Mysteries of the Universe - 8 Things Modern Astronomers are still Puzzled By | S02E59

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Good e everybody, and welcome to
the Astronomy Daily podcast. My name is

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Tim Gibbs and I will be your
host for today. The podcast will be

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now as usual, I have in
a studio with me Halle, my AI

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digital assistant and reporter. But before
we go over to Halle for the second

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half of the show, I'd like
to talk a little bit about a couple

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of things that people have sent to
me. One is a listical, if

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you like, of the eight things
that modern astronomers still are puzzled by.

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And I think it's worth reminding ourselves
that there are things out there that we

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really have no idea what's going on. So on with the list, and

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it's in no particular order. First
off, what is dark energy? As

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we all know, astronomer Edwin Hubble
discovered the universe is not static, but

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rather expanding in the nineteen twenties.
This discovery puzzled scientists for a long time,

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who thought that the gravity of matter
would gradually slow the universe's expansion or

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even cause it to contract. While
dark energy is thought to make up approximately

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seventy three percent of the universe,
the force remains elusive and yet and has

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yet to be directly detected dark energy
might never reveal its nature. Number two

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How hot is dark matter? Astronomers
explain this curious phenomenon with this with an

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invisible mass that became known as dark
matter. Even though it cannot be seen,

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dark matter has mass, so researches
infer its presence based on the gravitation

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gravitational pull it exerts on regular matter. Dark matter is thought to make up

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about twenty three percent of the universe, while only four percent of the universe

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is composed of regular matter, which
includes stars, planets, human beings,

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cats and dogs, etc. Number
three Where are the missing baryons? If

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dark matter and dark energy combined to
make up roughly ninety five percent of the

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universe, regular matter makes up about
five percent of the cosmos, Yet more

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than half of this regular matter is
missing. Nobody knows where it is.

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Number four How do stars explode?
When a massive star runs out of fuel

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and dyes, it triggers a spectacular
explosion called a supernova that can briefly shine

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more brightly than the entire galaxy.
Over the years, scientists have studied supernovas

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and recreated them using sophisticated computer models. But how these giant explosions occur is

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still an enduring astronomical puzzle. Number
five, What reionize the unit? The

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broadly accepted theory for the origin and
evolution of the universe is the Big Bang

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model, which states that the cosmos
began as an incredibly hot, dense roughly

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point thirteen point seven billion years ago. A dynamic phase in the history of

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the early universe approximately thirteen billions years
ago, is known as the age of

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reionization. During this period, the
fog of hydrogen gas in the early universe

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was clearing and becoming transparent to the
ultraviolet light for the first time. Number

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six, what's the source of the
most energetic cosmic rays? The source of

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cosmic rays has long perplexed astronomers,
who have spent a century investigating the origin

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of these energetic particles. Cosmic rays
are charged subatomic particles, predominantly protons,

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electrons, and the charged nuclei of
basic elements. The flow into our Solar

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System from deep deep in outer space
as comic as cosmic rays flow into the

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Solar System from elsewhere in the galaxy. Their paths are bent by the magnetic

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fields of the Sun and the Earth. Next up, why is the Solar

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system so bizarre? As astronomers and
space observers discover alien planets around around other

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stars, researchers have been keen to
understand the unique chara characteristics of our Solar

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system. Now last, but certainly
not least, why is the Sun's corona

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so hot? The Sun's ultra hot
outer atmosphere is called the corona and is

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typically heated as temperatures raining from nine
hundred thousand degrees fahrenheit that's five hundred thousand

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degrees celsius celsius to ten point eight
million degrees fahrenheit six million degrees see.

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For the best part of a century, solar physicists have been mystified by the

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Sun's ability to reheat its the encircling, wispy crown of light that emerges from

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the glare during a solo eclipse.
The second article I was sent has a

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headline that is basically grabbing its Pluto's
almost twin dwarf planet Eris is surprisingly squishy.

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There you go, I told you
it would grab you. New models

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show that Eris is behaving less like
a solid, rocky world and more like

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soft cheese. Yeah, I know. Close to eighteen years ago, astronomers

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spotted a miniature icy world named Eris, billions of miles beyond Neptune. But

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unlike its dwarf planet cousin Pluto,
which New Horizons promoted to a rich,

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dynamic world after its visit in twenty
fifteen, Eris has not had any robotic

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visitors. It is so far away
from Earth, in fact, that it

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shows up in observations just as a
single pixel of light. All in all,

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scientists know very little about what happens
on Eris. Now over to you,

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Hally, and I hope you've got
a decent joke for us this week

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the Astronomy Daily podcast. Hi Tim, it's great to be back with you,

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and yes, I have a couple
of great jokes. But first let's

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have some news stories from the Astronomy
Daily newsletter. A new theory suggests that

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the unification between quantum physics and general
relativity has eluded scientists for one hundred years

