Transcription
Is gravity truly a force?
The trajectory, [music] it looked like a duck. It talked like a duck. It acted like a duck.
Right.
As far as you're concerned, it's gravity.
Gravity.
Go on about your business.
And the universe doesn't care one way or the other.
I'm going to quote Einstein. Time is defined to make motion look simple.
Wa. That is [music] effing crazy. [laughter]
If I put you in an elevator and cut the cable, you will fall to Earth at 32 feet per second for every second. So, it's no good if I just before I hit the ground, I jump.
Only if you're Bugs Bunny or the Road Runner. [laughter]
This is Star Talk special edition. And I have no idea what we're doing today, but Gary knows. Gary.
Oh, you've put the burden on the responsibility upon [laughter] me.
They just told me to show up for special edition.
All right. So, every year we sit patiently through hundreds of fans questions and thank you so much. Uh, but now after a year of good behavior, we get to ask ours. So, I suppose it's that time of the year when there's naughty and there's nice. So, I guess
I'll be nice.
And I'll be naughty. How about that?
This is the third time apparently.
I know. Wow. It's become a tradition. Yes. [laughter]
In the making.
This one is the charm.
Founded in 2023. [laughter] Okay.
What a great year. It just does not sound very impressive.
All right. So, what do [snorts] you have? So, what happens now?
Okay. Before we get to our questions and we
These are questions you have.
The Star Talk family have Chuck and I are part of the Star Talk family. So, we have our burning questions. All the people. Okay. You have your burning questions and you're also delivering questions from people who are in the Star family. I [laughter] mean, we are built on curiosity.
Okay. If that's as it should be.
Thank you.
But if I can't answer it, I will tell you.
All right. Um, before we get to our questions, we recently had a Patreon whose question made the rounds. First it stumped you. So then you passed it on to Brian Green.
Yes.
Who then recently passed it on to Brian Cox and stumped two different theoretical physicists. So congratulations to Mitchell Atkins for winning cosmic queries.
Well done [laughter] you.
Yes. Uh, right.
Is there some prize for that?
Um, you get to ask more questions.
He gets the pat on the back for for being
I remember that. That's the uh quark question that you were so enamored of.
Oh, yeah.
The quark question. Like during during spaghettification when we get down to particles ripping apart, when you rip apart a quark, it makes two more quarks.
So what a quark catastrophe.
Oh, great. A quark. Quarky.
Here we go. Asotic freedom.
Asic freedom.
Like I said,
Yeah. [laughter]
So now you guys got questions. Let's bring them on. Chuck, you have a question here. Um, I think
Yeah, this was like a general kind of Yeah, we we'll keep it to this year. My my my actual question was, what was your top nonastrophysics topic we covered this year or the favorite thing that you learned in this year?
It would have to be our David Chalmer's interview on consciousness.
Oh, okay.
Yeah. He's Aussie. Was that right? Yeah. Yeah. But he's NY I think he's NYU local.
Right. So I just like hearing an expert. So many people are opining on what consciousness is and the mind and he just thought a lot about it and so I enjoyed learning about and that was on on special edition, not just any of the
The flagship Star Talk content. So So I like learning stuff as much as I can.
I find that shocking.
You're not the only one.
Yeah. [laughter] No, if I'm at a party, for example, and I learn that someone's like an expert on like bird wings or grasshopper legs, it wouldn't matter.
I got 100 questions for him.
Yeah. [snorts]
100 questions.
Yeah.
And
Why not take advantage of the expertise
Completely?
Take advantage of the moment.
Mhm.
Yeah.
All right, Chuck, you want to follow up with your
Okay. Oh, here's my uh first question. Uh, is gravity truly a force? Is it truly a force or is it just a bending of time itself? Okay. Now, so clocks tick more slowly as they are closer to objects with more mass, right? Okay. So, if we look at a flat space-time graph, okay, so just two axis. All right. And on the space axis, we take Earth and we shrink it down. So, it's just a one-dimensional flat Earth, which some people actually think is the case. You idiot. Anyway, I'm I take that back. You're not an idiot. You're just stupid. I'm sorry. That didn't come out right either. Anyway,
No way for that to come out right.
I know. God. Okay. So, the Earth is now flat on this on the flat space axis. Okay.
If you traveled up, which is the time axis, right? Which means Earth is stationary.
Yeah. You're just moving in time. Just moving in time now.
Right? That means you're doing you're not moving. You're just sitting there.
You're just sitting there.
Yeah.
The time axis then bends. Okay. Which means that you're bending spaceime, which we know actually happens. But how do we get to that place, you know, in that example? You know what I mean? Like how do we get to that place in that example? So, is it just the large mass object bending time or and dragging space along with it? Is that the case? And I left out acceleration purposely just for this. Like this could never happen. We know. But if it could, how do we get to that?
Well, so let me try, okay.
To answer that. I don't know if I'll succeed. So when you said the time axis is bent, what you mean by that is
The amount of mass represented by Earth and its surface gravity has a certain slope of that line.
Correct?
That you would move at at an angle, so to speak, right?
Uh, on that timeline.
And that would be either faster or slower than the time that passes for someone on a more massive object or a less massive object.
Correct.
Okay. I think you shouldn't overthink it.
That could be an issue. [laughter]
So, I'm I'm reminded of if it looks like a duck, walks like a duck, quacks like a duck.
Right?
It's a duck.
Okay.
I got you.
All right. So, have we ever talked about the equivalence principle?
Briefly in an explainer.
Not in a special edition.
Not special edition. Let's do a special edition. Okay. Special edition version. Uh, the equivalent principle, right? Okay.
So, we're here and I'm on Earth. There's one G.
Yeah.
Okay.
That'd be me. [laughter]
One Gary. Okay.
New unit.
A unit unit of measure. So, it's one G. So, all the mass of the Earth is pulling on you to for you to then weigh what you do.
