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The Winter 2010 issue of The Earth Scientist includes a variety of educational resources, ranging from astronomy to glaciers. Check out the other publications and classroom materials in our online store.

Quickie Questions - Humans and the Things They Do - Other Things They Do

Date Answered Questioner (age, location) Question Answer

February 5, 2010dan (age 11, Virginia) Why doesn't air pressure overcome the air in our bodies, and squish us scince there is a lot more air on top of us than in us? We don’t feel air pressure, because the air and fluids inside our bodies balance the air pressure around us.
February 1, 2010ishinj (age 13, sri lanka) what is black planet & is that thrue that the wold ends in 2012 In the context of Astronomy I don't know what a black planet is. Regarding 2012, there is no known scientific reason for such a catastrophe to happen.
January 25, 2010Dante (age 11, Pennsylvania) Is there an effect on evaporation rates when forming crystals from sugar and sugar substitutes? Yes, once dissolved, sugar is very difficult to re-crystallize because the water hangs on to the sugar molecules.
January 25, 2010Caitlin (age 13, New Zealand) Are the eels that i catch from our pond poisonous? we live on a farm so i mean our farm pond.The colour of the eels is a very light brown some times with spots.hope you can reply.....it would be a great help to know if we can smoke them to eat!! thankyou. For your own safety it would be better if you contact a local biologist to clarify your question. It could be a university department or a goverment office for wildlife or similar.
January 21, 2010saiannice (age 9, florida) how many years on Earth is 800 light years? A light-year is a unit of length. It is defined by the International Astronomical Union (IAU) as the distance that light travels in a vacuum in one Julian year (= 5.88 trillion miles or 9.46 trillion kilometers).
January 21, 2010chrissy (age 31, wisconsin) my son wants to know if it has been proven that peoples personalitys changes in a unusual or strange way during a full moon? While superstitions assert that lunar cycles affect human behavior, scientific studies find nothing to support them. This interesting article discusses this topic.
January 18, 2010Tom (age 45, Massachusetts) I recall a science teacher (professor?) saying that adding extra weight to the back of a vehicle actually does not improve traction in snow. This makes sense to me because the extra weight would cause more friction between the tires and the snowy or icey road. This friction to overcome in order to achieve forward motion. Thank you and happy holidays to you. And I agree with you. It is obvious, from day-to-day experiences, that heavier vehicles are less prone to slide (although, once out of control, they are harder to stop). In the case of a pick-up truck, with an uneven weight distribution, the addition of extra weight in the back will provide a better traction.
January 15, 2010Lawrence Childress (age 62, Texas) How did the Romans / Greeks produce fire? There are some indications that they used hitting stone against stone or flint against metal to generate a spark (the latest is still commonly used nowadays in gas lighters). Often the fire was kept running all day, like in churches or goverment places.
January 8, 2010Anne (age 13, India) why is earth's temperature going? and why is global warming taking place? We, humans, are the main culprit. Our web page Global Warming offers lots of information on this topic.
January 8, 2010Ellia (age 16, Las Vegas) What factors besides pH affect the corrosion of zinc metal by citrus juices? There is one important factor, how long is the metalic object exposed to the acid.
January 5, 2010josue (age 14, california) what is infrastructure Infrastructure can be defined as the basic physical and organizational structures needed for the operation of a society or enterprise.
January 5, 2010Krisha (age 13, Florida US) what was the impact caused by the invention of the xray? X-rays were discovered in late 1895 by W. C. Roentgen, a German physicist. Today x-rays are widely used in medicine and security applications (like airports). They are also a great tool for observing celestial bodies.
January 4, 2010manjunathan (age 18, INDIA) can we live in other planet Other planets conditions are extremely harsh and not suitable for human life. They can be transformed or space bases can be built at enormous cost, but there are still a long list of question about how such endeavour would affect the human body and mind.
January 4, 2010Patrick (age 16, Ghana) do tall buildings resist thunder strike? if yes how Yes, they are protected by lightining rods, a metal rod or conductor mounted on top of buildings and electrically connected to ground through a wire.
January 4, 2010jahnavi (age 11, india) is there waste in the space? Yes, our aticle Junk in Space! describes this increasing problem.
December 16, 2009Vanessa (age 13, nj) Is fluorite a fracture or a cleavage Fluorite is a good example of Octahedral Cleavage.
December 16, 2009shifa (age 9 years, u.a.e) is the world going to finish in 2012? There is not a single scientific fact that supports this catastrophic prediction.
