leslie's EARTH and SKY science weblog

Sunday, March 13, 2005

045 Why We Age: Cloze Test and Crossword Puzzle

Please click here for a Cloze Test on Why We Age. If you send me an email, I'll be quite happy to send you a crossword about this topic. Please put '045 Why We Age: Crossword Puzzle' in the Subject line.

044 Why We Age: HotSpots and Advanced VocabBox

age
animals
a scientist
human longevity
Steve Austad
Barshop Institute for Longevity and Aging Studies
San Antonio
Texas
prone to illness
muscles
mysteries in biology
humans' average lifespan
enchilada
biomedicine

Saturday, March 12, 2005

043 Why We Age: HotSpots and Intermediate VocabBox and Glossary and Vocabulary Double-Check

age: 'age' is a verb here, meaning 'to become old, to show the effects or the characteristics of increasing age'
animals: any of a kingdom (Animalia) of living things including many-celled organisms and often many of the single-celled ones (as protozoans) that typically differ from plants in having cells without cellulose walls, in lacking chlorophyll and the capacity for photosynthesis, in requiring more complex food materials (as proteins), in being organized to a greater degree of complexity, and in having the capacity for spontaneous movement and rapid motor responses to stimulation; a human being is considered chiefly as an animal by physical or nonrational factors
a scientist: here by science we can understand any one or any combination of animal biology (zoology), anthropology (physical), biochemistry,
Biomathematics, Biometrics, Biophysics, Cell biology, Ethology, Genetics,
Human biology, Human physiology, immunology, insect biology, medicine,(Entomology), microbiology, Molecular biology, palaeontology, pharmacology, plant biology (botany), radiobiology, symbiosis, virology, other biological specialities

human longevity: its study needs a multidisciplinary approach, integrating biological knowledge (studies on human biology and animal models) with demographic research.
Steve Austad: Dr. Austad's research interests focus on the biology of aging in humans, mammals, and birds. Both laboratory and field studies are used to address questions concerning the relationship between reproduction, diet, sex, and aging.
Barshop Institute for Longevity and Aging Studies: its goal is to identify the genes and underlying biological processes that enhance healthy aging and longevity
San Antonio: is one of America's most historic cities, with its Spanish roots reaching back to 1691 when an exploratory party, called an "entrada," headed by Domingo Teran de los Rios, made its way north out of Mexico where the Spanish had already been firmly entrenched for more than 150 years
Texas: is the largest of the continual continental states and the second largest overall. Alaska is the only state larger than Texas. The population of Texas is currently estimated at more than 22,000,000.
prone to illness: having a natural tendency to be sick more often than mates because they are biologically more sensitive than others
generalized decline in function: the functioning of your body depends on a range of biochemical reactions and counter reactions. With aging some of the body functions slow down, and are performed less perfectly.
muscles: muscles # 2 muscles # 3 muscles # 4 muscles # 5 a tissue composed of bundles of elongated cells capable of contraction and relaxation to produce movement in an organ or part
mysteries in biology: one of the mysteries of biology goes like this 'How does tooth enamel, the hardest mineral in the mammalian body, emerge from soft, organic gum tissue?', and there are many more.
humans' average lifespan: with few exceptions, 30,000 days is the average human lifespan - 40,000 if you're lucky. However, two-thousand years ago average life expectancy was less than 20 years or about 7,000 days. It is difficult to imagine, but most of our ancestors kicked the bucket before our modern legal drinking age.
enchilada: a Mexican dish consisting of a tortilla fried in hot fat, filled with meat, and served with a chilli sauce
biomedicine: the medical study of the effects of unusual environmental stress on human beings

So far so good. Now let's see the same vocabulary explanation together with the original text. Please click here for a GLOSSARY.

Now that you know everything about the topic, it is high time to test your vocabulary. Please click here for a DOUBLE-CHECK.

042 Why We Age: Text and HotSpots

Why We Age

All animals age. But they age at different rates. Mice live for about three years, bats nearly 40 years and humans to about 110. We ask a scientist why we all age -- next on Earth and Sky.

