00:00:08
Far out in space, in the center of a seething
cosmic maelstrom.
00:00:18
Extreme heat. High velocities.
00:00:26
Atoms tear, and space literally buckles.
00:00:39
Photons fly out across the universe, energized
to the limits found in nature.
00:00:50
Billions of years later, they enter the detectors
of spacecraft stationed above our atmosphere.
00:01:01
Our ability to record them is part of a new
age of high-energy astronomy, and a new age
00:01:10
of insights into nature at its most extreme.
00:01:15
What can we learn by witnessing the violent
birth of a black hole?
00:01:47
There have been times when our understanding
of the universe has reached a standstill,
00:01:53
when our grasp of the workings of time and
space, the nature of matter and energy, do
00:02:00
not fully square with what we observe.
00:02:06
In those times, opposing world views cannot
be resolved.
00:02:14
So it was in the spring of 1920, when astronomers
debated the scale of the universe.
00:02:25
The scene was the National Academy of Sciences
in Washington, DC.
00:02:32
On one side was the astronomer Harlow Shapley,
known for his groundbreaking work on the size
00:02:37
of our galaxy and the position of the sun
within it.
00:02:44
Shapley described the galaxy as an island
universe. As large as his measurements suggested
00:02:51
it was, it might indeed be all there is.
00:02:57
That included mysterious fuzzy shapes known
as spiral nebulae. He argued they were merely
00:03:08
On the opposing side, Heber Curtis argued
that some nebulae were also island universes.
00:03:15
That idea was not new.
00:03:18
165 years earlier, the German philosopher
Emmanuel Kant described the nebulae as galaxies
00:03:26
unto themselves.
00:03:27
“It is noted only in the Milky Way,” he
said,” that whitish clouds are seen; several
00:03:34
patches of similar aspect shine with faint
light here and there throughout the aether,
00:03:40
and if the telescope is turned upon any of
these it confronts us with a tight mass of
00:03:49
It took a new generation of powerful telescopes
for astronomers to finally measure the distance
00:03:54
to those mysterious objects.
00:03:59
Within a few years after the Great Debate,
Edwin Hubble reported data showing the spiral
00:04:05
nebulae lay far beyond the Milky Way. That
led to our current understanding of a universe
00:04:12
billions of light years across, filled with
galaxies, and expanding rapidly.
00:04:22
In the years since, essential details about
this dynamic universe have stubbornly resisted
00:04:28
our inquiries. The deeper we dug into the
nature of matter and energy, the more obscure
00:04:37
they seemed to become.
00:04:41
One of the deepest mysteries of all emerged
in the 1960s.
00:04:52
That was a time when nations were rapidly
expanding and testing their nuclear arsenals.
00:05:00
In 1963, the United States, Soviet Union,
and the United Kingdom signed the Limited
00:05:07
Test Ban Treaty, which prohibited above-ground
nuclear testing.
00:05:15
To verify compliance, the United States launched
six pairs of satellites known as Vela, from
00:05:22
the Spanish verb to watch over or keep vigil.
They were designed to record a distinctive
00:05:31
signal of nuclear explosions, called gamma
rays.
00:05:39
Gamma rays are an ultra high-energy form of
electromagnetic radiation, a term used to
00:05:45
describe particles called photons that travel
out from an energy source.
00:05:55
The lowest-energy form, radio, has a wavelength
of up to 300 meters. Though we can’t see
00:06:04
them, they are produced naturally, for example,
in flashes of lightning.
00:06:14
Our eyes are tuned to capture much smaller
visible wavelengths down to 400 nanometers,
00:06:20
or 400 billionths of a meter.
00:06:26
Carrying even more energy, ultraviolet light
has a wavelength as short as 10 nanometers.
показать еще
русский▼
English