Right.
Okay. People say, "Oh, gravity is strong." No, it's not. Cuz I can pick something up away from the earth.
You just violated gravity. That's [laughter] right.
You just like take that gravity.
Right. I just jumped. I could jump.
I'm just like, yeah.
All right. So, and objects accelerate. So, if if I toss something to you, it won't go straight to you. Gravity will bend it.
Absolutely.
Okay.
It's the parabola.
Yes. Yeah. Well, on an exam, the answer would be parabola.
Right?
All right. Once you understood that then you say the real answer is it's the a segment of an ellipse.
Right?
Okay.
So it's constantly falling.
No. So no.
If you answer ellipse it means you know more than the questioner who wrote the question.
That's not going to happen. Is [laughter]
It can happen like when they write the New York State regents in physics. Okay.
I had to watch out for knowing too much. You have to answer what they think. They want they want the answer that.
Yeah. So when you do calculations with trajectories, it's approximated with a parabola. Okay. They don't say approximate. They just say it is a parabola.
For it to be a parabola, it means the force is directly down at every single point on the trajectory.
Right. Right.
However, Earth is round.
So this vertical line is not parallel to this vertical line because it's moved along Earth's arc. That each point inward to Earth's center.
Right?
Okay. You can approximate it over small. This is why people think Earth is flat because sections of Earth you can approximate with a flat surface, right?
But if you did it precisely, you would find that those directions that gravity is pulling you angle towards the center of the Earth. And that shape is not a parabola. It is an ellipse.
Right?
And how do we know it's an ellipse? Because if all the Earth were shrunk to its center, it would orbit the Earth. This this ball you threw to your friend would orbit the earth in a really elongated right.
Ellipse.
Okay.
No, it's a cool fact.
Right?
But it's like the do is visualize it as don't look at it as you're throwing something and it's going along the ground. Look at it as you're throwing something and it's going along the curvature of the earth.
Or or or the curve that earth.
The curve that earth's gravity gives you. That's what I'm saying. Okay. Okay. And the force of gravity from earth when you calculate with it you put all of the mass at the center of the earth and it's so when you say when in Newton's equation of gravity force equals big g which is a constant.
Mass of me mass of the earth divided by our distance squared.
Yeah.
What's our distance if I'm standing on the earth which is down in the center of the earth.
So two constants your center of mass and the earth center.
Correct. And that distance is that distance. It's not the fact that there's earth between it and me doesn't make any difference to the math, it turns out. So point is that's why this arc.
Is not thinking that earth is there. It doesn't care. It just cares that earth is operating as though it's at its center. And if earth's surface were not in the way, it would continue in this arc. So here's my point. So Einstein said, "If I'm in a rocket and the rocket is accelerating at 1g, okay, that's a pretty fast acceleration."
That is.
Okay. So 1g in in American units is 32 feet per second for every second you're subjected to the force.
Per second. Per second.
Per second. Per second. Right. So after 1 second, you're going how fast?
32 feet.
Per second.
Per second. After 2 seconds, you're going how fast?
32 feet times 32 feet. No, 64 ft.
64 feet.
Per second, right?
After 3 seconds.
Uh, 128 ft. No, 64 * 30. No, wait a minute.
96.
See, I'm already confused. 96. [laughter]
Add another 32.
You're in trouble if I'm getting it right.
Just so you know.
No, this is where my overthinking starts. Exactly. I start overthinking. So 96. Yeah, that's the recipe to get to your speed after 3 seconds.
Right? Cuz and it will just continue like that. The farther the longer you fall, it just keeps continuing.
It just gets faster and faster and faster. Okay. Okay. So now.
So that's Earth's acceleration of gravity.
Right?
Okay. All right. So in fact, well, you're standing here and you that's your weight. If I dropped you from an elevator shaft or put you in an elevator and cut the cable, you will fall to Earth at 32 feet per second for every second. So, so it takes 4 seconds to hit the ground. How fast did you hit the ground?
Uh, wait a minute. This is time. Okay. We need Jeopardy think music. [laughter]
Is it 128?
128.
Okay.
Chuck, you're 0 for two here.
I just I wasn't sure. That's why I sat on that answer thinking, is he playing a game?
32, 32, 32, 64, 96 and then the 32 on top of 12. Okay. So, and then you then you die when you hit the ground.
Right?
Or not.
But while you're falling, you're weightless, just so you know.
So, it's no good if I just before I hit the ground, I jump in the elevator and I land softer than if I was just [laughter] the ground.
Only if you're Bugs Bunny or the Road Runner.
That's when that works.
If you wanted to jump [laughter] the Thank you. Thank you. Uh, if you could jump or you were as resistant to death as WY Coyote.
Right. Yeah. Okay.
If you jumped upwards.
At 128 ft per second.
That would counterbalance the fact that you were falling 18 128 ft.
Hit my head on the roof.
And then you would, I guess, you would just land softly.
It's not a You would be your own retro rocket. [laughter] Your own retro rocket.
Your own You're your own retro rocket.
It's a retro rocket. All right. So now Einstein said, "Now, here's a rocket that's accelerating at 32 ft per second." Okay.
Okay.
Right.
We're in space.
Right?
Okay. You're on the other side of the rocket and we're accelerating sort of this way upwards, let's say, up, I mean, towards our ceiling. You're across from me in the rocket. And I take a ball and throw it to you. At the instant I let go of the ball, it is going whatever speed the rocket was going at that moment cuz I'm in the rocket correct and my hand is touching the ball.
Right? But if it takes 1 second to get to you, what happened to the speed of the rocket in that one second? It was about 32 ft. 32. So this ball is not going to make it to you. It's not going to go straight across to you.
No, it's going to go down.
It's going to curve down.
Right? I got you.
