tell because
some of the bases are hidden behind the turns of
the helix, but it got close. Now that I have done
all this planning, it was time to finally
get started stitching. And I started by stitching
sort of the back of the helix– what would be in
the back in 3D– in gray so that I could lay
some of the base pairs over it. And then I’d hoped
that at the end, I could stitch the front
parts of the helix in 3D over the top of
some of the LEDs. And it kind of worked,
but I don’t regret it. I decided to leave the
Gemma board on the front. Originally, I wanted
to hide it on the back, but then I kind of
thought that the circuitry is one of the cool things
it exposed on the front might be kind of neat,
so that’s what I did. I first decided to stitch the
LEDs on with three main wires. The positive wires from the
[INAUDIBLE] pads on the Gemma would come down the outside of
the helix, and to the ground would run up the middle. This seemed like the
easiest circuit path. And with a little poking,
and prodding, and tightening of stitches, it worked. And it was 100% functional. But at this point, I
realized looking at it that each side of the
project was lighting up at the same time. And wouldn’t it
be so much cooler if, instead, each
strand of the DNA helix was lighting up
at the same time? And I decided that, yes,
that would be a lot cooler. So I undid all of the
stitching of the circuits that I had done
and started over. This time, I used a little tacky
glue to place all my LEDs first to keep them in line
while stitching, and this was way easier. The problem, though, is that
when you take this 3D helix, and you squish it
down to 2D, the paths of those different strands
are now overlapping. And I was really worried
about all of these overlapping wires that were probably
going to cause short circuits. So I had to figure out some
way to try and insulate the pads from one another. I decided to try
electrical tape. I started it by
stitching the ground wire through all of the LEDs,
then covered that and tape. Then I stitched one strand of
the helix, covered that up, and then stitched the other. And again, with a little futzing
around, it mostly worked. I realized at this
point that I seem to get a better
connection when stitching this way over the LEDs
rather than this way– I think because the
thread is touching more of the conductive
surface of the sequin. So I actually re-ddi
a lot of my ground stitching this
way at this point. But cool, it works. Now, one of the cool
load a code onto it that will control
what’s happening in all of these created circuits. It understands a language
called CircuitPython, which is similar to the
language Python, which I’ve done a little bit
of coding in before. Now I didn’t need this to
do anything super fancy, and I’m very new to the
language of CircuitPython. So really, all I
did was mess around with some of the
in some of their tutorials. I, though, think that
this is actually sometimes a really great way to
learn a new language is to have a piece of code that
works, and then mess around with the parameters,
and see what happens. And that way, you can figure out
what’s going on in that code. So here, it was really easy
for me to change parameters, and I got a really visual output
of what that code was doing. And for me, that was like
a really nice feedback loop of, OK, here’s
what I’m doing the code, here’s its output,
here’s how these things are working together. I started with
so that the two strands of DNA linked separately from one
another at different intervals. Cool. Originally, I had
wanted to use stitches to represent the hydrogen
bonds between the base pairs– so AT pairs have two
hydrogen bonds between them, and GC pairs have three– but with all of the electrical
tape and potential fire hazard I’d already created
on the back of this thing, I really didn’t
want to add any more stitches into the middle of it. So instead, I decided to use
a little bit of fabric paint to paint on the hydrogen
bonds between the base pairs. Once it was done, I
felt like it needed just a little something extra. So I added some colorful
French knots around the outside because I just like
embroidering French knots. And it was done. And here it is. I am pretty proud of it. I think I was
probably stretching my circuit-embroidery
skills by immediately trying to do something that had
28 different LEDs on it, but I’m still pretty
proud of how it came out. My insulating technique
was not perfect. And so you can
see that there are some that don’t always light
up every time, like this guy. This guy has a little
bit of a problem. So definitely some
lessons learned, definitely some things
I would do differently if I was going to do that again. But for a wild first
attempt at something, I’m pretty happy with it. But that’s one of
the things I really liked about this project. I’m not a master embroider. I’m not super great at coding. I remembered almost
nothing about circuitry. I do hope my PhD gives me
a little bit of expertise in the DNA area, but for three
out of these four things, I was not an expert. But I decided to
try them anyways. And I think a lot of us are
scared of trying new things or learning new things
because we’re not going to be an instant expert
in them, but I think that’s OK. I think we should be
trying those things. So whatever it is that you want
to try but you’ve been worried about trying it because you’re
not going to be an expert, do it. Now this video is
100% not a how-to. This, I feel like could possibly
be a fire hazard happening back here. But if you are someone who
has more experience in any of these things than I do,
I do welcome the comments on how I could have done this
better, how I could have saved myself some hassle and a little
bit of tearing my hair out to get this to work right
every time because I do want to try and do similar
things in the future. So if you have suggestions,
I’m going to welcome them in the comments down below. So thank you as always
to my Patreon patrons. Your support and encouragement
gives me the confidence to be able to try new
things and put it out into the world like this,
which I so appreciate. So thank you so much for that. Thank you to you for watching. If there’s something
that you want to see me try kind
of similar to this, let me know in the
comments down below. I’m really interested in
trying to get my hands doing more hands-on things again. And a big shout out
to AJ of LIB LAB. I’ll put one of
his videos up here for answering some
of my LED questions. And as always, remember to
go forth and do science. OK, I keep that back there. That looks kind of cool. It needs a little
bit of set dressing, but I like it back there.

