Atoms and Light: The Nature of Light, Matter, and Quantum Mechanics

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Күн бұрын

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This is the fourth lecture series of my complete online introductory undergraduate college course. This video series was used at William Paterson University and CUNY Hunter in online classes as well as to supplement in-person course material. Notes and links are present in the videos at the start of each lecture.
0:00:00 - lecture 1: The Nature of Light, part 1
0:27:18 - lecture 2: The Nature of Light, part 2
0:51:05 - lecture 3: Stellar Brightness and Magnitudes
1:16:41 - lecture 4: Color and Temperature
2:00:38 - lecture 5: Kirchhoff's Laws of Spectroscopy
2:05:55 - lecture 6: Atoms, Elements and Isotopes
2:42:26 - lecture 7: The History of the Atom
3:03:31 - lecture 8: The Bohr Model of the Atom
In this lecture series, we start with a two-part discussion on the nature of light and a summary of its wave-like properties. I'll discuss what exactly a photon is, and how it makes up all the colors of the electromagnetic spectrum. Next, I'll define the terms "brightness" and "luminosity", which are central to astronomy measurement. I'll also define the magnitude system, both apparent and absolute. We won't shy away from equations anymore, as I also derive how Pogson saddled all the future of astronomy with a Log-base-10 humbug. In the next lecture, I chat about how we exactly define color in astronomy using broadband filters. I also detail how color relates to temperature, what temperature actually is, and how blackbody radiation manifests in everyday life and in stars. Next up, I talk about how light interacts with matter, using Kirchhoff's Laws. Following this, I discuss the current state of knowledge about atoms, elements and isotopes. I chat about the periodic table, atomic numbers, what an atom is, how big they are, how they interact. Also, you'll learn about radioactivity. Because this is not at all intuitive, it's worth an extended discussion about the origin of the atom from Democritus to Plato and Aristotle to Dalton to Thomson to Rutherford. I'll show you all of the ways our view of matter has evolved, both philosophically and as a result of experiment. Finally, we end with a beginning quantum mechanical discussion. The Bohr Model of the atom is the standard way that introductory astronomy textbooks seek to demonstrate the link between atomic spectra and Kirchhoff's Laws of spectroscopy. It's important to motivate it with the essentials of quantum mechanics. Here, we add in Einstein's and deBroglie's and Schroedinger's contributions, but we lean back towards the "Astro 101" understanding of the atom.

Пікірлер: 45

@frozennorth3426 5 ай бұрын

I can’t believe that material of this quality and breadth is available anytime anyone wants it. What a gift to the world.

@Beencouraged777 4 ай бұрын

Right

@JasonKendallAstronomer 2 ай бұрын

You’re very welcome!

@DocSeville 5 ай бұрын

My dad always said the better someone could explain something the better they understood it. As far as im concerned this dude understands this stuff! Thank you for yhis amazing vid!

@Beencouraged777 4 ай бұрын

Right.

@frozennorth3426 2 ай бұрын

yep. a good teacher is worth their weight in gold :)

@thejorgelopez9135 5 ай бұрын

As someone who is completely obsessed with physics ( I have 2 constants of nature tattooed on my neck just to give you an idea of how obsessed ) but doesn’t have a formal education in physics, these videos are extremely valuable and informative. Please keep up the great work.

@Beencouraged777 4 ай бұрын

Right

@Peca.kaspic Ай бұрын

“No ragrets”

@mikehipps1015 5 ай бұрын

I wish I could stay watching but I have to sleep before I leave for work in five hours. I'll watch this soon. Thanks for your good work.

@LiftPizzas 5 ай бұрын

Thank you for these. Glad to see they're being updated, too.

@pavelzsilay1581 2 ай бұрын

One of the best explanations I have ever seen - well done 👏

@jimbernard8964 4 ай бұрын

Fantastic channel. So happy to find it. Thank you.

@user-pw9bh8vw4t 24 күн бұрын

Just excellent - thank you very much for all your efforts and teachings!

@JasonKendallAstronomer 23 күн бұрын

You're very welcome!

@Garenzo314 5 ай бұрын

How many times did you almost say "a disturbance in the force"? Loving the content and presentation. Thank you for this.

@longcastle4863 3 ай бұрын

Interesting that protons and electrons have exactly equal amounts of opposite charge despite being of vastly different masses.

@ilanle 5 ай бұрын

Thank you Jason

@paulmicks7097 2 ай бұрын

Great topic, thank you Jason

@JasonKendallAstronomer 2 ай бұрын

My pleasure!

@ioanbota9397 4 ай бұрын

Realy I like this video so so much

@bastiaanwilliams8398 5 ай бұрын

Thank you. Does this mean you cannot see further than the space between the light and your eye, when the light hits your eye?

