Los brotes de rayos gamma son destellos de rayos gamma asociados con explosiones extremadamente energéticas en galaxias distantes. Son los eventos electromagnéticos más luminosos que ocurren en el universo.
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00:00COSMIC FRONT
00:09COSMIC FRONT
00:15The universe seems to be a kingdom of tranquility,
00:19but sometimes it shows its most violent face.
00:23EXPLOSIONS
00:26The explosions on the surface of the sun cause powerful solar eruptions.
00:36The collapse of massive stars produces explosions known as supernovas.
00:41EXPLOSIONS
00:48But the monsters of the universe are phenomena that exceed the power of these explosions.
01:00Gamma-ray bursts are the most energetic events in space.
01:06Gamma-ray bursts are perhaps an example of the most extreme phenomena.
01:11We have a concentration of energy, much more energy than the one that the sun has released in its entire existence,
01:17emitted like a ray in a second, more or less.
01:20So, yes, they are very, very extreme.
01:25These monsters, which appear briefly and quickly disappear, are ghost slides.
01:31Scientists have taken half a century to begin to understand the nature of these explosions.
01:38We don't know when or where they will happen.
01:42It's like playing the video game, crush the mole.
01:48But in 2019, a team of Japanese scientists finally managed to carry out an observation
01:54that provided a more complete view of the phenomenon.
02:00These images of a gamma-ray burst were captured by these mirror telescopes.
02:12The energy contained in the explosion was formidable.
02:19When I saw the data, I wondered if it was true. It was amazing.
02:27A gamma-ray burst could also reach Earth one day.
02:37We think that in the past this could have happened,
02:41which had a great effect on life and caused a massive extinction.
02:50The monster that finally showed its face, the gamma-ray burst,
02:54is what we are going to look at next.
02:58Next, we will explore the nature of this phenomenon,
03:02the most massive explosions in the universe.
03:06The monsters of the universe, gamma-ray bursts.
03:09What are gamma-ray bursts, or GRBs for short, in English?
03:15Scientists have spent half a century uncovering the monster.
03:25A scientist has discovered that the gamma-ray bursts
03:30are the result of a chemical reaction
03:33in the atmosphere.
03:38A scientist spotted the bizarre monster by chance.
03:43This is Adam Goldstein, who is conducting his research with a space telescope.
03:52This is the license plate of my car.
03:56This is from when I moved to Alabama and they gave me the license plate.
04:00I changed the license plate of my car to a gamma-ray one.
04:07And this is an article in a local newspaper
04:11from my first day as a defender of the bursts.
04:15And so this is the date that we detected a GRB of an interesting intensity.
04:20It was my first day at work.
04:25In 2008, when Goldstein was still a postgraduate student,
04:28he made a historic discovery on his first day at work.
04:35So this was really a lot of good luck on that day.
04:39A lot of good luck.
04:43The Fermi Space Telescope is used to study these phenomena.
04:47From space, it monitors the skies 24 hours a day
04:51in search of gamma rays.
04:58These bright spots are gamma rays captured by the satellite's sensors.
05:03Look at this area.
05:13Here, high-power gamma rays were detected.
05:17This was the moment when a burst of gamma rays occurred.
05:20The analysis of the data revealed energy levels 100 times higher than those of a supernova.
05:26In addition, the emission of the rays lasted only about 100 seconds.
05:35This event was more energetic than any other burst of gamma rays observed to date.
05:40In our data, it was very, very bright.
05:44Gamma-ray bursts are the most powerful and energetic bursts in the universe,
05:50no exception.
05:53They're more powerful than a supernova or the solar eruptions.
05:58In my hometown, they put the Gamma-ray Burst Motte down
06:03because it was the most powerful burst in the universe.
06:07I'm from a very small town,
06:10and probably the only astrophysicist that ever lived in that town.
06:15And everyone thought it was amazing that this was happening on my first day of work.
06:21Gamma rays are a type of electromagnetic radiation.
06:25These waves can be ordered by their energy level
06:29in an electromagnetic spectrum that includes visible light,
06:33ultraviolet radiation, and X-rays.
06:37Gamma rays are the ones with the most energy.
06:41They're electromagnetic waves created by extreme conditions.
06:50When these gamma rays emit in an explosive way,
06:54the event is known as the Gamma-ray Burst.