October 27, 2009Jafar (age 20, India) What is the exact proportion between land and water on earth? The exact proportion, as you asked, is not an exact science. As it was stated by The encyclopædia of geography by Hugh Murray, William Wallace, Robert Jameson, Sir William Jackson Hooker, Thomas Gamaliel Bradford, William Swainson: "Geographers roundly estimate the ocean and its branches to occupy three fourths of the entire surface of the globe. But to ascertain the exact proportion between the land and water will afford them ample employment for ages to come..."
October 19, 2009rachel (age 17, minnesota) why cant radiosondes observe the mesosphere? They can! Just as an example of scientific studies of the mesosphere using radiosondes, see this scientific paper and this one
October 16, 2009Ashvin (age 13, Nepal) How do scientists calculate the distance between teo galaxies? Tell me the whole process There are several methods. The measurement of the disperson of the radiation emited by pulsars, the use of yhe oscillation of Cepheid Variable stars, the parallax method (the relative movement of nearby stars against the very distant stars as the Earth goes in its orbit). This forum discusses several of the methods.
October 13, 2009puvi (age 12, malaysia) do legendary creatures exist? Legendary creatures are exactly that, creatures created by human imagination along with legends of their mythical heroes. Dragons, unicorns, mermaids, etc. are fun, but not real!
October 9, 2009Ron (age 59, Illinois) What will happen here on earth when all the planets line up ? If your question is related with the 2012 myth, rest assured that no a single scientific fact support such cataclysmic claims. Not all planets will be aligned in 2012, Mercury, Venus and Saturn will be on the other side of the Sun. Furthermore, alignments can't cause earthquakes and volcanic activity (one of the most common claim). The Moon and the Sun's gravity have considerably more effect than any of the other planets on the Earth.
October 9, 2009Jessi (age 21, Tonga) Which side is shine? the one with white or the one is black? A shiny surface is one that reflects as much light as possible. If both sides are of the same material and with the same polish, the white side reflects more light.
October 9, 2009timmothy (age 11, michigan/ united states) what will happen in 2012 are we going to DIE? No, we are not going to die in 2012. There is no a single scientific fact that supports that idea.
October 6, 2009nathan (age 9, china) what causes weeks? A week is a time unit now equal to seven days. In the past, weeks of between 4 and 20 days have been used historically in various places. See this web page and this onefor more information.
October 6, 2009Sanduni (age 12, Sri Lanka) How to spot celestial objects in the night sky ? The best way is to use celestial maps. The website SkyMaps.com offers free Sky Maps Each Month, for anybody to explore, learn and enjoy the night sky. there are also many software packages that are very easy to use and to customize to your location.
October 2, 2009Jyoti (age 12, U.P. India) On which continent on Earth the Sun shines first in the morning and after that as the Earth moves which are the other continents it cover? It is just a convention adopted long ago. The International Conference in 1884 deemed that there would be a single Universal Day and that this would begin at mean midnight at Greenwich (Meridian 0), the rest of the meridians to the west will have their new day after that.
September 30, 2009Michelle (age 28, Kotzebue, Alaska) Found an egg shaped rock, approx 20 lbs and about 1 foot long and 7 inches in heighth, wondering if it would be a metorite rock. It would be better to take the rock to your local natural science museum or university, they will know who to ask.
September 17, 2009Cheyenne (age 13, New Zealand) What is a protein? Proteins are one of three major classes of food or source of food energy (4 kcal/gram) abundant in animal-derived foods (ie: meat) and some vegetables. A more scientific definition: Protein is a macromolecule composed of one or more polypeptides, each comprising a chain of amino acids linked by peptide bonds.
September 17, 2009Nicholas (age 84, Maryland, United States) If the ocean could be very deep (50 or 100 miles) and a ship sank.Would it go all the way to the bottom or could remain suspended somewhere along that depth due to buyancy of the salt water. (Archinedes) Thank you. Once all the air spaces on the ship has been replaced by water, the ship will sink all the way to the bottom.
September 16, 2009jean (age 41, new jersey) i found human figures inside some rocks, i would like to know if it true or my mind is playing tricks on me ? The best bet would be to take the rock to the closes Museum of Natural Sciences or University. They can find a specialist to study the rock.
September 15, 2009angelica (age 12, philippines) what is the famous line of nicolaus copernicus There are many, I especially like: "For I am not so enamoured of my own opinions that I disregard what others may think of them."
August 26, 2009Patti (age 16, Philippines) who is marcus valerius martial? Marcus Valerius Martialis was a Latin poet from the Iberian Peninsula best known for his twelve books of Epigrams, published in Rome between AD 86 and 103. You can see his biography here.
