The Earth's age in measurements you can understand - Joshua M. Sneideman
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0:07 - 0:09How old is the Earth?
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0:09 - 0:11Well, by counting the number of isotopes
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0:11 - 0:12in a sample of rock
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0:12 - 0:14that's undergone radioactive decay,
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0:14 - 0:17geologists have estimated the Earth's birthday,
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0:17 - 0:19when it first formed from a solar nebula,
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0:19 - 0:22to be 4.6 billion years ago.
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0:22 - 0:24But just how long is that really?
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0:24 - 0:25Here's some analogies
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0:25 - 0:27that might help you understand.
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0:27 - 0:31For example, let's imagine the entire history of Earth
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0:31 - 0:32until the present day
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0:32 - 0:34as a single calendar year.
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0:34 - 0:37On January 1st, the Earth begins to form.
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0:37 - 0:39By March 3rd, there's the first evidence
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0:39 - 0:41of single-celled bacteria.
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0:41 - 0:45Life remains amazingly unicellular until November 11th
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0:45 - 0:47when the first multicellular organisms,
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0:47 - 0:50known as the Ediacaran fauna, come along.
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0:50 - 0:54Shortly thereafter, on November 16th at 6:08 p.m.
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0:54 - 0:56is the Cambrian Explosion of life,
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0:56 - 0:58a major milestone,
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0:58 - 1:01when all of the modern phyla started to appear.
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1:01 - 1:04On December 10th at 1:26 p.m.,
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1:04 - 1:06the dinosaurs first evolve
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1:06 - 1:07but are wiped out by an asteroid
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1:07 - 1:09just two weeks later.
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1:09 - 1:12On December 31st, the mighty Roman empire
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1:12 - 1:15rises and falls in just under four seconds.
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1:15 - 1:16And Columbus sets sail
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1:16 - 1:18for what he thinks is India
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1:18 - 1:19at three seconds to midnight.
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1:20 - 1:22If you try to write the history of the Earth
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1:22 - 1:24using just one page per year,
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1:24 - 1:27your book would be 145 miles thick,
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1:27 - 1:28more than half the distance
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1:28 - 1:31to the international space station.
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1:31 - 1:33The story of the 3.2 million year-old
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1:33 - 1:36Australopithecine fossil known as Lucy
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1:36 - 1:38would be found on the 144th mile,
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1:38 - 1:41just over 500 feet from the end of the book.
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1:42 - 1:45The United States of America's Declaration of Independence
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1:45 - 1:47would be signed in the last half-inch.
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1:47 - 1:49Or if we compared geologic time
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1:49 - 1:51to a woman stretching her arms
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1:51 - 1:52to a span of six feet,
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1:52 - 1:54the simple act of filing her nails
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1:54 - 1:57would wipe away all of recorded human history.
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1:57 - 2:01Finally, let's imagine the history of the Earth as your life:
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2:01 - 2:02from the moment you're born
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2:02 - 2:04to your first day of high school.
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2:04 - 2:05Your first word,
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2:05 - 2:06first time sitting up,
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2:06 - 2:08and first time walking
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2:08 - 2:10would all take place while life on Earth
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2:10 - 2:13was comprised of single-celled organisms.
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2:13 - 2:15In fact, the first multicellular organism
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2:15 - 2:17wouldn't evolve until you were 12 years old
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2:17 - 2:19and starting 7th grade,
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2:19 - 2:20right around the time
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2:20 - 2:21your science teacher is telling the class
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2:21 - 2:23how fossils are formed.
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2:23 - 2:25The dinosaurs don't appear
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2:25 - 2:27until three months into 8th grade
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2:27 - 2:30and are soon wiped out right around spring break.
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2:30 - 2:32Three days before 9th grade begins,
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2:32 - 2:33when you realize summer is over
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2:33 - 2:35and you need new school supplies,
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2:35 - 2:39Lucy, the Australopithecine, is walking around Africa.
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2:39 - 2:40As you finish breakfast
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2:40 - 2:42and head outside to catch your bus
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2:42 - 2:4444 minutes before school,
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2:44 - 2:47the Neanderthals are going extinct throughout Europe.
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2:48 - 2:49The most recent glacial period
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2:49 - 2:51ends as your bus drops you off
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2:51 - 2:5316 minutes before class.
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2:53 - 2:56Columbus sets sail 50 seconds before class
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2:56 - 2:59as you're still trying to find the right classroom.
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2:59 - 3:01The Declaration of Independence is signed
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3:01 - 3:0228 seconds later
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3:02 - 3:04as you look for an empty seat.
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3:04 - 3:08And you were born 1.3 seconds before the bell rings.
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3:09 - 3:11So, you see, the Earth is extremely,
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3:11 - 3:12unbelievably old
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3:12 - 3:14compared to us humans
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3:14 - 3:15with a fossil record
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3:15 - 3:18hiding incredible stories to tell us about the past
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3:18 - 3:20and possibly the future as well.
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3:20 - 3:22But in the short time we've been here,
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3:22 - 3:23we've learned so much
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3:23 - 3:25and will surely learn more
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3:25 - 3:27over the next decades and centuries,
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3:27 - 3:29near moments in geological time.
- Title:
- The Earth's age in measurements you can understand - Joshua M. Sneideman
- Description:
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View full lesson: http://ed.ted.com/lessons/the-earth-s-age-in-measurements-you-can-understand-joshua-m-sneideman
The Earth is 4.6 billion years old -- but how can humans relate to a number so colossal, and where do we fit on the geologic timeline? Comparing the Earth's lifetime to one calendar year, events like the extinction of dinosaurs and Columbus setting sail took place relatively recently. Joshua M. Sneideman reminds us of our time and place in the universe.
Lesson by Joshua M. Sneideman, animation by Powerhouse Animation Studios Inc.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 03:45
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Jessica Ruby accepted English subtitles for The Earth's age in measurements you can understand - Joshua M. Sneideman | ||
Andrea McDonough edited English subtitles for The Earth's age in measurements you can understand - Joshua M. Sneideman | ||
Andrea McDonough edited English subtitles for The Earth's age in measurements you can understand - Joshua M. Sneideman | ||
Andrea McDonough edited English subtitles for The Earth's age in measurements you can understand - Joshua M. Sneideman |