07:04GAMMA-RAY BURSTS
07:10The Gamma-ray Bursts were first discovered in the middle of the Cold War.
07:21The United States had a series of BELA satellites
07:25to detect nuclear detonations from space.
07:33The objective was to find gamma rays
07:36generated in explosions of atomic and hydrogen bombs.
07:42In 1967, gamma rays of mysterious origin were detected.
07:51The surprising thing was that these emissions did not come from Earth,
07:56but from outer space.
08:04In addition, the area of space where these gamma rays came from
08:09was not occupied by the sun, the planets,
08:12or by bright stars or other corresponding celestial bodies.
08:22So, what were these gamma rays emitting?
08:26A scientist studied this phenomenon from the beginning.
08:29Astrophysicist Martin Rees.
08:36We didn't know exactly where these explosions came from,
08:40and the big question was whether they were coming from the Milky Way
08:45or whether they were coming from something much further away.
08:49This was the big question.
08:52The theorists were faced with a big problem
08:55if their origin was extragalactic.
08:57Where did the explosions of gamma rays come from?
09:01At that time, academic circles were divided into two schools of thought.
09:11Some adhered to the theory
09:14that the rays originated somewhere on the Milky Way.
09:22Others advocated the hypothesis
09:24that the emissions came from deep space,
09:27thousands of millions of light-years away.
09:34The distances from Earth proposed by these two theories
09:38varied so much that the nature of the explosions of gamma rays
09:42must have been totally different.
09:48In 1995, a meeting was held in Washington, D.C.
09:51to discuss this big question.
10:02The arguments of the Galactic Origin School
10:05were defended by Donald Lamb, from the University of Chicago,
10:09while Vodan Paczynski, from Princeton,
10:12advocated the theory of extragalactic origin.
10:15Martin Rees presided over the debate,
10:18which took place in front of an audience of 350 people.
10:26I think the arguments were quite even.
10:29In my opinion, there was not enough evidence to convince anyone.
10:33All the arguments were convincing,
10:36but I don't think any of them were enough
10:39to tilt the scale in one way or another,
10:41because it was really an unsolved issue.
10:48Could the debate between these two schools be resolved?
10:52More study was needed by the astronomers.
11:06Finally, in 1997, the stagnation ended.
11:09A new explosion of gamma rays
11:12settled the matter.
11:21The observation was made by Titus Galama,
11:24a postgraduate student at the time.
11:27We interviewed him 23 years later.
11:32Yes, 23 years ago.
11:35Basically in February, today.
11:37Yes, exactly 23 years ago.
11:40We detected the explosion of gamma rays 970228.
11:44This was on February 28, 1997.
11:49That day, Galama had reserved an optical telescope
11:53to carry out another series of observations.
11:58Then he received an alert
12:01that an explosion of gamma rays was taking place.
12:08It was a unique opportunity.
12:11Quickly, Galama directed the telescope
12:14to the place of the explosion.
12:21We had still one hour to observe
12:24the location of the 970228 explosion,
12:28and we used the time we had that night
12:31for another different gamma-ray explosion.
12:34Basically, we pointed in another direction,
12:37in the direction of this new gamma-ray outbreak.
12:42OK, look at this.
12:45This is the image of the discovery.
12:49We see here a bright object,
12:52a star-like object.
12:55All this, for example, here, are stars in our own galaxy,
12:58and this is similar, it's like the exact origin.
13:04What was seen in the image
13:07was an intergalactic space
13:10illuminated by the explosion of gamma rays.
13:15When we saw that point,
13:18I remember very clearly that we were like,
13:21OK, we did it.
13:24It was like amazing to see these little dots
13:27after 40 years or more of looking
13:30and trying to understand
13:33the origin of the gamma-ray outbreaks.
13:35We had detected that first post-luminiscence.
13:38Yes, we had the exact location
13:41in the signature of a gamma-ray outbreak.
13:45The Hubble Space Telescope
13:48provided a detailed image
13:51that allowed us to examine the area
13:54where the outbreak had occurred.
13:57It was a galaxy 8,100 million light-years away.
14:02The source of the gamma-ray outbreak
14:05was a galaxy in deep space.
14:13The implications of this were phenomenal.
14:16If such a distant event in space
14:19looked so bright from Earth,
14:22then in reality it was immeasurably brighter.
