Maravillas del universo Mensajeros - Documental -
A través de la luz podemos conocer toda la historia del universo y cómo también nos infundió la vida. Podemos leerla y sabemos que su velocidad es finita. Éste se descompone en varios colores que poseen una diferente longitud de onda.
Transcript
00:00Why are we here? Where do we come from?
00:16These are unrelenting questions and it is part of human nature to want to find the answers.
00:23We are able to trace our lineage hundreds of thousands of years in the past to the dawn of humanity.
00:35But our history goes back much further in time.
00:39Our history begins with the origin of the universe.
00:4313,700 million years ago, a universe full of countless stars and galaxies.
00:58A universe of inconceivable wonders.
01:03And all of them are connected to us.
01:08Because we are part of the universe.
01:12And its history is our history.
01:19And it is a story that we could not tell if it were not for one thing that connects us deeply with the universe.
01:29Light.
01:31Light shows us the wonders of our universe in all its splendor.
01:35The stars that are born in distant kingdoms and the galaxies frozen in time.
01:44But light is also the messenger of an era long forgotten.
01:49And the light of the farthest stars in the cosmos contains the history of the origin of our universe.
01:59Through light we can know the whole history of the universe.
02:06And also see how light infused us life.
02:17Wonders of the universe.
02:26Messengers.
02:36This is Karnak, one of the largest temples ever built.
02:46It has been here in Luxor, Egypt, 3,500 years.
02:53It is a beautiful and grandiose place.
02:57But to see the temple in all its splendor, you have to visit it during a spectacular event that occurs at the dawn of the winter solstice.
03:08The shortest day of the year.
03:16The stones that form these monumental walls were erected to celebrate that moment.
03:21In honor of Amon-Ra, the god of the sun.
03:27It is very short, just a little more than half a minute.
03:51The light of Amon-Ra falls on the avenue of the temple, perfectly aligning with the columns and flooding it with its light.
04:09This ancient civilization worshiped the sun as a god.
04:13And he had no reason to do so.
04:16The sun was the center of their lives.
04:19Today we no longer erect temples in honor of the sun.
04:24But our fascination with the stars was never stronger.
04:38Brighter than 95% of the rest of the stars in our galaxy.
04:43This is our sun.
04:49It is in the flower of its life.
04:52And it rules with all right our world from the heart of our solar system.
05:05The light emitted by the sun is diffused from the photosphere, its visible surface.
05:11The light radiates through space and bathes our planet with its light and its heat.
05:22But this special star disappears every day, every time it is hidden on the other side of the planet,
05:28as a wonderful reminder of one of the most fundamental elements of the universe.
05:33The light.
05:41But only when the light of our closest star fades,
05:45a true and magical wonder is revealed before our eyes.
05:52A cosmos full of suns.
05:58In the darkness of the night, thousands of stars pierce the firmament.
06:02But if we look closely, we will see a strip with hundreds of billions of stars,
06:08only on our Milky Way.
06:22From our planet we have a privileged view of the wonders of the galaxy.
06:32When we move away from Earth towards the borders of the Milky Way,
06:38our sun becomes another small point of light in an ocean of lights.
06:51If we move even further, we will see our entire galaxy unfold before us.
06:57A spiral that expands from a dense and luminous nucleus.
07:03The stars, like our sun, are not the only sources of light within this beautiful disk that rotates.
07:11There are other spectacular worlds in the galaxy that we know intimately thanks to the light they emit.
07:32This is the Nebula of the Lagoon.
07:43This cloud of dust and gas, visible from Earth in the dark nights,
07:48located in the Sagittarius constellation, seems beautiful and serene.
07:52But it is an oven in which new stars are forged.
08:14The Nebula of the Lagoon is a very special object.
08:18The Nebula of the Lagoon is one of the brightest in the Milky Way,
08:23and all for a new and young star located in its heart.
08:29A giant called Herschel 36.
08:41This star is 20 times more massive than our sun,
08:44and burns at a temperature five times higher,
08:48so the light that flows from its surface is blue.
09:03But this is not the largest star that exists.
09:09Analyzing the light of countless suns,
09:12we have discovered a star that would eclipse even Herschel 36.
09:27At 75 billion million kilometers.
09:32This is Eta Carinae.
09:35This super star has a mass 100 times larger than our sun.
09:43And its luminosity is 4 million times greater than that of the sun,
09:48which makes it one of the brightest stars in the Milky Way.
