SciTech Now Episode 515

In this episode of SciTech Now, finding true darkness; securing 3D printed products; the reclassification of Planets; and restoring the Forest’s ecosystem.



Coming up, finding true darkness.

We're protecting one of the last and wildest wildernesses.

Protecting 3-D-printed products.

So just like we take a paper and we make a photocopy of it, a similar process is now feasible for 3-D-printed parts also.

What makes a planet.

Pluto is the most complex, most amazing body in space other than planet Earth.

Using fire to protect forest.

So we were having a fire every 2-year, 3-year cycle to try and get what you're seeing here.

It's all ahead.

Funding for this program is made possible by...


I'm Hari Sreenivasan.

Welcome to our weekly program bringing you the latest breakthroughs in science, technology and innovation.

Let's get started.

Across the world, lights, billboards and neon signs are aglow in the night sky.

With the rise of these electric lights, it's difficult to find true darkness, but Mark Bailey, amateur astrophotographer and proprietor of the Torrey House-Alpenglow Observatory in Torrey, Utah, is determined to keep at least his corner of the world in the dark.

Our partner, 'Science Friday,' has the story.

Darkness for humans can be really scary.

One of the reasons that we find ourselves now looking for more of it is because we've done such a good job getting rid of it.

As soon as we had light through fire, we utilized that, and the consequence from switching from fire to electric light is that we didn't have to earn those photons anymore.

All of a sudden, we could illuminate our whole night without much cost and without seemingly a consequence.

And because we conflated light at night with safety, all of a sudden, our natural night disappeared.

When we're walking around the city at night, we can see evidence of our lack of awareness of how to protect natural night by an ever-present acorn-shape light fixture.

We experience glare from that light bulb, which tells our brains that it's time to be awake, so we'll increase adrenaline production and stop making melatonin, which helps us go to bed.

Basically anytime there's lights that just seems like it's to be there, not to illuminate something specific that someone needs to see, that's when we know we're doing more harm than good.

You really have to leave the city to find true darkness.

Here in Torrey, you're kind of the center of the Colorado Plateau.

We're 7,000 feet high, and the east and west horizons are low enough that as the Sun sets, it casts a shadow out into the eastern sky, and that shadow begins to rise, and it has a dark color at the bottom, and then it turns lighter, and there's actually some colorations of orange, and then it goes back into almost the daytime sky of blue.

It is one of the best spots in the 48 states for an astronomic observatory.

♪♪ I'm Mark Bailey, and I'm the proprietor of the Torrey House-Alpenglow Observatory, which was my father's, is my father's.

He asked me to move it down here because he had it up in Salt Lake City, which is heavy light pollution.

So I don't know.

I'm an amateur astrophotographer.

♪♪ Capitol Reef National Park is an International Dark-Sky Association Dark Sky Park.

We're protecting one of the last and wildest wildernesses, so our access to the sky in its raw form without our light pollution is important for an intrinsic sense of wilderness, but it's important in our own selfish sense as humans to keep in touch with the physical humans that we are, that have senses to see this kind of thing.

♪♪ Just below that cloud is Mars.



The horizon.

But then you see that bright one is Jupiter.


Mm-hmm, sure.

The word has been getting out a little bit that we have this observatory, and people are naturally drawn to this kind of telescopic portal to the deeper cosmos.

Oh, my gosh.

Yeah, that is Saturn.


If you give it a minute, give it some nights...

Oh, there she is. start to wake up to the human that you are.


When we can't see the night sky in its natural splendor, we're missing out on 50 percent of the information we've gathered since we've been a species about how to be ecologically situated.

[ Traffic noise ] So in addition to messing with our sleep-wake cycles, too much light at night, even through our closed eyelids, can result in higher rates of breast cancer, can increase anxiety, depression, heart disease.

Our bodies literally don't know when and how to rest.

It's the biggest step we've taken away from being integrated into our ecology.


At first, anybody and everybody is just drawn to the majesty of a dark night they just could never see in the city.

♪♪ Seems like people are just as thrilled as if they'd gone to a favorite music concert or seen... better than a movie.

Just let the night present itself.