14:31This showed that gamma-ray outbreaks
14:33are explosions that generate energy
14:36on a monstrous scale.
14:47Scientists had the firm hope
14:50that one day they would understand
14:53the true nature of this monster
14:56in the depths of outer space.
14:59To this end, a project was launched in 1994.
15:02Its location is on the island of La Palma,
15:05in the Canary Islands, Spain.
15:14At an altitude of 2,200 metres,
15:17we found two unique telescopes facing each other.
15:22These are the MAGIC telescopes.
15:25They are the instruments used in an international project
15:28in which scientists from 12 countries participate.
15:32This is the MAGIC-1,
15:35the first of the two MAGIC telescopes.
15:38As you can see, it's quite a big telescope.
15:41The reflector has a diameter of 17 metres.
15:48Surprisingly, this 17-metre mirror
15:51is the telescope itself.
15:54It is a very large telescope,
15:57with a diameter of 1,000 metres.
15:59This is the telescope itself.
16:03It is segmented into a thousand smaller mirrors.
16:11All these mirrors must be coordinated
16:14so that it functions as a single telescope.
16:25The angle of each of these units
16:27is individually adjusted to make up a giant mirror.
16:39In fact, this telescope does not point directly
16:42at celestial bodies.
16:48It has some characteristics similar
16:51to those of optical telescopes,
16:54but, as you can see, there is no dome.
16:57We need the atmosphere
17:00to detect gamma rays.
17:04When gamma rays from outer space
17:07enter the Earth's atmosphere,
17:10something strange happens.
17:15Gamma rays have a lot of energy,
17:18so when they collide with the atmosphere,
17:21they break down into a cascade of electrons.
17:23At that moment,
17:26the electrons emit a faint blue light,
17:29the so-called Cherenkov light.
17:36The MAGIC telescopes,
17:39with their gigantic mirrors,
17:42capture this residual Cherenkov light
17:45to study gamma rays.
17:48The conventional way to detect gamma ray bursts
17:51was to use space telescopes
17:54to observe these phenomena directly.
17:57On the contrary,
18:00the MAGIC telescopes observe the rays indirectly,
18:03focusing on the atmosphere from the Earth's surface.
18:06In fact, it is about using any available means
18:09to study this dodgy phenomenon.
18:12The idea of studying gamma ray bursts
18:15through the observation of Cherenkov light
18:18was conceived by Masahiro Teshima
18:21from the University of Tokyo.
18:24The idea was to test something
18:27that had never been done before.
18:30The idea of measuring the bursts
18:33was to measure the energy
18:36generated by the light
18:38The idea of measuring the bursts
18:41of gamma rays originating in space
18:44did not seem possible to most scientists.
18:47But we, the physicists,
18:50if there is something that can be seen,
18:53we want to see it.
18:56So we built the MAGIC
18:59in the belief that the rays should be visible.
19:02It was a risky bet at first.
19:05But they faced a challenge.
19:08Nature dodges gamma ray bursts.
19:19How is it possible to capture something
19:22that disappears after a short period of time?
19:25The solution was to make the telescope
19:28as light as possible,
19:30in order to orient it quickly
19:33towards the source of the burst.
19:36If you look closely,
19:39you can see that the global shape of the telescope
19:42is similar to an egg.
19:45In order for the telescope
19:48to be as light and resistant as possible,
19:51we built a frame
19:54like the shell of an egg.
19:57You can see the cables
20:00and the construction of these telescopes
20:03makes them light,
20:06but durable at the same time.
20:10Let's compare the weight of these telescopes
20:13with that of the SUBARU telescope on the island of Hawaii.
20:19The SUBARU is 8.2 metres in diameter
20:22and weighs 555 tonnes.
20:25On the contrary,
20:27the MAGIC telescopes,
20:30with a diameter of 17 metres,
20:33weigh only 70 tonnes.
20:36This shows how relatively light it is.
20:41As a result,
20:44they move with this agility.
20:47The MAGIC telescopes can point
20:50to any part of the sky
20:53in less than 30 seconds.
20:56This is an amazing speed
20:59for a large telescope.
21:16The first MAGIC telescope
21:19was finished in 2004.
21:22However, at the beginning
21:25it did not detect any gamma-ray explosions.
21:30Almost all of us started to lose hope.
21:33After four or five years
21:36trying to detect gamma-ray explosions,
21:39it seemed an impossible goal.