Smartphones, TVs, computers, iPads, and many
other modern miracles are made possible by power-efficient LED screens. But the real impact goes well beyond our brightly
lit gadgets. Lighting accounts for 20-30% of global electricity
consumption and about 6% of greenhouse gas emissions. Given that LED bulbs use around 80% less energy,
and last 25 times longer than incandescent lighting, they have the greatest potential
impact on energy savings globally. But when the first LEDs were introduced in
the 1960s, they didn’t have much use. It wasn’t until the ‘90s, when Japanese
scientists discovered the missing link needed to complete the color spectrum: the blue LED. Here’s how the color blue changed lighting. After Thomas Edison invented the light bulb
in 1879, incandescent lights lit much of the 20th century. The problem is they waste a lot of energy,
lost in the form of heat, and they don’t last long. Fluorescent lights started being used in the
1930s. Although much more efficient than incandescent,
they’re not an ideal replacement. They contain toxic mercury, age significantly
if they’re frequently switched on and off, and are prone to flicker. There needed to be a better solution. In 1961, Gary Pittman and James R. Biard of
Texas Instruments accidentally invented the first practical light emitting diode while
trying to make a laser diode. The first LEDs emitted infrared light, invisible
to the human eye which later became useful in things like remote controls. And for the next three decades, advances were
made to include red and green, but they couldn’t quite get to blue – which was needed to make
white light. But the appeal was obvious: Unlike ordinary
incandescent bulbs, LEDs don’t have a filament that will burn out, they don’t get hot,
and they require a lot less energy. So the biggest electronics companies raced
to create a powerful blue LED. But the problem of the missing color plagued
them for nearly 30 years. The key ingredient, a chemical compound called
gallium nitride proved difficult to grow in a lab. Scientists tried and failed, ultimately turning
their attention to other “more promising” semiconductor materials for creating blue
light. But a number of favorable circumstances lead
a scientist from a small chemical company in Japan called Nichia to finally make the
discovery: Firstly, by virtue of having little to no budget,
scientist Shuji Nakamura was forced to create red and infrared LEDs from scratch, using
parts he scavenged and fixed by hand. Most companies in the ‘80s were creating
LED material using commercially available equipment. This experience, which took him around 10
years and featured monthly explosions in the lab, would later prove invaluable when doing
trials for blue LEDs. The second reason was his decision to use
gallium nitride, a material considered a “dead end” by other scientists. But his motivation for using the chemical
compound was personal: getting his Ph.D. According to Nakamura, writing papers on less
promising candidates for blue light would make it much easier for him to get the necessary
papers published for his degree. Again he went back to the lab, not taking
holidays and not varying his daily routine. But this time was different. He convinced Nichia to buy the equipment for
small modifications to the commercially available equipment — his extensive experience building
red and infrared LEDs aided the alterations. Just over a year later, Nakamura made his
first successful growth of gallium nitride. His method, called “two-flow MOCVD”, is
still used to this day. From this, and discoveries of other Japanese
scientists around that time, he was able to produce the first brightly shining blue LED. Nichia is still a leader in the LED industry,
used by Apple and other electronics manufacturers. In 2014 Shuji Nakamura was awarded the Nobel
Prize in physics for his invention, along with two other Japanese scientists who developed
high-quality gallium nitride materials prior to Nakamura’s breakthrough. The small, energy-efficient, and extremely
bright LEDs started a light revolution and are now used in almost every piece of electronics. Without it, much of what we use today wouldn’t
be possible. It also has life-changing implications in
the developing world: With LEDs, solar panels and small batteries are more than enough to
power the homes of the 1.2 billion people who lack access to electricity. Most of those people are still burning wood
or gas for light which is not only inefficient, it causes pollution. It’s estimated that switching all lighting
to LEDs would reduce annual carbon dioxide emissions by about the same amount as that
produced by three-quarters of the cars in the U.S. That’s a potentially bigger impact than
wind or solar power. And with global warming due to human activity
generating catastrophic effects on the planet, the desire for saving energy is bigger than
ever.