August 21, 2009casey (age 57, New Jersey) can man reproduce thunderstorms?? As far as I know, it is still not possible. Scientists have tried to seed clouds with diverse degrees of success, and to create conditions for lightning. But a full thunderstorm is very complex, and I don’t believe it has been done.
August 21, 2009kierra (age 17, ohio) how dose the rock cycle illustrate the conservation of matter During the rock cycle the material that forms the rocks is just reused to form new types of rocs. Roks are destroy, but the substance is not!
August 20, 2009Jim (age 80, USA) What is the weight, in pounds, of a cubic foot of basalt? Solid basalt is 3011 kilograms per cubic meter, which converts to 188 pounds per cubic foot.
August 20, 2009Benjamin (age 48, Texas/U.S.A.) What is the current estimated amount of greenhouse gases generated daily by the 130,000+ commercial airlines flights over the continental U.S.? Although aviation is considered one of the less polutant forms of travel, consider this fact: CO2 emissions from the jet fuel burned per passenger on an average 3200 kilometers (1992 miles) airline flight is about 353 kilograms (776 pounds). I am not aware of a total estimate for all comercial flights.
August 17, 2009Alexander (age 7, Saint louis, U.S.A.) How do rockets challenge earth's gravity? Rockets use the energy from its combustble to lift itself (and any load) against the gravity pull. Scientists have calculated very precisely the thrust needed for an object to levae Earth gravitational field.
August 12, 2009miss yuhee (age 17, ,malaysia) why influenza H1N1 was called by that name? See Influenza A virus nomenclature for a full explanation.
August 10, 2009benjamin (age 11, germany) what is space trash Space debris or orbital debris, also called space junk and space waste, are the objects in orbit around Earth created by humans, and that no longer serve any useful purpose. See this web site for more information.
July 27, 2009Brenna (age 13, Iowa) What does UTC stand for? UTC is the Coordinated Universal Time, a time standard based on International Atomic Time (TAI) with leap seconds added at irregular intervals to compensate for the Earth's slowing rotation. An interesting information about the use of UTC (and not CUT) can be found here.
July 27, 2009Kryshana (age 14, Georgia) What is the doomsday device and its relevance to the atom smasher and the "secrets of life"? A doomsday device is a theoretical device, usually a weapon, with the potential to destroy all life on Earth, and even Earth itself.
July 22, 2009Emma (age 11, England) Do you use a ruler to join the plot points when you are drawing a graph? It depends of what kind of plot I need! For a multipoints plot I would do it by hand, smoothing the curve as I go through the points (there are many mathematical methods to do the same, they are commonly used in all plotting programs).
July 20, 2009Barry (age 50, Oregon, USA) If I run my gasoline engine inside the greenouse will that help them, they love Co2. They may love CO2, but your lungs don't! Be carefull with running any combustion engine in an enclosed space.
July 17, 2009Barry (age 50, Oregon, USA) If I run my gasoline engine inside the greenouse will that help them, they love Co2. They may love CO2, but your lungs don't! Be carefull with running any engine in an enclosed space.
June 17, 2009Aaron (age 15, Kenosha) What is an example of phylum sarcomastigophora? The phylum Sarcomastigophora includes many abundant and ecologically important forms. All are either unicellular or colonial, and may be either autotrophic or heterotrophic . There are two main groups, the flagellates (subphylum Mastigophora) and the amoebas (subphylum Sarcodina). See this website for more information.
June 2, 2009Austin (age 11, New Jersey) Do you know nay information about the Aztec gods Tlaloc, Quetzalcoatl, and Huitzilopochtli? Oour website offers information on many mythological figures. Here you can find information about Tlaloc, Quetzalcoatl, and Huitzilopochtli.
June 2, 2009Austin (age 11, New Jersey) Do you know nay information about the Aztec gods Tlaloc, Quetzalcoatl, and Huitzilopochtli? Oour website offers information on many mythological figures. Her yoou can find information about Tlaloc, Quetzalcoatl, and Huitzilopochtli.
June 2, 2009Basauri (age 60, Mexico City) ¿Cuál es la traducción de lo que dice la PIEDRA ROSETTA?
or "Which is the translation than it says STONE ROSETTA?"
El texto de la Piedra Rosetta es una declaración de Ptolomeo V sobre impuestos y estatuas en templos. El texto completo puede ser consultado aquí.
May 18, 2009Suneet (age 65, USA) What causes space junk to fall on to the earth? According to first law of Newton, the objects should continue to remain in motion in space. There are several causes for space junk to fall back to Earth. For example, if due to solar activity we have a geomagnetic storm, the atmosphere would be heated, and would expand. This, in turn, would increase the drag ratio acting on orbiting objects.