Wednesday, March 2, 2005

Can bats be the key to human longevity?
JB: This is Earth and Sky. A listener writes, "Why do we age? Do our bodies somehow lose their ability to fight off disease?"
DB: We asked Steve Austad, at the Barshop Institute for Longevity and Aging Studies in San Antonio, Texas. He says that, although people do tend to become more prone to illness as they age, aging is much more than that.
Steve Austad: If you think about it, you know nobody that's 50 can sprint as fast as they could when they were 20, even if they're the healthiest 50 year old in the world. And the difference between that -- what they were at 20 and what they are at 50 -- that's what aging is all about. It's that generalized decline in function. And it just isn't your muscles. It's everything. And to me this is one of the most exciting mysteries in biology because if you think about it, animals are almost defined . . . by the fact they can repair damage that happens to them. And yet, aging . . . is the accumulation of damage that for some reason our bodies just simply refuses to repair.
JB: Austad says that curing one disease at a time -- such as heart disease or cancer -- might only extend humans' average lifespan by 5 or 10 years. But the best way to preserve human health would be to slow down aging.
Steve Austad:. . . It's the big enchilada for me, in the whole field of biomedicine, is figuring out what causes it and then figure out whether we might be able to manipulate the rate at which it occurs.
DB: More from Steve Austad next time. We're Block and Byrd for Earth and Sky.
Author(s): Marc Airhart
© 2005 Byrd & Block Communications Inc. Permission to use, copy and distribute these materials without fee is hereby granted, provided that the above copyright notice appear in all copies and the materials are not redistributed for profit.

041 Why We Age: Sound and Text

Why We Age

All animals age. But they age at different rates. Mice live for about three years, bats nearly 40 years and humans to about 110. We ask a scientist why we all age -- next on Earth and Sky.
Wednesday, March 2, 2005

Click here for LISTENING

Click here for original article WHY WE AGE

Click here for PICTURE

Fruit bat photo © 1997-2005 Chicago Zoological Society.

Can bats be the key to human longevity?
JB: This is Earth and Sky. A listener writes, "Why do we age? Do our bodies somehow lose their ability to fight off disease?"

DB: We asked Steve Austad, at the Barshop Institute for Longevity and Aging Studies in San Antonio, Texas. He says that, although people do tend to become more prone to illness as they age, aging is much more than that.

Steve Austad: If you think about it, you know nobody that's 50 can sprint as fast as they could when they were 20, even if they're the healthiest 50 year old in the world. And the difference between that -- what they were at 20 and what they are at 50 -- that's what aging is all about. It's that generalized decline in function. And it just isn't your muscles. It's everything. And to me this is one of the most exciting mysteries in biology because if you think about it, animals are almost defined . . . by the fact they can repair damage that happens to them. And yet, aging . . . is the accumulation of damage that for some reason our bodies just simply refuses to repair.

JB: Austad says that curing one disease at a time -- such as heart disease or cancer -- might only extend humans' average lifespan by 5 or 10 years. But the best way to preserve human health would be to slow down aging.

Steve Austad:. . . It's the big enchilada for me, in the whole field of biomedicine, is figuring out what causes it and then figure out whether we might be able to manipulate the rate at which it occurs.

DB: More from Steve Austad next time. We're Block and Byrd for Earth and Sky.

Author(s): Marc Airhart

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© 2005 Byrd & Block Communications Inc. Permission to use, copy and distribute these materials without fee is hereby granted, provided that the above copyright notice appear in all copies and the materials are not redistributed for profit.

Thursday, March 10, 2005

040 Global Fresh Water: Cloze Test and Crossword Puzzle

Please click here for a Cloze Test on Global Fresh Water. If you send me an email, I'll be quite happy to send you a crossword about this topic. Please put '040 Global Fresh Water: Crossword Puzzle' in the Subject line.