10:06The light of these worlds connects us intimately with the wider universe.
10:14But the light reveals many more things to us.
10:18Because finally, in the light, we can read the history of the universe.
10:30We all underestimate the light.
10:33We are so used to it that it has become the backbone of our lives.
10:41We need it for everything we are,
10:45to be able to be, to live.
10:49Light is the thing that has allowed us to understand the universe.
10:53We do not give importance to light,
10:57but it has an extraordinary property that allows it to reveal many things.
11:05A property that shares the energy of the oceans of the world.
11:10The waves.
11:14Dr. Sasha Shidiwi, astrophysicist, is in the Bay of Jeffries in South Africa.
11:30A wave is basically just an energy transfer.
11:34It is just a collection of peaks and valleys
11:38that move from the high seas to the shore.
11:41While they wait for the arrival of the waves,
11:45the local surfers tell us something about the nature of the waves.
11:51They perfectly illustrate the movement of energy through the sea.
11:56They always remain in the same place,
12:00showing that it is not the water that moves to the shore,
12:04but only the energy that is in it.
12:07And when the waves arrive,
12:11the surfers only move up and down
12:15and the waves pass under them.
12:19Just as the waves break on the shore,
12:23releasing their energy on the beach,
12:27the waves of light that come from space
12:31bring their energy to the surface of our planet.
12:34Stars, constellations and galaxies
12:38are waves of light that we are detecting with our eyes.
12:42So, in a way, we are connected to the rest of the universe.
12:49Our other senses, hearing, touch, taste and smell,
12:53are limited by distance,
12:57but light makes vision something exceptional.
13:01The waves of light are special.
13:05They have the ability to transcend all distances.
13:09They travel uninterruptedly through stellar space,
13:13thousands of millions of kilometers away,
13:17extending this sense to the confines of the universe.
13:21But the waves of light not only allow us to look at space,
13:25they also help us to travel through time.
13:33To understand how light allows us to see the past,
13:37we must know a property of all waves, its speed.
13:51The speed of light
14:04Like light, sound also travels like a wave.
14:11Studying the speed at which sound waves travel,
14:15it is possible to show something that all waves share, including light.
14:20They all have a speed limit.
14:24Very few people have faced the speed limits of waves,
14:28and Dave Southwood is one of them.
14:32He has piloted military reactors for the RAF for 30 years.
14:37This is the Hawker Hunter.
14:41In 1953 it broke the absolute world speed record.
14:45This aircraft model at the time was the fastest on the planet.
14:48What makes this jet special is that it is able to break the sound barrier,
14:52although with difficulties.
14:56To achieve the speed of sound,
15:00Dave will have to launch his Hunter from the sky.
15:05To break the sound barrier with the Hunter,
15:09you have to understand physics and aerodynamics,
15:13and you have to ascend to a great height and launch with the aircraft.
15:19Dave has to ascend to 42,000 feet
15:23to have enough altitude to try his supersonic zambullida.
15:40The maximum speed of sound waves, depending on the altitude,
15:44is approximately 1,200 kilometers per hour.
15:48Or Mach 1.
15:58Dave continues to gain altitude.
16:12The speed increases and the Mach indicator continues to rise.
16:15Dave has to do everything possible
16:19to make his plane fly faster than his own sound waves.
16:46When Dave is launched, he approaches Mach 1.
16:50And the plane begins to reach its own sound waves,
16:54which cannot travel faster.
16:58In a few seconds, while Dave falls to the surface,
17:02it breaks the sound barrier.
17:06On land, it sounds like a sonic explosion.
17:16Sound waves have a maximum speed limit
17:20that can be overcome with the right machine.
17:27But the speed of light is something completely different.
17:35It was always thought that light waves were different,
17:39that they traveled at an infinitely fast speed
17:42and that light seemed to arrive from an object to our eyes instantly.
17:48The truth was accidentally discovered by a scientist a few centuries ago
17:52who studied precise movements like a clock
17:56of the planets and their moons.
18:05Jupiter, the fifth planet from the sun and the largest in the solar system,
18:08was the center of attention at that time.
18:14It was even suggested that Io, the closest moon to Jupiter,
18:18acted like a sidereal clock.
18:23When the moon Io emerged from the shadow of the planet,
18:27it marked a unit of time like the needle of a clock.
18:39A young Danish astronomer named Ole Christian Roma
18:43observed Jupiter from the Paris Astronomical Observatory.