I think it's because we evolved under the night sky, and we're feeling home.

We have precious few reminders that we're connected and that there are things bigger and more important than us, and I think that there's nothing that gets us there quicker than staring into a glittery abyss that is really clear that we both deeply belong and don't matter at all.

I had the misfortune of losing a brother to suicide.

I didn't realize how troubled he was, and when I think of Mike the most is often under a starry night.

I've gotten up at 4:00 because the Moon has finally gone down, and that's the one chance that night to see it completely dark, and I think of my brother, and I often ponder the fact that the stardust that became me became conscious, and I wonder... he's out there in it, and it makes me glad to be alive.

♪♪ ♪♪ The night sky with the sense of my brother in my mind expands me, I hope, makes me a better person.

♪♪ ♪♪ ♪♪ ♪♪

As more 3-D-printed products reach the market, so does the increased risk for counterfeit parts.

Nikhil Gupta is an associate professor of mechanical and aerospace engineering at New York University's Tandon School of Engineering.

He joins us now to discuss a new security measure -- three-dimensional quick response codes, QR codes, and we've seen them.

If you've taken a flight, you've seen now that you can do most of your boarding passes with QR codes, and you see them in other countries a lot.

How would you use a QR code, and how would you 3-D print it?

QR code is an example, but you can do the same thing with bar code or any other code given our method.

So what 3-D printing is doing is giving us a method where we layer material in order to build a large-scale part, and this layer-by-layer printing process is very important because we can hide information, or encode information inside, when the part is being printed.

So we take advantage of this method, and we put a QR code in one of the layers, and then the part keeps building.

Eventually this part -- from outside this code is invisible.

Mm-hmm. you will need a method like ultrasonic imaging or CT scan in order to get that code and validate the part.

So when I look at an object now -- you have a couple of samples here -- essentially, if I looked at... This sample is... What is it, titanium?

This is our titanium part, and after printing the QR code in one layer, we cut it open so that you can see and validate the code exists there.


...but if this was completely built.

Like, from the back side, if you look at it, there's no sign of a code being there.

But basically if you scanned it somehow, you'd be able to see that there's a code inside.


If you scan it using CT scan, which is a common technique people already use on 3-D-printed parts to look for defects inside or any abnormalities...

Mm-hmm. you can also catch some of these codes.

Because I guess the concern is, is that as 3-D printers become more common, that you could actually create more and more counterfeit product.

Exactly, and it's not just creating counterfeit product, but people can actually genuinely buy products and then reverse-engineer them using 3-D scanners and just make copies.

So just like we take a paper and we make a photocopy of it, a similar process is now feasible for 3-D-printed parts also.

But people can also copy QR code.

That's a legitimate worry as well...


...if they know that the code exists, so what we did in an example like this that if you look at it, it just looks like a cloud of points.


Inside the cube, there's tons of little pink dots here, so as soon as I look at it, I can see, and I look at it dead-on.

I can see exactly what looks like a QR code, but that's a composite of all of these different layers that have gone into it.


So you've printed each of those dots but at different layers in the cube.

Right, and their distance is also controlled.

Their location is controlled, so if this was printed as a sphere, then you would really have a hard time to figure out from which direction you have to see inside.

So besides the security component, what else does a QR code help?

At this point, tracking of authentic 3-D-printed parts is a big problem because people can just make copies.

And think of examples like prosthetics or implants that go inside people's body.


So there's no way to figure out if the implant was genuine or counterfeit if it is inside somebody's body already, but the CT scan can still figure out even inside the body whether the part was genuine or not.


So there is a lot of value in this kind of technology.

What inspired this?

So we started working into design-based security method, so people have been working on securing the 3-D printing chain for a long time, but being a mechanical engineer and material scientist, my thinking was that there needs to be something in the design itself because the most secure resources have been breached very easily in recent past for computers.

So now what we are trying to do is we are going to put all of this information in the design stage, so even if the password is breached, you still have a method inside which is very difficult to either copy or decode by the hackers who stole the files.

So this is something that let's say a company, a medical device manufacturer, that is going to start printing 3-D implants, they would use this at a sort of functional design layer before they even started printing, right?