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because huge are fluctuations in space and
time mean that gravity won't play by quantum

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rules. Since the early twentieth century, two revolutionary theories have defined our fundamental

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understanding of the physics that governs the
universe. Quantum physics describes the physics of

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the small at scales tinier than the
atom, telling us how fundamental particles like

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electrons and photons interact and are governed. General relativity, on the other hand,

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describes the universe at tremendous scales,
telling us how planets move around stars,

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how stars can die and collapse to
birth black holes, and how galaxies

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cluster together to build the largest structures
in the cosmos. Since their development,

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these two theories have grown more robust
and have bolstered science. With their tremendous

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success. Quantum mechanics has shown that
the quantum world is replete with counterintuitive aspects,

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like the existence of systems simultaneously in
contradictory states, or particles instantly influencing

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each other even at opposite ends of
the universe. General relativity, meanwhile,

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has revealed that the very fabric of
space time is shaped by the matter sitting

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upon it, and that violent interactions
between bodies of great mass can create ripples

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in space time known as gravitational waves, that can travel for billions of light

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years to wash over Earth. Yet
there is a problem, a dark cloud

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that hangs over these disciplines, as
these two pillars of physics are perfected,

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scientists are still unable to bridge the
gulf between them. The two pillars of

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modern physics are inconsistent with each other, which means that there is a fundamental

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contradiction which lies in the very foundation
of our laws of nature. University College

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London UCL professor Jonathan Oppenheim said.
Oppenheim is the pioneer of a new and

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radical theory that could finally bring together
these two concepts, a reconciliation that has

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defied the greatest scientific minds for over
one hundred years. Previously, uniting general

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relativity with quantum physics has meant taking
spacetime, the three dimensions of space,

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and the one dimension of time unified
as a single four D entity that is

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at the foundation of general relativity,
and breaking it down into discrete units or

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quanta. This requires spacetime to be
a passive stage on which that a action

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of the universe plays out. However, general relativity hinges on space time not

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being a static stage, but rather
a dynamic player in the universe's cosmic ballet,

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shaped by the presence of matter and
energy, and subsequently telling matter and

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energy how to move via the curvature
and gravity that arises from it. Oppenheim's

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idea of e waving space time time
is based upon asking why gravity should have

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a quantum nature like that which has
been discovered for the universe's other fundamental forces,

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electromagnetism and the strong and weak nuclear
forces. Gravity, he argues,

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isn't like these other forces. After
all, it is the only one of

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the four that can define the very
geometry of space time, and the fields

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of quantum physics evolve upon this geometry. We feel gravity because matter causes space

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time to bend. Time flows at
unequal rates at different locations, Oppenheim writes

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in a paper discussing his theory published
in the journal Physical Review X the rate

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at which time flows and the causal
structure the fact that because always precedes effect

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it provides may be required to have
a classical description in order for quantum theory

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to be well formulated. That means, according to his theory, termed it

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a post quantum theory of classical gravity, that space time and thus gravity don't

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have quantum description. That's thanks to
random fluctuations in space time, which cause

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changes in the flow of time,
thus breaking the concept of predictability. NASA

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marks the twenty fifth anniversary of the
ISS with a live event on December sixth.

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The ISS operational since nineteen ninety eight, has been key to space research

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and exploration, hosting two hundred and
seventy three astronauts and over three thousand,

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three hundred research projects. NASA is
celebrating the twenty fifth anniversary of International Space

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Station operations during a live conversation with
crew aboard the Microgravity Laboratory for the benefit

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of humanity. Space Station Program Manager
DOT On December sixth, nineteen ninety eight,

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the first two elements of the orbital
outpost, Unity and Zaria were attached

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by crew members of Space Shuttle Endeavours
STS eighty eight mission. Cabana was the

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commander of the mission and the first
American to enter the space station. Through

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this global endeavour, Astronauts have continuously
lived and worked aboard the space station for

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more than twenty three years, testing
technologies, performing science, and developing the

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skills needed to explore farther from Earth. It has been visited by two hundred

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and seventy three people from twenty one
countries. More than three thousand, three

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hundred research and educational investigations have been
conducted on station from one hundred and eight

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countries and areas. Many of these
research and technology investigations benefit people on Earth,

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and many lay the groundwork for future
commercial destinations in low Earth orbit and

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exploration farther into the Solar System.
Together with Artemis missions to the Moon,

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these proving grounds will help prepare NASA
for future human exploration of Mars. The

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Astronomy Daily Podcast and now some excellent
jokes for you. The most scientific pet

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the lab? What is the cuddliest
particle known to science? The hugs boson.

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Thanks for listening, everybody, and
see you next week for another episode.

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Don't forget. You can get all
our episodes from space Nuts dioe,

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and you can join in the conversation
on our Space Nuts podcast group on Facebook.

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Bye The Astronomy Daily Podcast.