039 Global Fresh Water: HotSpots and Advanced VocabBox

global fresh water
access to safe water
a scientist hydrological phenomena
managing the global supply of fresh water
Pacific Institute for Studies in Development, Environment, and Security
global climate change
fresh water ecosystems
climate and water
powering hydroelectric dams
producing steel
producing plastic
irrigation drip irrigation
hydrologic cycle
a river
a watershed

038 Global Fresh Water: HotSpots and Intermediate VocabBox and Glossary and Vocabulary Double-Check

global fresh water: water is fundamental to human life but is often a scarce resource. Demand for fresh water is rising: the consequence of a growing world population and increasing demand in developing countries.
a billion: in America, is a thousand million. That would be written 1,000,000,000. Interestingly, in England, the British define a billion as a million million. That would be 1,000,000 times 1,000,000 which would be written as 1,000,000,000,000.
access to safe water: water covers more than 70% of the earth’s surface and would seem to be an inexhaustible resource. Considering that more than 97% of this water is salt water existing in our Ocean’s and 1.8% locked in our polar ice caps. This leaves less than 1 % of all the earth’s sources as fresh water to sustain all living things..... including humanity. Of this it is unclear how much remains unpolluted.
a scientist: hydrologists study the distribution of water. They may research the flow or discharge of water along a river or over a dam. Hydrologists often work as a team with other scientists. Hydrologists are interested in lake or river levels and how these levels affect commerce, shoreline erosion, etc. Some hydrologist work as researchers in universities. Others may find employment with engineering firms that design and build sewers, channels, and other water related structures.
global supply of fresh water: of all water on earth, 97.5% is salt water, and of the remaining 2.5% fresh water, some 70% is frozen in the polar icecaps.
Dr. Peter Gleick: is co-founder and President of the Pacific Institute for Studies in Development, Environment, and Security in Oakland, California. His research and writing address the critical connections between water and human health, the hydrologic impacts of climate change, sustainable water use, privatization and globalization, and international conflicts over water resources.
Pacific Institute for Studies in Development, Environment, and Security: is dedicated to protecting our natural world, encouraging sustainable development, and improving global security. Founded in 1987 and based in Oakland, California, it provides independent research and policy analysis on issues at the intersection of development, environment, and security.
Oakland: a port and industrial centre in West California on San Francisco Bay. It was damaged by earthquake in 1989.
California California # 2
global climate change: climate is the average pattern of weather over the long term. The earth’s climate has warmed and cooled for millions of years, since long before we appeared on the scene. There’s no doubt that the climate is growing warmer currently; indications of that change are all around us.
water systems: the public drinking water systems provide drinking water to 90 percent of the population [USA].
how much water we get: less than 1% of the world's fresh water (or about 0.007% of all water on earth) is readily accessible for direct human uses.
when we get it: the amount of fresh water is, of course, dependant on rainfall and this varies according to the geographic location of the island and climate conditions. There is normally a “wet season” that replenishes water supplies for the subsequent dry season.
where we get it: it is found in lakes, rivers, reservoirs and in underground sources.
water quality we get: contamination is the impairment of water quality to a degree that reduces the usability of the water for ordinary purposes or creates a hazard to public health through poisoning or the spread of diseases.
climate and water: the distribution of water within the Earth system is vitally important for humankind and life in general. Of the two most important climate parameters, temperature and precipitation, the latter simply is water and the former is dominated by water in its role of distributing heat over the planet.
advancing technologies: the sound management of water resources through
advancing water resources and related environmental research, promoting water resources education, improving exchanges of information and expertise, networking with other organizations who share common interests and goals providing an international forum on water resource issues