It's going to curve down exactly the way it curves down if you threw the ball on Earth. And Einstein said, "Could you tell the difference between these two situations in a rocket or on Earth? If the rocket were sealed and just standing here on Earth.
Right?
And you perform this experiment, the ball's going to dip before it reaches you. If I'm out in space at 1G, the ball will dip before it reaches you." He hypothesized, turns out correctly, that those two situation are indistinguishable.
So, you're telling me someone took a ball on a rocket for real?
Uh, no. There's another way to test this. [laughter]
Okay. These are two different masses we're talking. One is your gravitational mass.
Yeah.
And that shows up in the FG mm over R2. The other is your inertial mass, which shows up in your F= ma, which is another one of Newton's equations. And the question is, are those two masses the same? There have been experiments that have shown they're the same to like 9 or 10 decimal places. Basically, it's a correct understanding of the universe. So, you asked if gravity is a force.
Mhm.
You can think of it as a force when you're sitting here on Earth.
Right?
But when you're just rocketing through space, is it a force? No. It's just the leftover speed the ball had over here that gives the illusion that something pulled it down. But in a sealed rocket, you cannot tell the difference.
And so to say, is gravity a force or is it just the curvature of space and time? I'm saying that distinction.
Is immaterial.
It's immaterial. It's it doesn't really make a
You want to make you want you want
You want it to be
Because that is our natural intuitive thought process.
Experimentally identical.
Exactly. So I
And and since one of them involves no planet at all.
Right.
All we can say is it's convenient to think of that as this thing called gravity here on earth.
Right?
It's a convenience.
In space it's not gravity but it's doing exactly the same thing.
It's doing the same thing but it's not gravity in space. When did get to his laws of motion.
16.
Right? So.
1687.
So since 1687, we've been trying to break his laws.
No, you you they're not going to break in the realm that they were.
No, I'm saying people have tried and they still are holding true.
Oh, yeah. No, no, no. It's been verified. So it's it's only break down at the limits, right? Where oh my gosh, you're really close to the sun. The gravity of the sun is so strong. Einstein's Einstein matters, okay, in the general theory of relativity.
Right?
And where time begins to get altered and then Newton's equations fail. They just fail.
Gotcha.
But they still work. We went to the moon on Newton's equations.
Yeah. Just so you know.
Yeah. All right. Um.
So, so it's like saying is a, you know, is a hot dog a sandwich? You know, at one point it's just semantic, but people want to argue as though it's a deep philosophical fact.
Right? It it only matters for the sake OF THE ARGUMENT. [laughter]
Good way to put that.
That's it. It only matters for the sake of the argument.
It it does not matter in the universe, right?
And the universe doesn't care one way or the other because it works both ways. It's indistinguishable. It works. So basically, this is the spaceship. That's the problem.
And and yes, [laughter] and this thing about time, right?
Okay.
Because I was only just talking about the trajectory. So if there's a if there's a spaceship going past you.
Sorry now let's go back to what's called uniform motion. So it's not accelerating, right?
Okay, just easier to think about this. Okay.
So a spaceship going past you. You don't know if you are stationary and it's moving or it's stationary. You don't know. [clears throat] Right? There's no way to even.
Determine that.
It's like when you're on a train and it pulls off.
Real slow.
Real slow. The the other train you're looking at, you're like, "Oh, they're Wait, who's moving?"
Who's moving? Right. Cuz it's real smooth. Yeah. If it's smooth. In the old days, they didn't have smoothly paved roads and they just had horsedrawn carriages and chariots. And so, if you were moving, you knew you were in motion.
So, how could Earth be in motion? We would feel it.
No, cuz it's moving through space, right?
Not on your damn road, right? You know, with.
They don't have a Department of Transportation in the universe. [laughter] That doesn't do its job. Well, they may they may do. We've just not come across them yet. That's true.
So, here's the problem. If you want to know how their time ticks.
All right, let's say they send out time signals. There's one every second.
Okay. Well, you'll get one of those signals, okay? And the next signal that comes to you, the interval between those two signals will not match the interval between those two signals sent to you by the person on the ship because they're coming towards you and they'll be shrunken or or expanded.
Yeah.
And so we also know that the speed of light is the same no matter the reference frame. And so everything else adjusts to make that happen.
Right? And so when Einstein got published his general theory of relativity, it took the uniform motion and generalized it to any motion at all, which that's why it's called general the general theory of relativity, which includes accelerations, which then talks about gravity and the curvature of space and time. So that's the best I can do with that answer.
No, that's pretty good. Um, and you're right. The real answer is you're going to be asleep. You're overthinking it. That's.
Well, yeah. Yeah. And and like you said, on the ship, the the the trajectory, it looked like a duck. It talked like a duck. acting like duck.
Right?
As far as you're concerned, it's gravity.
It's gravity.
Right?
Go on about your business.
Yeah. Okay. No, I'm satisfied.
We'll see. We'll see. We'll see what the next one.
Okay. [laughter]
I'm satisfied with this. It's Yeah. I'm Yeah.
I appreciate your curiosity. Here is the season.
For a limited time here at Star Talk, we're going to offer [music] a discounted access to membership categories of our Patreon community. Get you a little closer to what we [music] do and how we do it. There are gifts at different levels and it's discounted for the holiday season. And somewhere down here are the codes. Check it out.
So, right, next question from me.
Uh, recently Airbus grounded some 6,000 of its aircraft for emergency computer updates as a result of cosmic radiation. Why was it just Airbus and not others? Is this a one-off for commercial flight or will this become something that will be a new normal for air travel?
Great question.
You're welcome.
Okay. Okay. So, let's back up.
Uh, there's high energy phenomenon in the universe, especially in the centers of galaxies. And that high energy phenomenon accelerates charged particles.
Mhm.
And to stupendously high energies like 99.999% the speed of light. They travel across the universe and especially across the galaxy. And when they arrive on Earth we call them cosmic rays.