I had a student in my online
using body heat to generate electricity via
Peltier/Seebeck devices. I explain what these devices do in
another Science Short, and I have been
fascinated by them for many years. He wanted to power LED’s
heat. The student’s question was quite coincidental
in its timing as I had ordered a pile of these
thermoelectric tiles for a science short, and I had a
the body heat of large livestock to power simple
electronic devices on the animal. Partly out of
curiosity and partly because of my friend’s enquiry,
heat from my hand to see just how much voltage and
current one of these thermoelectric generating
tiles could produce. It was impractically
small – at best I could get maybe 0.15 volts –
though it was usually down around 0.05 volts – a few
milivolts. Normally you use these tiles with a much
higher temperature heat source. So I explained all of this to
the student and that it would require so many tiles
just to get a slightly useable voltage that it
would be pretty impractical. He wrote back a week or two
out, the LTC3108 from Linear technologies. I
investigated and was blown away by what these guys and
girls in the lab had developed! The chip was
specifically designed to harvest energy from extremely
low voltage power sources, and in particular,
peltier generation tiles. I got a few of these
breakout boards made by the Chinese company CJMCU, and
to my amazement, was able to light up a white LED
just with body heat from my hand! In this science
short we’ll look at the exact circuit I used and how
they managed to pull off this amazing feat, so
you can do this at home too!I was frankly astonished at what
these guys had accomplished. They took voltages
as low as 20 milivolts and boosted it to
voltages high enough to drive even white LED’s! AND with
useable current, all with a frankly very poor
temperature differential on the tile. Even
germanium transistors require 15 times
more voltage just to forward bias them! So you can
see why I was amazed – the engineers had managed to
develop an on-chip MOSFET transistor with an
insanely low forward bias voltage combined with an
ultra-low voltage drive circuit which switches the
incoming, ultra-low voltage through a transformer to
boost it to a higher, useable voltage. While
the chip was specifically designed with
Peltier tiles in mind, it is, effectively, a really
sophisticated joule thief. Besides Peltier tiles, it
can be used to harvest any ultra-low to low
voltage energy source including small solar panels,
intertial generators or even picking up
electromagnetic fields around us! And it can be used as to
trickle charge a supercapacitor or battery for
times of no power production! I have to give kudos
to Linear Technologies here – I am
datasheet here, and the links to everything will be
provided in the description. When you take a
look at the datasheet, you’ll quickly see that there is
multiple configurations because it can be
used with multiple energy sources. Solar panels and
inertial generators naturally produce a
much higher voltage than peltier tiles, so the
circuit will be different because you no longer
need the booster transformer. But the first
circuit in the datasheet is the one of interest as this
is the circuit diagram we will use. In fact,
what CJMCU does not tell you is that this IS the
circuit diagram of their breakout board! All of
these parts have already been included on the
board. Linear Technologies did not include any
component labels on the datasheet sample circuit,
and the component labels on the breakout board are
hopelessly buried beneath the soldered components.