21:42The observatory increased its performance
21:45by adding another telescope
21:48and increasing its sensitivity
21:51while Teshima and his colleagues
21:54continued with the observations.
21:57I wasn't ready to give up yet.
22:00If we improved the instruments,
22:03we could probably detect them in the end.
22:06That's what I thought.
22:12Then, on 14 January 2019,
22:1515 years after the observations began,
22:18the long-awaited day arrived.
22:29It happened at 8.57.25.
22:42In the observatory room,
22:45the alarm that alerts
22:48to the detection of a gamma-ray explosion rang.
22:56Had they finally managed
22:59to detect a gamma-ray explosion
23:02with the MAGIC telescopes?
23:05The long vigil for the monster-sideral dodge,
23:08the gamma-ray explosion,
23:11was about to bear fruit.
23:14With what face would the MAGIC telescopes
23:17of La Palma be shown?
23:27That memorable day was at the service
23:30of Midnusari Takahashi,
23:32of the University of Tokyo.
23:44The date was January 14, 2019.
23:47Takahashi began his observations
23:50at sunset.
23:53This was the third week
23:56I started working.
23:59That night, I woke up
24:02and began to carry out
24:05all the operations normally.
24:09What he could not imagine
24:12was what the universe had prepared
24:15for him two hours before his turn.
24:21The alert that suddenly popped up
24:24in the observation room announced
24:27the appearance of a gamma-ray explosion.
24:29That alert was issued by a space telescope
24:32that was constantly monitoring the cosmos
24:35in search of gamma rays.
24:38It had detected a gamma-ray explosion.
24:41It was the first time
24:44I had missed an alert,
24:47so it was quite shocking.
24:50When a gamma-ray explosion reaches Earth,
24:53the first to detect it is a space telescope.
24:56It immediately calculates its approximate location
24:59and transmits it to the stations on Earth.
25:02This data is then sent to observatories
25:05all over the world.
25:12The data on the gamma-ray explosion
25:15reached the MAGIC telescopes
25:18at 20 hours 57 minutes and 25 seconds.
25:26Immediately, the telescopes began to move
25:29to point in the direction of the explosion.
25:45At 36 seconds from the alert,
25:48the telescopes began to record data.
25:56Both telescopes pointing towards the sky
25:59began to capture the Cherenkov light.
26:04Seeing the data on the screens,
26:07Takahashi was stunned.
26:10That screen shows the results
26:13of the data analysis that is carried out in real time.
26:16At first, I was looking at this screen
26:19that controls the telescopes,
26:22but then I looked over there
26:25and I saw an extraordinary intensity.
26:28That's when I knew
26:31that this was not a normal event.
26:37This graph shows the intensity of the Cherenkov light
26:40that the telescopes captured that night.
26:44While the maximum values in the graph
26:47usually do not vary much,
26:50Takahashi saw how they did not stop rising.
26:56The yellow areas are where the Cherenkov light was observed.
27:00Gamma rays were flowing towards the ground
27:03like torrential rain.
27:06I had never seen anything like it,
27:09and I was amazed.
27:12The signal was so strong
27:15that at first I thought
27:18that something was not working well.
27:21But then I realized
27:23that something was not working well.
27:28Takahashi took a photo with his cell phone
27:31and sent it to Teshima and the other members of the project.
27:38Takahashi sent me a photo from his cell phone.
27:41When I saw it
27:44and checked the results of the online analysis,
27:47I thought,
27:50wow, this is what we are looking for.
27:54The persistence in their observations
27:57finally rewarded Teshima and his colleagues
28:00with the capture of the monster from outer space.
28:05In Japan,
28:08a member of the analysts immediately started working.
28:12The energy of the gamma rays,
28:15as derived from the Cherenkov light,
28:18was amazingly high.
28:23This graph shows the results
28:26of the energy analysis of the gamma rays
28:29reaching the Earth.
28:32Until then, scientists had observed gamma rays
28:35with lower levels of energy,
28:38to the left of the graph.
28:41But this event showed very high levels of energy,
28:44unprecedented to date.
28:47This made it clear
28:50aspects of the nature of the explosions of gamma rays
28:53unknown to us.
28:56The theory that explains the gamma rays of lower energy
28:59does not explain this type of gamma rays,
29:02which are a great discovery.
