Geometric Optics: Crash Course Physics #38

Рет қаралды 852,384

Күн бұрын

LIGHT! Let's talk about it today. Sunlight, moonlight, torchlight, and flashlight. They all come from different places, but they’re the very same thing: light! It’s what makes it possible for us to see the world around us, so it’s worth a close, hard look. For instance, how does light travel? When you flip that switch in the bathroom to brush your teeth, how does light move from the light bulb, to the mirror, and into your eyes?
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Пікірлер: 426

@crashcourse Жыл бұрын

We made quiz questions to help you review the content in this episode! Find them on the free Crash Course App! Download it here for Apple Devices: apple.co/3d4eyZo Download it here for Android Devices: bit.ly/3TW06aP

@gergeapeach 6 жыл бұрын

Two helpful hints: Watch with captions and at 0.75x speed. And pause often to think if needed.

@CB-gz7bx 5 жыл бұрын

Thank you

@owencoukell388 5 жыл бұрын

1.5 speed with no captions: Badass mode

@itswarhawk 5 жыл бұрын

@@owencoukell388 Ur cool but I don't wanna fail my exam lol

@ori5278 5 жыл бұрын

@@owencoukell388 ok

@ori5278 5 жыл бұрын

That doesnt really help apart from the pause often part

@theangmister 7 жыл бұрын

WE NEED CRASH COURSE MATHS

@ayadimishra 7 жыл бұрын

Angelo Thavaratnarajah I second this!!

@malhaar5880 6 жыл бұрын

U goddamn right

@niaschim 6 жыл бұрын

3blue1brown in the mean time

@thebge1237 6 жыл бұрын

Try searching for the youtube channel y mx+c The guy teach malaysian math but i think it will still teach you something

@thebge1237 6 жыл бұрын

Btw he speak english

@ThePositiveTarot 5 жыл бұрын

I sometimes watch the videos twice... The first time I just listen and get what I can get, which usually is a broad idea of what the topic is about, then watch it again the second time while concentrating, pausing, contemplating and taking screenshots as necessary

@sofiatovedal7663 5 жыл бұрын

Why do everyone complain about the speed of her speech? All crash-course videos are like this, it's the whole point to squeeze a bunch of information into a short video.

@ameerhamza4816 5 жыл бұрын

But it's not possible. People who don't know can't get this so fast

@justfr4nk468 5 жыл бұрын

exactly, at least it's not boring as a 3-hour class, and it's the same data but faster and more simplified

@symbolofpeace.3846 4 жыл бұрын

Oh come on friends... You can slow down the video by yourself ... I also felt that it's too fast, but there's way to solve the issue.... They are really doing a good work.

@aksharaa5376 4 жыл бұрын

@@symbolofpeace.3846 i definitely agree with you. it's best to fix the problem by fixing ourselves, rather than blame others. crashcourse does really put in a lot of effort, and we should appreciate it, rather than complaining

@sarahzhao9347 7 жыл бұрын

She was wrong that the image is always upside down for converging/convex lenses. If the object is closer than the focal point, you will end up with a vitual image that is upright.

@_gammingsultan7162 5 жыл бұрын

🖒

@hiyashah2335 5 жыл бұрын

Periodt

@KatherinePierce_81 5 жыл бұрын

Yeah

@brittniep9219 4 жыл бұрын

If you struggle with following along at her natural speed (to make an information packed short video), I recommend choosing the 75% speed option. It is still relatively quick but much easier to follow along with for those of us that aren't as fast of auditory learners! :)

@kiasmorningstar 7 жыл бұрын

I personally struggle with holding thoughts more than 15 to 20 seconds at a time. The quick pace of this series is just right to hold my attention, and I feel the amount of information is just right. I have sat through these traditional courses, and after waiting for people who don't understand to ask all their questions I am already thinking of something else other than the subject matter. Thank you crash course.

@Chris-vx9qp 7 жыл бұрын

I learned and easily consumed more knowledge from this 10 minute video than I did in a week's worth of intense focus towards this exact subject in science class.

@millie9858 5 жыл бұрын

When you got a science test next and didn’t understand anything in class

@jebus6kryst 7 жыл бұрын

The Star Wars reference was awesome.

@fossilfighters101 7 жыл бұрын

@avinashbinand9272 6 жыл бұрын

I'm so glad this channel exists. It's the only thing apart from my dad keeping me from failing physics.

@flamedragon07 4 жыл бұрын

I agree. I love the Rogue One and the Last Jedi Prophecy references. Keep up the wonderful work. Yes, I wish they had Crash Course Math also. I could use the math help.