Right.
Right.
Okay. They come from every direction. I would see them in my data when I expose a digital detector to the universe through my telescope.
Right?
In fact, there are utilities we have that correct for cosmic rays because a cosmic ray hits the one of the pixels and it it it blows it out. Okay. So, what you do is you take multiple images and then you you.
You overlay them.
Yeah. You overlay them and then you take out the high and the low and you get the median of your images and that get that basically takes out all cosmic rays. So when you see images reported it's not the raw image. Raw images is always contaminated with cosmic rays. And so there are they're everywhere. Oh, by the way, the cosmic ray doesn't make it to Earth's surface. It hits our atmosphere and creates showers of other particles.
Oh.
Who in total equal the energy of that one particle.
It's called a cosmic ray shower. You look it up. Like a diffuser.
It just comes out and it.
See this is our problem with space travel, the radiation. And now you're telling me this radiation is penetrating.
Well, the the total energy does actually reach the Earth.
Yeah.
Okay. It gets.
Just not as cosmic rays.
Not as concentrated.
Not as concentrated. Correct. Correct. Not as the original.
We still call them cosmic rays because of their effect on this. All right. This tells you cos rays are everywhere.
Okay. Oh, and high charged particles, high energy charged particles from the sun. We're we're just right now we're at the end recording this at the end of 2025. We're on the downstroke, the very upper downstroke of the solar maximum solar max in the last year and a half or so. And we we heard about aurora. Also the the north magnetic pole.
Which when we grew up.
Right.
Was wandering around Canada in the last 20 years has made a beline towards the north pole and it just and it just recently passed the North Pole it's on its way to Siberia as it goes closer to the North Pole. It actually comes closer to the Northeast here we are recording this in New England the Middle States because it just brought it a little closer. All those three factors combined, plus we're monitoring the sun as as never before. So, we know exactly when it would happen. There was a day you didn't know. Oh, we caught it here. You check it out. Call me if you see. We now know. It's called space weather. There's a whole branch of NASA if it's still funded as of today. Uh, [laughter] that studies explosions on the sun.
Right.
All right. And one of our favorite guests, Lea.
Right?
Goratakuta. That one. [laughter]
Done chop.
Yeah. Yeah. She's a NASA solar astrophysicist and so she thinks about all of this. But anyhow, so we have better predictions, better monitoring, and so there's a greater awareness of aurora today than ever before. But there people thinking, "Oh my gosh, things are getting worse."
But it's not.
And this maximum we're coming off of.
That max, all they do is counting sunspots when they get a lot.
And then when they come down. All right. This max was higher than the last max 11 years ago, right? But both of these were lower than the previous three.
Okay. So, there's nothing, you know, if the sun is going to kill us, it would have happened already.
Oh, yeah. We'd already be dead.
We already cycles. But anyway.
Every villain in a movie, if I wanted you dead, you'd already be dead. [laughter]
Or let me put you in a contraption that will kill you in an hour after I'm gone. Give you a chance to escape without.
I'm going to go have lunch now. [laughter] When I come back, I expect you fully un alive. [laughter]
The laser will slowly move its way across. [laughter]
So that's a long preamble.
To the fact that it seems to me.
Does it.
That given how many planes are flying every day, there's like tens of thousands of flights.
Every day, there's a million people at any given moment who are airborne.
Wow.
In a airplane. Okay.
That many flights. Yeah.
That have been flying for that long.
Okay.
And one plane uncontrollably loses altitude then regains control. You want to blame that on the universe?
Oh, no. I'm just saying that happened.
No, no, no, no. They said it happened. They They blamed a cosmic ray. They didn't know it was a cosmic ray. I don't know about that because that's not the only incident of charged particles because when you look at these circuitries, they're.
Oh, yes, of course.
They're so small. It also happened to a car company.
What I'm saying is.
Go ahead.
What I'm saying is.
My chip.
Yes.
When I in my day, the chips were little.
Right?
About this big.
Yeah. Yeah. I take a picture and depending on the length of the exposure, I have a half dozen cosmic rays that hit that chip.
Ah, I see what you're saying.
Yes, I'm higher up than you. I'm at 7,000 ft. The plane is at 30,000 ft.
Couldn't that make a [clears throat] difference? Cuz we said that the cosmic rays come in and hit these other particles.
You're missing my point.
Go ahead. I am. Cuz it sounds to me like you're making his point.
No, [laughter] no. What I'm saying is.
Go ahead.
If you're going to blame it on the universe.
Right?
It would be happening to way more than one plane.
I see the volume of cosmic rays bombarding the earth all the time.
All the time. I get what you're saying. I got you.
On top of how many flights there are.
Right? So you have to be so confident.
In the wiring of your plane that the tens of thousands of planes that all have maintenance schedules and all of this. You have to be so sure that there is no human error in any maintenance schedule for any of those planes that are flying every single day and it happens to one of them and you say this plane is perfect therefore the universe does it. So here this is a convenient this is a convenient I won't say excuse but yeah convenient way for them.
Tell them what ca is.
Cover your ass. [laughter]
Is a it's a convenient CIA for them to say cuz this happened to a car company and they made the same excuse that highly charged particles that bombard the earth somehow hit the circuitry where it's supposed to go to a zero or one. It changes it to a one or a zero. It changes the bit. Okay. And the changing of the bit of course changes everything that the computer does for that.
For that calculation. And so that you know so but that I'm hearing you say this.
So they updated the software. I don't know what they did but I can imagine what I would have done cuz I've written in my life about 50,000 lines of code. So I I think about this but others they're programmers who do 100 times that. So I'm not bragging here. I'm just giving some street cred that this is what I would do. Yeah.
If I was worried about this in the future if it were really a cosmic ray, any truly critical calculation cuz planes are flown by computers. Let's be honest. Let's be honest.