29:05For decades we had tried to confirm this without success.
29:08Confirming it is a very important step forward.
29:12The fact that the gamma rays emitted by the monsters
29:15from outer space are so energetic
29:18was a pioneering discovery.
29:24Well, then,
29:27what source could be capable of generating
29:30such a dramatic amount of energy?
29:33Astrophysicist Martin Rees
29:36has been dealing with this mystery for a long time.
29:39Each explosion of these
29:42had to imply at least something as dramatic
29:45as the destruction of a star.
29:48At least as dramatic as a supernova.
29:50And indeed, the brightness of an explosion of gamma rays
29:53was actually much brighter
29:56than that of a supernova,
29:59for just a few seconds.
30:02A supernova arises
30:05when a giant star collapses.
30:16In an instant, it emits a tremendous amount of energy.
30:19However, the phenomenon of the supernova
30:22is far from being enough
30:25to explain an explosion of gamma rays.
30:28In that sense,
30:31Rees has a theoretical explanation
30:34of the conditions that have to be given
30:37for a star to be able to release
30:40such high levels of energy when it explodes.
30:43Now, if we have a star,
30:45which was spinning very fast,
30:54and was therefore not a sphere,
30:57it was flattened
31:00because it was spinning around an axis in this way,
31:03then when the energy is released in the center,
31:07instead of the energy going up
31:10to the star,
31:12it will try to find the easiest way out.
31:18And it will come out
31:21like a jet.
31:27The calculations show
31:30that the jets are emitted at relativistic speeds,
31:33close to the speed of light.
31:43It is known that there are galaxies in space
31:46that emit jets of gamma rays from their centers.
31:52These jets are generated by black holes
31:55that emit them with monumental energy.
32:06If we think of the explosions of gamma rays
32:09as the release concentrated in a jet of light,
32:12the energy of an explosion,
32:15this would explain why its enormous energy
32:18can exceed the power of a supernova.
32:26So, the obvious conclusion.
32:29We detect an explosion of gamma rays
32:32and the jet points directly at us.
32:35Otherwise, we don't see it.
32:38A black hole appears
32:41when a giant star dies.
32:45And the result is an emission of these jets.
32:56The monstrous energy of an explosion of gamma rays
32:59is visible when we have a visual in a straight line
33:02of one of these jets.
33:08This is not the only mechanism
33:11revealed by the observation of the MAGIC telescopes.
33:18From the data analysis
33:21other details of the nature
33:24of the explosions of gamma rays also emerged.
33:38The relativistic jet collides with the surrounding matter of the star
33:41and disperses.
33:48At that moment, the electrons of the jet collide at high speed
33:51with the photons of the surrounding space.
33:56The result is the creation of new gamma rays.
34:02The creation of new gamma rays occurs in two stages.
34:07This is the mechanism that takes place
34:10in the explosions of gamma rays.
34:20For the first time in history,
34:23the MAGIC telescopes clarified the nature
34:26of this cosmic monster.
34:31When they gave me the news,
34:34I was in the seventh heaven.
34:37I looked at the observation data
34:40with great surprise and with great joy.
34:45I am very glad that we did not give up.
34:53The biggest explosions in the universe,
34:56the explosions of gamma rays,
34:59are the first and exciting cry of a newborn
35:02at the moment when black holes are created.
35:08The most energetic phenomena in the universe,
35:11the explosions of gamma rays.
35:16Most of these events happened years away
35:19in deep space.
35:22But if one of them took place near the Earth,
35:25it would be a miracle.
35:28It would be a miracle.
35:31It would be a miracle.
35:34It would be a miracle.
35:37It would be a miracle.
35:40It would be a miracle.
35:47An explosion of gamma rays could cause
35:50a widespread extinction on our planet.
35:56In fact, in Norway,
35:59evidence has been found that such an event
36:02could really have happened.
36:07Hans Nackram, a geologist at the University of Oslo,
36:10guides us to the site.
36:16Well, here we see some rocks
36:19that go from 440 to 470 million years old.
36:27More than 400 million years ago,
36:30when this layer of rock was formed,
36:33a massive extinction took place on Earth.
36:37This rock is approximately
36:40445 million years old.
36:43Below us, it is 443.
36:46That is, the transition between the Ordovician
36:49and the Silurian is approximately in this area.
