SciTech Now: Episode 614


[ Theme music plays ]

Coming up... what we know and don't know about gravity.

We know what it does, but we don't know how it does what it does.

...indoor farming...

Our overall goal is to reduce energy use in food production in controlled environment agriculture.

...the unique properties of squid eyes...

The resolution of their eyes is approaching that of humans, and their retinas are much more sensitive than ours are to light.

...learning tech lessons for the future...

This class has really helped me with work ethic and working with peers more.

It's all ahead.

Funding for this program is made possible by...

Hello. I'm Hari Sreenivasan.

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

Let's get started.

'Nobody knows what gravity is, and almost nobody knows that nobody knows what gravity is' -- that's a quote from the book 'The Trouble with Gravity: Solving the Mystery Beneath Our Feet.'

Author Richard Panek is here now to tell us about the scientific search for answers about this still mysterious force.

I thought this was all solved.

I thought, you know, we had Newton and the apple falling, and there it was.

Right. Well, I think that that's what most people thought -- think, and that's what I thought before I started doing the research on the book, and then I thought, 'Well, we don't really know what gravity is.'

And that just blew my mind.

So, how are scientists -- I mean, we go to school.

We learn this.

We have tons of analogies, really talk about it, but what is it that we don't know?

Well, we know what it does, but we don't know how it does what it does.

We don't -- We don't know what the cause of the effect is.


You know, if you drop something, you say, 'Well, that's gravity.'

Well, you're saying that it's the of gravity that the apple drops.


But we don't know why the apple actually drops.

[ Chuckles ]

And Newton himself said that -- you know, he said -- he said, 'All I'm doing is showing you the math.

And I don't know what the cause of this is.'

But after that, it worked so well -- the math worked so well that...


...that people just kind of assumed that it was an attraction at a distance, and that's what -- that's what we're taught.

That's what -- That's what everybody called it.

But Newton himself said, 'I don't know what it is.

I don't -- I don't -- I'm not saying it's an attraction.'

Hm. But we fight gravity every day.

But we do.

And did you know that walking is actually -- what scientists call it is a controlled fall?

[ Laughs ]

Because, with every step, you're actually surrendering to gravity.


You're falling, and then you're stopping yourself.

But that's what walking actually is -- it's falling.

Okay. So, I mean -- well, and it -- it costs energy to fight gravity this way, right?

Of course, yeah, yeah.

I mean, whether it's you're feeding stock to stand up or ourselves to have calories to move throughout the day and keep ourselves, I guess, in a controlled fall.

Right. Exactly. Exactly.

So, is there -- I mean, and put gravity on the on the -- on the spectrum of the forces that surround us because we think about it as this absolutely undeniable -- here it is on this planet.

This is what it is.

On the moon, it's a little less.

We've seen astronauts bouncing around.

[ Chuckles ]

But here -- here we are.


And we tend to think that it's very strong because it defines our lives.

But, in fact, if you're talking about the four forces, the strongest force is the strong nuclear force.

And it's about 10 times stronger than electromagnetism, which itself is about 10,000 times stronger than the weak nuclear force.

The weak nuclear is 10 to the 30, which is a 1 with 30 zeros after it, stronger than gravity.


So gravity is very much the outlier.

And, in fact, I brought a little demonstration.

Take this refrigerator magnet.


You have the entire -- the entire mass of the Earth, which is about 6.6 sextillion tons.


We have this paperclip, which is a quarter of an ounce.


And the paperclip is there because -- staying on the table because of the gravitational attraction force -- whatever...


...of this 6.6 sextillion ton object beneath us.

And here comes magnetism.

That's it.

[ Both laugh ]

So magnetism is that much infinitely stronger because we can pull that paperclip away from this giant source of gravity?

Yep. Mm-hmm. Right.



And we don't really pay that much attention to it because we don't think of magnetism -- as strong as it is, we think, 'Oh, gravity is the one that must be stronger.'

Yeah, yeah, yeah.

So, in this -- in this quest to figure out what we know about gravity, what did you find?

I found that the problem today -- we have Einstein's theory, but the problem is that it doesn't play well with quantum mechanics.


So until scientists can resolve that, we're still not going to really know what gravity is.

But I also found in my research how pervasive gravity is -- once you notice it -- how pervasive it is in culture throughout civilization.

So, for instance, creation myths -- virtually all of them begin with the division of earth and sky.

And that division wouldn't be there, wouldn't make sense, wouldn't be so fundamental if we didn't identify with one of those two.


If we didn't see this as familiar and that as mysterious.

And then, because it's mysterious, we assign...

All kinds of powers to it.




So, then, are we now closer to understanding it today than we were when Newton started doing the math?

Well, I think that we're -- we're closer, certainly, after Einstein.


