It's a new decade, and at times like these, we often take the opportunity to look back and see how far we've come.

Scientists who came before us made sure our food and drugs are free from poison and built the devices that make our modern lives possible.

So as we forge ahead into the new year, let's take some time to think the intrepid researchers, volunteers and even the occasional dog who got us to this point first up.

Imagine volunteering to be poisoned in the name of making food safer for everyone.

That really happened in the early 20th century.

These experiments weren't terribly safe or ethical or rigorous, but they are the reason you can be confident your food doesn't have washing powder in it.

Let's go to Stephan for more.

I think we can all agree that food is pretty great, so participating in an experiment where almost all you have to do is eat three delicious meals every day for up to a year.

Sounds kind of like the dream.

But imagine knowing that hidden in one of the foods, maybe the butter.

Maybe the freshly picked peas is a substance that's probably toxic.

It sounds unthinkable today, but that was the set up of some of the strangest and most infamous human experiments in American history.

Known as the Poison squads.

They ran for five years, starting in 1902 And even though they wouldn't pass any scientific ethics committee today, they were revolutionary at the time because people started to realize that maybe they should make sure the things they're safe to eat before eating.

The trials were the brainchild of Harvey Washington Wiley, the head chemist with the U.

S Department of Agriculture.

Back then, food additives didn't have to be tested or even put on labels.

And he wasn't really okay with the idea that no one in America had any way of knowing what they were actually eating unless they had grown or raised it themselves.

Formaldehyde, for example, regularly popped up in milk to keep it from sour.

Yeah, the known carcinogen that we used to preserve dead bodies would also often find borax.

A mineral that contains sodium and boron in meat made the meat firmer, which made it seem fresher, especially when combined with an extra pinch of salt and red food color.

These days, borax is a common ingredient in things like detergent and pesticides, and we're not talking tiny, insignificant amounts of this stuff either.

But no one had bothered to investigate whether these additives were actually safe to eat.

So with 5000 bucks from the government, Wiley hired a chef, promised a bunch of otherwise great free food and recruited a dozen healthy young men as volunteers.

He took their weight and vitals made them collect their urine and feces and gave them weekly physical.

Then they started with a low dose of a specific chemical and went up, stopping on Lee.

When the men were too sick to continue, the first poison squad tackled borax, and it's derivative boric acid because they were so calm.

At first, the chef had the chemicals in butter or milk.

But the volunteers could taste the metallic flavor and instinctively avoided it because no one wants to eat butter that tastes like their silverware.

Wylie still needed the men to get the right dosage, so he just put the borax and pills for them to pop about halfway through their meals.

Bon appetit.

Guys on the poison squad reported stomach pains and feeling less hungry when they were fed to 23 grams of borax a day, four grams.

They became very tired, developed headaches and couldn't work normally.

Sounds like an average Monday to me, but apparently in their case, it was caused by the borax through other trials.

Wylie also found that if they took a lower dose of half a gram a day for long enough, they'd get similar symptoms.

Today, we know that eating Boar X can cause tissue damage, which could eventually lead to fund things like vomiting and convulsions.

So thanks for saving us from that one poison squad.

Thankfully, though, almost no one walked away from these experiments with any obvious long term problems.

Wylie also tested copper sulfate, which was added to things like canned peas to make them bright green, as well as formaldehyde, sodium benzoate and Saleh Selic acid.

And while the effects on the men varied wildly, concluded that none of the additives were safe.

Today, any scientists looking back at these trials would be horrified by not only the ethical problems because giving people potentially deadly substances even if they know about them is never okay, but also the poor experimental design.

For one thing, the participants knew they were eating a potential poison, which could have easily skewed the symptoms they reported and made them feel more sick than they actually were.

Not to mention that, for the most part, the experiment had no real control group.

In between testing each substance, the squads were given a break for several weeks.

They weren't asked to continue reporting symptoms or to keep collecting their urine or fecal sample.

You also can't really conclude much from a small and specific group of people widely thought that if healthy young men got sick, the same chemical would also be unsafe for women and Children.