@edwardbackman744 7 жыл бұрын

Why do I even watch these I can only follow them for the first 3 minutes

@chingalingaling 5 жыл бұрын

Pause button. Notebook.

@kurtpace1545 5 жыл бұрын

I know cause they are thrash

@ThePositiveTarot 5 жыл бұрын

Slow down and/or repeat

@aster4405 5 жыл бұрын

@@kurtpace1545 no u

@shanthala1345 5 жыл бұрын

@@kurtpace1545 they'r not!😭iam surviving high school! thanks to crash course.

@darknightofthesoul8980 7 жыл бұрын

If only more ants had umbrellas.

@fossilfighters101 7 жыл бұрын

@AlexandreG 6 жыл бұрын

Dark Night of the Soul now I understand I was an evil kid

@tiaradsouza2072 6 жыл бұрын

Dark Night of the Soul I.

@dapet2258 4 жыл бұрын

I did that with other bugs. I wish other bugs had umbrellas too.

@Dribbles88 7 жыл бұрын

Love it!!! We cover this in Physics 223 but in great detail. Great review!! THANKS!! Keep them coming please!

@jahsoka8307 5 жыл бұрын

1:16 Last Jedi prophecy!!! They knew🤔

@adventure9119 7 жыл бұрын

I love the Rogue One reference :D

@andrianinikolaou6618 7 жыл бұрын

Great video! Such videos are extremely important to me, as my school teacher is useless 😂 We this I finally got to understand reflection. Very helpful! 😊❤

@frhneil1463 6 жыл бұрын

Great video! I have a physics exam tomorrow and i just not into reading tonight, and thought that this video explain almost everything from my text book! Greater ways to study, P/s : read that some people thought that the teacher is talking too fast. I think that's not a problem though, some people need to study in a fast way, so they need to make a video no longer than 10 minutes. For those who can't catch up what she is saying (which happens to me too) I recommend you guys to pause the video to digest all of the information in your mind before moving on to another new information. Have a great day ! ♡ And the animation is so cute!

@fawazsm 4 жыл бұрын

5:23 focal length of lens depends on refractive index also ... the relation given there is that of a mirror.

@bridger1221 Жыл бұрын

This video alone got me through grade 10 optics! Thank you so much crash course!

@user-yc7ub3dj5t 7 ай бұрын

This video has taught me more than the hours worth of lectures I attended for this part of Physics lol, channel never fails

@Emily-on9jq 6 жыл бұрын

You know you've watched too much CrashCourse when you recognize that the animation is Scout Finch.

@dianaanonymous5794 5 жыл бұрын

THANK YOU THIS HAS HELPED ME IMMENSELY

@Zikiss 5 жыл бұрын

0:21 Love the Mirror Master appearance.

@andomadsen3743 7 жыл бұрын

Turning a blurry world into a high-definition experience... yep, very much an accurate summary of my experience each time I update my spectacle prescription.

@orianmenashe8661 6 жыл бұрын

You guys are amazing this video helped me alot with my physics exam!!!

@whatthefunction9140 7 жыл бұрын

OMG I thought that robot was wacking it for a sec. 0:56

@MisterBrrown 7 жыл бұрын

lol

@idontgiveafuckaboutanythin4310 7 жыл бұрын

Dylan T u have a dirty mind

@suhanahussain7 6 жыл бұрын

@Idon'tgiveafuckaboutanythingH Lol u have it too...xD

@H3yItsAmanda 6 жыл бұрын

SAME

@Danilego 6 жыл бұрын

it’s K2SO!

@TheFireflyGrave 7 жыл бұрын

I've never tried noticed that straw illusion, one day I'll have to give it a try... maybe right now.

@miguelsobrevilla7673 5 жыл бұрын

Appreciate, I have an astigmatism. Thanks. The angle is the result of crying, then a promise. Side rear mirrors are based on this theorem.

@conormahon845 4 ай бұрын

Thank you for giving the ant an umbrella

@howareyou9158 7 жыл бұрын

I have been waiting for this topic for one year!

@clintgolub1751 6 жыл бұрын

This was exactly what I was looking for!

@erickgudin 4 жыл бұрын

great! all your videos are so clear and useful!

@yousefabdelgaber7498 4 жыл бұрын

This was the first crash course physics video I could keep up with first go

@sunnysingh-lh8nw 7 жыл бұрын

She is a wonderful teacher that makes the topic very clear.... She is flawless..... Love crash course physics because of her. Thanks

@hayakiliyanni9920 4 жыл бұрын

she has a good pronounce in English and we have to slow the speed to understand it actually the correct pronounciation make it difficult for me but still i can understand the way of teaching. and i can understand everything about light in this video

@TGC40401 7 жыл бұрын

I like this show. Keep it coming lol... Although I've already done lots of this stuff lol

@lilit3552 7 жыл бұрын

Thank you so much, this really helps me.