powering hydroelectric dams: hydro-electric power plants convert the kinetic energy contained in falling water into electricity. The energy in flowing water is ultimately derived from the sun, and is therefore constantly being renewed. Energy contained in sunlight evaporates water from the oceans and deposits it on land in the form of rain. Differences in land elevation result in rainfall runoff, and allow some of the original solar energy to be captured as hydro-electric power.
irrigation: is a system of watering crops and plants using ditches and small canals to run water from rivers to plants.
susceptible: hypersensitive to external changes
upstream: in a direction opposite to that of a stream's current
hydrologic cycle: Earth's water is always in movement, and the water cycle, also known as the hydrologic cycle, describes the continuous movement of water on, above, and below the surface of the Earth. Since the water cycle is truly a "cycle," there is no beginning or end. Water can change states among liquid, vapor, and ice at various places in the water cycle, with these processes happening in the blink of an eye and over millions of years.
a river: it is fresh water flowing across the surface of the land, usually to the sea. It flows in a channel. The bottom of the channel is called the bed and the sides of the channel are called the banks.
a watershed: it is the area of land where all of the water that is under it or drains off of it goes into the same place.
affect: to produce an effect upon, as a: to produce a material influence upon or alteration in b: to act upon (as a person or a person's mind or feelings) so as to bring about a response; influence
So far so good. Now let's see the same vocabulary explanation together with the original text. Please click here for a GLOSSARY.

Now that you know everything about the topic, it is high time to test your vocabulary. Please click here for a DOUBLE-CHECK.

037 Global Fresh Water: Text and HotSpots

Global Fresh Water

Today, more than a billion people on Earth lack access to safe water. Up next -- a scientist talks about managing the global supply of fresh water in this century -- after this on Earth and Sky.
Tuesday, March 1, 2005


JB: This is Earth and Sky, on managing fresh water, globally.
DB: Dr. Peter Gleick is Director of the Pacific Institute for Studies in Development, Environment, and Security in Oakland, California. He talked to us about Earth's supply of fresh water in this century.
Peter Gleick: Without a doubt, global climate change is a real problem. And without a doubt global climate change is going to affect our water systems - how much water we get, when we get it, where we get it, the water quality we get -- and we're not prepared to deal with that yet. We're not really thinking about climate and water together.
JB: He says the challenge facing us is to use fresh water efficiently -- while advancing technologies that let us do the things we need to do with less water. That's less water for things like powering hydroelectric dams, producing steel and plastic -- and irrigation. Irrigation alone accounts for more than seventy percent of the fresh water humans use.
DB: But water crosses borders, and that's why, says Gleick, decisions concerning fresh water management are increasingly becoming political issues.
Peter Gleick: One of the great challenges with water is that, in a sense, we all live downstream. We're all susceptible to people upstream from us doing something to water -- either in a hydrologic cycle, in a river, in a watershed. The things we do affect other people who use that water.

036 Global Fresh Water: Sound and Text

Global Fresh Water

Today, more than a billion people on Earth lack access to safe water. Up next -- a scientist talks about managing the global supply of fresh water in this century -- after this on Earth and Sky.
Tuesday, March 1, 2005
Click here for LISTENING
Click here for original article Global Fresh Water
Click here to view PICTURE

JB: This is Earth and Sky, on managing fresh water, globally.
DB: Dr. Peter Gleick is Director of the Pacific Institute for Studies in Development, Environment, and Security in Oakland, California. He talked to us about Earth's supply of fresh water in this century.
Peter Gleick: Without a doubt, global climate change is a real problem. And without a doubt global climate change is going to affect our water systems - how much water we get, when we get it, where we get it, the water quality we get -- and we're not prepared to deal with that yet. We're not really thinking about climate and water together.
JB: He says the challenge facing us is to use fresh water efficiently -- while advancing technologies that let us do the things we need to do with less water. That's less water for things like powering hydroelectric dams, producing steel and plastic -- and irrigation. Irrigation alone accounts for more than seventy percent of the fresh water humans use.
DB: But water crosses borders, and that's why, says Gleick, decisions concerning fresh water management are increasingly becoming political issues.
Peter Gleick: One of the great challenges with water is that, in a sense, we all live downstream. We're all susceptible to people upstream from us doing something to water -- either in a hydrologic cycle, in a river, in a watershed. The things we do affect other people who use that water.
JB: For links to more about global fresh water, come to earthsky.org. We're Block and Byrd for Earth and Sky.
Author(s): Eleanor Imster
© 2005 Byrd & Block Communications Inc. Permission to use, copy and distribute these materials without fee is hereby granted, provided that the above copyright notice appear in all copies and the materials are not redistributed for profit.