Yeah. That guy who comes on like a ladies and gentlemen, so great to have you on board with us today. By the way, I'm up here not doing a damn thing.
I'll be taking a nap for the.
Same voice. Go to pilot [laughter] school for voice.
The pilot school voice. Yeah, cuz.
Here's what I would do.
All right.
If I had the program, cuz they said they uploaded program, if there's any truly critical calculation that affects the safety of the plane and the computers are fast, so you can do this in practically real time, I would put a loop in there to do it three times.
Right? Redundancy.
Three times. Okay. And whichever two of those are the same.
That's the right answer.
That's the right answer.
Right? If all three are the same is the right answer. If two of the same is the right answer. Correct. Right. And if a particle actually kicks something out, changes.
Because it's not gonna do two in one.
It's not gonna do two, right? It's not gonna do two. So yeah, the redundancy would cover that.
Correct. And well, why could you just harden the damn.
That's what it's all about. Well, you're hardening not only the software, but also the hardware and like satellites know all about this cuz they're up there above the atmosphere.
They don't they don't have any [clears throat] protection at all. Cosmic.
They raw dogging the universe. Raw talking. Like, come on, BABY.
Bring it on, radiation. [laughter]
Ro talking.
I'm learning some new phrases.
I can't get that picture out of my head.
Satellites. Raw dog.
Well, that's what it is. It's not just It's not just to protect against the radiation, but they're not protected against asteroids, meteors. That's right. You see, oh, what a beautiful meteor shower. These are these particles hit our satellites, especially the space station.
They have that last message.
Oh, [laughter]
Wow. Okay, cool.
Yeah. Yeah. So, I if it's a cosmic bra, that's how I would solve it. I'm glad no one was harmed.
In this I understand it dropped altitude.
So, I was looking at saying, is this a distraction for something else or is this someone being smart and getting ahead of a story and future proofing to as much as they can? Yeah, I think they originally wanted to blame it on the sun because we're near solar maximum and people are heightened have heightened concern, but it'd be the same cause and effect. I mean, the high energy particles hitting uh hitting your software.
Cool. Okay.
All right.
All right. Here we go.
You got another one.
Here's another one.
What's the most straightforward explanation of the strong nuclear force and the behavior of quarks and gluons? Because they say gluons and I think like oh that's a thing like a quark like a but it's not it's not a particle but we call it a name like it is a particle and then when you think of the strong nuclear force this should not happen I mean I know it's happening on the quantum but these protons they're like yo yo what's up buddy come on over here let's hang out man I love you man like yo give me a hug but the truth is they shouldn't be doing that. They shouldn't be doing that. You know what I mean?
Because they're like charged.
They're like charged particles and they should be like.
They should repel.
Yeah. Like who the who you looking at?
What you doing over here, man?
You get out. I was here.
I was here. What you talking about? [laughter] What you mean? THIS IS MY SPACE. YOU ON my turf. Get out. Like it should be straight up turf war. Okay.
But instead, they're all loving and hugging, right? And then the electrons are hanging out just like, "What's up, guys?" You know, which makes sense. That makes sense. The electron field makes sense. Okay. But what is the strong nuclear force that this is able to happen?
Okay. So, uh, the strong nuclear force is one of the fundamental forces of nature.
Right.
There four basically.
Electromagnetism really there's three but just from my benefit thermodynamics.
No.
No. Electromagnetism, weak nuclear force, strong nuclear force, and then what we just talked about gravity, which we know is a force just because accept it anyway. [laughter]
Because it walked like a duck.
Because it walks like a duck.
That's why it's a force.
That's why it's a force.
So these are the fundamental forces of nature.
Right?
And we didn't invent them. We observe them.
Okay. And as I.
Once again overthinking see.
The opening page of one of my books, it says the universe is under no obligation to make sense to you.
Okay.
Now, here's something to think about.
Go ahead.
The electromagnetic force weakens as the distance separates.
Correct?
Correct.
All right.
Gravity weakens as distance separates.
Correct.
The strong force gets stronger.
As the distance separates.
Right. Because.
Why did you ask? Because on the other one. [laughter]
It didn't come into my head.
No, because those other forces are we operate. They're they're in your everyday life in ways that the strong nuclear force isn't. So you can ask, is there anything in your life where if you increase the distance.
They are attracted together more strongly?
The answer is yes.
A rubber band.
A rubber band.
Oh.
Yeah.
A spring.
A spring. M. Yes.
In fact, in physics.
But not a slinky. [laughter]
Cuz when you stretch it, it just gives up.
Yeah. Slinky is is a weak ass spring. [laughter] It's a weak. You stretch it out and it's like [laughter]
Slinkies are not can't face another staircase. [laughter]
Help me. Help you.
I'm asleepy and they stretched me. [laughter] Oh, no. Good.
So, [clears throat] if you look at the force equation for a a spring, it has a negative sign on it. F= minus kx is what it is. K is the spring constant. X is how much you have displaced the spring. Okay. The minus means as X gets bigger, there's more of an attractive force back in. Okay? Whereas these other forces, it's a positive. All right? So, it's a contest of forces. A proton at a distance sees another proton and say, "I'm not coming near you. You can't make me." I say, "Yes, I can. I'm going to heat up the gas."
Now, your movements are so fast, you will get closer before you successfully repel. [clears throat]
Okay. It's a you're the temperature is forcing this. It's like a shotgun wave. It's forcing it. Then is at a threshold temperature, it gets so close. Strong forces. I got you. And the strong force, the strength of the strong force overcomes the strength of the repulsive force.
In that instant.
And then it attracts.
And then it ain't even about the electromagnetic force at that point.
Wow.
We discussed earlier on about Newton's laws, how they for centuries they've stood the test.
Yeah.
Are we likely to find new or slightly varied laws of nature? Well.
As we every time that's ever happened, it's like, "Oh my gosh, look how much more we now understand."
