Gorgeous Photos of California's Super Bloom | Reader's Digest

Gorgeous Photos of California's Super Bloom | Reader's Digest

Microsoft Word - TheModernView.doc - TheModernView.pdf

Microsoft Word - TheModernView.doc - TheModernView.pdf



In the standard model, there are only 12 fundamental particles of matter,
together with another one called the Higgs boson.
The electron is perhaps the most famous of all 12 particles.
It has two heavier cousins, the muon and the tau.
Then, each one of these has a companion neutrino,
like Don Quixote and Sancho Panza.
So an electron neutrino, a muon neutrino, and a tau neutrino,
making for a group of six particles called leptons--
from the Greek for light weight.
The other six particles are known as quarks.
Of the six quarks, the most important are
called the up and down quarks, which make up particles
like the proton and the neutron.
So, according to modern particle physics,
everything that exists in the universe--
every kind of matter or material--
is made of these 12 particles.

Microsoft Word - HistoryOfTheAtomIIITheBohrModel.doc - HistoryOfTheAtomIIITheBohrModel.pdf

Microsoft Word - HistoryOfTheAtomIIITheBohrModel.doc - HistoryOfTheAtomIIITheBohrModel.pdf

Albert Einstein published a different paper,
which is the one that would give him a Nobel prize in 1921.
In this paper, he proposed something quite revolutionary--
that light can be a wave, as people had known for a long time,
but it could also be interpreted as being made
of little bullets, called "photons."

Microsoft Word - HistoryOfTheAtomIIThompsonToRutherford.doc - HistoryOfTheAtomIIThompsonToRutherford.pdf

Microsoft Word - HistoryOfTheAtomIIThompsonToRutherford.doc - 

HistoryOfTheAtomIIThompsonToRutherford.pdf



Meanwhile, in France, Pierre and Marie Curie
were investigating the kinds of radiation
that emanated from different chemicals and realized
that there were three different kinds of radiation, which were then called
alpha, beta, and gamma particles.
Together, with the x-rays, they made for a very bizarre quartet of stuff
coming out of matter.

  

Microsoft Word - HistoryOfTheAtomIGreeksToDalton.doc - HistoryOfTheAtomIGreeksToDalton.pdf

Microsoft Word - HistoryOfTheAtomIGreeksToDalton.doc - HistoryOfTheAtomIGreeksToDalton.pdf



In the case of modern atoms, the force that binds them together
is electricity.

For example, water is made of a combination of two atoms of hydrogen
and one atom of oxygen, the famous H2O formula.
The amazing diversity of materials that we see in nature
comes from this incredible ability that atoms have to combine with one another
to create different kinds of molecules.
From very simple-- like water--
to incredibly complex ones--like a protein, which can have millions of atoms.

Microsoft Word - WhatIsMatter.doc - WhatIsMatter.pdf

Microsoft Word - WhatIsMatter.doc - WhatIsMatter.pdf

 What is the world and everything in it made

of? Galaxies, stars, planets, people, rocks, where did all

this stuff come from? How can we

know? These are the fundamental questions that we will study in the next two weeks. As we

investigate the material composition of the world, we'll find very deep clues about the nature of

reality and what we can and cannot

know about it.

Everyone wonders at some point in life about the origin of all things. This rock, for example,

where did it come from? What is it made of? Why is it so different from a living thing? It's

amazing to think that the material composition of th

e world was actually the first question asked

in philosophy. Thales of Miletus, in about 650 BCE, changed the way people thought about the

world. Instead of saying that God or different gods made everything in nature, he tried to

understand nature from wit

hin nature, offering rational answers to describe the physical nature of

reality.

New Physics Beyond The Higgs? : 13.7: Cosmos And Culture : NPR

New Physics Beyond The Higgs? : 13.7: Cosmos And Culture : NPR

 Late last year, when most people were getting ready for the holidays, physicists at the Large Hadron Collider (LHC) machine at CERN,
the European Organization for Nuclear Research, made a startling
announcement: Their two massive detectors had identified a small bump in
the data with an energy level of about 750 GeV.

 This level is about six times larger than the energy associated with the
Higgs particle. (To go from energy to mass divide the energy by the
square of the speed of light.) For comparison, the mass of a proton, the
particle that makes the nuclei of all atoms in nature, is about 1 GeV.
The Higgs is heavy — and this new bump, if associated with a new
particle, would be really heavy.