18:48Roma followed the orbit of Io
18:52and recorded every time it reappeared from behind the shadow of Jupiter.
18:56But the clock seemed to alter the time.
19:00The doctor in astronomy, Francisco Diego,
19:04tells us the genius idea of the clock.
19:08Here is Roma with his great telescope
19:12in the Paris Observatory
19:16observing the movements of Io around Jupiter
19:20and timing them very carefully.
19:24Then something very strange happened.
19:28Roma realized that this movement was not constant.
19:32It seemed to be slower and then faster and then slower and faster.
19:35That happened every year and Roma had observed that for 10 years.
19:39Then he thought, well, it is impossible that Io
19:43has different speeds around Jupiter.
19:47It cannot change speed. What's going on?
19:51Roma knew that the orbits of the planets and the moons are constant.
19:55Io's speed was not changing.
19:59What was changing was the relative position of the planets and the moons
20:02between them throughout the year in their orbit around the sun.
20:06Roma had an incredible intuition.
20:10Because if I'm here, closer to Jupiter,
20:14I can see Io emerge from the shadow of Jupiter
20:18from this position
20:22when the light has traveled this distance.
20:26And a few months later I will continue to see Jupiter
20:29with Io orbiting around it.
20:33But now I'm seeing it from this position,
20:37so the light has had to travel a greater distance.
20:41Roma began to think and said, it is the speed of light.
20:45Light has a speed. It does not travel instantly.
20:49It takes time to get from there to here.
20:53Roma had realized that the additional distance
20:57that the light had to travel to Earth
21:01had to be the cause of that delay.
21:05He had shown for the first time and conclusively
21:09that the speed of light is finite.
21:12All physicists know today what their speed is,
21:16regardless of the way they study it.
21:20It's 300 million meters per second.
21:24In the time it takes to snap your fingers,
21:28light travels seven times around the world.
21:32The speed of light is 3 times 10 to the power of 8 meters per second.
21:36In old-fashioned units,
21:39one foot per billionth of a second.
21:43About that far every nanosecond.
21:47It's quite slow if you think about it.
21:59In the vacuum of space,
22:03light travels at a speed of 10 billion kilometers per second.
22:06That's the distance of a light year.
22:10But the light year is also a measure of time.
22:14And it's this connection with time
22:18that makes it possible to study the speed of light.
22:22And it's this connection with time
22:26that makes it possible to study the speed of light.
22:30And it's this connection with time
22:33that makes the finite speed of light have significant consequences.
22:37And it's this connection with time
22:41that makes the finite speed of light have significant consequences.
22:52The finite speed of light is crucial
22:56because it takes time to travel from a distant object to our eyes.
22:59The further away an object is,
23:03the further back in time we will see it.
23:23For the doctor in astronomy, Petri Vaisanen,
23:26the speed at which light travels
23:30opens a window to the past of our universe here in East Africa.
23:44When I look at my hand, which is very close to me,
23:48the light takes a while to reflect in it until it reaches my eyes.
23:52Very little time, but still it takes a while.
23:56I never see anything in the present moment.
24:00We are always looking at the past.
24:04On Earth, the distances that light travels are relatively small,
24:08so that the time it takes to travel to our eyes is imperceptible.
24:12But if we consider it from an astronomical scale,
24:16the implications are much more important.
24:20The sun is about 150 million kilometers away.
24:23So we see the sun as it was eight minutes before,
24:27in the past, in history.
24:31If we go even further into our cosmic garden,
24:35it is possible to see even further into the past.
24:40Saturn is 1,400 million kilometers from the sun.
24:44We see its brilliant rings of ice
24:48as they were an hour ago, in the past.
24:54And we can only observe Neptune,
24:58the outermost planet of the solar system,
25:02as it was more than four hours ago.
25:08When we look at the sky on a night without clouds,
25:12we see the light that has traveled from far away.
25:16Among the stars of the Milky Way
25:19appears a faint spot of light.
25:29This is another galaxy outside ours,
25:33called Andromeda.
25:39This beautiful spiral galaxy
25:43is 25 million million million kilometers away from Earth.
25:46It is the most distant object visible to the naked eye.
25:52The light emitted by this mass of spinning stars
25:56connects us with an extraordinary moment in human evolution
26:00and with our most distant ancestors,
26:04giving the African plains an additional meaning.
26:082.5 million years ago,
26:12the first humans, Homo habilis, traveled these plains.
26:16And while that was happening,
26:20Andromeda's rays of light began their journey through the universe.
