IRA FLATOW: This is Science Friday. I’m Ira Flatow.

I want you to imagine for a moment the earth not as a rocky ball, but as a giant bar magnet. And our bar magnet earth is circling a much bigger bar magnet, the sun. Now imagine the enormous magnetic bubbles, the fields created by these two magnets, bumping, and scraping, and pushing against each other.

How’s that working out? Understand that shoving match or quartet of spacecraft is surfing those magnetic waves. And they’ve beamed back a few clues reported this week in the Journal of Science. My next guest has that story and other selected short subjects in science.

Amy Nordrum is an associate editor at IEEE Spectrum here in New York. Welcome back.

AMY NORDRUM: Hi, Ira.

IRA FLATOW: So what are the spacecraft out there doing?

AMY NORDRUM: So the spacecraft that we’re talking about, they’re part of a NASA experiment called MMS. And they are exploring this phenomenon known as magnetic reconnection. And this is a phenomenon that occurs in the interaction between the magnetic fields that the earth has that protects us from the solar winds coming off of the earth, and those carried by the solar winds in our direction.

So when these solar winds hit the magnetosphere of the earth, they collide and form this big crash in these forces of charged particles. And in some cases, the magnetic forces from those two fields will actually connect with each other. And we call this a magnetic reconnection.

And this is the phenomenon that scientists have known about for a while. They’ve theorized about how it occurs. They’ve observed its effects in phenomenon here on earth, like the aurora.

But they’ve never really gotten a close look at it before. And that’s what this experiment is all about.

IRA FLATOW: So they add up? They connect like a tunnel?

AMY NORDRUM: Right. So usually the forces are traveling in what you can think of as opposite directions. It’s almost like– the researcher I spoke with, James Drake from the University of Maryland, he described it as two trains traveling in opposite directions. And then their tracks suddenly switch and become one. And they crash into each other for a brief moment.

So this can last for a little while before the fields return to their respective opposite directions. But while it does happen, it creates this huge release of energy. And that’s what the scientists are trying to observe with these spacecraft.

IRA FLATOW: Wow. So that would affect space weather.

AMY NORDRUM: Absolutely. So the charged particles that come in from the sun in these solar winds actually make their way into our magnetosphere during these events. And that’s what we see in the aurora and a number of other phenomena. Like you’ve heard maybe of satellites and power grids actually getting knocked out by magnetic storms and big geomagnetic storms.

And that’s what we’re talking about here. So they’re hoping by taking a closer look and getting their first observations from within one of these events, they might eventually be able to predict some of these storms happening and give us a little bit of a heads up.

IRA FLATOW: Because we depend so much now on radio waves, all kinds of waves. We’re wave– we’re wirelessly connected.

AMY NORDRUM: This radio show depends on it.

IRA FLATOW: It does. Wow. See the little box with wires in front of you?

AMY NORDRUM: Absolutely.

IRA FLATOW: Well, let’s move on to your next story. It’s about a prehistoric find under the sea. You don’t hear much about finds under the sea, do you?

AMY NORDRUM: So this is a very interesting site in Florida that was just recently discovered and reported today in Science Advances. So this site in Florida is about 45 minutes from Tallahassee, actually is in a river. So the stone tools and the mastodon bones that archaeologists found at the site were 30 feet underwater and required some special techniques to excavate them.

The other interesting thing about these fossils and the stone tools especially are that they have been dated back to 14,550 years ago.

IRA FLATOW: 14,000 you say.

AMY NORDRUM: Yes.

IRA FLATOW: Years ago.

AMY NORDRUM: Yes. And if you’ve been following archeology, you know there’s a big debate within the field about when humans first arrived in the Americas. And for a long time, the theory was that it was roughly 13,000 years ago humans came over the land bridge. But now we’re seeing more and more sites pop up throughout the Americas, including this new one, that suggests that maybe humans might have been here before.

IRA FLATOW: You can’t get much further from the land bridge than Florida, right?