May 18, 2009aaron (age 10, united kingdom) is the world coming to an end in 2012 because all over the internet it says its coming to an end like more earthquakes and globel warming and all that stuff and the asteroid. There is no scientific reason for such a disaster to happen.
May 18, 2009Nitya (age 11, California) What are th advantages and disadvantages of bringing Martian rock to Earth to look for organisms? Without being completely sure of what your question is about, I can easily imagine a couple of pros and cons. PROS: Better equipment, bigger team of scientists. CONS: possibility of contamination of the sample, absence of the original environment.
May 7, 2009DEMILADE (age 14, CANADA) why can't one use a ballpoint pen in space Actually this is a myth. Read this extract of the Astronaut Pedro Duque's Soyuz/ISS Diary for his experience with a normal ballpoint pen in space.
April 30, 2009andrew (age 50, australia) how old are our atoms in our body? In general the question can be asked as: How old are atoms? Please, visit this page for an interesting discusson on this topic.
April 30, 2009monika (age 15, india) what is pollution? i want to make a project based on pollution.for class 11 .plz help me & give me tips for good result.now plz............... Pollution is defined as undesireable change in the physical, chemical, or biological characteristics of the air, water, or land that can harmfully affect the health, survival, or activities of human or other living organisms.
April 27, 2009Joe (age 50, Ayrshire, Scotland) When a spaceship goes into outer space why does the earth not fly off into the distance, since it is travelling at around 250,000mph round the sun? Because althought the force acting on both bodies (earth - space ship) is the same, the acceleration that each one gets is inversely proportional to the mass. The mass of Earth is substantially bigger than the mass of the rocket, and the resultant acceleration is very close to zero.
April 27, 2009jennifer (age 16, CA) im conducting an experiment my topic is
"difference between female and male n indurance running"
my quietion is
how would i be able to test someones fitness ??
For a middle/high scool level project, the simplest way would be to measure heart rate before and after an exercise, and express the results as fractions of heart rate after excerse/heart rate before exercise. A fitter persone would have a smaller increase on heart rate after the exercise.
April 20, 2009jazmine (age 12, utah) should we continue the exploration of the moon? Yes, I believe so, but without stopping the support to other fields of study, including the advancing of the study of our own Earth.
April 17, 2009jamie (age 9, canada) why do scientists study about rocks,minerals and thelayersof the earth? There are many reason, from simple scientific curiosity, to the need to know our planet to make better use of its resources, and the possibility to predict natural disasters.
April 16, 2009Amia (age 12, USA) How does dew get on the grass in the early morning,like what gets condensed? During the day, water accumulates in the air as vapor. At night, when the temperature decreases, the air capacity to hold water vapor diminishes up to the "dew point", whn the atmospheric water condenses and form the dew.
April 15, 2009jess (age 13, canada) my science teacher told us that "the moon" and "the earth" aren't really the names but that it should be earth and moon is that true????? he compared it to say if you lived on mars you wouldn't saty i live on "the mars" you would just say i live on mars thanx It is just a semantic consideration. As a curiosity, in Spanish it is used in the same way: La Tierra, La Luna.
April 14, 2009warisha (age 18, pakistan) why poulition is increasing on our earth? One of the main pollutants is the CO2 emited by cars' and trucks' tailpipe, as a result of the combustion of fosil combustibles, a relatively recent technology..
March 25, 2009brandon (age 12, united states Al) what is the deinition for river bed A stream or river bed is defined as the channel bottom of a stream or river or creek; the physical confine of the normal water flow.
March 24, 2009Alyssa (age 15, Virginia) What is the name of the scale used to measure a hurricane? The Saffir-Simpson Hurricane Scale is the name of the system used to measure the intensity of these massive storms.
March 23, 2009muthu (age 20, india) electrons are always revolve around a nucleus but what happened when it is involving in covalent bonding or some other bond? In general, a covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. See this page for a simple description of this bond.
March 16, 2009Alfredo (age 17, Mexico) What is Punnett's square? A Punnett square is a chart which shows/predicts all possible gene combinations in a cross of parents whose genes are known. See this page for more information.
March 16, 2009Cody (age 12, Ohio) what is the difference between pyrite and gold? There are some clear differences. Gold is heavy, does not shine (does not reflect the sunlight). It is gold in color, and dull. Pyrite, on the other hand, is not heavy, it shines, and is yellow in color.
