Messengers of Time and Space Fulldome show

本站添加: 2026-05-12

[00:00:21]Among the billions of stars of the Milky Way galaxy, a small blue ocean world orbits a single sun. And rising from that world's vast Pacific Ocean, the island of Hawaii and its high peak, Maaya, a mountain of profound significance to native Hawaiians and also to astronomy.

[00:00:57]Stable air flows from the ocean across the mountain, creating exceptionally dry and clear skies. As the sun sets, the Gemini North telescope opens to the heavens, ready to capture light from across the cosmos.

[00:01:30]Astronomy has come a long way since the days of the lone astronomer peering through a telescope. The Gemini North telescope is controlled and monitored from a control room in the nearby coastal town of Hilo.

[00:01:49]Every time I come in for a night shift, I feel pumped. I even get butterflies in my stomach. At most telescopes, you just follow the plan. And okay, most nights it's like that here, too. But with Gemini, there's always a chance you'll get to observe something completely unexpected and just mind-blowing.

[00:02:18]Detailed observing plans are made in advance with telescope time allocated to different targets. But the universe is dynamic and unpredictable. And at Gemini, everything can change in a moment if something goes bump in the night.

[00:02:43]A revolution is unfolding in astronomy, driven by entirely new ways of understanding the cosmos. The Gemini North telescope and its southern twin in Chile are forerunners in a collaborative network that includes some of the most ambitious and innovative physics research facilities on Earth.

[00:03:10][Music] Looking up at the dark night sky, the universe appears calm and tranquil. We see the same stars as our ancestors, their longtraveled starlight delivering the message of their continued existence.

[00:03:41]Yet we also know the universe to be an active place where dynamic events can be watched unfolding even on human time scales. Some of the greatest discoveries in astronomy came from studying such phenomena. Astronomers call them time domain events.

[00:04:06]The most obvious time domain event is the moon's changing appearance. Orbiting the Earth each month, it is lit from different angles by the sun. By charting the moon's movements, early astronomers were able to predict its phases and also those rare occasions when the moon passes directly between the Earth and Sun. A total solar eclipse is an awesome spectacle. With the face of the sun obscured, its dynamic outer atmosphere is visible as are the distant [Music] stars. In 1919, an eclipse inspired an expedition to West Africa, where stormy skies cleared just in time. Photographing stars near the sun during totality helped to confirm Einstein's theory of general relativity. As predicted, the view of the stars was distorted as their light passed through the sun's gravitational field.

[00:05:27]Early astronomers also charted the slow movements of our solar systems planets as seen from the changing viewpoint of our orbiting Earth.

[00:05:40]The complex but predictable loops and progression of the planet's positions against the background stars allowed astronomers to determine the structure of the solar system and our place within it. Later, the more extreme orbits of periodic comets were used to confirm Newton's theory of gravitation.

[00:06:07]These icy visitors make only fleeting visits from the dark outer solar system, shedding tales of dust and gas in the sun's warmth. The predicted reappearance of Hal's comet in 1758 confirmed the theory's ability to explain their motion.

[00:06:31]But the most dramatic time domain events visible to early astronomers were stellar explosions. These are however rare. Only a handful were recorded before the invention of the telescope. In China, astronomers noted them as guest stars.

[00:06:52]Records from 1054 describe one particular guest star that grew so bright that it was visible in broad daylight. We now understand these events as supernovas, the explosive death throws of massive stars.

[00:07:19]Modern telescopes reveal the aftermath of these violent events. The outer layers of the dying star are ejected across vast distances forming intricate clouds of gas and dust called nebula. These ethereal structures are enriched by rare elements forged in the ferocity of the explosion.

[00:07:45]carbon, oxygen, and iron, the building blocks of life. The remnant of the 1054 supernova is known as the Crab Nebula, a popular target for backyard telescopes. Buried deep within the nebula, only the core of the original star remains, now a neutron star.

[00:08:14]crushed to incredible densities by its own gravity. Just one tablespoon would weigh as much as a cruise [Music] ship. Studying time domain events allowed astronomers of the past to revolutionize our understanding of the cosmos. But even today, the universe brings us unexpected surprises. The Gemini telescopes are at the forefront of studying such events. So, you have a plan for the night, but you never know when you might get an alert. That means another observatory has spotted something weird. Gemini can react super fast, so we're often the first to follow up on these things.