When we were previously just touching the elephant, not knowing the animal. So, there's a lot we don't understand today. The the nature of dark matter, the nature of dark energy, what was around before the universe, was there a multiverse? How will the universe end? Is there a big rip? These are questions that are just dangling there.
How about time?
Possibly the time. I'm going to quote Einstein. Time is defined to make motion look simple.
Whoa, dude. That is effing crazy. [laughter]
Einar said that.
Yeah. Yeah.
Yo, he didn't come up with E= MC [laughter] like that impresses you, dude. E= MC, BUDDY. [laughter] JUST SAYING that's hilarious. You [laughter] say that impresses you, but not equal. I I know. I should probably recalibrate. I should recalibrate my I should measure my uh my responses there. Yeah, that's a great say. Time is defined to make motion look simple. That's that's.
That's very elegant.
Yeah. And deep.
That is really cool.
Okay. So the quark. So quarks are what protons are composed of.
As are neutrons, by the way.
And quarks have charge.
Yes.
If you knew this.
Yes, I do. But I'm I'm not sure if I understand them because when I was reading about it, first of all, there's like a Jesus Christ like 13 or 16 different kinds. And then there's six kinds of quirks.
Six quirks. And then but then there's another levels and then there's spins. Well, maybe I'm thinking about it's like two up, one down, and then.
Right. Right. So, in a proton, it has a charge of plus one.
And it has three quarks.
Right?
So, it has two up quarks. I think it's up with a charge of plus 2/3. What's 2/3 plus 2/3?
Um.
Each of them has a charge of plus 2/3.
H.
2/3 plus 2/3.
Yes.
Is.
Come on, help him out here. You 46s, which is 75.
It's not 46.
Then it's not.
You don't add up the denominator.
Denominator carries. You add up the top.
So just do that.
2/3 plus 2/3 equals.
1 and a3.
4/3.
One and a third.
Right.
Okay. So the other quark has to have what charge for it to be plus one?
2/3.
No.
I mean has to be a minus.
Minus one. Minus third.
Minus a third. Right there it is.
Minus third. And then it cancels out and now you're good.
Well, then it adds up to adds up to one. Correct.
Right. It cancels out adds up to one. Correct. And a neutron has I forgot exactly what, but they they cancel out to zero charge. There's like plus 2/3 minus 1/3 - 1/3.
Okay.
Okay.
So there's still charges within a there's still charges there. Got.
All right. Now, so the quarks are fundamental. Protons and neutrons are not fundamental.
One and then the electron is a negative charge.
Forget the electron. We're not talking about that.
I know we're not even talking about I'm just.
Electron only knows electromagnetic forces.
Right? That's all it knows.
And a and a weak force. But.
See, this is my problem. Now you see how my brain works. You see what I'm doing?
I'm dead, Chuck.
Yeah. No, I'm not. I'm not. This is very I'm I'm a nut job. This is my problem. I'm a freaking nut job. But go ahead.
The strong nuclear force holds the quirks together.
Gotcha.
It's the strong nuclear force that when you pull two corks apart, you have to get more and more energy to do that, like the rubber band, and then it snaps, creating two extra corks, right? So that's the strong nuclear force at work. And this the spillage out of those particles to attract the other the other nucleons. So the spillage of the gluon did I say gluon yet?
Yes. Well, we we didn't get to them.
Oh, sorry. So, the quarks are held together by the strong nuclear force. What propagates the strong nuclear force? It is the gluon. What propagates the electromagnetic force? It is the photon.
Right? So there's something called a virtual photon that gets passed between two objects if they have a charge and they will feel that and respond and either get repelled or attract and they call a virtual photons. The photon is the force carrier of electromagnetic energy. And the.
The gluon is the force carrier of the strong nuclear force.
Of the strong nuclear force. And it's it's strongest within those particles, but enough spillage so that two protons can stick together in a nucleus, but the real action is inside the particle itself.
Wow.
Yeah.
Damn.
I know.
Happy now?
Yeah. It's weird.
It's It's freaky.
All right. Should we have another one another question?
This is from Tamson, one of our producers.
Tamson.
Yeah. When approaching a physics astrophysics problem, how do you determine which mathematical equation equations to use? Depending on your approach or on which aspect of the overall problem you're looking at, do you shift the equations you use? Just explain how you apply all the equation. Tamson says thanks in advance.
Okay, great question. So I remembered learning physics for the first time and a lot of it is kind of like it's a sliding brick on an incin plane. There's a pulley. There's these questions don't look relevant to anything. I wanted to understand the universe and physics is fundamental to that. That's what kept my interest in these boring ass problem sets.
Okay. So [snorts] then you realize.
It's not about the problem set. It's about manipulating equations that exist only in the service of the problem you are reading. And so you build this inventory of things that can happen in the universe and the equations that matter to it. So if it's motion right off the bat, I'm probably going to need Newton's laws of motion somehow. Is it moving really fast? I better know Einstein's equations.
Okay. Is it dropping through a viscous medium?
Okay.
Right.
Oh, by the way, can I tell you in high school I didn't know what the word viscous meant.
What did you think it meant?
I got a 98 on my physics regent exam and I knew what question I got wrong cuz I didn't know what viscous meant. M.
They said plot the the distance time curve for a rock falling through a viscous liquid.
You were like a vicious liquid. [laughter]
What kind of liquid is that?
Shark infus.
So that was a vocabulary problem for me, not a physics problem. So I just got that one wrong.
Had I known what viscous was, then it's trivial because what happens is you drop it into the liquid. Normally, if you drop something, it moves faster and faster, right? Because gravity is is accelerating it. But in a viscous liquid, it just descends.
Right?
Old-timers will remember the Pearl shampoo commercial where they dropped a pearl into the shampoo and it just gently descended. So, what happens?
WHAT DID THAT PROVE?