26:24Those rays of light have only just begun to arrive now.
26:38It is exciting to think that the light of Andromeda
26:42that we see now originated 2.5 million years ago,
26:46almost at the same time that our ancestors
26:50began to travel the same place where we are now.
26:57Within those 2.5 million years,
27:01everything we know about human history happened here.
27:05It is simply incredible.
27:09The scales of time and distance are enormous.
27:13And our own civilization is
27:17just a snap of a finger compared to them.
27:20Thanks to telescopes,
27:24we can look beyond the times of our first ancestors.
27:28In fact, we can become virtual time travelers.
27:44This is Centaurus A.
27:47It is only 10 million light-years away.
27:51It is an active galaxy with a gigantic dust cloud
27:55and star formation regions at the bottom, here.
28:10Now we are approaching 100 million light-years away.
28:13This is NGC 520,
28:17two colliding galaxies that create many stars.
28:23When these galaxies collided violently,
28:27the dinosaurs still dominated the Earth.
28:34This is another beautiful example of a colliding galaxy.
28:38We can see two galaxies. One is this and the other is here.
28:41And it looks like a bell or a bird.
28:45That is why we call it the Bird Galaxy.
28:49It is 650 million light-years away.
28:53Life was still confined in the oceans of the world
28:57when these galaxies collided.
29:01It is like an archaeological excavation. We are seeing the past.
29:05And the further we look, the further we travel in time.
29:08But there is an image that can take us even further.
29:14Hubble's ultra-deep field
29:18that takes us directly to the limits of our universe.
29:29This image, captured by the Hubble Space Telescope
29:33in orbit around the Earth,
29:35recorded a part of the sky for almost a million seconds,
29:39approximately 11 days,
29:42and took this incredibly deep image of the universe
29:46in which very distant and faint objects can be seen.
29:50We can also see some stars from our own Milky Way,
29:54but for the most part, what you see are incredibly distant galaxies.
30:00It is estimated that there are 10,000 galaxies in this image
30:03and each of them contains, in turn, billions of stars,
30:07all as massive as our sun.
30:16In fact, some of the furthest away galaxies observed so far
30:20are in this image,
30:23and they are 13,000 light-years away.
30:28So we are talking about an incredibly large universe.
30:34It does make you realize how extremely small we are.
30:49In this image we see the farthest galaxies
30:53as they were 13 billion years ago,
30:56when the universe was in its infancy.
31:00And not only that,
31:03these galaxies also tell us something much deeper.
31:07They give us a clue about how our universe began.
31:17In its exploration of the cosmos,
31:20the Hubble Space Telescope recorded bright galaxies of all existing colors,
31:25but all the galaxies located at the limits of the visible universe were red.
31:36These are some of the galaxies that Hubble found.
31:43Its red light tells us about the origins of the universe.
31:48But to understand why we must explore a beautiful property of all stars,
31:52the color.
32:11For many centuries it was thought that light only illuminated the world,
32:15allowing us to see, but nothing more.
32:23Now we know that each ray of light
32:26contains enormous amounts of information and data.
32:32And part of that information is written in its color.
32:43The physicist and professor Brian Cox
32:46has traveled to one of the most spectacular wonders of nature on Earth.
32:52The Victoria Falls.
33:08The rainbow above them is a permanent feature of these falls.
33:13It occurs because the dew of the falls acts like a natural prism
33:17that shows that the white light is very far from being colorless.
33:26Rainbows are formed because the white light of the sun
33:30breaks down in the colors that make it up
33:33when it passes through the drops of water in suspension
33:36that surround the falls.
33:38Imagine a ray of light coming out of the sun
33:41and a drop of rain comes in and then it is reflected in its interior.
33:44It comes out and reaches my eyes.
33:51Each color is reflected in a slightly different angle,
33:55showing all the colors in a splendid rainbow.
34:01What separates each color is another property of light.
34:06Each wave of light has a different length.
34:10So, for example, the red light
34:13has a relatively long wavelength.
34:16Then you go to yellow and then to blue.
34:19And blue has a relatively short wavelength.
34:23So what we see as colors
34:26is really just the different wavelengths.
34:34These colors not only give color to our world,
34:37they also explain the origins of our universe.
34:45But light waves are not immutable.
34:48They can change.
34:53A ray of light does not always remain in the same wavelength.
34:57It can be stretched or it can be crushed.
35:00And when you crush the light, its wavelength is reduced
35:03and everything moves towards the blue end of the spectrum.