 At the more abstract, a new physics event at energies six times higher
than where the Higgs was found would mean that we are edging a bit
closer to the Big Bang, the event that marks the origin of the universe.
There is a huge gap in energy between the Higgs and the Big Bang, of
course, but getting new data at higher energies can clarify how to move
closer. This kind of fundamental physics has a very noble heritage, as
it traces its origins to the beginnings of Western philosophy and even
beyond — to questions related to our origins. If we picture creation as a
puzzle, every new piece we discover helps us understand our origins a
little better. The new bump may not give us a final answer (it's not
clear we can ever get there), but it'd certainly make the picture
clearer.

Game Of Quarks: A Guide For The Perplexed : 13.7: Cosmos And Culture : NPR

Game Of Quarks: A Guide For The Perplexed : 13.7: Cosmos And Culture : NPR

 In total, six quarks are enough to explain all hadrons found so far: up,
down, charm, strange, bottom, top. For example, a proton is made of two
up quarks and a down quark. We can represent a proton as (uud). Quarks
are bound together in the proton by particles called gluons (yes, they
glue them together). A neutron is made of the combination (udd). You can
play the same game with the other hadrons, which come in two types:
baryons (three quarks, like proton and neutron) and mesons (made of a
quark and an anti-quark). An anti-quark is like the original quark but
with opposite electric charge.

Pushing The Frontiers Of High-Energy Physics Links Humanity : 13.7: Cosmos And Culture : NPR

Pushing The Frontiers Of High-Energy Physics Links Humanity : 13.7: Cosmos And Culture : NPR

 CERN has just finished the first run of the upgraded LHC, reaching
energies that almost doubled those of the previous runs, the ones that
found the Higgs. The machine works by colliding protons against protons
head-on, after accelerating them clockwise and counterclockwise to
speeds approaching the speed of light. The particles fly around a
17-mile circular tunnel, buried about 300 ft. underground. At some
spots, within devices called detectors, the particles are made to
collide with one another. A detector is essentially an amazingly
sensitive camera, capable of recording the trajectories of the particles
that fly off from the collision point.

Enough Already With This 'Theory Of Everything' : 13.7: Cosmos And Culture : NPR

Enough Already With This 'Theory Of Everything' : 13.7: Cosmos And Culture : NPR



However, even if we are successful in building a unified theory of
the known four forces (a difficult proposition to believe in these days,
given the lack of observational support after four decades), it will
only be a temporary and incomplete unification, never a TOE or "final"
theory.

Science, even at its most fundamental level, is an ongoing process of discovery that feeds on our never having all the answers.

Search For A Final Theory: A Holy Grail? : 13.7: Cosmos And Culture : NPR

Search For A Final Theory: A Holy Grail? : 13.7: Cosmos And Culture : NPR

 The goal of elementary particle physics is to obtain a description of
matter in its most fundamental form. These indivisible bits of stuff
have certain properties, such as mass and electric charge, and can
interact via four forces: gravity, electromagnetism, and two that only
manifest themselves at nuclear distances, the strong and weak forces. A
Final Theory would unify these four forces into a single one, showing
that, at very high energies such as those prevalent near the Big Bang,
these four forces were one. As the universe expanded and cooled, this
force would gradually split, until it became the four forces we know
today: unification dissolves through cosmic history. At present, superstring theories
are the best candidates for such unification, although they remain far
from achieving this goal. Such theories actually go beyond the notion of
elementary particles: the fundamental entities are wiggling strings of
energy that move in nine spatial dimensions: as with guitar strings,
different modes of vibration carry different amounts of energy, each
identifiable with an elementary particle of matter.

Microsoft Word - InterviewWithMaryJaneRubenstenTheMultiverse.doc - InterviewWithMaryJaneRubenstenTheMultiverse.pdf

Microsoft Word - InterviewWithMaryJaneRubenstenTheMultiverse.doc - InterviewWithMaryJaneRubenstenTheMultiverse.pdf

 Goldilocks principle.

This one is just right, and I've got a

Universe. So the question is, how did each of these constants

--

the weak nuclear force, the strong

nuclear force, gravity, the cosmological constant, the mass of the electron

--

how did all of these

get precisely to t

he value they need to be so that we could get the kind of Universe we have?

And strictly philosophically speaking, the easiest answer is, well, somebody must have done it. I

guess somebody must have set each of these constants just right to give us this k

ind of Universe.