36:52At this point, 80%
36:55or more of marine species
36:58went extinct.
37:01During this period,
37:04the sea was a paradise for trilobites and other living beings.
37:07However,
37:10about 440 million years ago,
37:13a massive extinction took place
37:16of the living beings that lived in the Somerian waters.
37:19These families disappeared
37:22during the period of extinction.
37:25At the same time, we have corals,
37:28coral fossils, that is,
37:31coral reefs developed during this period.
37:34This genus went extinct.
37:37However, in this case,
37:40there is no specific evidence
37:43that points to the cause of this massive extinction.
37:51In other massive extinctions,
37:54there are causes that we can see on the rocks.
37:57For example, a massive volcanism,
38:00the impact of an asteroid.
38:03But in this area, we cannot
38:05determine any of these specific causes.
38:18It is possible that the massive extinction
38:21was the work of an explosion of gamma rays.
38:24This surprising thesis has been proposed
38:27by the physicist Brian Thomas.
38:30Thomas has made a simulation
38:33of what would have happened
38:36if an explosion of gamma rays
38:39had taken place closer to Earth,
38:42about 6,000 light-years away,
38:45and those rays had descended on the planet.
38:48What I'm showing here is a map
38:51of the destruction of ozone in the Earth's atmosphere.
38:54So, the event occurs,
38:56the ozone layer begins to wear out immediately,
38:59and we see it spreading out across the globe.
39:03Although the radiation of the gamma rays
39:06would only last a dozen seconds,
39:09the ozone layer would decrease for years.
39:17So, what we see here
39:20is the global average decrease.
39:23We can see that there is a drop
39:26in the global average decrease,
39:29and then it's about ten years to recover.
39:32So, it takes about ten years
39:35to return to normal conditions.
39:38Any organism that is exposed to sunlight
39:41would be exposed to this increased ultraviolet radiation.
39:44We believe that this could have caused
39:47a massive extinction when it wiped out
39:50some of the most important organisms
39:53in the base of the tropical chain.
39:56440 million years ago,
39:59there was an explosion of gamma rays on the Milky Way.
40:10The resulting jet travelled to Earth.
40:17These ultra-energy gamma rays
40:20destroyed the ozone layer
40:23that protects the Earth.
40:27This drop in the ozone layer
40:30allowed ultraviolet radiation
40:33to reach the surface of the planet.
40:41The living beings exposed to
40:44these high levels of ultraviolet radiation
40:47went extinct.
40:50The tropical chain broke,
40:53and a massive extinction took place.
40:56It was under the premise of an explosion
40:59of gamma rays 6,000 light-years away.
41:02So, that's quite far away.
41:05If we moved closer, we'd have a much more dramatic effect,
41:08and it becomes less likely.
41:11This is not going to happen so often,
41:14but it certainly could happen at a smaller distance,
41:17and the effect would be much more dramatic.
41:20Could we reach an explosion of gamma rays
41:23at some point in the future?
41:27A star whose death is predicted to happen soon
41:30is Betelgeuse,
41:33in the constellation of Orion.
41:36Recent changes have been observed
41:39in the luminosity of this star.
41:48Betelgeuse is 640 light-years away from Earth.
41:51Is our planet in danger then?
41:53As far as whether or not an explosion of gamma rays will occur,
41:56we don't know.
41:59It's not a really fast-spinning star,
42:02and probably, for an explosion of gamma rays to occur,
42:05a star has to be spinning very fast.
42:08So, it could or could not produce an explosion of gamma rays.
42:11There is, on the other hand, another object in the cosmos
42:14that could possibly generate an explosion of gamma rays.
42:16We're talking about a star in the constellation of Sagittarius,
42:197,500 light-years away from Earth.
42:22Thomas believes that the greatest danger is posed by this star,
42:25known as WR104.
42:28It's a particular kind of star.
42:31In this case, we see this spiral pattern.
42:34As the star spins,
42:37it's a particular kind of star.
42:40And, in this case,
42:42we see this spiral pattern.
42:45As the star spins, it emits gas and dust
42:48as it gets closer to the end of its life.
42:51It's kind of uncertain,
42:54but maybe this one points more directly to us.
42:57It's a better candidate than any of the other stars we know.
43:02By a sequence of photographs,
43:05it was determined that the star is directly above us.