March 10, 2009Bilal (age 13, Canada, Saskatoon, SK) while the hubble space telescopecan take pictures many light years away why can't it take a picture of gliese 581 c which is only 20.5 light years away??? The optical observations of exoplanets is not an easy task. The bright and mass of the star in the system makes difficult the direct observation. Other instruments, like the High Accuracy Radial Velocity for Planetary Searcher (HARPS) are used. HARPS is a spectrographic instrument that splits light to find wobbles in different wavelengths. Those wobbles can reveal the existence of other worlds.
March 4, 2009Johnna (age 11, America) What is the difference between Titans and gods? The Titans, also known as the elder gods, ruled before the Olympians overthrew them. The ruler of the Titans was Cronus who was de-throned by his son Zeus.
March 2, 2009Andreas (age 19, Sweden) How does a nuclear winter affect the climate and what creatures would become extinct?
Would the oxygen levels drop/how much?
How long would it last?
Nuclear winter describes the predicted climatic effects of nuclear war. It is also used in a similar way for the effects of an asteroid impact or a supervolcano explosion. In any of these cases, severely cold weather and reduced sunlight for a long period of time (months or years) would be caused by the large amounts of smoke and soot injected into the Earth's stratosphere due to the detonation of large numbers of nuclear weapons. Such escenario has not happened in recorded history, but there is no doubt that the devastation, due to cold temperatures and lack of sunlight, of the main agricultural areas would have a huge impact in the human population.
February 27, 2009JUANITA (age 9, NEWJERSEY/U.S.A.) HOW CAN LATITUDE AND LONGTITUDE LINE BE HELP AND WHO USES THEM Everyone using a map need to know and understand the latitud/longitude system. It permits to locate a specific point on a map.
February 24, 2009Hargobind (age 11, St.Louis, Missouri) How could it be possible to have humans be living on Mars in 2009 I believe we are very far from having a human colony anywhere outside our planet, with the only exception of the International Space Station.
February 20, 2009devon (age 18, Canada) what are we doing that is causing greenhouse gases?????? The main sources of greenhouse gases due to human activity are: burning of fossil fuels and deforestation leading to higher carbon dioxide concentrations. Land use change (mainly deforestation in the tropics) account for up to one third of total anthropogenic CO2 emissions.[20] livestock enteric fermentation and manure management,[22] paddy rice farming, land use and wetland changes, pipeline losses, and covered vented landfill emissions leading to higher methane atmospheric concentrations. Many of the newer style fully vented septic systems that enhance and target the fermentation process also are sources of atmospheric methane. use of chlorofluorocarbons (CFCs) in refrigeration systems, and use of CFCs and halons in fire suppression systems and manufacturing processes. agricultural activities, including the use of fertilizers, that lead to higher nitrous oxide (N2O) concentrations. From Greenhouse gas.
February 19, 2009Kaylan (age 11, Texas) Is a Dalmation Stone a sedimentary, igneous or metamorphic? Dalmatian Stone, or orbicular Rhyolite, is an igneous rock.
February 10, 2009Darcie (age 11, Australia) why cant we see Jupiters moons? Using telescopes we can!
February 9, 2009leny (age 19, philippines) who is the founder and father of trigonometry??? The Greek mathematician Hipparchus is condidered to be the founder of trigonometry. He produced the first known table of chords in about 140 BC.
February 8, 2009cya (age 14, india) sir,can you please give some of the sites related to science including astronomy?like http://www.windows.ucar.edu/comments/askAScientist.html&& I would suggest that you start with our website Windows to the Universe (http://www.windows.ucar.edu/). We cover many aspect of human knowledge, including science and astronomy, and also offer many linnks to other sites.
February 5, 2009sudiang (age 16, philippines) what is the control measures of green hous effect There are many measures being adopted to slow down the green house effect. Some of them are of big scale, some others can be done at our own house. Here are some tips: 1.Car pool or find another way to travel in order to preserve the earth's natural resources. 2.Reuse house hold items. That way our land fills don't fill so quickly. 3.Compost your left over friut and vegetable parts. It can give you rich soil and also reduces the amount that goes into the landfills. 4.Don't sit around the house waisting electricity when you can be outdoors and playing in the sun. 5. Recycle your paper, beverage containers, milk jugs, and tin cans so that they can be used to make new material and so that we don't waiste natural resources.
February 5, 2009Zania Avalos (age 11, California) I heard that in 30 more years there will be a bigger earthquake than ever and alot of people might die,is that true? Scientists are still working toward a consistently succesful prediction of earthquakes. It is currently very hard to predict seismic activity for such a long time.
February 4, 2009Alex (age 12, Maine, USA) When Mt. St. Helens erupted, scientists dated the new rocks formed from the eruption using the Radiometric dating systom. Although the rocks were less than 20 years old, the dating systom said they were over 2000000! Is the Radiometric dating systom really reliable? If it is not, how do we know how old the universe is? All of the methods under the definition of Radiometric Dating are very accurate. This detailed article offers a good review of the methods in a clear language.