Exactly, yes, so it has to go within the design process somewhere.

All right.

Nikhil Gupta, thanks for joining us.

Thank you very much.

What makes a planet a planet?

In 2006, the International Astronomical Union stripped Pluto of its planet status.

Philip Metzger, a planetary scientist at the University of Central Florida, joins me now to discuss the reasoning behind the reclassification of planets, and I suspect you find fault with that.

You are a 'Pluto should be a planet' guy.

That's right.


Glad to be here today.

So tell me, what was wrong with their ruling, and what were the rules that they imposed when they kind of kicked Pluto out of the planetary club?

Okay, well, there were a number of things wrong with it.

First of all, we contend that taxonomy, the classification of objects in nature, is actually a vital part of the scientific process, and therefore it's not subject to voting.

It should be only handled by scientists publishing papers and arguing in conferences, and it gets established by consensus, so it was a major violation of the scientific process to begin with.

Second of all, it violated 500 years of progress in the tradition of Galileo in refining what we mean by a planet, and it disrupted our entire literature by changing the terminology, attempting to change it, but the planetary scientists have largely ignored that decree in 2006, and we continue to use the word planet in different ways instead.

But what they said in 2006 was that to be a planet, a body has to orbit the Sun.

It has to be large enough to be rounded, and it has to clear its orbit, or more charitably, we would reinterpret it to say it has to gravitationally dominate its orbit, and we take issue with the part about orbiting the Sun and the part about clearing an orbit.

We don't think a planet has to orbit the Sun or clear an orbit.

Okay, so by your definitions, Pluto would be a planet, but then so would lots of other things, right?

That's true, yeah, and in fact, scientists have always called lots of other things planets besides the eight gravitationally dominant Sun-orbiting bodies.

Galileo called our Moon a planet, and so have almost all lunar scientists ever since then, and we call the large moons around Jupiter and Saturn, for example, planets, and we call the large geologically complex bodies like Ceres and Pluto planets even though they don't dominate their orbits gravitationally, and there are good scientific reasons for this.

Okay, so I was going to say, what are the reasons for calling all of these other objects planets when people are, I don't know...depending on when they were educated, they might be calling them moons, or they might be calling them planets?

Yeah, well, so there's a long tension between cultural concepts about nature and scientific progress about nature, and we see these tensions happening in other fields as well such as in biology centered around questions of evolution.

Despite this struggle between planetary scientists, how does this impact what we see in a textbook, in a classroom, how young people are educated about what a planet is and is not?

Well, I think one of the problems with the IAU's definition is that it really took away the excitement of discovering planets.

When they told us that there are exactly and only eight planets in our solar system, and these are the names, they took all of the air out of the room because up until then, we were very excited.

The public was very excited because we were starting to discover new planets.

Our telescopes had gotten better, and now we know that there are at least 150 planets in our solar system, possibly as many as 450, and yet nobody knows this, and the reason nobody knows it is because they've been told wrongly that these are not planets.

They're just the leftover junk from planet formation similar to asteroids.

Well, we've now had a spacecraft fly by one of these bodies, Pluto, and we found out it's not anything like an asteroid.

It's in fact, in my opinion, the second-most interesting planet in our solar system after the Earth.

It's the most complex, most amazing body in space other than planet Earth.

If there are all of these other planets.

We're not talking about habitable life-forms per se, but if we say we have a solar system with 100 more planets in it, how does that change how we perceive the universe?

Well, so first of all, there might actually be life on Pluto.

There could be.

The conditions are right.

We believe that it has an underground ocean, that surprisingly Pluto must have enough radioactive decay occurring in it to keep its interior warm so that the ocean has stayed liquid even until now, and we know looking at the surface of Pluto, there's organic material, and so the right molecular chemistry is there, so it is possible that Pluto is a second location in our solar system that can have life, but it's important I think first of all because it gives the correct message about the central truth of progress in planetary science.

We've discovered that the solar system is not this simplistic, clockwork order of just seven or eight bodies in sequence moving outward from the Sun all perfectly ruling their orbits forever.

Instead, we've learned that it's actively changing.

It's dynamic.