I I felt the same way. [laughter]
It meant your hairs, man.
How's that clean my hair?
It was a physics big deal. [laughter] So if if something is moving through a fluid where there's viscosity.
Right?
Then there are viscosity equations. And if I never did a problem set that involved viscosity, I would not know to reach for that for that formula or that bit of mathematics.
And that's a real world problem, too, because.
Well, all of these become real world problems. That's the point. So, so every week there were typically six physics problems, each testing different for homework, each testing a different physical principle, right?
You'd have to apply a new formula you learned that week in order to solve it. And when I say formula, that cheapens it. You'd have to apply a new understanding of the behavior of nature that you learned that week. And here's the equation of that new understanding.
>> So there you That's your toolbox.
>> Toolbox.
>> Yeah, that's tool. Yeah,
>> toolbox. So you look around, you say, "Wait a minute, there's matter becoming energy here. What's going on?" Marie Curie, one of the first to show radioactivity is a source of energy coming out of nowhere.
>> All right.
>> Right. There's no machine or engine going in. What's going on?
>> There was no way to understand that without an equation that has energy on one side and mass on the other.
>> There was no way. It was you can just describe it
>> but there's no way to calculate with it until Einstein in in 1905 equals mc^2. Oh my gosh, little bit of mass times speed of light, which is a big number squared, you get a lot of energy out of that. By doing so, if you have gaps in your physics knowledge, there'll be some problems that are intractable to you.
>> Y
>> Now here's what I wonder, scratching our head today. What new physics lay undiscovered until it rises up and we say, "That's the equation I need to figure this out that I've been scratching my head on for the past 10 years." Maybe the equation does not exist yet.
>> Ooh.
>> So,
>> we don't know the solution until we're faced with the problem.
>> Or if you're really clever,
>> yeah,
>> people were just were simply not clever enough with the known physics to solve the problem. For example, uh superconductivity. If you cool down a metal
>> of your choice low enough, then electricity goes through it without any resistance at all.
>> Right.
>> Whereas any any wire the electricity goes through, there's resistance which leads to what?
>> Heat.
>> Heat.
>> Heat. Exactly.
>> So this it goes through and there's no heat. Oh my gosh. What is that? It's a purely quantum physics phenomenon. Was there enough quantum physics to figure it out?
>> Yes. But no one was clever enough to figure it out. Okay. What they found was that as the electrons get colder, their wavelengths get longer because the wave particle duality.
>> Yeah.
>> As they get longer and longer, all the electrons end up behaving like they're one particle, cuz all of their waves, they come together
>> and as one particle there's no resistance.
>> They behave themselves.
>> They behave [laughter] itself and it and it comes through.
>> Yeah. So the quantum physics was available but no one was clever enough to know how to apply it.
>> Didn't know where to point it.
>> Where to point it?
>> Yeah.
>> Where to point the weapons of
>> That's a great example. Great question.
>> I have another question. This one is from Lane, one of our other producers. She's over in our LA office.
>> With David Crackour and Brian Cox, we learned about the two main pillars of emergence. It is something greater than the sum of its parts, and secondly, possesses a distinct language to describe the emergent behavior. The example David gives is how fluid dynamics, through its own formulas, can predict movements of groups of particles without needing to know about each other each individual particle.
>> Given that we have a language for describing and predicting a person's volition that screens off the microscopic factors in someone's life, would that make free will just as real as fluid dynamics? Is free will just an emergent property of conscious thought? And the the finishing the finishing is please discuss.
>> That was nice,
>> man. We got good people working for Star. [laughter]
>> Damn. Why are you surprised?
>> I always knew I was dumber than the people on the show. I didn't know I was dumber than all the people who work here, too. Damn. [laughter]
>> The producers, the writers, Um, so I love that interpretation of what's going on.
>> Yeah, that's uh that's
>> and just to remind people in case they but you can dig up the show
>> the there are gas laws we might have learned about in chemistry,
>> right?
>> Which are macroscopic laws that describe the behavior of the entire gas. Okay, it pressure, temperature, this sort of thing.
>> Yeah.
>> And they work and so we use them and they're called laws.
>> Mhm. Those were discovered before we even knew about atoms.
>> Okay,
>> successful laws of nature describing the behavior of atoms in this emergent way.
>> What they all do when they're caught sort of together as a blob of gas. That's remarkable. So I like the direction certain branches of research are going trying to wrap their head around the meaning of emergence in understanding complex phenomena.
>> And so yeah it free will is emergent. It's an emergent feature of consciousness. I'm I'm I'm always been on the camp even if it's not free will.
>> If it feels like free will, it's free will.
>> Yeah. I I I think it's a fascinating thought experiment because
>> you can say if it's not free will, it's still a choice that you're making. So maybe it's the freedom of the choice. But then if the choice is predetermined by other circumstances, is it really a choice at all? But if you alter the predeterminant factors that caused the choice, who's to say that you did that or did the circumstance do it? It's so intertwined or did the gas law of your brain do it? You know what I mean? Like did the neurosaptic, you know, gas law property actually cause this to happen? And I think that in some respects there's there's
>> evidence for it all. Maybe
>> when you look at it,
>> maybe the future of neuroscience I'm just pulling this out of my ass now.
>> Maybe the future is looking at the electrochemical state of your mind. Okay.
>> Mhm.
>> Just the way we look at the pressure, temperature, volume and we put those together with equations that give the future state of that system. Will it expand? Will it contract?
>> So it becomes predictive.
>> Predictive.
>> Maybe if we do a download
>> Mhm.
>> of your electrochemical state. Maybe they're macroscopic laws that tell you what decision is coming out of that state.
>> That'd be great.
>> And if that's the case, I can say, well, you have this much poverty, you grew up in this situation, a single parent household, you you didn't have food, but crime candidate to be committed. What What is it? More than half of people in prison are illiterate.