February 4, 2009William (age 64, NY, USA) I believe I have found a fossilised rock with organisms imbibed in it. This rock was found on a small beach in Newfoundland. How do I find out more about it? Thanks The easier way is to approach your local Museum of Natural Sciences.
February 3, 2009Viola (age 13, United States) I am studying about Autumnal Equinoxes and cannot find out when the year of 2008's will be. Can you guys help me out? Here you can find a table with the equinoxes and solstices from 2000 to 2020.
January 29, 2009Asif (age 24, Pakistan) if a hellicopter is suspended in air and earth rotates about its axis for 12 hours, where will the hellicopter land after 12 hrs,new position or old position and why? There are many factors to keep in mind in order to offer an exact answer to this question. Most importantly the condition of the atmosphere at this particular place. Where there winds? Was it during the night, day, a combination? How high is the hellicopter suspended? At what latitud? Season? etc.
January 28, 2009kajal (age 13, india) Sir if i have to become an astronaut what should be my i q and what knowledge should i gain at my age? This is a real example of NASA requirements:

NASA National Aeronautics and Space Administration Lyndon B. Johnson Space Center Houston, Texas Announcement for Mission Specialist and Pilot Astronaut Candidates

Astronaut Candidate Program
Basic Qualification Requirements
Applicants must meet the following minimum requirements prior to submitting an application. Mission Specialist Astonaut Candidate: 1. Bachelor's degree from an accredited institution in engineering, biological science, physical science, or mathematics. Degree must be followed by at least three years of related progressively responsible, professional experience. An advanced degree is desirable and may be substituted for part or all of the experience requirement(master's degree= 1 year, doctoral degree= 3 years). Quality of academic preparation is important. 2. Ability to pass a NASA class II space physical, which is similar to a civilian or military class II flight physical and includes the following specific standards: Distant visual acuity: 20/150 or better uncorrected, correctable to 20/20, each eye. Blood Pressure: 140/90 measured in sitting position. 3. Height between 58.5 and 76 inches. Pilot Astronaut Candidate: 1. Bachelor's degree from an accredited instuition in engineering, biologicaal science, physical science, or mathematics. Degree must be followed by at least three years of related progressively responsible, professional experience. An advanced degree is desirable. Quality of academic preparation is important. 2. At least 1000 hours pilot-in-command time in jet aircraft. Flight test experience highly desirable. 3. Ability to pass a NASA class I space physical which is similar to a civilian or military class I flight physical and includes the following specific standards: Distant visual acuity: 20/50 or better uncorrected, correctable to 20/20, each eye. Blood pressure: 140/90 measured in sitting position. 4. Height between 64 and 76 inches. Citizenship Requirements Applicants for the Astronaut Candidate Program must be citizens of the United States. Note on Academic Requirements Applicants for the Astronaut Candidate Program must meet the basic education requirements for NASA engineering and scientific positions -- specifically: successful completion of standard professional curriculum in an accredited colloege or university leading to at least a bachelor's degree with major study in an appropraite field of engineering, biological science, physical science, or mathematics. The following degree fields, while related to engineering and the sciences, are not considered qualifying: -Degrees in technology(Engineering Technology, Aviation Technology, Medical Technology, etc.) -Degrees in Psycology(except for Clinical Psycology, Physiological Psycology, or Experimental Psycology which are qualifying) -Degrees in Nursing -Degrees in Social Sciences(Geography, Anthropology, Archaeology, etc.) -Degrees in Aviation, Aviation Management, or similar fields.

January 28, 2009cya (age 14, india) why do humans have wrinkles on their skin when they are old? The two basic organic reasons for the degradation of our skin as we age because are that we lose the two main building blocks for skin health, collagen and elastin. Of course, there are external factors that could accelerate this process. From gravity (which we can't do anything about) to a long list of other causes that we can, up to certain point, control: sun damage, smoking, dehydration, diet, lack of sleep,etc.
January 23, 2009elspeth (age 13, Australia QLD) what does it mean when you write about a moon's diameter and write the number times another number, for example (Telesto) 30X16 let's say that you have the mass of our planet expressed as 5.98 x 1024 kilograms. This is call scientific notation. It means that the number up front (in this case 5.98) should be multiplied by a 1 followed by 24 zeroes. The result in this particular case will be: 5,980,000,000,000,000,000,000,000 kilograms (Wouldn't you agree that it is easier to express such a large number in scientific notation?)