Thursday, March 03, 2005

035 Zodiacal Light: Cloze Test and Crossword Puzzle

Please click here for a Cloze Test on Zodiacal Light. If you send me an email, I'll be quite happy to send you a crossword about this topic. Please put '035 Zodiacal Light: Crossword Puzzle' in the Subject line.

034 Zodiacal Light: HotSpots and Advanced VocabBox

zodiacal light
dawn
Southern Hemisphere
planets and moons in our solar system
planets and moons in our solar system # 2
orbit the sun

dust in the plane of the solar system
sunlight bouncing off dust grains
ecliptic
twilight
equator

033 Zodiacal Light: HotSpots and Intermediate VocabBox and Glossary and Vocabulary Double-Check

zodiacal light: it is a faint, roughly triangular shaped glow of light extending away from Sun; the spectrum of the zodiacal light is the same as the solar spectrum, reinforcing the deduction that it is merely sunlight reflected by dust in the plane of the planets

dawn: time at which there is enough light for you to distiguish objects and when you can start outdoor activities

Southern Hemisphere: the part of the Earth's surface that is south of the equator; it contains four continents [Africa, Australia, South America, and Antartica] separated by four oceans [South Atlantic Ocean, Pacific Ocean, Indian Ocean, and Antarctic Ocean]

eerie pyramid of light: mysteriously frightening light of triangular shape

planets and moons: a moon is a natural satellite rotating around a planet; while moons vary in size, each moon is much smaller than its planet; almost 140 moons are known in the Solar System; several moons are larger than the planet Pluto and two moons are larger than the planet Mercury; there also are many small moons that may be asteroids captured by their planets

solar system: consists of an average star we call the Sun, the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto; it includes the satellites of the planets; numerous comets, asteroids, and meteoroids; and the interplanetary medium

orbit the sun: the planets, most of the satellites of the planets and the asteroids revolve around the Sun in the same direction, in nearly circular orbits; when looking down from above the Sun's north pole, the planets orbit in a counter-clockwise direction;

nearly flat plane: the planets orbit the Sun in or near the same plane, called the ecliptic

dust in the plane of the solar system: the solar system is always plowing through interstellar material; the Sun's giant magnetic field thwarts much of the dust from entering the solar system but the magnetic field weakens periodically, on a cycle that lasts roughly 22-years; the cycle is related to an 11-year cycle of sunspot activity

sunlight bouncing off: zodiacal light is produced by sunlight reflecting off particles of dust present throughout much of the solar system; the amount of material needed to produce the observed zodiacal light is amazingly small
dust grains: if it were in the form of 1mm particles each with the same albedo (reflecting power) as Earth's moon each particle would be 5 miles from its neighbours

ecliptic: it is the geometric plane that contains the orbit of the Earth; the orbits of most planets in the Solar System lie very close to it

twilight: twilight is the time before sunrise and after sunset when sun light reflected from particles in the upper atmosphere illuminates the lower atmosphere and the surface of the earth

northern part of Earth's globe: it is the half of a planet's surface (or celestial sphere) that is north of the equator; on Earth, the Northern Hemisphere contains most of the land and population

equator: it is located at zero degrees latitude; the equator runs through Indonesia, Ecuador, northern Brazil, the Democratic Republic of the Congo, and Kenya, among other countries; it is 24,901.55 miles (40,075.16 kilometers) long; on the equator, the sun is directly overhead at noon on the two equinoxes - near March and September 21; the equator divides the planet into the Northern and Southern Hemispheres

So far so good. Now let's see the same vocabulary explanation together with the original text. Please click here for a GLOSSARY.

Now that you know everything about the topic, it is high time to test your vocabulary. Please click here for a DOUBLE-CHECK.