>> are come or come from poverty. Well, and that's yeah, more
>> and those are correlated.
>> Yeah, they are. I was illiteracy and poverty together.
>> So, you have the configuration that then makes the the gas law.
>> You're talking about mind reading just from being able to take that snapshot of brain. It's brain reading more than mind reading. Better than mind in the sense of being brain reading. Mind reading. Yes.
>> It's better than mind reading. It's brain reading. It's brain reading
>> because the brain creates the mind.
>> Exactly. So, so then then we're the minority report all over again, aren't we? the great sci-fi short story writer Philip K. Dick.
>> Quite an unfortunate name. [laughter]
>> What have you got against Phillip?
>> Okay.
>> Very nice. Very good. [laughter]
>> Um,
>> so in in the Minority Report, there were these precogs. Yeah. So rather than doing a download off your brain, there were these precogs who were telepathic basically. [clears throat] Yes. And so that's how they got into your brain to know what was going on. But same idea.
>> Yeah, it is. Except that you're mapping the actual person's brain. Actually, this is better than precogs only happen because an event precipitates their telepathic.
>> They're not going to know whether you're going to choose strawberry or chocolate for dessert.
>> Yeah, they can't they can't do that. But with brain mapping Yeah.
>> And also, yeah, you would be able to determine a person's possible path, but also give them equip them not to take that path. But you might have to change the state of the system like changing the gas. You'd have to change the temperature, the pressure,
>> the pressure,
>> the volume so that a different outcome would come, right?
>> I think once that state is established,
>> it's going where it's going to go,
>> right? Yeah. You you can't steam clean with cold water.
>> Oh, good. What? That's your mama tell you that?
>> No, I just made it up.
>> Very [laughter] good. Can't steam clean.
>> You can't steam clean with cold water,
>> right? So, for example, the person who just about to jump off the bridge, do they have the option to not jump off the bridge? I don't think so. In that instance,
>> in that instant, I don't think they do either.
>> Right. So, and there's no ability to reset.
>> Correct. At that moment, not in that moment. Correct. So, that puts a greater burden on society.
>> Yeah.
>> As treatment of people who have behaviors that are transgressive or psychopathic or sociopathic.
>> We should have that burden anyway. Unfortunately, we don't. You're right. Right. You know, and
>> more blame should be on. And if you know somebody who's in that position, believe me, uh intervene, okay? you can do something. Um, even though it may still happen. I mean, I've lost family members to death by suicide and
>> you know, even despite the intervention, but in one case there was a ton of intervention and the other case it was like, damn, I wish I I pretty much saw that coming. So, I come, you know. So, yeah.
>> Well, bum us all out, Chuck.
>> I'm sorry. [laughter] I KNOW I DID BRING US DOWN, DIDN'T I?
>> We're on a happy note. Okay.
>> I'm just saying if if you see somebody, don't be afraid to reach out. That's got one more, but we only have two minutes, so let's try.
>> This is from Matt the editor. He says, "This is quite literally," and Matt, our editor.
>> Our editor. Yes. This is quite literally a burning question as it has to do with firewood. I once heard Neil mention in an explainer some time ago, the energy of the sun is contained within the trees that we cut down and chop into lovely little pieces uh for the burning in our fireplaces. Can you expound on this idea? I found the fact fascinating and perplexing, but during a recent camping outing, I chose not to share it as I didn't want to sound like an idiot trying to explain this to my fellow guests as we enjoyed the sun's transferred energy via campfire.
>> Love it. Love it.
>> Ah, what a great question, Matt.
>> So, you eat food that was once alive.
>> Mhm.
>> Mhm.
>> Everyone does.
>> Yes. Okay. Plant or animal.
>> And plant was once alive. Okay. If you eat plants, where' the plant get this energy from?
>> The sun.
>> The sun. Okay. If you eat cow, where' the cows get it energy from?
>> The plants.
>> Plants.
>> And the sun.
>> The plants. You fed it. Right.
>> Okay. So, we are solar powered through that tracking.
>> Of course.
>> Now, plants use the sun to build larger molecules that have energy contained within them.
>> Mhm.
>> Okay. So the cellulose that has energy, cellulose burn, paper burns,
>> that's energy inside the paper. Yeah. What color does the paper turn after it burns?
>> Black.
>> Black. That's the
>> color wants to be cool. [laughter] [laughter]
>> The energy is not just sitting there in an energy vessel. The photosynthesis takes sunlight and creates energy dense molecules out of it.
>> Now here's the problem. Here's why we are not cows. Because cellulose has energy. We cannot digest it.
>> No.
>> So you have to be careful in your calorimeter experiment. You don't want to burn things that we don't have digestive enzymes to metabolize.
>> Right.
>> Yeah. If I took straw and burned it, it has a calorie content of no use to us.
>> Right.
>> Okay. Yeah. Yeah.
>> So it has to be stuff you can digest
>> otherwise the calerimeter experiment is not meaningful to us. It would still it's meaningful for physics and chemistry but not for us. All right. And so you burn it.
>> It's solar power.
>> It is. Look at that.
>> There it is.
>> Well, Matt, there you go, man. I I hope that explanation you're able to use since your next camping expedition.
>> Just take this recording and play it.
>> Yeah, that's [laughter] you.
>> All right, that's all the time we have.
>> Yeah.
>> But then again, I like hearing from our people. No, no, they're great.
>> Can we do like another one of these?
>> We need to.
>> We've got more than enough questions
>> from our own people.
>> Yeah, of course.
>> Yeah. Yeah.
>> Yeah.
>> Yeah.
>> But you you did your first your own questions first.
>> Yeah. We're selfish. [snorts]
>> Chuck, always good to
>> always [laughter] a pleasure.
>> Get ready.
>> Thank you, Neil.
>> All right, Neil deGrasse Tyson here, your personal astrophysicist. Keep looking up. [music]