We think Uranus and Neptune may have actually swapped places at one time because the action of the Kuiper Belt dragging Saturn slowed it down and caused resonances, so it's a very dynamic, changing place, and so the central message is not static order.

The central message is all this amazing dynamism that has even resulted in us being able to be here today.

All right.

Philip Metzger from the University of Central Florida, thanks so much for joining us.

It was my pleasure.


Years of timber harvesting and urbanization have devastated this North Carolina forest.

Now the US Forest Service is working to restore the forest ecosystem by actually setting fire to the land.

Take a look as this story unfolds.

This is not what we want.

So this stand here was planted in loblolly back in the 1970s when the main goal of the Forest Service was to produce timber, and loblolly was a faster-growing species.

So this is what we want.

These trees here started growing here in about 1890.

This is the longleaf pine forest.

It is the natural ecosystem in North Carolina's Coastal Plain.

Centuries of timber harvesting and urbanization removed most of the longleaf pine forest across the Southeast.

That's why the US Forest Service is restoring the longleaf pine forest in Croatan National Forest, but to do that requires fire.

Once the loblolly pine trees are harvested, fire is vital to restoring the longleaf pine forest.

It is one of the nation's most endangered ecosystems.

So we were having a fire every 2-year or 3-year cycle to try and get what you're seeing here established.


So this was just burned just a couple months ago.

Are you amazed?

Look at this now.

It's all green.

Yeah, it recovers pretty quick with the moisture that we've received and all of that stuff.

The type of soil allows quick growth, so having fire in the area knocks down the understory where we can actually have more manageable fire, and it also opens up the sunlight and oxygen air to get new growth.

Longleaf pine is very dependent on fire to survive.

It grows as a grass when it's little, so the fire can burn over it, and it clears everything else around it, and it responds back really quickly.

It's naturally just adaptive to fire regimes, so then your longleaf in the grass stage is a seedling, which this is one right here.

See, it looks just like a clump of grass, so when the fire burns over it, it just burns it as if it's grass, and the bud is below the surface and is protected from the fire.

It spends 2 to 3 to 5 years just growing its root system, and it just stays as grass, and then eventually something clicks in it, and it starts in a shoot elongation and starts growing up.

Just pine bark in general, especially in longleaf, the bark is a very good insulator.

To kill the tree, the fire is going to have to hot enough to pop the cambium that's inside behind the bark where all the nutrients flow up and down.

So this bark just insulates the tree, and also with the fissures in here, the heat will kind of channel up the tree instead of just sitting here.

That careful management helps preserve and restore the longleaf pine forest, which is a mix of tall trees and savanna plus bogs and raised swamps called pocosins.

This longleaf pine savannah-type ecosystem prior to European settlement was about 90 million acres.

As of today, we have around 4 million acres of that habitat left.

The majority of that habitat is on national forest land across the country.

The longleaf pine is one of the most ecologically important tree species in the South.

Nine hundred plant species plus hundreds of birds, mammals, reptiles and amphibians are found in the longleaf pine forest.

A small difference in elevation makes a huge difference in the vegetation and how water is retained on the landscape.

Twenty-nine of those species are endangered, including the red-cockaded woodpecker.

A big thing about woodpeckers is we call them primary cavity excavators, so they're the birds that go in and make the cavity into the tree.

A whole suite of species will use that cavity for nesting, for some life stage.

With such a unique landscape, it's not surprising that Croatan is also home to the largest collection of carnivorous plants of any national forest.

Here on the Croatan, you know, we have the Venus flytrap.

Again, they tend to be found in these nutrient-poor areas that aren't too dry, aren't too wet, has to be just right, and so, you know, they can't just grow anywhere.

And when you're a little carnivorous plant laying flat on the ground, it doesn't take much to shade you out, and none of these things can live without sunlight.

They're completely fire dependent.

The small different little micro-habitats within the larger landscape just increases your diversity, increases the value, the ecological value, of that area.

And that wraps it up for this time.

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Until then, I'm Hari Sreenivasan.

Thanks for watching.

Funding for this program is made possible by... ♪♪ ♪♪ ♪♪ ♪♪ ♪♪ ♪♪