032 Zodiacal Light: Text and HotSpots

Zodiacal Light

This is the best time of year to see the zodiacal light before dawn from Earth's Southern Hemisphere -- and in the evening from the northern part of the globe. The zodiacal light -- after this on Earth and Sky.
Monday, February 28, 2005


JB: This is Earth and Sky, on an eerie pyramid of light -- seen before sunrise or after sunset -- called the zodiacal light.
DB: The planets and moons in our solar system orbit the sun in a nearly flat plane. And there's also dust in the plane of the solar system. The zodiacal light is really sunlight bouncing off these dust grains in nearby space. Since this dust orbits in the same plane as the planets and moons near us in space, we see the zodiacal light along the same path across our sky traveled by the sun, moon and planets.
JB: This pathway from east to west across our sky is called the ecliptic. And if you'll think of the ecliptic or plane of the solar system turned on its side -- stretching up above the sunrise or sunset point -- you'll have an idea of what the zodiacal light looks like. It's like a cone or pyramid of light. You won't see it in twilight -- but instead in the hour before morning twilight begins -- or in the hour after evening twilight ends.
DB: You need a dark sky to see the zodiacal light. Late February, March and April are the best time to see it before dawn from Earth's southern hemisphere. At the same time, these months are the best time to see the light in the evening from the northern part of Earth's globe.
JB: The closer you are to the equator, the easier it is to see the zodiacal light. While driving on country roads, people sometimes mistake the zodiacal light for the light of a city or town just beyond their horizon.
DB: For today, that's our show. We're Block and Byrd for Earth and Sky.
Author(s): Deborah Byrd
© 2005 Byrd & Block Communications Inc. Permission to use, copy and distribute these materials without fee is hereby granted, provided that the above copyright notice appear in all copies and the materials are not redistributed for profit.

031 Zodiacal Light: Sound and Text

Zodiacal Light

This is the best time of year to see the zodiacal light before dawn from Earth's Southern Hemisphere -- and in the evening from the northern part of the globe. The zodiacal light -- after this on Earth and Sky.
Monday, February 28, 2005
Click here for LISTENING
Click here for original article ZODIACAL LIGHT

JB: This is Earth and Sky, on an eerie pyramid of light -- seen before sunrise or after sunset -- called the zodiacal light.
DB: The planets and moons in our solar system orbit the sun in a nearly flat plane. And there's also dust in the plane of the solar system. The zodiacal light is really sunlight bouncing off these dust grains in nearby space. Since this dust orbits in the same plane as the planets and moons near us in space, we see the zodiacal light along the same path across our sky traveled by the sun, moon and planets.
JB: This pathway from east to west across our sky is called the ecliptic. And if you'll think of the ecliptic or plane of the solar system turned on its side -- stretching up above the sunrise or sunset point -- you'll have an idea of what the zodiacal light looks like. It's like a cone or pyramid of light. You won't see it in twilight -- but instead in the hour before morning twilight begins -- or in the hour after evening twilight ends.
DB: You need a dark sky to see the zodiacal light. Late February, March and April are the best time to see it before dawn from Earth's southern hemisphere. At the same time, these months are the best time to see the light in the evening from the northern part of Earth's globe.
JB: The closer you are to the equator, the easier it is to see the zodiacal light. While driving on country roads, people sometimes mistake the zodiacal light for the light of a city or town just beyond their horizon.
DB: For today, that's our show. We're Block and Byrd for Earth and Sky.
Author(s): Deborah Byrd
© 2005 Byrd & Block Communications Inc. Permission to use, copy and distribute these materials without fee is hereby granted, provided that the above copyright notice appear in all copies and the materials are not redistributed for profit.

Tuesday, March 01, 2005

030 Internal Heat: Cloze Test and Crossword Puzzle

Please click here for a Cloze Test on Internal Heat. If you send me an email, I'll be quite happy to send you a crossword about this topic. Please put '030 Internal Heat: Crossword Puzzle' in the Subject line.