@olohijeozolua8366 4 жыл бұрын

I love listening to you 😍😍😍 so much to learn 😍😍😍

@sfruizmiranda 5 жыл бұрын

I LOVED THE MIRROR MASTER REFERENCE!

@ArianaCabello 5 жыл бұрын

They just had to use the rogue one reference which made my night 😂😂😂

@shamnamuneer6597 6 жыл бұрын

Crash course is my favourite channel 😍😍😍😍

@valerianmp 7 жыл бұрын

A good thing to start a day

@zainababdullah6690 6 жыл бұрын

Thanks so much 💙

@Jana-cw8xf 5 жыл бұрын

really helped me understand! thanks x

@Robotcazplays 7 жыл бұрын

Exam in two days, this is on it and this really helps Thanks.

@helenehamamji8363 5 жыл бұрын

Thank you so much for this video, it helped me a lot! But it would be better if it was a little bit slower because it was kind of difficult for me. Otherwise the video is good. Have a nice day !

@ayadimishra 7 жыл бұрын

CRASH COURse MATH PLEASE 😢😢 now that we have CS , MATH NEXT!!😣 ...btw, thank you for CS 😊

@Vipin-kq5mg 5 жыл бұрын

Thank you so much... You saved my life... Wonder Woman 😍😍😍😍

@ahmedabdalla8849 7 жыл бұрын

At 7:02 you stated that convex lenses always create upside down images. But don't they create erect ones if the object is with a focal length of the lens?

@shashwatsingh9698 7 жыл бұрын

umm....isnt the magnification for lenses v/u instead of -v/u in general... also i think the sign in the lens formula is wrong.

@FireBucket 7 жыл бұрын

Will you guys do an episode about shadows and darkness ?

@sookiesister312 4 жыл бұрын

This is very helpful thank you

@josiahmongru8197 7 жыл бұрын

cc is a life saver

@MrJayPuff 5 жыл бұрын

Awesome job!

@yeknomican 6 жыл бұрын

The whole point of "Crash Course" is that it is presented in a "crash" of information. The whole reason why it works is as a supplement to proper lectures, or with liberal use of either the pause button, or the replay button. This has been true since the beginning of this channel. - verdatum

@FishTankEnjoyer Жыл бұрын

You did very good!

@160p2GHz Жыл бұрын

Wish I'd had this resource when I was first learning this :*D

@princyprincy9649 4 жыл бұрын

So helpful for revise 🤗🤗thank u

@nat29_ 4 жыл бұрын

want a lesson for separation of compound in mixtures and composition of a mixture

@ollieoreoo 5 жыл бұрын

Bombed my first optics test so I'm here XD thank u

@StillMintTea 4 жыл бұрын

That unfinished 5x5 always distracts me ( the cube, ppl)

@AyeshaKhan-gp9on 6 жыл бұрын

I'm soooooooooo glad that Shini went slow this time. In the videos on electricity, magnetism, electromagnetism and Maxwell's equations, all she did was show equations at a breakneck speed.

@Hamraali 10 ай бұрын

great explanation!

@sfruizmiranda 6 жыл бұрын

I loved the Mirror Master reference

@jamaluddin9158 7 жыл бұрын

hang on, doesn't convex lens form a virtual image when the object is placed between focus and pole?

@shawnsea624 2 ай бұрын

Thanks!

@gabrielserafin5215 6 жыл бұрын

The infinite Rey pun has so much more meaning now !

@spanishlatte9422 4 жыл бұрын

Isn't it a concave mirror is the converging lens while the convex the diverging? I'm confused.

@smotmot 5 жыл бұрын

Is there a mistake at 3:15? Says the higher the index of refraction the smaller the angle, shows the opposite.

@pasteltwighlights9437 4 жыл бұрын

i had to watch this on my online class 😭

@heimskr2881 4 жыл бұрын

Im doing that now :)

@ahhhmadXD 7 жыл бұрын

i cannot see far that good, so I need glasses. when i watch to far away via mirror near me, why isnt the image clear? as light comes from reflection on mirror

@TheLowstef 7 жыл бұрын

The info box at about 5:30 is wrong. The focal length is half the radius for mirrors, not lenses. The lens formula is more complicated

@tapansapre8578 6 жыл бұрын

Really informative video!!!!!!!!!!!!!

@user-eq7mc4vy6b 7 жыл бұрын

Thank you very much. There are some of them 1; 17; 15; 25 I want the rest of the episodes translated into Arabic.