November 12, 2008quincy (age 13, philippines) what is gradation in geological term? The distribution of the various sized particles that constitute a sediment, soil, or other material.
November 11, 2008nelly (age 43, new york) THREE FACTORS THAT AFFECT OUR CLIMATE Regional or global climate can be affected by many anthropogenic and natural causes. A violent volcanic eruption, or meteorite hit, can produce enough atmospheric contamination to block the sunlight. The burn of forests (natural or man-made) can also have an important role. The release of industrial contaminants (including the automobiles tail-pipe gases) to the atmosphere is maybe one of the most important factors to consider.
November 6, 2008Marc (age 11, United States of America) How come we can not tell when a earthquake happens? There are so many known (and maybe many other unknown) factors related with earthquakes that scientists have not been succesful predicting earthquakes, but serious efforts are being made, and there is the real possibility that soon we will be able to predict them.
November 6, 2008Marc (age 11, North Caronlina United States of America) How come we can not tell when a earthquake happens? There are so many known (and maybe many other unknown) factors related with earthquakes that scientists have not been succesful predicting earthquakes, but serious efforts are being made, and there is the real possibility that soon we will be able to predict them.
November 6, 2008ANYN (age , Arizoka) When was glass first made by man? It is not well known where and when the first man-made glass was produced but it is thought to be in Mesopotamia (located today in the Iraq/Syria area) between 2000 and 3000 B.C. as indicated by written records found in this area. More information here.
November 6, 2008ashley (age 11, united states) what is the study of the entire atmosphere called? Aeronomy is a branch of science that deals with the atmosphere of the Earth and the other planets with reference to their chemical composition, physical properties, relative motion, and responses to radiation from space.
November 5, 2008EmTa (age 10, USA) What can kids do to stop global warming? WE ALL NEED FIRST TO EDUCATE OURSELVES ON THIS TOPIC. And we also need to educate our parents and friends. There are many things to do, from producing less trash and using fluorescent lamps, to walk or ride more our bikes instead of drive to everywhere. In this article you can find 50 Things To Do To Stop Global Warming.
November 5, 2008abhinav (age , india) what is the mechanism LARGE HADRON COLLOIDER? The Large Hadron Collider (LHC) is a huge (world's largest) high-energy particle accelerator, intended to collide opposing beams of protons or lead ions, moving at approximately 99.999999% of the speed of light. Please, visit its website for more information: LHC.
November 3, 2008Sarthak (age 14, India) Why are the star images larger for brighter stars? Because there is more light to be collected by the lenses of the telescopes.
October 22, 2008Alvyn (age , ) It seems to be from analysis of pictures taken by the Chandra X-ray Observatory. Quoting from this article: "In 2002, astronomers obtained a deep Chandra observation that shows ripples in the gas filling the cluster. These ripples are evidence for sound waves that have traveled hundreds of thousands of light years away from the cluster's central black hole."
October 21, 2008Linnea (age 13, USA) I've been thinking of universal time and distance measurements and I am curious if this has not already established, has it? What I mean is a standard which is consistent throughout the universe, ie like a unit of distance = Planck Length, but how can time be represented universally? Universal Time (UT) is a timescale based on the rotation of the Earth. There are several versions of it, the most commonly used being UTC and UT1 (see this link). Now, for a nice discussion of how time applies to the universe, see this article.
October 16, 2008cya (age 13, india) sir,please answer my this question. sir,can't we send a satellite in space and let it wander over there with a video recorder? by this we will know a lot about space and discover new planets,moons,stars,galaxies,aliens and lots more and we would even (atleast to some extint) that how huge is universe. while using a video recorder we would have to use a lot of tape. and sir,can you please that how bubble gums (chewing gums) are prepared with poly(styrene-butadine)and why do they stick to our skin and not to our teeth. and sir, can you please also tell if there are aliens in the dragon's triangle in pacafic ocean or if aliens ever came to area 51 in U.S.A??? Something similar is already being done. All satellites have sensors that observe and collect information about our planet, the sun, and the space, and then it is send to Earth.
October 9, 2008shruti (age 15, india) why is the flow of electric current opposite to the flow of electrons This is an old discussion with many sides. If an electric current is invariably made of negatively-charged particles (electrons), the your statment is true, but this is not always the case! There are instances when electric currents can really be a flow of positive particles. See this page for a good discussion of this topic.
October 9, 2008candice (age 18, new zealand) is there anything currently happening to prevent the artic ice melting and disrupting the ocean conveyor belt?? Yes, actions are being taken to prevent the effects of the climate changes. International agreements to reduce the use of greenhouse gases are in effect, the development of new techniques to reduce the amount of dangerous gases from autos and industry are already showing results (for example, catalytic converters, hybrid cars, etc.), the use of solar and wind energy is spreading, etc. But what I think is the major accomplishment is that humanity has come to realize that we cannot keep abusing of our home planet as until now.