[00:09:16]The solar system is peppered with small bodies of rock and ice. Telescopes pick them up as tiny dots moving against the background stars. But some aren't like the others. On October 19th, 2017, astronomers using the Pan Star Survey Telescope on Maui's Halakala noticed a small object moving against the background stars. But they realized something was strange. Given its path, it was going fast, very fast.

[00:10:02]They sent out an alert and Gemini stopped what it was doing to focus on the dot as did dozens of other telescopes. Asteroids and comets orbit the sun. But astronomers quickly realized that this new object was not held by the sun's gravity. Rather, it was an interstellar visitor passing through the solar system.

[00:10:31]Nothing like this had ever been seen before, and there was only a short time to make observations before it departed back into deep space. Karen Meech, an astronomer at the University of Hawaii's Institute for Astronomy, was one of the first to study the object. She noticed something else unusual. It was winking.

[00:10:56]There was a brightness range of a factor of 10 to 1, which was remarkable because we'd never seen anything in the solar system with a brightness range this big. Brightness variations of small objects like asteroids offer clues to their surface composition, shape, and rotation. As they spin, they reflect different amounts of light.

[00:11:22]Taken at face value, this implies that one side is about 10 times longer than the other side. The interstellar visitor was calculated to be about a/4 mile long. Later, it would be given a Hawaiian name to honor the place where it was discovered. The name Omua Mua carries the meaning a messenger that reaches out from the distant past. Astronomers had just 3 months to observe Omua Mua before it was lost forever in the darkness of space. It will never return.

[00:12:39]The ability to react quickly to unusual time domain events is key to being able to study unusual fleeting objects.

[00:12:49]But first, you have to spot them. High on the mountain of Seropon in Chile, the Gemini South telescope has a new neighbor, an entirely new type of telescope, the US National Science Foundation and Department of Energy's Vera C. Ruben Observatory.

[00:13:14]Reuben Observatory is named in honor of the American astronomer who laid the foundation for key areas of modern astronomy. Most notably by providing the first convincing evidence of the existence of dark matter. Dark matter remains one of the greatest mysteries in astronomy. We don't know what it is, but we see the effects of its gravity in the lens-like distortion of light from distant galaxies and in the motions of their stars. The Reuben telescope has a wide eye and nimble grace.

[00:14:11]In just one glance, it captures light from an area the size of 45 full moons, giving it the largest field of view of any telescope of its size. By directing light into the world's largest astronomical camera, Reuben is recording the cosmos in incredible detail.

[00:14:34]One single image would fill 400 Ultra HD TVs. Despite its size, Reuben is remarkably agile, rotating quickly enough to capture a new image every 30 seconds. At this speed, it can survey the constellation of Orion in just 21 minutes and the whole sky every two or three nights. By repeatedly scanning the sky over a 10-year period, Reuben is slowly creating the ultimate time-lapse movie where cosmic time domain events are the star actors.

[00:15:29]A powerful data center compares the rapidly incoming images, spotting even the tiniest of changes from earlier nights. This process generates a flood of new discoveries from asteroids and comets to supernova explosions and events stretching to the extremes of the observable universe. Where such events were once rare and startling for astronomers, Reuben can pick out as many as 10 million every night. This changes [Music] everything. The sheer number of new discoveries is overwhelming.

[00:16:16]Sophisticated computer systems are required to sort out the mundane from the unique and select the best targets for other observatories around the world to investigate. As Reuben and the global network of observatories scurry to capture light from the dynamic sky, other facilities offer an entirely different perspective on the cosmos.

[00:16:45]Astronomers of the past could detect exploding stars, planets, and galaxies. Because these objects either emit or reflect light toward us, light acts as an untiring messenger, carrying information across the vast void of space. Beyond the colors we can see, light exists in other forms which carry different information. Together these make up the electromagnetic spectrum which includes high energergy gamma rays, visible light, infrared, microwaves and low energy radio waves.