35:05But if you stretch it and increase the wavelength,
35:08everything moves towards the red end of the spectrum.
35:11That's known as the red rush.
35:16The farthest galaxies in the confines of the universe
35:20were full of blue stars, young and hot.
35:24But when their light left those galaxies
35:27and traveled through the vastness of space,
35:30the short-wave lengths grew to become red.
35:34So the interpretation of the fact
35:37that all the farthest galaxies look red
35:40is that space has stretched more and more.
35:43The light has stretched and the whole spectrum of the galaxy
35:46has moved towards the red end of the spectrum.
35:52As space stretches,
35:55galaxies move further and further apart.
35:58And that can only mean one thing,
36:01that the universe is expanding.
36:07If we went back in time,
36:10then all the galaxies would be closer to each other in the past.
36:16And if you rewind and go back and back in the past,
36:20everything indicates that at some point in the farthest past,
36:23all the galaxies were piled up on top of each other.
36:27And that means that the universe then
36:30was much smaller than it is now.
36:33And that could have had a beginning.
36:36And that is the Big Bang theory.
36:53In a violent instant, 13 billion years ago,
36:56our universe was born.
37:24It is often thought of the Big Bang
37:27as a single explosion that expanded through space.
37:38It is hard to imagine,
37:41but the Big Bang did not explode in space.
37:44It created space.
37:47And that space continues to expand inexorably
37:50in all directions since then.
37:55Even today, those galaxies continue to travel.
38:17Due to the incessant expansion,
38:20our universe now has 93 billion light-years in diameter.
38:27But surprisingly,
38:30we know how it evolved from that tiny point
38:33to this immense cosmos.
38:39And that is so because the project of the entire universe
38:42was written by the Big Bang.
38:45That light is still there.
38:48We just have to know how to find it.
39:03The visible light is only a small fraction
39:06of all the light in the universe.
39:09In any case,
39:11at both ends of the visible spectrum
39:14there is something very mysterious,
39:17the invisible light.
39:24The cosmologist and professor Justin Jonas
39:27has traveled to the spectacular Namibian desert
39:30not to see that light, but to feel it.
39:33The sand heats up a lot during the day.
39:36If you put your hand on the sand,
39:39you can feel the thermal radiation that emits.
39:42That heat is actually light.
39:45It is a light with wavelengths longer
39:48than those we are used to seeing,
39:51and it is called infrared radiation.
39:54It is a light that we cannot see,
39:57but we can feel.
40:03This infrared light is emitted
40:06by practically everything in the universe.
40:09Even humans emit it.
40:14But the story does not end in infrared light.
40:17There are wavelengths of invisible light
40:20that are even longer,
40:23and all we need to detect them
40:26is a simple radio.
40:29The longest waves in the universe
40:32are radio waves.
40:45When the radio is not tuned,
40:48we do not hear any emitter,
40:51we only hear a hissing.
40:54That hissing is the radio waves.
40:57And those waves are emitted by all kinds of objects,
40:59including radio waves,
41:02and this radio can capture them.
41:05And the most intriguing of all
41:08is that a small fraction of the radio waves
41:11that this receiver is capturing
41:14come from the light emitted in the Big Bang.
41:17That light emitted at first
41:20could provide us with a map of the whole universe.
41:23And that light has a very short wavelength
41:26that will represent the sand
41:29like this wave.
41:32But these waves have been traveling through space
41:35since the beginning of the universe,
41:38more than 13 billion years,
41:41and during that time the universe has expanded.
41:44And in that process it has effectively lengthened those waves,
41:47which are now much longer,
41:50and those long waves are now actually radio waves.
41:55These stretched waves have a name,
41:57Microwave Background Radiation,
42:00or CMB,
42:03which completely fills the universe.
42:08This light spills all over the Earth.
42:11If we could see it,
42:14there would be no night.
42:17It would illuminate everything.
42:21In 2001,
42:24NASA's WMAP probe
42:27confirmed the CMB.
42:31That image revolutionized our idea
42:34about the origins of the universe.
42:38This is an image of the microwave background radiation
42:41taken by the WMAP probe
42:44over several years.
42:47For an inexperienced eye, it may not say much,
42:50but in reality it is one of the most incredible images
42:53that humans have ever made.
42:56The WMAP probe showed that the CMB
42:59contained small temperature differences
43:02that correlated with the density differences
43:05in the primordial universe.