And we can -- because of -- because of Einstein, we can do things like have GPS technology, which wouldn't work without -- without the general theory of relativity.

But -- But we're still puzzled as to what it is and when you see it in extreme forms -- for instance, a black hole -- you know, we see -- you know, we've taken a photo of a black hole, but we don't know what happens inside of that...


...and where gravity is strongest, so...

Are there alternate theories besides Einstein's that are coming up -- at least even being debated, saying, 'Hey, here's rules'?

Yes. You know, string theory was an attempt to do that.

String theory is still -- is still in -- in the -- in the stage of not having been empirically...



It's still just a theory.

And -- And other people are coming up with ideas, like there might be parallel universes that maybe have an attraction or whatever between them, and maybe gravity is so weak in ours -- so bizarrely weak in ours because it's just a remnant of this force in another universe.

I mean, these are ideas that people are throwing around.


They'd be very difficult to prove.

So, you've spend all this time chasing down what we know about gravity.

Do you feel like you know now?


[ Chuckling ] No.

I think it's -- [laughs] it's more mysterious than ever.

But I love the fact that it's a mystery.

I love the fact that this thing we take for granted and we all think we know without even thinking about it is actually this mystery.

You know, if you say to the average person, 'We don't know what gravity is,' the person will say, 'Well, of course we do.'

Yeah, yeah.

And you say it to a scientist, and they'll go, 'Right. Yeah, we don't.'

[ Laughs ] Alright, the book is called 'The Trouble with Gravity.'

Richard Panek, thanks so much.

Thank you.


Hi. I'm Amy Ross.

I'm a spacesuit engineer.

I design spacesuits like these.

This is '#AskNASA.'

I'm here to answer your questions.


For the Artemis missions, astronauts will wear spacesuits like these, and they'll be able to walk on the Moon in a spacesuit like this.

The xEMU stands for 'Exploration Extravehicular Mobility Unit,' so xEMU.

On the front of the suit here, this is called the display and control unit.

And this is how they control the backpack or life-support system of the spacesuit.

The new generation of spacesuits with xEMU has a lot more mobilities, so they're able to do the science we need them to do, such as geology -- pick up rock samples -- and also interact with Rovers.

But can she do dab?

Yes, she can.

She can also floss.

[ Laughter ] There are new technologies in the suit, so we're implementing new materials, and we have more bearings in the suit, and that allows her to move better.

We make spacesuits for humans.

They will be wearing the suit when we send the first woman to the moon and the next man in 2024.

Yes, the layers of the spacesuit protect against all the harsh conditions on the lunar surface, including moon dust.

So, the boots are very different -- more like a good hiking boot, and they have adjustment for better fit.

'Donning' is a term we use for putting on the spacesuit.

'Doffing' is taking it off.

So why does NASA have two Artemis spacesuits?

This is the Orion Crew Survival Suit, and it's different than the xEMU that you just saw.

And Dustin's going to tell you all about it.

Thanks, Amy.

This is the Orion Crew Survival Suit.

This suit is worn during launch and entry of Orion.

This suit is also designed for contingency operations.

If we had an emergency in deep space, the crew could actually survive in this suit and live for up to six days.

Is this spacesuit comfortable?

Oh, the spacesuit is very comfortable.

It's multiple layers of fabric, but they're all very form-fitting and tailored specifically to the occupant.

It fits perfectly to the person and, also, perfectly to the seat that they sit in.

So, why is the spacesuit orange?

Well, the original versions of the suit were actually blue, and we actually egressed into the water -- a fancy word for getting out of the vehicle -- and we practiced our search and rescue ops.

Orange is the most visible color for search and rescue crews coming to retrieve the crew.

Hey, what's that on your leg?

Oh, you mean these?

These are actually oxygen bottles.

So if we were to have to disconnect from the Orion capsule, they provide us about 30 minutes of air if an emergency was to occur on orbit.

Hey, is that a space fanny pack under your arm?

Oh, this?

This is actually... my life preserver unit in case I had to jump out of Orion into the water.

I can pull these tabs and deploy it.

So everything about this spacesuit really is built for survival.

What's the spacesuit material experiment?

We're sending some spacesuit materials to Mars to test them in the Martian environment.

This experiment will show how our helmet materials and our soft goods hold up in the Mars atmosphere.

Our spacesuits really are a spacecraft -- human-shaped -- that protect our astronauts.

These are the next generation Artemis spacesuits that will go to the Moon and on to Mars.

Do you have a question for NASA?

Send your questions to our experts on Twitter using #AskNASA.


In Upstate New York, Cornell University is tackling the question of how to best develop crops that can grow and survive year-round.

We visit the indoor greenhouse at Cornell to learn more.