What the multiverse does is it gives you an alternative explanation. It says, look, if Universes are

being generated all the time, then those Universes could each try on different values. You could

have a Universe with a whole lot of gravi

ty, and a Universe with a whole lot of cosmological

constants, and the ones that wouldn't support life just wouldn't work out. But every once in a

while, a Universe will have the right combination of constants that it needs to give us a Universe

filled wit

h stars, and we seem to be in one of those Universes.

Microsoft Word - InterviewWithDavidKaiserTheMultiverse.doc - InterviewWithDavidKaiserTheMultiverse.pdf

Microsoft Word - InterviewWithDavidKaiserTheMultiverse.doc - InterviewWithDavidKaiserTheMultiverse.pdf

Now, there are proposal

s, as you know. Some people wonder, if these really are separate

bubbles

--

I tend to think about the multiverse as like a big bathtub. And like in a bathtub, you can

have lots of bubbles. And sometimes in a real bathtub, some bubbles will coalesce. This is

something you've studied in detail, right, for a long time.

Microsoft Word - TheUniverse.doc - TheUniverse.pdf

Microsoft Word - TheUniverse.doc - TheUniverse.pdf

That is, the matter that makes up galaxies, etc. Doing that, plus using a different set of

observations, scientists are actually able to tell how old the universe is

--

that is

--

how long it has

been expanding. T

he current answer is that the universe has been expanding for 13.8 billion

years,

that is, the time since the origin of the universe, the event we call the Big Bang. Our cosmic

horizon is then the bubble of information where we live, the distance light ha

s traveled since the

Big Bang, a sphere with a radius of about 46 billion light years. There may be more universe out

there, like there is more ocean beyond the horizon, but we can't see it.

Circling back to the nature of reality, we see that cosmology te

lls us that there are aspects of the

world that are unknowable to us.

The Importance Of Being Human : 13.7: Cosmos And Culture : NPR

The Importance Of Being Human : 13.7: Cosmos And Culture : NPR

 It's easy to bash humans. We are making a mess of this world. We kill
each other. We are incapable of respecting differing points of view. We
are selfish, destructive, parasitic. I'm sure you could add a few
derisive comments of your own here. I remember, as a teenager, how
infuriated I became when I learned about holy wars, about how people can
actually justify killing others based on faith. Not that other wars are
any better. But what happened, I wondered, to the most basic of
notions, shared by all major religions, that life is sacred?

  The jumps from single-celled to multi-cellular organisms and then to
highly functioning, intelligent beings are immensely unlikely, depending
on a series of random, unrepeatable accidents. Even if complex life
exists elsewhere in the cosmos, and we can't say that it doesn't, it is
so far removed from us that for all practical purposes we are alone. And
if we are alone and can think, we are rare and precious. And if we are
rare and precious, we have a new directive that goes beyond the
destructiveness that has ruled human history for millennia. We must
preserve life at all costs, be the guardians of this world. To counter
the Copernican Principle, we should develop a "humancentrism":
we alone have the power to ruin or to save this precious world we live
in. And I don't mean this in some kind of naive, la-la way. I mean it
quite literally. If we don't mend our ways, we will only have ourselves
to blame. Judging from the past few thousands of years, no one, alien
intelligence or God, will come to our rescue. It's really up to us.

Welcome To The Third Copernican Revolution : 13.7: Cosmos And Culture : NPR

Welcome To The Third Copernican Revolution : 13.7: Cosmos And Culture : NPR

 As Earth became just another planet in the First Copernican revolution
and the Milky Way just another galaxy in the Second, our Universe would
become just another universe among countless others, each with its
properties, private histories, and creation events. This would, among
all of its remarkable consequences, be essentially a Third Copernican
revolution, now removing the centrality of our Universe in favor of an
eternally-existing multiverse.

It’s Albert’s world. We just live in it. - Technology & science - Science - A Century of Einstein | NBC News

It’s Albert’s world. We just live in it. - Technology & science - Science - A Century of Einstein | NBC News



Rigden suggested that “the first contribution that Einstein made that
dramatically affects our lives was that he did it with the power of his
mind.”


Einstein “wasn’t blessed with experimental data — it was mostly abstract ideas,” he said. “That is a distinctive aspect of homo sapiens: We have a big brain. ...


“He is a standard because of what he did. And how he did it.”