43:15As time went by,
43:18gravity began to work in the densest areas,
43:21making them more and more dense.
43:24Atoms were formed,
43:27which began to group,
43:30forming the first structures.
43:34Over time,
43:37those structures grew so massively
43:40that they collapsed,
43:43reaching temperatures of up to 1,000 degrees Celsius.
43:46At the same time,
43:49the atoms began to form
43:51so massively that they collapsed,
43:54reaching temperatures of more than 10 million degrees Celsius.
43:57Hydrogen fused,
44:00releasing huge amounts of energy.
44:06200 million years after the Big Bang,
44:09the first stars were born in the cosmos.
44:15Throughout the universe,
44:18countless suns exploded into life
44:22as the first stars were born.
44:26The buildings were torn down.
44:29The instruments went out of order.
44:32The rockets were fired.
44:35The rockets were fired
44:38in a wide array of different colors.
44:41The gas and gases were released from the rockets,
44:44and the stars were formed,
44:47creating the first atomic star,
44:49And finally, the stars grouped and formed vast galaxies.
45:07Only thanks to these minimal differences in density in the primitive universe, we have
45:11the rich and varied cosmos that we know today.
45:19Without them there would be no planets or stars or galaxies.
45:25The universe would not exist, and space would look the same in all directions.
45:44Nine billion years after the Big Bang, those small differences in density led
45:50to the formation of a star in a dark and current region known as the Orion Sphere,
45:56near the arm of Perseus, in the galaxy of the Milky Way.
46:08We call that star the Sun, and its light illuminated our embryonic solar system.
46:26Studying the light of the heavens, we have been able to understand the origins and evolution
46:30of our universe.
46:36And light is also key in a final turn of the history of our universe.
46:43The emergence of complex life, including us.
46:55These are the rocky mountains of British Columbia, Canada.
47:01At these peaks there is an instant of an extraordinary era of the Earth.
47:09Paleontologists like Dr. Paul McNeill come to this place over and over again.
47:17Because here is one of the richest fossil deposits ever discovered, Lulitas de Vargas.
47:25It may only look like fragments of rocks, but the fossilized creatures inside tell us
47:30a fascinating story.
47:34Five hundred and five million years ago, this whole region was covered by water.
47:38It was something like what today is the Florida coast.
47:41There were animal communities living in the reefs at that time, and periodically there
47:45were large mudslides that buried these animals, helping to preserve them.
47:52This is simply one of the most important fossil deposits in the world.
47:57The animals we find here lived in an era in which for the first time animal life began
48:01to grow in size.
48:07Until that moment, life on Earth had not evolved beyond some very simple organism
48:12of soft body.
48:13And then, suddenly, the complexity of life erupted in what we call the Cambrian explosion.
48:29One of the most interesting animals we find here in Vargas is the trilobites, which is
48:33a kind of classic fossil.
48:36We can see that they have a tail, a series of segments that form the middle of the body
48:40and also that it has large eyes in the shape of a half moon.
48:44The trilobites are one of the first animals that we find in the fossil record with well-developed eyes.
48:50Their ability to see makes the trilobites an incredibly successful species, but they
48:56were not the only animals that took advantage of the power of light.
49:01Another one of those amazing animals that we find here is a small animal called picaia.
49:06A lot of people say that it looks like a little slug.
49:10This animal could have the ability to distinguish light from darkness.
49:17Although it did not have well-developed eyes, some scientists think that it could be one
49:22of the first creatures capable of detecting the light that flooded our universe for
49:26billions of years.
49:29And that, without a doubt, is important because we could be related to this little creature
49:34that looks like a worm.
49:37If we look at it closely, we will see that it actually has a tail and that means that
49:41this little animal belongs to the group of the so-called tailed.
49:46Scientists are currently studying the picaia again.
49:50If it were really one of the first tailed, the group of animals from which the human being would arise,
49:56then perhaps we owe this little animal the evolution of our ability to see.
50:03Light is what has really given us the key to interpret not only life on Earth,
50:08but also our place in the universe.
50:15Light created us.
50:19And not only did it give us the opportunity to enjoy the spectacle of our universe,
50:25but it also allowed us to understand it.
50:34Thanks to light, we have witnessed the birth of stars in remote places.
50:42Of galaxies lost in time at the limits of the visible universe.
50:52And of our own cosmos a few moments after it all began.
51:00Light has allowed us to tell the story of the universe.
51:11Thanks to light, we have witnessed the birth of stars in remote places.