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'CEA' stands for 'controlled environment agriculture' -- means that we're growing crops in a way that we can manipulate the growing environment... everything from light and temperature to relative humidity and carbon dioxide concentration, and doing that so that we can produce fresh plants year-round.

So the main goal of our CEA group is to reduce reliance on natural resources so to improve the energy efficiency and water and nutrient use efficiency in production.

By looking at several new technologies, one of which is lighting -- so, energy is one of the most expensive inputs in CEA production, second behind labor.

And lighting, in particular with LED lights, has made it a lot more energy-efficient.

So it really dramatically reduces energy costs.

With LED lighting, we also have the really unique opportunity to also change the spectra, or colors, of light that we deliver plants, and so then we can control how the plant grows, so the shape or size or whether or not the plant flowers.


The purpose of my study here is -- what I'm investigating is the effects of blue light on vitamin C production and a couple of different growth factors in the tomatoes.

So my treatments are a 'no blue,' which would just be our white...and red for a little bit extra intensity.

And then, our other treatments are a low blue, a medium blue, and a high blue.

So these are just different percentages of blue combined with red light.

And what we look at is things like seedling heights when they're growing and developing to this stage, and we look at flower number once they get to the flowering stage.

And then, once they get to the production stage, we look at yield per week, we look at fruit number, and we look at things like Brix, which is a measure of sugar content in the tomatoes.

And we also look at the vitamin C production.

Being able to say that, you know, we can manipulate nutritional value with our lighting -- just the lighting -- is really important information for growers, both on a large scale and for niche growers.


One of the other technologies that we look at is the way that we -- we grow the plants hydroponically, so the different systems, the lighting conditions, the nutrient solution conditions.

And so, if we can optimize the nutrients and water supply that we deliver to the plant, then we can deliver a uniform repeatable fresh quality crop year-round.

In terms of optimizing how the plants grow, we usually think about two things -- one is the root zone, and one is the aerial conditions.

So, within the root zone, in that hydroponic nutrient solution, we're delivering the water, and then all of the 12 essential nutrients that the plants need within the water, and, as well, dissolved oxygen.

So the roots need oxygen to -- to breathe.

And so we're capturing and reusing and recirculating this hydroponic nutrient solution to control the root zone.

Then, in the aerial environment, the things that we're controlling are the temperature, the light, carbon dioxide, and then relative humidity.

And then, besides optimizing how the plants grow, we can manipulate the environment so that we're reducing disease or insect pressure.

GLASE is a consortium between three universities -- Cornell, Rutgers, and RPI.

And our overall goal is to reduce energy use in food production in controlled environment agriculture.

So that's the overall goal.

But we also have close to heart and, you know, in our minds not to jeopardize the quality of the foods that are being produced in CEA.

And so my part is not only energy, but looking at the whole plant.

This is called a pulse-amplitude modulated fluorometer.

And what it does -- it allows us to speak to the plant.

We use light.

We ask a question.

The plant responds back to us in light, and we pick this up using very sensitive fiber optics.

One thing that we're working on in GLASE is to ensure that the food that we're growing with advanced technologies has good nutritional content for the consumer.

And so we isolate the different pigments that are we know are healthy for us under the various light recipes or other environmental conditions.

So, there are several benefits of CEA.

One of them is having this access to fresh, locally grown foods.

Then, I feel like there's -- there's also these educational benefits.

So, many schools are growing -- growing their own produce hydroponically as a way of educating children both scientifically what plants need to grow and thrive, but, also, where their food comes from.

And if people have an understanding of where their food comes from, that can help them make choices that allow them to be healthier individuals.

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Biophysicist Alison Sweeney is using chemical analysis and X-ray reflectants testing to study the reflective proteins inside squid eyes, which possess unique properties.

Our partner 'Science Friday' has the story.

There is a vast literature on vertebrate lens biochemistry.

We've got this whole sort of messy Gemisch of proteins in there.

But a squid lens is infinitely more elegant than our eye.

The resolution of their eyes is approaching that of humans', and their retinas are much more sensitive than ours are to light.

And when you dig into the nitty-gritty of how nature figured it out, I'm forever blown away at the level of nuance to get it to work.

My name is Alison Sweeney, and I study the evolution of novel materials in nature.

Organisms are made of stuff.

[ Chuckling ] The tree is made of wood, and a human is made of skin and bones and muscles.

You know, so we can think of these things as materials the way engineers do and ask the question, how did they get that way over the course of evolution?

And if you were a Martian who swooped down and scooped up exactly one animal off of Earth, you are more likely than not to get something transparent and bioluminescent that came from 400 meters in the ocean, 'cause that's where, you know, 99% of the space is.

And if you were really interested in how does it work, probably you should be studying animals from the deep ocean.

So, midwater squid just hang out in this pretty darn empty void.