@jaquelineq.3334 2 ай бұрын

THANK YOU

@seditt5146 5 ай бұрын

Perhaps you could help e. From Light perspective Time does not progress. Since Wavelength and Frequency are a function of such how could I determine what a Photon sees when time and Space do not exist for it. I keep coming back to a rest mass that is small albeit different for each Frequency. Without it these frequencies , mass time and everthing else seem meaningless

@JasonKendallAstronomer 5 ай бұрын

It's important to note that there is zero evidence of light having any mass, and that's not for lack of trying to find and determine it. It is truly puzzling since light has momentum, which is dependent upon wavelength. This all arises from the constancy of the speed of light. Another way to get a foothold is to note that light does not have a rest frame. This means the very idea that "time does not progress for light" is not really defined. It's just one way of saying that "light has no experiences". There's a funny implication with saying only that "time doesn't exist for photons", and that is that "space doesn't exist either". Essentially, what you're running into is a paradox. That's why you're wheeling around trying to find an offramp with frequency-dependent mass. Photons with different masses would have different "experiences" in their (non-existent) rest-frames(???) as they are observed to propagate. Since this does not happen, experimentally, and as a fundamental postulate of SR, you'll find that there is no solution. Just like Einstein did. kzfaq.info/sun/PLyu4Fovbph6ezYDf2FI2b8a3KMCqEr3oL&si=P9eWhrV60zRk8rRO

@jfairway1 3 ай бұрын

Photons don’t have eyes, they don’t see anything.

@n-da-bunka2650 Ай бұрын

What's the mass of a quark? Is it close to the size of an electron?

@paulmicks7097 3 ай бұрын

Jason thank you for extremely excellent vidiget series, i have a question... What if science knowledge came before religion, would you be considered a charman or priest in such a place ?

@illumencouk 4 ай бұрын

@12:28 - our physically seeing these various forms of waves interact is best demonstrated in Tsunami footage where billions of litres of water can be seen flowing in one direction, then within minutes another, other parts of the harbour will appear to not be under the same effects and behave 'normal'. Slow play speed and the sound turned off is how I study the footage.

@illumencouk 4 ай бұрын

Oh and the mysterious loss of buoyancy effects many of the vessels. Bermuda Triangle style.

@TheMemesofDestruction 4 ай бұрын

2:42:06 - Stuff does things. ^.^

@schr75 Ай бұрын

Great video as always but you have misunderstood a thing. The beep sound in the Apollo communications are called a Quindar tone and was used to switch between transmission modes on the tracking network, not as a kind of "over" signal. en.wikipedia.org/wiki/Quindar_tones

@JasonKendallAstronomer Ай бұрын

Oh, thanks for the note! Great to know!

@tnekkc 3 ай бұрын

I thought there was an absolute speed relative to the cosmic background radiation.

@shannonbarber6161 9 күн бұрын

You need to draw the Greek metaphor out and give them more credit. Fire is energy which is carried by photons. Transmutation is how nigh all elemental matter was made other than hydrogen and a bit of He & Li IIRC. Stars, the gods, do rip apart atoms. E=mc² means phlogiston is correct. On & on. As soon as you find a hard edge, any rock or a knife's edge, you know the (solid) world is quantum. If it was continuous with no crystallization then everything would always have to behave like fluids.

@garyjones6142 3 ай бұрын

So those ancient Greeks thought of the atom as the smallest element of matter that cannot be further cut. True enough until we eventually figured out how to cut them to pieces in things like an atomic bomb. Good thing Alexander the Great didn’t know that, just saying.

@albin2232 5 ай бұрын

There is no light. Everything is darkness.

@yecto1332 4 ай бұрын

Why do u think that

@e7ebr0w 5 ай бұрын

Perhaps I misunderstood a photon.... I thought a photon was the amount of light per second. A photon is one second long I mean. That's how wavelength and frequency are determined. So saying photons per second makes me think I'm wrong

@DrDeuteron 5 ай бұрын

Physics does know about our system of units.

@spitgorge2021 4 ай бұрын

Nope. A photon is a particle.

@dsas1469 5 ай бұрын

The speed of light is not a constant. Scientist of slowed light to a stop in a lab.

@JasonKendallAstronomer 5 ай бұрын

When we say that it's a constant, we mean to state that the speed of light in a vacuum is constant. It is well known that light has different speeds in different media. I gloss over this in these videos for the sake of simplicity, not because I'm unaware. All that being said, one quite interesting thing about light's speed being slower in water, is the visible Cherenkov radiation seen in commercial nuclear reactors. All the best!

@peterleveillee1321 4 ай бұрын

There is no dark side of the Moon really, as a matter of fact, it's all dark.

@ivankaleoniefuchs333 5 ай бұрын

haha...If you could travel faster than das constant of light's speed, then you would not visually see any light at all, und you could see anything in our known universe...Everything would appear to you to be only black (nothing). You would not be able to determine when you will arrive or where you will arrive because you could not determine path, distance, or time. Simply because "our" math indicates something to be possible, or even probable, does not conclude it truly exist, that it will ever exist, or that it can ever happen. Humanity will never travel farther in space than our own Solar System for a gazillion reasons that are well-known already. Humanity will "possibly" colonize das Moon, but I have much doubt Humanity will ever colonize Mars or any other place in our Solar System before we exhaust all of our natural resources required to do it. I doubt Humanity will ever evolve into a Class 1 civilization. "If" Humanity survives long enough to see our own Sun begin it's nuclear death of Hydrogen to Helium phase then we will witness our own demise as it expands und consumes das last of our Human species still attempting to exist under-ground. Humanity will never land a manned-mission in das Proxima Centuri planetary system. Auf Wiedersehen :-)