So I have labeled the circuits and their
corresponding components here for your convenience. All you need to add to the
breakout board is the transformer, the thermoelectric
tile, jump a couple of solder points and make some
connections between Vaux, VS1 & VS2 to select your
output voltage. Easy peasy. So taking a look at the board,
this is the way you get it. Because the breakout
board was designed for multiple purposes (including
source voltages that do not need to be stepped up
through a transformer), this whole
transformer half of the circuit board can be removed,
and you need to order the transformer separately. To
use Peltier tiles, you will need the 100:1
transformer, I used a Coilcraft 752 surface mount
transformer from Mouser. Do note, I believe this
transformer has been outdated and replaced and
will probably have 253P written on it instead of
the 752S written on mine. But really, any 100:1
transformer will do. If it’s not a surface mount
transformer, just solder wires to the solder pads with
the primary side here and the secondary here. You can solder the surface mount
transformer with a reflow workstation or even just
use a heat gun – preferably a heat gun with a
nozzle reducer on it to get the air jet as small as
possible. Put the board flat and level on a heat
resistant surface, or perhaps on a circuit board
holder – just make sure it’s flat and level. Line
the dot on the transformer up with the dot on
the circuit board. There was enough solder on the
transformer and solder pads that I didn’t need
to add any solder. Heat the board and transformer
up until the solder melts and use a toothpick or
something non-metallic to finely position the
transformer. Let it cool. You’ll need to also solder these
pads together as obviously we’re keeping and
using this snap-off half of the circuit board. At the top of page 3 on the 3108
datasheet, you’ll see the output voltage options
and how to wire VS1, VS2, Vaux and Ground to get the
regulated output voltage you need. In my case,
went with 3.3 volts output. So I have VS2 grounded
and VS1 connected to Vaux, which happens to be how
Linear Technologies set it up in their schematic. Also solder together all ground
connections. They should all be connected to the
ground plane on the board, but it seems to me there
was one or two that for some reason weren’t
connected, and my board didn’t initially work until I
soldered them all together. You don’t have to do this of
course, but I soldered some dupont connectors to my
board for convenience. Now I have quick connects at
Vout and Ground for the output voltage, VST and
ground for the storage capacitor if you want to use it,
and Vin and Ground for the input voltage from the
peltier tile. You’re now ready to rock! It is important to get the
polarity right from the Peltier tile. Usually the cold
think that normally the hot side is exposed to
extreme heat that might burn off the ink or blacken the
hot side. So they put the ink on the cold side. As
long as there is a temperature differential with
the cold side colder than the hot side, then it will
generate electricity with the red wire
being positive. So make sure the red wire goes to
Vin and the black wire goes to ground. You should
now be able to generate enough power to run an
LED just from your body heat. You can put a few of the tiles
in series to make sure you get over that 20
milivolt hump, and you can also add a supercapacitor to
the Vst output and ground. This is optional, but
any extra power above and beyond what’s being drawn
from Vout will get diverted to storage in the
supercapacitor. During times of power demand and no
power supplied at Vin, the chip will use the stored
sure you check out the other science shorts on this
channel and of course, please take a moment to
video on social media – and thanks! You can
check out other science shorts, or my workshops and
online courses at TechValleyScienceCentre.com –
notice the Canadian spelling of the word “Centre.”
This project actually involved some more
advanced electronics, but we cover beginner
electronics in several of my workshops held around the
country, or in my online courses such as my “Robotics:
Learn by building” series of courses where we start
with electricity and electronics in our learning
about robots and how to build them. You can check
those out on JetPackAcademy.com Have a great day!