AMY NORDRUM: Yes. So, well, actually in Chile, Monte Verde is another site that’s older. So that is much further away.

So that might open up the possibility of a different route. Maybe they didn’t come over from the land bridge. Maybe they came by sea in some way, shape, or form.

IRA FLATOW: Were these the Clovis people?

AMY NORDRUM: So the Clovis people were the ones that, for a long time, were thought to be the first humans in North and South America. And they were the ones who were theorized to come over from the land bridge.

But these new sites would be pre-Clovis. So they would be before.

IRA FLATOW: That’s exciting.

AMY NORDRUM: Yes.

IRA FLATOW: This week, you wrote about the next generation in cellular data. Get ready for 5G.

AMY NORDRUM: It’s an exciting moment to be a wireless engineer. This has been referred to as the Halley’s Comet of wireless engineering. You only see it come around once or twice within the course of your entire career if you’re working in this field.

So your phone and my phone, right now they were working at about 4G LTE service. And then a lot of places they’re still relying on 2G and 3G. But we’re trying to work to get to 5G in the next couple of years.

But to do this, we need about 1,000 times more capacity on the spectrum that we’re using than we have today. And so in order to work toward this, there’s been some experiments lately in trying to increase the spectral efficiency, which you can think of as the number of users that you can cram into a radio channel at once.

This week, a couple of researchers at the University of Bristol in England and then also from Lund University in Sweden reported a new world record on spectrum efficiency. They were able to transfer 22 users at once on a single radio channel.

So that gets us a little bit closer. And we’ll be watching this to see how much more they can improve that over the next couple of years.

IRA FLATOW: Now, is this for voice or is this for data?

AMY NORDRUM: So this is for data. And this would be– this is achieved through a technology called massive MIMO, in which–

IRA FLATOW: Massive MIMO.

AMY NORDRUM: MIMO, M-I-M-O.

IRA FLATOW: I love it.

AMY NORDRUM: And it’s achieved using a lot of different antennas. A huge array of antennas. there’s 128 of them.

And your typical base station only has about four. So you can imagine what an increase, what a boost this gives you in this huge array of antennas. And this is one of the technologies that’s being tested out as potentially pointing the path forward for 5G.

IRA FLATOW: So it’s not just jamming a bunch of antennas together. You have to get the algorithm changed.

AMY NORDRUM: Right.

IRA FLATOW: The software has to be changed too.

AMY NORDRUM: So the tricky part when you add all these antennas in is you have to be able to route the signals properly. And that can be a really difficult process. So there’s a lot of sophisticated signal processing algorithms that need to be written in order to make sure that these signals, these 22 signals traveling on the same channel are getting to the right spot.

IRA FLATOW: And Facebook is involved in trying to get this working, right?

AMY NORDRUM: Yes. Facebook is trying a different array that has about 96 antennas. And it’s called ARIES. And they reported another record about a month ago for new spectral efficiency.

So they’re trying to use it for a slightly different purpose. They actually want to use it to distribute internet out to rural areas from cities. But it’s a similar technology.

IRA FLATOW: Well, we can’t wait for that. It’s all Wi-Fi. Everything’s going– phone calls are all going Wi-Fi now. You’re doing FaceTime and all this other stuff.

AMY NORDRUM: Right. I think 5G service will be really great for those of us who get it. I think we can expect to see it in cities first. And then the rural areas will likely follow after that.

IRA FLATOW: All right. That’s terrific. Thank you very much. Thanks for taking the time to be with us. Amy Nordrum, an associate editor at the IEEE Spectrum here in New York.

And now it’s time to play Good Thing, Bad Thing. Because every story has a flip side.

Now we go back to 2014. A strange disease begins affecting sea stars, starfish, off the Pacific coast. A gruesome wasting disease that infected some 90% of the sea star’s in the area.

And now it appears that some starfish are making a comeback. Or are they?

