If molecules were people... - George Zaidan and Charles Morton
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0:08 - 0:10Say two people are walking down the street,
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0:10 - 0:12and they bump into each other.
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0:12 - 0:14They'll just shake it off and walk on.
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0:14 - 0:17Sometimes that happens with molecules too.
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0:17 - 0:19They just bounce off each other, and that's that.
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0:19 - 0:21But what if two people were to bump into each other,
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0:21 - 0:23and during that collision,
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0:23 - 0:24one person's arm got severed
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0:24 - 0:28and reattached to the other person's face?
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0:28 - 0:29Now that sounds really weird,
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0:29 - 0:31but it's similar to one of the many ways
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0:31 - 0:34that molecules can react with each other.
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0:35 - 0:37Two molecules can join and become one.
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0:37 - 0:39One can split apart and become two.
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0:39 - 0:41Molecules can switch parts.
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0:42 - 0:44All these changes are chemical reactions,
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0:44 - 0:46and we can see them happening around us.
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0:46 - 0:48For example, when fireworks explode,
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0:48 - 0:50or iron rusts,
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0:50 - 0:50or milk goes bad,
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0:50 - 0:51or people are born,
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0:51 - 0:52grow old,
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0:52 - 0:53die,
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0:53 - 0:54and then decompose.
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0:55 - 0:58But chemical reactions don't just happen willy nilly!
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0:58 - 1:00Everything has to be right.
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1:00 - 1:02First, the molecules have to hit each other
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1:02 - 1:04in the right orientation.
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1:04 - 1:06And second, they have to hit each other hard enough,
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1:06 - 1:08in other words, with enough energy.
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1:08 - 1:09Now you're probably thinking
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1:09 - 1:12that a reaction just happens in one direction and that's it.
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1:12 - 1:13Sometimes that's true.
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1:13 - 1:16For example, things can't unburn
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1:16 - 1:17or unexplode.
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1:18 - 1:21But most reactions can happen in both directions,
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1:21 - 1:23forward and reverse.
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1:23 - 1:25There's no reason that our face-arm guy
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1:25 - 1:27can't bump into armless girl,
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1:27 - 1:30reattaching that arm back to its original socket.
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1:30 - 1:32Now let's zoom out a bit.
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1:32 - 1:33Now let's say that you've got
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1:33 - 1:35a thousand people on the street,
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1:35 - 1:36and all of them start with their limbs
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1:36 - 1:38normally attached.
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1:38 - 1:40At the beginning, every collision is a chance
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1:40 - 1:44for Person A to transfer an arm to Person B's face.
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1:44 - 1:45And so at the beginning,
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1:45 - 1:46more and more people end up
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1:46 - 1:49with arms attached to their faces or arms missing.
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1:49 - 1:51But as the number of people with arm-faces
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1:51 - 1:53and missing arms grows,
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1:53 - 1:57collisions between those people become more likely.
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1:57 - 1:59And when they bump into each other,
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1:59 - 2:00guess what?
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2:00 - 2:03Normal-appendage people are reproduced.
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2:03 - 2:06Now the number of limb transfers per second forward
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2:06 - 2:08will start high and then fall,
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2:08 - 2:10and the number of limb transfers per second backward
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2:10 - 2:12will start at zero and then rise.
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2:12 - 2:14Eventually they'll meet,
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2:14 - 2:15they'll be the same.
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2:15 - 2:16And when that happens,
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2:16 - 2:19the number of people in each state stops changing,
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2:19 - 2:21even though people are still bumping into each other
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2:21 - 2:23and exchanging limbs.
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2:24 - 2:25Now how many people do you think
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2:25 - 2:27there are in each state?
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2:27 - 2:28Half and half, right?
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2:28 - 2:30No, well, maybe.
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2:30 - 2:31It depends.
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2:31 - 2:32It could be 50/50,
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2:32 - 2:33but it could be 60/40
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2:33 - 2:34or 15/85,
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2:34 - 2:35or anything.
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2:35 - 2:39We chemists have to get our little, gloved hands dirty
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2:39 - 2:41- ah, well, we're in a lab so not really dirty -
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2:41 - 2:43to figure out what the actual distribution
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2:43 - 2:45of molecules is.
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2:45 - 2:46Even though each of limb transfers
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2:46 - 2:50is a pretty dramatic event for the people involved,
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2:50 - 2:50if we zoom out,
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2:50 - 2:53we see population numbers that don't change.
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2:53 - 2:55We call this nirvana equilibrium,
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2:55 - 2:58and it doesn't just happen with chemical reactions.
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2:59 - 3:00Things like gene pools
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3:00 - 3:02and highway traffic show the same pattern.
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3:02 - 3:05It looks pretty still from 30,000 feet,
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3:05 - 3:06but there is lots of crazy stuff
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3:06 - 3:08happening on the ground,
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3:08 - 3:10you just need to zoom in to see it.
- Title:
- If molecules were people... - George Zaidan and Charles Morton
- Description:
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View full lesson: http://ed.ted.com/lessons/chemical-reactions-zaidan-and-morton
When molecules collide, chemical reactions can occur -- causing major structural changes akin to getting a new arm on your face! George Zaidan and Charles Morton playfully imagine chemical systems as busy city streets, and the colliding molecules within them as your average, limb-swapping joes.
Lesson by George Zaidan and Charles Morton, animation by Neighbor.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 03:25
Bedirhan Cinar edited English subtitles for If molecules were people... - George Zaidan and Charles Morton | ||
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Jessica Ruby accepted English subtitles for If molecules were people... - George Zaidan and Charles Morton | ||
Jessica Ruby edited English subtitles for If molecules were people... - George Zaidan and Charles Morton | ||
Jessica Ruby edited English subtitles for If molecules were people... - George Zaidan and Charles Morton | ||
Andrea McDonough edited English subtitles for If molecules were people... - George Zaidan and Charles Morton |