Far as you're concerned, life on Earth is this infinite 3-dimensional, featureless watery realm, which means that there's not a lot of structure other than the light itself.

People are often surprised to learn how much light is actually down there.

So, at 400 meters depth, there is as much light at noon as there is on a full moon night on land.

If you're a squid that's been evolving for 400 million years to live at that depth, you can see great.

You probably have as much visual perception as we do at noon because their eyes are much more sensitive.

One of the things that makes squid eyes as sensitive as they are is the design of their lens.

If you want to be more sensitive to light, you want to bend light as quickly as you can to your retina, so you focus as much light as possible on a given spot on the retina as you can.

To do that, you want a really bendy, powerful lens, but you don't get a very crisp image out of a spherical lens.

Squids have figured out how to fix this by making the lens denser at the center and less dense at the edge so that you get a completely crisp image at every point on the retina.

It's really sort of a neat trick to find a way to put proteins together in a whole bunch of different densities such that none of them are going to require any energy to maintain that structure, and they will never coagulate over the lifetime of the animal.

A lens is, like, literarily made of S-crystallins -- all of the stuff in there is S-crystallin protein.

And everybody thought that you just had sort of a bunch of these dissolved in solution.

And the thing that made them weird was that they never broke, and they never aggregated.

So we got squid, and we pulled their lenses out, and then we stuck squid lens tissue in a vacuum chamber that is situated in the middle of an X-ray flight tube.

The X-ray source sends a beam of X-rays through your sample.

When the X-rays hit the sample, they're going to scatter off, and the pattern of X-rays that we observe on the detector tells us what the structure of the sample was before the X-rays.

What we saw was a squid lens genuinely self-assembles into this really cool higher-order complex optical structure.

So self-assembly is this concept that I would like to figure out how to make a Lego castle -- that, if I had a bunch of little bricks, put it into a bag, and shake the bag, the castle will just come out again.

That's essentially what the squid lens proteins do.

It's non-trivial to make these things.

You know, if we knew how to make a little lens that built itself out of basically free materials, we would do that.

[ Chuckles ] We don't know how to do that.

And the beauty of evolution is you don't have to know what you're doing -- you have to keep changing it until it works.

So, by studying how the evolutionary process has found self-assembly that works, you know, basically we can leverage 400 million years of iterative learning to show us how to make shortcuts at the engineering bench.

[ Computer keys clacking ] ♪♪

A high-school tech class in Platte City, Missouri, is giving students hands-on technical experience.

There's a computer help desk where students fix other students' laptops while others work with virtual reality.

Students say these experiences are teaching them skills needed to succeed in today's workforce.

We get the story through our American Graduate: Getting to Work initiative made possible by the Corporation for Public Broadcasting.


I was in charge of implementing a student technology help desk.

The help desk is a program where students can bring in their devices.

We've taken Chromebooks that aren't majorly damaged and fix them up and return them to students.

So, I'm replacing the battery in this one.

I felt that the kids needed or deserved a richer experience.

Now it has sort of morphed into its second iteration, which is students come in and not only commit to customer service and fixing Chromebooks, but they do their own self-driven, self-motivated projects.

They'll set goals in those projects, and then I try to provide them resources and materials.

A group of students -- they were interested in filmmaking and documentaries, so they watched several documentaries, and now they have become a full-fledged video/documentary crew.

This class has really helped me with work ethic and working with peers more.

I have to go and put what their ideas are -- put them along with my ideas and make one video.

Another kid is working with Unity to create a virtual-reality experience.

All the, like, big gaming companies -- they use something like Unity, where they would assemble their levels and scenes.

I want students to get a sense of time management, project management.

A lot of companies and businesses are allowing people to work at home.

So I think they need to have that motivation to be able to complete a project on time without somebody over their shoulder, telling them to do it.

Now it's kind of nice to be self-driven, and I can learn what I want when I want to.

Usually, when I run into a problem during schoolwork, I just kind of give up, and I'm like -- well, if I can't ask the teacher, if there's not an answer key, I'm just kind of stuck.

But now, when I run into a problem, it's like I got to turn to the Internet and solve it myself.

It's frustrating until you figure it out, and once you figure it out, it's a great feeling knowing that I solved this on my own and that I can do this on my own.

Funding for this program was provided by the Corporation for Public Broadcasting as part of the public media initiative American Graduate: Getting to Work.


And that wraps it up for this time.

For more on science, technology, and innovation, visit our Website, check us out on Facebook and Instagram, and join the conversation on Twitter.

You can also subscribe to our YouTube channel.

Until then, I'm Hari Sreenivasan.

Thanks for watching.

Funding for this program is made possible by... ♪♪ [ Theme music plays ] ♪♪ ♪♪ ♪♪ ♪♪ ♪♪