I got an electronic kit just in time for my
birthday, so in this project let’s open it up and explore some of the things we can
do with LittleBits To start this project, I’m using the CloudBit
starter kit, and the LittleBits space kit. Opening it up, you can see all kinds of sensors,
switches and motors, including this little power module, that hooks to a USB cable or
a 9 volt battery for power. Each little module has magnets built into the ends so you can’t
connect them the wrong way. Instead, they click themselves into position for you, making
simple circuit building a snap. Now if we connect an LED to the end of the
button module, you can see in less than 5 seconds we’ve made a flashlight, that works
each time we press the button. If we switch out the button with the sound
trigger module, we can turn on the light with a snap or a clap. Alright, let’s take this to the next level
with the CloudBit module. This little piece snaps just about anything to the internet,
and you’ll see how it works in just a second. Now if we bring in a remote trigger and this
owl puppet I found laying in the kids play room, we can build a secret circuit to monitor
the kids. First off, let’s cut a small hole in the
feathers of the puppet, just big enough to expose the sensor. This little device is going to let us know
when someone’s using a remote control. So let’s snap some wires to either side of
the sensor, then snap it to the CloudBit module, making this circuit wifi compatible. I chose to snap my circuit to a mounting board
for convenience, and added a little bit of duct tape, to keep the 9 volt battery beside
the circuit. Our remote detector circuit is complete, and
now all we need to do is hide it. You can see the sensor hides pretty well in the forehead,
and to get it all working, all we’ll need to do is throw the power switch. Alright, let’s go ahead and tuck everything
inside the puppet so it’s snug and secure, and completely concealed. Now I set this one beside the TV in our kids
playroom because our kids are in the habit of sneaking up to watch TV after we’ve all
gone to bed. The difference now is that when they press any button on the remote, the sensor
in the puppet triggers the circuit, and sends a text message to my phone, letting us know
that some little body is watching TV. I also found these could be used to detect
a thief. I made this circuit, in less than 10 seconds, by replacing the remote sensor
with a light sensor and an LED. When the light sensor is covered, you can see the circuit
goes into standby mode, but reactivates when light hits it again. I tried taping this inside my safe, along
with a little note for any would-be intruder, and if you watch carefully, you can see that
when the door closes, the LED shuts off and the circuit switches to standby. Now if anyone gets inside it lights up, scaring
away a potential thief, and sending an alert that someone just opened your safe. Now there are over a million circuit combinations
that you could make with these snap together circuits, and for one final project, I tried
connecting a LittleBits AC switch inline with a small space heater. The circuit uses an
infrared transmitter to activate the switch, which can be done remotely by setting a few
simple commands on www.ifttt.com. So now instead of heating an empty house all day, simply
send a text message on your way home from work, to turn on the heater. This way you’ll
save energy, and and still come home, to a nice warm room. Well there are a few projects I tried with
electronics in the process. Well that’s it for now. If you liked this project, perhaps
you’ll like some of my others. Check them out at www.thekingofrandom.com

These police dogs aren’t looking for illegal
drugs or explosives. They’re looking for something
that most of us have on us at all times: cellphones. Every crime is usually touching some sort of digital evidence. Cellphone’s ubiquitous. Everybody has a cell phone, so
it’s important a lot of times to find these devices if
they are hidden or discarded. Narrator: Detective George
Jupin is the proud owner of Selma, the first dog ever trained to sniff for electronics. Selma is part of a pilot program at the Connecticut
State Police Department. The program trains dogs to
find devices that store data. Since 2012, they’ve trained
nine dogs and they’ve shared their knowledge with
other police departments so they can train their own dogs. Selma and the other dogs in
training aren’t just looking for cell phones. They’re looking for anything
that might store data. Things like thumb drives,
computers, SD cards, and cameras. Before the program existed,
investigators had a hard time finding digital evidence. And they found as they were
doing their investigations that they were missing pieces. They could find paperwork, but they were missing devices
that could have stored a lot of information, and
they asked if, “Is there any chance that we can train a
dog to find a thumb drive?” I think was the first thing they asked. A lot of the work we do
is crimes against children or child exploitation work
where we’re looking for devices that have illegal content on them. So that can range from
desktop or laptop computers to smartphones and removable
devices like USB drives or flash drives. Narrator: In 2015, an
electronic-sniffing dog found a hidden thumb drive
at Jared Fogle’s house. It ended up being a key
piece of evidence in the case against the former Subway spokesperson. The dogs are used in other scenarios too like counter-terrorism cases where someone could be
storing documents or plans on a hidden thumb drive. Or in cases of fraud where
proof of fraudulent businesses or forged documents could be
found on a concealed laptop. We got called out to a
scene where the concern was that there might
be some hidden cameras throughout the house. Brought Selma in and
we searched the house – each floor of the house
and each room in the house and when we got into one of the bathrooms, Selma alerted to a vent.