[00:17:36]But we can now go so much further by going beyond light to welcome previously unseen messengers with new stories to tell. Messengers like cosmic rays, nutrinos, and gravitational waves. These travelers are invisible and can't be seen. However, they do sometimes reveal their presence. The beautiful auroras of the northern and southern skies have entranced sky watchers for millennia.

[00:18:27]We now know their light is created when cosmic rays from storms on the sun collide with the gases of our atmosphere. Cosmic rays are a mix of particles flung at high speeds from stars, supernovas, and the discs surrounding black holes. They hurdle through space at close to the speed of light. In recent years, rare detections of ultra high energy cosmic rays have also revealed previously unknown sources which have yet to be explained. Cosmic rays often arrive accompanied by more ghostly companions, nutrinos, which pass quietly, not only through our atmosphere, but through our bodies and the earth itself.

[00:19:31]Nutrinos move through matter almost entirely unimpeded. Unlike light, they can escape the stars core directly, bringing information from deep inside our sun and also early warning of distant supernovas.

[00:19:54]Slippery as they may be, nutrinos can be detected within vast subterranean tanks of special fluids. Their rare interactions are revealed by tiny flashes of light.

[00:20:21]But even more elusive than nutrinos are the messages carried across the cosmos in the subtle rippling of the very fabric of the universe. Located in remote regions of Louisiana and Washington state, the LIGO Observatory's twin detectors are part of a global network of instruments that detect gravitational waves.

[00:20:50]Gravitational waves are predicted by Einstein's general theory of relativity. Einstein showed that gravity is caused by massive objects like Earth distorting spaceime, a fourdimensional continuum of space and time.

[00:21:08]Gravitational waves are formed when moving objects create distortions in spaceime that ripple outward through the universe at the speed of light. But how do you detect these ripples? The answer is in how they affect the path of light.

[00:21:34]Only the most powerful gravitational waves can be detected and even then the measured effect is [Music] tiny. To achieve this, LIGO and similar observatories must create two perfectly matched beams of laser light.

[00:21:56]LIGO beams its lasers through a vacuum down two tunnels set at right angles to each other. Each tunnel is 4 km long, about 2 and 1/2 miles. But even that's not long enough to detect an effect. The light must be reflected some 300 times back and forth along each tunnel.

[00:22:37]If a gravitational wave passes, the space through which the beams travel is distorted, causing the beams to travel slightly different distances. So, they're no longer perfectly matched.

[00:22:51]Even after magnifying the effect by reflecting the beams hundreds of times, the difference is smaller than the nucleus of an atom, but it can be enough to make a detection. On August 17th, 2017, LIGO detected a strong gravitational wave event confirmed by another detector in Italy.

[00:23:23]Astronomers around the globe scrambled to locate the culprit and found a rapidly fading light source within a distant nondescript galaxy known only as NGC 4993.

[00:23:43]An event of this magnitude could only have been caused by the collision of exceptionally massive objects. In this case, the collision of two neutron stars, a rare phenomenon known as a kilonova.

[00:24:27]Kilanovas had long been predicted but never before seen. Dozens of telescopes including Gemini South soar and the Victor MB Blanco telescope worked together to observe the Kilanova's changing light.

[00:24:48]Light from different parts of the spectrum brought different information. Gamma rays, ultraviolet, x-rays, and radio waves. But perhaps the most important story was that told by infrared light.

[00:25:06]Here, astronomers found evidence of the creation of gold and platinum. An extraordinary discovery that finally solved the mystery of how these heavy elements came to exist in the [Music] universe. Without LIGO, the Kilonova would have passed unnoticed and without the quick response of telescopes like Gemini, its significance would have remained unknown.

[00:25:40]It really feels like we're at the brink of something. The question isn't if we'll make a world changing discovery, but when or even how often.

[00:25:56]It is a privilege to be part of this huge community of astronomers, data scientists, engineers, and everyone else who work to make this possible. Time domain astronomy is coming of age. We are living through a profound transformation in how we study the cosmos. From our small blue planet, we witness massive cosmic collisions, track interstellar visitors, and chronicle the history of the universe.

[00:26:39]This revolution in astronomy is revealing once hidden wonders and uncovering entirely new mysteries. What new discoveries are waiting to be made? We need only to listen to the whispering messengers of time and space.

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