43:08In other words,
43:10there's a possibility that an explosion of gamma rays
43:13could point directly to Earth.
43:18It's a little bit farther away
43:21than the cases we've studied in connection with the Ordovician,
43:24so it might not have such a dramatic effect,
43:27but there's a lot of unknowns here.
43:30We might see some extinction associated with this.
43:36Where in the vastness of space
43:38do the monsters lurk?
43:46Scientists are still studying the explosions of gamma rays.
44:01Adam Goldstein is the physicist
44:04who won the nickname Gamma Man.
44:06When he saw an explosion of gamma rays
44:09while he was still a postgraduate student,
44:12his good fortune with discoveries continues.
44:16So this happened pretty early in the morning.
44:19It was shortly before eight in the morning
44:22at our local time.
44:25So I was still in my pajamas,
44:28and the alarm went off.
44:31On August 17, 2017,
44:33Goldstein was on duty
44:36as a member of the Fermi Space Telescope
44:39of gamma rays surveillance team.
44:42In our data, the GBM data,
44:45it was, you know, like a short GRB,
44:48nothing very special about it.
44:51But a few minutes later,
44:54a colleague of ours who works in gravitational waves
44:57sent us an email saying,
44:59wake up, this has its equivalent gravitational wave.
45:05At the same time that the explosion of gamma rays was detected,
45:09gravitational waves were also recorded
45:12in a Louisiana observatory.
45:17Gravitational waves are disturbances in spacetime
45:20foreseen by Einstein in his Theory of General Relativity.
45:25They are generated when large celestial bodies
45:27experience a violent movement.
45:36In 2015, the existence of these waves was demonstrated for the first time.
45:44However, the gravitational waves
45:47and the explosions of gamma rays
45:50had never been detected at the same time.
45:53These observations happened virtually simultaneously
45:57and also came from the same direction.
46:05I couldn't believe it.
46:08It was unbelievable.
46:11It took me a while to digest it.
46:16The analysis of the data of the gravitational wave
46:19revealed that what had happened
46:22was the fusion of two neutron stars,
46:25a cataclysmic event.
46:30The jets that were created in this event
46:33produced an explosion of gamma rays.
46:40These observations showed that the explosions of gamma rays
46:44could be caused by other mechanisms,
46:47as well as by a supernova explosion
46:49or a giant star, as we have already mentioned.
46:56Well, that's how science works.
46:59You answer some questions,
47:02but then the door opens to more questions, right?
47:05And you never have enough.
47:08You always want more observations.
47:13On the island of La Palma,
47:15one of the leading places in the world for astronomical observation,
47:19a new project is being prepared.
47:24It is a large telescope,
47:2723 metres in diameter.
47:31Its aim is to penetrate deeper into space
47:34and expand the search for the explosions of gamma rays.
47:42This next generation of telescopes
47:45will join the HESS telescopes in Namibia,
47:48in southern Africa.
47:58The new telescope moves at a higher speed,
48:01making it possible to observe an event
48:04less than 20 seconds away from its detection.
48:07In 2018, the first of these new telescopes was completed
48:11and is now operational.
48:16Four of these large telescopes
48:19will be installed by 2023.
48:22Other telescopes are planned for Chile,
48:25in South America.
48:37At present, the astronomy of the explosions of gamma rays
48:40is being studied enthusiastically.
48:47With the MAGIC telescopes,
48:50we can see up to 7,000 light years in space.
48:53With this new telescope,
48:56we can see up to 12,000 light years.
48:59This is a great advance.
49:02The visible universe will multiply by more than 10.
49:04The gamma rays will be visible in the universe 10 times more.
49:07We could still discover celestial bodies,
49:10monsters that we have not yet seen.
49:13I am very excited about this.
49:24The further we probe into space,
49:27the deeper we will delve into the past of the universe.
49:30The explosions of gamma rays are an important key
49:32and that is why we want to study many of these events
49:35and this is being made possible with the new space telescopes.
49:45Half a century of scientific research
49:48has culminated in the capture of this monster of the universe,
49:51the explosions of gamma rays.
49:58But we have only understood a small part of the whole.
50:01When the continued observation of the explosions of gamma rays
50:04allows us to gain a broader view of the phenomenon,
50:07we will get to know the universe in a completely new way.
50:30NASA Jet Propulsion Laboratory, California Institute of Technology