029 Internal Heat: HotSpots and Advanced VocabBox

internal heat
inside Earth
energy
move continents
cause earthquakes
build mountains
the Earth's interior
cloud of gas
dust in space
particles
planetesimals
rocks
Earth's crust
interior
radioactive decay
disintegration of natural radioactive elements
subatomic particles
collide
energy of motion is converted to heat
primary heat source
shifting of land plates
sun's heat
weather
erosion

028 Internal Heat: HotSpots and Intermediate VocabBox and Glossary and Vocabulary Double-Check

internal heat: the thermal energy produced and stored inside the earth
inside Earth: the inner core, the outer core, the mantle, and the lower layers of the crust
inner core: it is thought to be a solid sphere of iron and nickel; there are conflicting theories concerning its size but its radius must be about 775 miles, i. e. some 1,250 kilometers; it exists under fantastic pressure, i. e. some 3 million times that of atmospheric pressure at sea-level; its temperature is about 11,100 F, i. e. 6,150 C, and it is about the same as the temperature of the surface of the sun
outer core: it is made up of liquid iron and nickel; the motion of the liquid metals on the solid inner core produces the magnetic field of the earth [this is what scientists call the dynamo theory]; it is about 2,700 miles, i. e. 4,350 kilometers thick; the temperature of the outer core is about 7,200 to 9,100 F, i. e. 4,000 to 5,000 C
mantle: it is a plastic layer of rock which extends from the mantle down to the outer core; the rock is mainly olivine, i. e. magnesium iron silicate; near the mantle the molten rock is thick or even brittle; deeper down it is thinner liquid; the mantle is heated by the decaying of radioactive elements
crust: it is only 5 miles, 8 kilometers, thick beneath the oceans, and 25 miles, i. e. 40 kilometers, thick under the continents; it is devided into immense 'tectonic' plates; it is composed mainly of granites under the continents, and basalts under the oceans
energy: the fundamental energy source within the Earth is heat, primarily provided by radioactive decay in the mantle
move continents: the liquid mantle is moved by the heat as any boiling liquid; moved by convection currents in the liquid mantle the tectonic plates slowly grind against each other in a process known as 'continental drift'
cause earthquakes: sites where continental plates meet are areas of intense geologic activity, including earthquakes
build mountains: sites where continental plates meet are areas of intense geologic activity, including building mountains
Earth's interior: the inner core, the outer core, the mantle, and the lower layers of the crust
cloud of gas and dust in space: most scientific work has centered on the theory that the sun and planets were formed by the slow condensation of a gigantic cloud of dust and gas
particles: until 1932, the "elementary" particles were the electron, proton, and neutron; we now know of hundreds of other elementary particles
planetesimals: nearly 5 billion years ago, the solar system was just a giant cloud of gas; gravitational forces made the cloud contract; the cloud was not homogenous, therefore not only one object was formed in the middle of the cloud (the Sun), but a large number of small objects called planetesimals, or planet building blocks, formed around the Sun
rocks: minerals that make up part of the earth's crust
Earth's crust: the upper layer of the Earth, is not always the same; crust under the oceans is only about 8 km thick while continental crust can be up to 40 km thick; also, ocean crust is made of denser minerals than continental crust
interior: a part, surface, or region that is inside the Earth
radioactive decay: materials that emit alpha, b beta, and g gamma radiation are said to be radioactive and to undergo radioactive decay
disintegration of natural radioactive elements: radioactivity is the property of some elements or isotopes to spontaneously emit particles of energy by the disintegration of their atomic nuclei; this process is known as radioactive decay; as a sample of radioactive material decays, it becomes stable and nonradioactive; the amount of time it takes for half of a sample of radioactive material to decay into a stable substance is called its half-life
subatomic particles: in physics, a subatomic particle is a particle smaller than an atom; these include atomic constituents such as electrons, protons, and neutrons (protons and neutrons are actually composite particles, made up of quarks), as well as particles produced by radiative and scattering processes, such as photons, neutrinos, and muons
zip away: generally it means 'it is safe to jump'; here in this context it means 'escape'
collide: crash together with a violent impact
energy of motion is converted to heat: the Law of Conservation of Energy states that energy is neither created nor destroyed but changes from one form to another; the total amount of energy stays the same
primary heat source: this is the main source of energy inside the earth
shifting of land plates: it refers to the drifting of tectonic plates
sun's heat: the sun's energy that is radiated to, and trapped in the earth
weather: the day-to-day meteorological conditions, esp. temperature, cloudiness, and rainfall
erosion: the wearing away of rocks and other deposits on the earth's surface by the action of water, ice, and wind

So far so good. Now let's see the same vocabulary explanation together with the original text. Please click here for a GLOSSARY.