It's not really how biology works, though, and a few dozen white guys didn't exactly represent all of America.

But even though there were a lot of flaws with this experiment, it was the first time somebody thought to test food additives and study them one at a time.

Later, research that was actually reliable lead to almost all of these additives being banned from food except for sodium benzoate, which is a common preservative in acidic foods, like orange juice and soda, but we only use it because we've tested it and it's considered safe.

Journalists love covering the happenings in the D.

C lead kitchen.

So people across the country started thinking seriously about the things that might be used to preserve their food.

In 1906 partly because of the public's new awareness, Congress passed the Pure Food and Drug Act, a precursor to today's more rigorous regulations.

Those concerns also led to the creation of the FDA, which is the organization that makes sure the ingredients in your food aren't going to kill you.

For the most part, anyway, if you decide to crack open 10,000 cans of baked beans, there's not much they can do to help that one's on you.

Since Wiley was so instrumental in protecting America's food, he's often called the father of the agency.

So the poison squads were a really horrible idea and full of sketchy science.

But because of the progress we've made since then, going to the supermarket today is a whole lot safer.

I don't know.

I hear formaldehyde laced beans.

They're pretty tasty.

A lot of our historical episodes have looked at medicine and health.

Maybe that's because saving a lot of lives is a pretty good way to be remembered.

But it's not just drugs that have changed our lives for the better.

Like all the work that went into bringing you the phone that's probably in your pocket right now, or at least somewhere within arm's reach Before phones.

Theo Ubiquitous Pocket electronic device Was the calculator less glamorous?

Sure, but there's a lot going on with that little four function piece of plastic your teachers passed around in elementary school.

Here's Hank with more.

We don't think of pocket calculators as being all that special these days.

They're cheap, easy to use and your phone conduce all that stuff anyway, right?

But the development of the pocket calculator mirrors the electron ICS revolution that brought us smartphones and modern computers.

In fact, some technologies we now take for granted found their first widespread use and electronic calculators in the 19 sixties and seventies, and the first sword of compact electronic calculators couldn't fit in your pocket.

They were the size of a typewriter and demanded so much power that they needed a wall outlet.

For example, the Anita Mark eight was available in the early 19 sixties and cost as much as a car at the time.

It performed basic arithmetic functions by using vacuum tubes, basically airtight chambers with filaments inside, which could shuttle electrons and precise ways to generate currents and active switches.

The name was short for either a new inspiration to arithmetic or a new inspiration to accounting, which gives you a clue as to who bought these expensive machines.

And soon there were a couple of major technological leaves that revolutionized calculators and also the rest of electronics and the whole world.

First, for calculators to become cheaper, more portable and less fragile.

Vacuum tubes were replaced with transistors and integrated circuits.

The transistor functions like a gate for electrons.

Basically, by applying electrical power, it can either be opened or closed.

These binary states are still the basic idea behind all electronics.

And typically transistors are made from a material called a semiconductor, which sometimes conducts electricity and sometimes doesn't.

Early transistor electronics, like the super popular transistor radio for consumers would string individual transistors together.

In Siri's, transistors were way smaller and sturdier than vacuum tubes.

But more complex devices like computers were still fairly big.

In the late 19 fifties, though, engineers invented the integrated circuit, a single semiconductor chip that had all parts of a circuit on it, including many transistors.

One of those engineers worked at Texas Instruments Company, knew it had something good on its hands, but struggled to find a good consumer outlet for these compact chips.

That is, until 1965 with the design of the first prototype Elektronik pocket calculator.

It was code named Cal Tech, measured about 10 by 15 centimeters and could perform the four basic arithmetic functions.

Addition, subtraction, multiplication and division.

It's chip required the equivalent of thousands of transistors.

They even built a version for testing without integrated circuits, which, according to one designer, took up on entire two tiered, two meter tall desk.

So integrated circuits really packed a punch These days we call the microchips, and we put them in the everything.

Altec also printed out results on a roll of tape using a thermal printer.

This was also pretty new at the time and worked by basically melting text into a special type of paper.

Like the receipts.

You go to the grocery store.

T.