Microsoft Word - GeneralTheoryOfRelativity.doc - GeneralTheoryOfRelativity.pdf

Microsoft Word - GeneralTheoryOfRelativity.doc - GeneralTheoryOfRelativity.pdf

So now, when a planet is moving on it, it's going to have an orbit which deviates from a straight

line, like this. And so Einstein's insight was to say that planets go around the sun in elliptical

orbits, because the cu

rvature of space around the sun makes it so. And that's what we call

gravity.

 

 

Compare Einstein's gravity with Newton's. In Newton's world, gravity acted instantaneously at a

distance, like some kind of ghost. Newton didn't like this, but his theory was go

od enough to

describe many phenomena. Einstein changed everything. Space became a physical entity,

deformable by mass and from the relationship between mass and energy, E equals mc squared,

also by energy. Even light, heavy energy bends space. In Einstein'

s world, space is plastic, part

of physical reality, as is time. 

 n 1917, Einstein applied his new theory to the universe as a whole. If we know how much

matter there is in the universe, we can calculate its geometrical shape. Hence is born modern

cosmology, the application of

general relativity to the whole universe.

Microsoft Word - EinsteinsMuse.doc - EinsteinsMuse.pdf

Microsoft Word - EinsteinsMuse.doc - EinsteinsMuse.pdf

Einstein's new theory with the speed of light being constant for every inertial observer had

amazing consequences. First, an object in motion shrinks in the direction of that motion

--

something called "length contraction." Second

, clocks in motion slow down

--

that is, they tick

-

tock slower. Third, the mass of an object in motion increases. The closer to the speed of light the

object moves, the shorter it is, the slower time passes, and the more massive it is.

The Equation That Blew Up The Cosmos : 13.7: Cosmos And Culture : NPR

The Equation That Blew Up The Cosmos : 13.7: Cosmos And Culture : NPR

 To a large extent, the equation also changed the way we understand
ourselves, as suddenly, from its folded mathematical convolutions, the
universe itself became a dynamic, evolving entity, endowed with a
history. Within this history, the birth and death of stars, and the
creation of the chemical elements and their gathering into complex
compounds in nascent planets, became a persistent feature. Life unfolded
here, as it could have elsewhere, as part of this grand cosmic drama of
which we are integral players. Big Bang, black holes, warped spacetime,
wormholes, time machines, even our GPS devices all depend in some way
on Einstein's remarkable creation, a new way to describe gravity.

Microsoft Word - WhatIsLightPartII.doc - WhatIsLightPartII.pdf

Microsoft Word - WhatIsLightPartII.doc - WhatIsLightPartII.pdf

   In1905, Einstein published a paper with the basic ideas of his special

theory of relativity. One of

the consequences of this new theory was that light propagates in emptyspace without an ether.Furthermore, it always moves with the same speed of about 300,000 kilometers per second.

Microsoft Word - WhatIsLightPartI.doc - WhatIsLightPartI.pdf

Microsoft Word - WhatIsLightPartI.doc - WhatIsLightPartI.pdf

What Is Light, Part I

MARCELO GLEISER: We have seen that astronomers collect light, or, more generally,

electromagnetic radiation, to study all sorts of objects in the universe, from nearby planets to

faraway galaxies. But what is light? It's all over the place, but it's a very

strange thing. You can't

hold onto it, it doesn't seem to have weight, and we completely depend on it in our lives.

The nature of light has been a mystery since very early on. Skipping to Isaac Newton, in the 17th

century, he would say that light is made

of tiny little bullets

--

atoms of light. This is what we call

the atomistic description. Newton was influenced by Greek philosophers from a long time ago

who believed that everything is made of tiny particles

--

indivisible little bits of stuff called

atom

s.

However, also in the 17th century, the Dutch physicist Christiaan Huygens had a different point

of view. He believed that light was made of waves

--

that it waved through space as it propagated

from one point to another, something like a water wave. So

you can see that, even 400 years ago,

people were already conflicted about the nature of light. Is it made of particles or is it a wave?

The discussions continued until the turn of the 19th century, when the English scientist Thomas

Young showed, quite co

nvincingly, that light is indeed a wave. He built what is now called a

double slit experiment, where a wave of light coming from a source is made to pass through two

holes. Once that happens, the waves of light will interfere with one another, sometimes

en

hancing their intensity, sometimes cancelling it out altogether so that when you project the

light onto a screen, you will see a sequence of bright and dark fringes.

