How much does a video weigh? - Michael Stevens of Vsauce

624,116 views ・ 2013-04-24

TED-Ed


Please double-click on the English subtitles below to play the video.

00:14
Bean bags are awesome.
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But I see a few people out there who are standing,
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we've got some over here,
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and standing takes more work than lounging.
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Using the Live Strong Organization's online database
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of weight loss resources,
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you can calculate
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that by the time I'm done with this speech,
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those of you who are standing
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will have burned 7.5 more calories
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than those of you who are bean-bagging it.
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(Laughter)
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Okay, here's a question,
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speaking of weight loss, specifically weight,
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this speech is live.
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I'm actually here in front of you guys,
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we're all here together.
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But this speech is being recorded
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and it will become a video that people can access all over the world
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on computers, mobile devices,
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televisions.
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I weight about 190 pounds.
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How much will the video weigh?
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Asking questions like that
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is what I do every week on my channel Vsauce.
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For the last two years,
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I have been asking really fun questions,
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mind-boggling questions,
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and approaching them as sincerely as I can,
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celebrating scientific concepts and scientists.
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And I research and write
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and produce and host
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and edit and upload
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and run the social media all by myself,
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but it's not lonely,
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because Vsauce has more than 2 million subscribers,
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and every month, my videos are seen by more than 20 million people.
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Yeah.
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(Applause)
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It's very exciting.
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I've found that asking a strange question is a great way to get people in,
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not just people, but fans.
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And fans are different than just viewers or an audience,
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because fans want to come back.
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They subscribe to you on YouTube
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and they want to watch everything you've made
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and everything you plan to make in the future
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because we are curious people
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and sparking curiosity is great bait.
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It's a great way to catch a human.
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And once you've caught them,
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you have this captive audience that you can,
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with the goal in mind of answering the question,
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accidentally teach a lot of things to.
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So, let's take a look at some of my videos.
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Here are eight of them.
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But down here in the lower-right corner,
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"What Color is a Mirror?"
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When people see that,
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it's very difficult not to click, because you think,
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"Come on, are you serious?
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How could you possibly answer that question?"
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Well, so far, 7.6 million people have watched
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this five-minute video about what color a mirror is.
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And in that episode, I answer the question
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and I get a chance to explain what would normally be kind of dry topics:
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optics,
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diffuse versus specular reflection,
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how light works, how light works on the retina,
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and even the etymology of color terms
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like white and black.
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Okay, spoiler alert:
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mirrors are not clear,
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they are not silvery,
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like they're often illustrated.
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Mirrors, technically speaking,
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are just a tiny, tiny, little bit ...
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green.
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You can demonstrate this by putting two mirrors next to each other,
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facing so they reflect back and forth forever.
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Look down that infinite reflection, and it will get dimmer,
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because some light is lost or absorbed every time,
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but it will also become greener,
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because green light,
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that is light of a wavelength that we perceive as green,
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is best reflected by most mirrors.
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Okay, so, how much does a video weigh?
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Well, when you stream a video onto your computer,
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that information is temporarily stored
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using electrons.
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And the number of electrons on your device won't actually increase or decrease.
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But it takes energy to store them in one place,
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and, thanks to our friend Albert Einstein,
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we know that energy and mass are related.
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Okay, so here's the thing:
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let's say you're watching a YouTube video
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at a really nice resolution, 720p.
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Assuming a typical bit rate,
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we can figure that a minute of YouTube video
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is going to need to involve about 10 million electrons on your device.
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Plugging all those electrons and the energy it takes to hold them
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in the correct place for you to see the video,
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into that formula,
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we can figure out that one minute of YouTube video
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increases the mass of your computer
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by about 10 to the negative 19th grams.
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Written out, it looks like this.
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(Whistle)
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That's like nothing.
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You could call that nothing, and you wouldn't really get in trouble,
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because the best scales we've ever invented
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that we could try to use to actually to detect that change
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are only accurate to 10 to the negative 9th grams.
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So, we can't measure it,
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but we can, like we just did, calculate it.
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And that's really cool because when I was a kid,
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my school had two shelves of science books.
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That was really cool,
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but I read all of them within, like, two grades,
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and it was hard to get more books
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because books are heavy, you need space for them
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and moving books around is tougher than what we can do today.
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With numbers that small,
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I can fit thousands of books
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on my own little personal electronic reader.
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I can stream hours and hours
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and days and days of YouTube video
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without my computer ever getting measurably heavier.
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And as information becomes that light,
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it becomes a lot more democratic,
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meaning that more teachers
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and presenters and creators and viewers than ever before
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can be involved.
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Right now, on YouTube,
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there is an explosion of content like this happening.
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The three Vsauce channels are down there in the corner.
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But everyone else, all together, collectively,
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their views dwarf what I can do alone
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or with the people that I work with,
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and that is really, really exciting.
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It turns out that tapping into people's curiosity
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and responsibly answering their questions
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is a brilliant way to build fans and an audience
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and get in viewers.
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It's even a great way for brands and companies
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to build trust.
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So, calculating the weight of a video
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is kind of a funny question,
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but I cannot wait to see what we ask and answer next.
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As always, thanks for watching.
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(Applause)
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