Now that you know everything about the topic, it is high time to test your vocabulary. Please click here for a DOUBLE-CHECK.

027 Internal Heat: Text and HotSpots

Internal Heat

The heat inside Earth contains enormous amounts of energy -- enough to move continents, cause earthquakes and build mountains. Up next -- we talk about where all this heat comes from -- after this on Earth and Sky.
Sunday, February 27, 2005


DB: This is Earth and Sky. A listener's question, "What is the source of the heat in the Earth's interior?"
JB: A lot of Earth's heat is thought to be leftover from when our planet formed, four-and-a-half billion years ago. Earth is thought to have arisen from a cloud of gas and dust in space. Solid particles, called "planetesimals" condensed out of the cloud -- they're thought to have stuck together and created the early Earth. Bombarding planetesimals heated Earth to a molten state. So Earth started out with a lot of heat -- but, even now, new heat is being produced.
DB: Many of the rocks in Earth's crust and interior undergo a process of radioactive decay. That's the disintegration of natural radioactive elements. This process produces subatomic particles that zip away -- and later collide with surrounding material inside the Earth. Their energy of motion is converted to heat -- to create Earth's primary heat source. Without radioactive decay, Earth would have fewer volcanoes or earthquakes -- less shifting of land plates and building of vast mountain ranges.
JB: The heat energy produced by Earth is enormous, but it's 5000 times less than what Earth receives from the sun. The sun's heat drives the weather and ultimately causes erosion.
DB: So while the Earth's heat builds mountains, the sun's heat destroys them. With thanks to the National Science Foundation, we're Block and Byrd for Earth and Sky.
Author(s): Bizy Kubala, Mohan Rao, Marc Airhart, Deborah Byrd
© 2005 Byrd & Block Communications Inc. Permission to use, copy and distribute these materials without fee is hereby granted, provided that the above copyright notice appear in all copies and the materials are not redistributed for profit.

026 Internal Heat: Sound and Text

Internal Heat

The heat inside Earth contains enormous amounts of energy -- enough to move continents, cause earthquakes and build mountains. Up next -- we talk about where all this heat comes from -- after this on Earth and Sky.
Sunday, February 27, 2005
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Click here for original article INTERNAL HEAT

DB: This is Earth and Sky. A listener's question, "What is the source of the heat in the Earth's interior?"


JB: A lot of Earth's heat is thought to be leftover from when our planet formed, four-and-a-half billion years ago. Earth is thought to have arisen from a cloud of gas and dust in space. Solid particles, called "planetesimals" condensed out of the cloud -- they're thought to have stuck together and created the early Earth. Bombarding planetesimals heated Earth to a molten state. So Earth started out with a lot of heat -- but, even now, new heat is being produced.


DB: Many of the rocks in Earth's crust and interior undergo a process of radioactive decay. That's the disintegration of natural radioactive elements. This process produces subatomic particles that zip away -- and later collide with surrounding material inside the Earth. Their energy of motion is converted to heat -- to create Earth's primary heat source. Without radioactive decay, Earth would have fewer volcanoes or earthquakes -- less shifting of land plates and building of vast mountain ranges.


JB: The heat energy produced by Earth is enormous, but it's 5000 times less than what Earth receives from the sun. The sun's heat drives the weather and ultimately causes erosion.


DB: So while the Earth's heat builds mountains, the sun's heat destroys them. With thanks to the
National Science Foundation, we're Block and Byrd for Earth and Sky.

Author(s): Bizy Kubala, Mohan Rao, Marc Airhart, Deborah Byrd

Please let us know what you think!

Saturday, February 26, 2005Monday, February 28, 2005


© 2005 Byrd & Block Communications Inc. Permission to use, copy and distribute these materials without fee is hereby granted, provided that the above copyright notice appear in all copies and the materials are not redistributed for profit.