We are now going to repeat Young's experiment, but using a more modern apparatus than hum

an

hair and candlelight. What I have here is a helium neon laser, which has red light, as you can see.

And I have it aimed at the wall, but it's passing through what we call a diffraction grating or a

grid that I can adjust the width of it. And, as I chang

e the width of this diffraction grid, what's

going to happen is that the pattern projected on the wall is also changing. And it is very, very

hard to explain the result of this experiment using a particle theory of light, and that's why,

during the 19th ce

ntury, the wave

-

like theory of light won.

You can use your imagination to play with light and its diffraction properties. For example, when

you look at clouds with the sun behind them and you see a silver lining, that's an example of

diffraction

--

of ligh

t bending around an obstacle. Can you think of any other examples from

everyday life?

Another effect is known as refraction of light, when light hits an object and changes its direction

of propagation. This is what happens during a rainbow, as sunlight go

es through water droplets

in the atmosphere. If you have a prism or just a crystal ornament and you can make sunlight go

through it, you will see it being separated into the colors of the rainbow

--

from red to violet.

Or you can do that with a water spray

and a hose. Or, even better, you can surprise me and come

up with something quite different to show sunlight spreading into its colors. Let me know!

With the acceptance of the wave theory of light, it became clear that different colors are basically

wave

s of different wavelengths. A wavelength is just the distance between two successive crests

of the wave. For example, red light has a longer wavelength than violet light. Instead of

wavelength, you can also use frequency, which is the number of wave crests

that pass by a point

in one second.

In the case of light or any electromagnetic radiation, if you multiply the wavelength by the

frequency, you always get the speed of light, which physicists represent with the letter c. Since

the speed of light, c, is c

onstant, a high frequency wave has smaller wavelength and a low

frequency wave has longer wavelength.

It turns out that the light that we can see with our eyes is just a tiny window in the

electromagnetic spectrum. The typical wavelength of visible light

varies from about 400 to 700

nanometers, where a nanometer is one billionth of a meter

--

very tiny. Examples of

electromagnetic waves of shorter wavelength than visible light are ultraviolet, x

-

rays, and

gamma rays. On the other side of the spectrum, waves

that have longer wavelength than visible

light are infrared, microwaves, and different kinds of radio waves.

The energy packed in a wave of electromagnetic radiation is directly proportional to its

frequency. So red light, having lower frequency than blu

e or violet light, has less energy than

these two. The most energetic kind of electromagnetic radiation are gamma rays

--

typical of

nuclear phenomena. If a source emits gamma rays, you can be sure that nuclear physics is

involved.

Going back now to the na

ture of reality, we realize that the picture of the world that our senses

are able to construct is incredibly limited. In a sense, Plato was right

--

we all live in a cave: The

cave of our limited perception of reality. After all, our eyes evolved to captur

e only a very small

fraction of the whole electromagnetic spectrum.

All around us, there are other kinds of electromagnetic radiation

--

invisible kinds of light that are

as real as visible light, even if we can't see them. That's why one of the roles of s

cience is to

amplify our perception of reality. The tools we use are a sort of window into invisible aspects of

what's out there. The more we can see with our tools, the more complete our picture of reality is.

But, as we know, there will always be somethi

ng that is beyond what we can grasp, so that the

very essence of reality will always remain elusive.

Island Of K

nowledge

,

Part II

PROFESSOR: From Newton to Einstein, what we see is an incredibly accelerated growth of our

understanding of the universe. This growth was possible because measuring tools became

increasingly sophisticated: Telescopes that could see farther and farther out

into the universe;

microscopes that could see further and further into the nature of matter and of life itself. Side by

side, with those tools, incredible mathematical developments and sophisticated experiments

allowed scientists to understand nature in un

precedented ways.

The so

-

called three pillars of the classical physics world view were solidified in the 19th century.

First, mechanics, the study of motion and the laws of gravity. Then, electromagnetism, the study

of electric charges and magnetic fields

, and how electric charges in motion can generate

magnetic fields. And, finally, thermodynamics, the study of heat that led to steam engines and

the Industrial Revolution, and to the laws of conservation of energy and the growth of entropy or

disorder.

A

scientist of the late 19th century saw the universe very differently from Galileo, Kepler, and

Newton, and, certainly, very differently from the Greeks. As science advanced, world views

changed. The closed cosmos of the Greeks became the open cosmos of New

ton, where every star

is a sun and could, in principle, have planets orbiting around it. New planets were discovered,

Uranus and Neptune.