Here to talk about the good and the bad of the sea star saga is Lesanna Lahner. She’s a veterinarian at the Seattle Aquarium. She’s at KUOW studios in Seattle. Welcome back.

LESANNA LAHNER: Thank you so much for having me.

IRA FLATOW: So is there good news here?

LESANNA LAHNER: Yeah. There is good news. There are reports that there are some baby sea stars being seen along the coast. So that is the good news.

However, the bad news is that we did experience similar numbers of baby sea stars last spring. And unfortunately, by around midsummer when these guys reached dinner plate size, they did start to succumb to star wasting disease as well. So we are cautiously optimistic about the potential resurgence of sea stars and sea star populations at this time.

IRA FLATOW: Well, you had such a small, few words for the good news. And you went right to the bad news.

LESANNA LAHNER: I know. I’m sorry. I know.

Well, it’s good news if you’re a sea otter. So on that side of things, sea otters eat sea urchins. And sea stars eat sea urchins.

So if you’re a sea otter, you’re going to have a lot more groceries right now. Because we do know that sea urchin populations have increased along the coast without their primary predator sea star. So it is good news for them.

IRA FLATOW: Well, do you have to wait to see if and when they grow up, as you say, that they’ll survive or not? It’s too early to tell?

LESANNA LAHNER: It is. And it seems like there is an age for this disease. It seems like younger sea stars are not as susceptible. And once they reach roughly 10 centimeters in diameter, they seem to be more susceptible to sea star wasting disease.

IRA FLATOW: Now, when you were here last time, you were talking about signs that a virus was to blame for this wasting disease. Is that still the thought now?

LESANNA LAHNER: You know, we’re still working on the viral component. And Dr. Ian Hewson at Cornell is still doing some amazing work on that. There’s still a lot to learn.

And I know, when I talk to my sister who is a physician, she says, why are you still working on this? If this were one of my patients, I hate to say it, but I’d have it figured out.

IRA FLATOW: Easy for her to say.

LESANNA LAHNER: I know, exactly. So I have to remind her of two main things. Number one, we don’t know what’s normal or baseline health for sea stars. So I’ve been working a lot on that.

And then number two, sea stars actually don’t have health insurance. So we also have to figure out ways to support this work.

So I’ve been busy looking at what is normal see star blood work. And what does the blood look like when it’s diseased? And those kind of changes are actually incredibly valuable for helping us figure out what’s happening with these guys.

IRA FLATOW: Well, couldn’t the sea star be sort of a canary in the coal mine for the oceans there?

LESANNA LAHNER: Exactly. Exactly. So just like we look at coral and the fact that coral bleach in response to a variety of factors. Heat, even cold, pollution, all of those things cause coral to bleach. And coral don’t have many ways to show that they’re diseased or stressed.

Sea stars are probably very similar. They don’t have a multitude of ways to show us that their environment is changing and they’re not doing well in that environment. So we have to look closely at what’s changing in the environment that might be exacerbating or causing them to waste.

IRA FLATOW: Because it’s very rarely one thing. Its always some stressor there, right?

LESANNA LAHNER: Exactly. Especially in the marine environment where these guys are bathed in different viruses and bacteria all the time, and really rely on a very unique water chemistry to stay healthy. So it’s a challenging thing to figure out these wildlife diseases, particularly when they’re underwater.

IRA FLATOW: Well doc, thanks for taking time to be with us today.

LESANNA LAHNER: Well thank you so much.

IRA FLATOW: Dr. Lesanna Lahner, a veterinarian at the Seattle Aquarium.

Copyright © 2016 Science Friday Initiative. All rights reserved. Science Friday transcripts are produced on a tight deadline by 3Play Media. Fidelity to the original aired/published audio or video file might vary, and text might be updated or amended in the future. For the authoritative record of ScienceFriday’s programming, please visit the original aired/published recording. For terms of use and more information, visit our policies pages at http://www.sciencefriday.com/about/policies.