@shyambhadra2009 6 жыл бұрын

Do you have any videos about convex and concave mirrors?

@renjunsriceroll 7 жыл бұрын

i got lost at reflection and refraction when its already like my third time learning and two exams of that topic

@TheSammycorreia 7 жыл бұрын

You guys should do a series on marketing ... Great vids

@ThePhoenixpaw 7 жыл бұрын

So, how do you calculate "Dioptre"?

@satyamsingh9695 5 жыл бұрын

Thank you Very much Mam😊😊😊

@geoffreypagcaliwagan3024 7 жыл бұрын

had a test about this last monday. wouldve been really helpful :(

@mentalaids3220 7 жыл бұрын

@convergentseries3508 7 жыл бұрын

exams lul

@thomaskoning3985 2 жыл бұрын

This video taught me more than my physics professor in a month

@satyamsingh9695 5 жыл бұрын

You Saved my Literally

@zachydrogeo 5 жыл бұрын

now I'm wondering if optometrists know as much physics as engineers...

@veronicas8270 4 жыл бұрын

I was thinking the same thing! They must know something about all of the lenses they switch in front of my eye. Probably not as much as engineers, but they must know stuff about light and lenses.

@brittniep9219 4 жыл бұрын

Optometrists do have to take physics! They then specialize differently than engineers.

@ekim5589 7 жыл бұрын

Question: for the last two sentences, she said that if the "image is upside down like in our converging lens, then the height is a negative value. And the ratio of the image distance to the object distance is also negative" If the equation is m [magnification] = hi/ho= -di/do, then how can this be true? If the image height is negative, shouldn't the image distance to object distance be positive to maintain the original equation?

@hidude1354 7 жыл бұрын

You are correct that magnification can be shown from height and distance, but your formulas are incorrect. For height, it is: -(Object Height/Image Height). And for distance: -(Object Distance/Image Distance). Therefore, both equations are equivalent.

@volume8831 5 жыл бұрын

What’s good is that you can go back and listen again if you get distracted compared to skl Lol.

@thomnasilikeswordfighting5506 7 жыл бұрын

great video! :D

@arielthomas8737 4 жыл бұрын

0:47 is looking more likely every day

@iancostello3923 6 жыл бұрын

Who is the designer who does these animations and does he/she get technical assistance on them?

@vincentpranayj8599 6 жыл бұрын

Awesome

@VNCCentral 5 жыл бұрын

Do nọt like the speaker's way. Crazy

@joshuamitchell5530 7 жыл бұрын

7:03, not exactly true as a convex lens can produce a virtual image which is upright.

@hidude1354 7 жыл бұрын

In terms of Real Images, she is correct.

@geethanjalinagiri9714 5 жыл бұрын

What my teacher couldn’t do in ten weeks, crash course did in less than ten minutes

@ichigossbm4636 7 жыл бұрын

More of this woman. Plzkthx.

@Flemagrimm 7 жыл бұрын

Generalized Yang-Mills Theory: Crash Course Physics #7,212 when?

@abo3zzzam 7 жыл бұрын

The way she says Phenomenal.. 👌

@eatingtacos000 7 жыл бұрын

Hate to be that guy, but you really have a special ability to explain a relatively simple concept in the most confusing way possible. If your audience includes people who do not know what refraction is, then speeding through the sentence "this phenomenon of light rays changing direction at the interface between media" is going to leave them clueless. I know the point of this channel is to teach quickly, hence "crash course", but you aren't teaching at all when you talk like that. Just some advice from a teacher. Peace.

@verdatum 7 жыл бұрын

FWIW, it's REALLY hard to write something that's compact and makes perfect sense to all audiences on the first viewing. And this is especially true in the realm of physics. I think that's part of why the viewcounts on CC Physics tend to be particularly low. I often try to think of how I could write a better episode on the topics, and yeah, it ain't easy.

@ajaxhopper9859 7 жыл бұрын

Following Feynman Of course, this is meant to _supplement_ a physics class, not necessarily replace it.

@torestgard1681 7 жыл бұрын

Legend Length: the problem is that before your brain has processed the information in this sentence, the presenter is far into the next sentence. The natural pause between the sentences, whatever originally was there, has been edited out to speed it up even further. It is speeding through complex sentences which is the problem, not the complex sentence in itself.

@mirandachen4846 7 жыл бұрын

Following Feynman c

@ayadimishra 7 жыл бұрын

Following Feynman I agree, this has made it less enjoyable , she just seems to be speaking , not teaching...I needed help with my exams , but that didn't work out well I guess 😖