The cosmos appeared to be a very ordered machine, an accurate clockwork mechanism. It

became clear that, as science a

dvanced, the way we saw the world and our place in it changed.

To illustrate this, consider the Island of Knowledge metaphor. Imagine that all that we know

about the world fits in an island, the Island of Knowledge. The more we know about the world,

the mo

re the island grows.

However, as with any good island, the Island of Knowledge is also surrounded by an ocean, in

this case, the ocean of the unknown, of what we don't know about the world. You may think that,

as we learn more and more, the island would o

ne day cover all the ocean of the unknown. That

one day, science would have answers to all questions. But that is not what happens. Because, as

the island grows, so do the shores of our ignorance, the boundary between the known and the

unknown.

We know th

is already. For example, consider astronomy before and after the telescope. The new

tool allowed scientists to develop a new world view, that with the sun in the center. And it

allowed scientists to ask questions they couldn't have even imagined before. Th

is happens often

in the history of science. New tools and new discoveries solve some problems, but also bring out

new ones.

The island of knowledge grows, but the ocean of the unknown is potentially infinite, at least as

long as we keep asking questions a

bout the world and developing new and more powerful tools

to study it. Even more dramatically

--

as we'll see soon

--

in the ocean of the unknown, there are

regions of the unknowable. There are questions that we can ask about the world that science

cannot an

swer, unless we break the laws of nature as we know them today.

There are two main reasons why our knowledge of the world is finite. First, as we have seen, our

tools can only see so far. They can only probe so deep into nature. And second, nature itself

limits what we can see and observe. Perhaps the most obvious example of this in the context of

cosmology is the fact that the speed of light is finite. It's very fast, but it's still finite. In empty

space, or the vacuum, light can travel at about 300,000

kilometers per second, or about 186,000

miles per second.

If you blink your eyes, light goes 7 and 1/2 times around the earth. If we now consider that

modern cosmology tells us that the universe had a beginning about 13.8 billion years ago, this

means tha

t, from our perspective here on Earth, we can only see things

--

or receive information

from things

--

that are at a distance smaller to how far light traveled in '13.8 billion years. This

distance is huge, but it's not infinite.

Remember, that we get infor

mation from the universe from collecting light. Not just visible light,

but many kinds of light. Or better, electromagnetic radiation. And all of these travel at the speed

of light. So the farthest point that we can see or get information from is an object

which is as far

as light has traveled in 13.8 billion years. This is what we call our cosmic horizon.

In astronomy, we like to use light years as a measure of distance. As the name says, a light year

is the distance that light can travel in one year. To

give you an idea, the distance between Earth

and Pluto is about 5 and 1/2 light hours, or 327 light minutes. So this means that if someone sent

us a message from Pluto, traveling at the speed of light, like the spectacular photos from the New

Horizons prob

e, it would take 5 and 1/2 hours to reach us.

[CLOCK TICKING]

Moving farther out, the distance between the Sun and the nearest star to Earth, called Alpha

Centauri, is about 4 and 1/2 light years. You see how far stars are from one another. Now, let's

mo

ve further out still to consider our galaxy, the Milky Way. The Milky Way has a diameter of

about 100,000 light years. If I turn a flashlight on at one edge of the galaxy, it will take 100,000

years for light to reach the other end.

If we keep moving outw

ards, the nearest galaxy to the Milky Way is the Andromeda galaxy at

about two million light years. Typically, galaxies are tens or hundreds of millions of light years

away from one another. Now we can go back to our question: How far would light travel in

the

age of the universe of 13.8 billion years? A simple answer would be 13.8 billion light years. But

that's not quite right, because the universe is not static. The universe is expanding. Galaxies are

moving away from one another at enormous speeds.

Thi

s expansion adds to the distance that light can travel, like a surfer riding on a wave. So the

actual distance that light travels since the Big Bang is about 46 billion light years. Again, a huge

distance, but not infinite. This has a very, very important

consequence to us. It means that we

live in a cosmic bubble of information. We can only know what's going on in the universe within

this bubble of information, the distance that light has traveled since the Big Bang.