Inside that vent, we discovered there was a miniature camera. Narrator: So how exactly do
these dogs manage to smell something that, to us,
doesn’t have much of a scent? Humans have about 6 million olfactory receptors in our noses. Dogs have up to 300 million. So, they obviously have a
much better sense of smell. To get these dogs to sniff
out electronics specifically, the K9 team sent a bunch
of devices to their lab which was able to isolate
one specific scent. The compound we use is
triphenylphosphine oxide, TPPO for short. TPPO is a chemical that coats memory chips to protect them from overheating. With TPPO isolated, handlers can train the
dogs to locate devices. All that is, is a simple
food reward system. We have the dogs smell the odor,
they’re rewarded with food. Smell the odor, rewarded with food repetitively. Narrator: The dogs learn
to associate the smell of the chemical with being fed and that’s what motivates
them to search for it. They start out by smelling
the pure chemical in a jar so they can really master the scent. Once a dog gets that down,
they move on to real devices to see if they can
identify the smell of TPPO when it’s inside a device. And even though all dogs
have a good sense of smell, they aren’t all right for the job. Jupin: We’re looking for
dogs that are methodical in their searches, that
aren’t easily excitable, that can be around a lot of people, that can be in areas that are confined. And the temperament of the
Labradors fits that profile and that’s why we use them exclusively. Narrator: Once the Labradors
know the TPPO scent, the real training starts. Halligan hides devices in cars
and then sets them on fire. This is to train the dogs to
identify the smell of TPPO even if the device has been torched. The dogs also do room searches. So they become familiar with searching an indoor environment. When a dog locates a device, it sits down to alert its handler. The handler then asks the
dog to point to it again. And then gets more food. Man: Show me? That’s a good boy. Narrator: The dogs only get fed if they’ve smelled TPPO first. That way, they continue to
stay motivated to find it. Man: Good dog. That’s a good boy. Narrator: But don’t worry,
they do get enough food. And they even get to have
normal lives outside of work. She comes with me to work and
she comes with me back home. I mean, she’s like family.

Electronics work by shuffling electrons through
circuits and logic gates to perform calculations, but in doing so they have to overcome resistance,
which wastes energy and generates heat. So instead of forcing electrons to push each
other along, what if we just made them do the wave? Electrons have a negative charge; it’s a
fundamental part of what they are. They also have a property called spin, and
this spin can be oriented either up or down. If the spins of the outermost electrons in
an atom are aligned the same direction, they’ll generate a magnetic field,
making the atom a tiny magnet. If all the atoms in a material have their
magnetic fields aligned the same way, the material will act as a magnet. (I could make the Insane Clown Posse joke, but I won’t. I’m not going to do it. It’s 2018 and we’re officially laying
the magnets joke to rest.) Anyway, it’s possible to reverse the direction
of the magnetic field of an atom in a material by applying energy. When that happens, the strength of the magnetic
field in that area drops a bit; it’s effectively the same as a partial reversal
of all the tiny magnets in that group. This partial reversal spreads, like a crowd
doing the wave at a stadium, passing the energy that dampened the magnetic field along. This wave of energy can also be thought of
as a particle, called a magnon. Just like electrons in a circuit, a magnon
can be used to carry information, with some advantages over moving electrons, like using
less energy and generating less heat (which is good, because sometimes I worry about what
my laptop is doing to me when it’s atop my lap.) But while the silicon circuits that conduct
electrons are relatively easy to make, the magnets that transport magnons are not. One reason we’re still using electronics
instead of magnonics is because the media that carry magnons well are notoriously hard
to make and harder to combine with other materials. Currently most magnonic researchers use a
material called yttrium iron garnet — or YIG — to carry the waves. A film of high quality YIG has to be grown
on a matching lattice structure like gadolinium gallium garnet. Hard to say, harder to combine
with other substrates, like silicon. So researchers started exploring elsewhere,
and came across a material first made in 1991. This material, called vanadium tetracyanoethylene,
was the first carbon based magnet that was stable at room temperature. Well so long as it wasn’t exposed to oxygen,
in which case it can burst into flame. But aside from the surprise fire, it’s great
for studying magnonics, keeping the magnons just as stable as YIG while they persisted
for record-breaking times. If researchers can make a practical material
for magnons to travel through, then the next step is making digital logic gates like the
transistors in a chip. Fortunately researchers don’t have to figure
out entirely new transistors that can respond to magnons. It’s possible to convert a magnon into an
electrical signal thanks to something called the inverse spin Hall effect, and then it’s
just a matter of sending electrons through the transistor like we’ve always done. This means researchers could combine magnonics
and electronics, bringing them one step closer to smaller, faster, more efficient computers. For now though researchers are exploring other
materials that might work even better than vanadium tetracyanoethylene. Hopefully they find one that doesn’t catch
fire when you crack a window. Dive deeper into the future of computing and
watch this video here, where I explain how using photons in computers instead of electrons
could make light-speed computing possible. Don’t forget to subscribe for more science
and tech videos every week, and thanks for watching!