I team actually wanted on electronic display.

But that technology wasn't great.

Yet led is that the time had poor visibility.

Ladies work based on passing an electric current or field through a semiconductor, which causes electrons to shift around and emit light.

The color of the light can be altered by introducing different elements, which is easier said than done.

It's taken decades to make Ellie D's in every color of the rainbow.

Early on, gallium and arsenic based led is were only capable of emitting infra red light and very dim red light because of the way electrons move through those particular elements.

Lots of pocket calculators after the Caltech did feature red led displays, but they demanded a ton off battery power because those early systems weren't very energy efficient.

The next revolution and calculators was the liquid crystal display, or LCD.

Liquid crystals have molecules that are free to move like liquid.

But conceptual into an ordered state like a crystalline, solid dual identity means they can block or transmit light and switch between states rapidly.

When there's an input like electricity.

That's why we use them In Elektronik displays.

The first LCDs were fragile and on Lee worked at high temperatures, but a breakthrough came in perfecting a mix of chemicals that behave as liquid crystals at room temperature.

Other developments made them quicker and more durable as well.

LCDs used less power than L E D's so calculators could run off a watch battery instead of large battery packs alongside digital watches.

Pocket calculators were the first widespread consumer use of the LCD display.

Nowadays, you'll hear about led and LCD technology is when you're researching what kind of TV you might want to buy.

Over the next few decades, calculators became slimmer, cheaper and more powerful.

They evolved from specialized tools for business to a status symbol to a basic tool that you're probably going to get for free as a promo at on event at certainly where I got mine.

But all this development eventually slowed to a crawl, so you wouldn't carry a separate calculator either.

Unless you're still in school.

I need it for the S A T or something.

They've stayed basic machines to help with learning, not flashy, Internet enabled devices, and that is how the golden age fizzled.

But calculators played a huge part in the consumer electronics revolution, popularizing display technology and the computer chip itself.

Nothing to sneeze at.

Funny, you should mention sneezing.

Yes, we're headed back to the world of medicine, specifically the flu.

There's a bacterium out there in the world called Hemophilus influenzae, which has nothing to do with influenza.

But for a while, scientists thought it did so.

They gave it that name.

How could they make such a huge mistake?

Stephan explains.

If you're coughing, sneezing are starting to feel under the weather.

You might blame a virus or possibly a bacteria, which is not something humans have known to do for very long.

Around 400 BC doctors might have blamed an imbalance of the four vital humors for your illness.

And around the 17 hundreds they might have pointed to an invisible disease carrying fog instead.

But today we know pathogens, viruses, bacteria and certain other microbes are responsible for many diseases.

But linking specific diseases to the microbes that cause them has been surprisingly tricky.

In 18 82 a scientist named Robert Coke demonstrated that the bacterium mycobacterium tuberculosis causes tuberculosis, and in 18 90 he also published a framework for future scientists to make similar discoveries, she created a checklist for researchers to reference any time they're trying to link a pathogen to a disease.

The steps are as follows.

First, researchers had to be able to find the pathogen in sick organisms, but not in healthy.

One second, it could be grown in pure culture, which means that a sample of the microbe could be taken from a sick organism.

And then the microbe could grow independently in 1/19 century version of a Petri dish.

Third, if they exposed a healthy organism to the stuff that they grew in Step two, that organism would get sick with the same disease.

And finally, though this step is sometimes considered optional, the same microbe that was isolated in Step one must be found again in the organism made sick and Step three.

These steps are now known as Coke's postulates.

The idea is that if the microbe meets all of the postulates, then you know it's the cause of the disease.

Unfortunately, his postulates had a few problems.

Take postulate one.

Tuberculosis can actually be found in healthy individuals that's called latent tuberculosis.

So it doesn't meet Cokes first.

Postulate.

This situation just didn't show up in his experiments, which were done in Guinea pig hostile.

It three isn't perfect either, assuming that any healthy organism exposed to a pathogen will get sick, ignores differences and immune systems.

Healthy organism might be able to fight off the infection or might already be immune to the disease.

But it was the second postulate that caused the most confusion.