The universe may continue beyond this

point, just like when you are standing at the beach and

you look at the horizon. We know that the ocean continues beyond the horizon, but we can't see

what's out there. Well, it's about the same with the universe. The universe may continue beyond

our cosmi

c bubble of information, our cosmic horizon, but we can't know what's beyond it. So if

you ask me "What's going on with the universe outside our cosmic bubble?" We can speculate,

and we can say that, probably, it looks very much the same as around here. Bu

t we can never

know for sure, because we cannot get any information from objects that are outside our cosmic

horizon. This is an example of what I call an unknowable question in science. You can ask it, but

we can't answer it.

Island Of Knowledge, Part I

MARCELO GLEISER: Last week, we saw how the Greeks started to think about nature in adifferent way. Instead of using myths to explain natural phenomena, they started to ask questions

about nature and tried to answer those questions with rational arguments.

We also saw how

Plato's Allegory of the Cave was the first serious reflection on the nature of reality.

From Greece, we went to the Renaissance where the first pioneers of modern science developed

a completely new way of thinking about the cosmos. Modern

science was born from the

combination of two main ideas: The use of tools to measure and observe natural phenomena with

increasing precision and the use of mathematics to search for patterns in the data that reveal what

scientists call the "laws of nature

." We saw that, after thousands of years of an Earth

-

centered cosmos, Copernicus put the sun at the center and how Galileo, Kepler, and Newton worked to

confirm this new cosmic worldview that would profoundly changed the way we picture the

cosmos and our p

lace in it. This week, we will continue our exploration of the universe

--telling

the story of how Newton's law of gravity changed into Einstein's view of the universe based on

his famous theory of relativity. We will explore modern ideas of cosmology, ofthe Big Bang,and even recent speculations that our universe is not all there is

--

being, instead, part of a

multiverse, possibly infinite in space and eternal in duration.

Can Science Crack The 'Hardest' Question? : 13.7: Cosmos And Culture : NPR

Can Science Crack The 'Hardest' Question? : 13.7: Cosmos And Culture : NPR

 The more popular phrasings go something like, "Where did the world come
from?" or "Why is there something rather than nothing?" This is the
question of creation, of how the universe and everything in it came to
be. And, although we've made great progress towards understanding the
universe and its history, we are still far from understanding its
origin.

Introduction to Question Reality

!

MARCELO GLEISER:

Welcome to Question Reality. My name is Marcello Gleiser, and I will

be your instructor f

or this

very unique and exciting course based on my book, The Island of

Knowledge. For the next

few weeks, we'll dive deep into some of the most fundamental

questions in science and

philosophy, questions that have occupied the minds of some of the

greatest

thinkers of all

ages.

How do we know what is real? What is the world made of? What is

the Big Bang? Who are we

in this vast expanding universe? How much can we know of the

world and ourselves? How can

we find meaning when we are surrounded by so much doub

t and

mystery?

The course is divided into three main segments

--

cosmos, matter and mind. In all three, we'll

examine some of the most challenging questions in science and philosophy following a

historical

approach. We start with the first ideas on the topi

c and move forward to the frontiers

of current

knowledge.

In cosmos, we'll trace the evolution of our changing world views from the Greeks to

the Big

Bang and the multiverse. In matter, we start in ancient Greece and explore how the

concept of

atom evolved into modern quantum mechanics and the search for the fundamental

building

blocks of matter at CERN. In mind, we examine the nature of mathematics and

computers,

exploring their connection to the greatest mystery of all, our own consciousness.

After an introduction to these topics through brief video lectures and reading short blog posts,

we

will help you discuss with your classmates the nature of reality and knowledge about the

world

around us. We'll ask for your opinions and viewpoints as well

as reflections on how your

own

knowledge is changing. You'll go out into your community of friends, family and

colleagues to

find out their ideas on some of the course topics. We'll schedule live events

where you can "Ask

Marcello Anything" about reality,

philosophy and science. We can't wait to

start this adventure

into reality with all of you.

If you think you know what reality is, think again.

For example, here you have a cloud chamber

where you can see the tiny tracks cutting through

the suspended mist

. These tracks are

actually subatomic particles raining from the skies and from

underground. Without the right

tool, you wouldn't know they existed. But here they are, part of

our physical reality.

As Antoine

de Saint Exupery said in his classic book, The

Little Prince, "what is essential is

invisible to the

eye." In this course, we'll learn to look beyond appearances as we explore the

deepest

aspects of reality.

Does The Multiverse Make Sense? : 13.7: Cosmos And Culture : NPR

Does The Multiverse Make Sense? : 13.7: Cosmos And Culture : NPR