October 8, 2008cya (age 13, india) is it true that a black hole can be formed by a 27 kilometre long machine if the the protons are being crashed at the speed of light? There is no any true in that. This experiment, knwon as article offers a nice review of the topic.
October 6, 2008Frank (age 30, The State of Indiana) Dear Sir or Madam,
Is there any treatment or process which an organic material, such as wood or other plant fibers, can undergo which would render it comparable in strength and hardness to rival Bronze or Iron Age tools which does not involve a modern process, such as the application of sophisticated resins?
I know this seems like a strange question, but it's for a book I'm writing. Finding a "yes" answer to this question would really be a boon, but my own research hasn't yielded any results. The problem is I don't know enough about physics or chemistry to figure it out on my own.
During the Bronze Age techniques for smelting copper and tin from naturally-occurring outcroppings of copper and tin ores were developed, which allowed the creation of a bronze alloy by melting those metals together, and casting them into bronze artifacts. I (personally) don't believe there is a simple method to obtain similar results with organic materials.
October 3, 2008Hasmin (age 10, Philippines) who introduce the system of classifying or grouping living things? Linnaeus developed a Binomial Nomenclature (two name system) in which each organism has a genus (first) and species (second) names.
September 30, 2008andrea (age 17, pittsburgh) what time in history did mythology start There is no particular time for the begining of mythology. Different cultures described what they saw under their own terms, frequenly relating the shapes they saw on the sky with their particular gods.
September 30, 2008alaina (age 15, North Carolina, U.S) In what order does the nitrogen cycle go in? Nitrogen is a part of living things like plants and animals. Nitrogen is also a part of non-living things like the air above and the dirt below. Nitrogen does not stay in one place. It moves slowly between living things, dead things, the air, soil and water. These movements are called the nitrogen cycle. More information on our web page The Nitrogen Cycle.
September 29, 2008cya (age 13, india) sir, can you please tell how many marks do we have to bring to be an astronaut? and what should be our I.Q? and how many hours do we have to study? This is a real example of NASA requirements:

NASA National Aeronautics and Space Administration Lyndon B. Johnson Space Center Houston, Texas Announcement for Mission Specialist and Pilot Astronaut Candidates

Astronaut Candidate Program
Basic Qualification Requirements
Applicants must meet the following minimum requirements prior to submitting an application. Mission Specialist Astronaut Candidate: 1. Bachelor's degree from an accredited institution in engineering, biological science, physical science, or mathematics. Degree must be followed by at least three years of related progressively responsible, professional experience. An advanced degree is desirable and may be substituted for part or all of the experience requirement(master's degree= 1 year, doctoral degree= 3 years). Quality of academic preparation is important. 2. Ability to pass a NASA class II space physical, which is similar to a civilian or military class II flight physical and includes the following specific standards: Distant visual acuity: 20/150 or better uncorrected, correctable to 20/20, each eye. Blood Pressure: 140/90 measured in sitting position. 3. Height between 58.5 and 76 inches. Pilot Astronaut Candidate: 1. Bachelor's degree from an accredited instuition in engineering, biologicaal science, physical science, or mathematics. Degree must be followed by at least three years of related progressively responsible, professional experience. An advanced degree is desirable. Quality of academic preparation is important. 2. At least 1000 hours pilot-in-command time in jet aircraft. Flight test experience highly desirable. 3. Ability to pass a NASA class I space physical which is similar to a civilian or military class I flight physical and includes the following specific standards: Distant visual acuity: 20/50 or better uncorrected, correctable to 20/20, each eye. Blood pressure: 140/90 measured in sitting position. 4. Height between 64 and 76 inches. Citizenship Requirements Applicants for the Astronaut Candidate Program must be citizens of the United States. Note on Academic Requirements Applicants for the Astronaut Candidate Program must meet the basic education requirements for NASA engineering and scientific positions -- specifically: successful completion of standard professional curriculum in an accredited colloege or university leading to at least a bachelor's degree with major study in an appropraite field of engineering, biological science, physical science, or mathematics. The following degree fields, while related to engineering and the sciences, are not considered qualifying: -Degrees in technology(Engineering Technology, Aviation Technology, Medical Technology, etc.) -Degrees in Psycology(except for Clinical Psycology, Physiological Psycology, or Experimental Psycology which are qualifying) -Degrees in Nursing -Degrees in Social Sciences(Geography, Anthropology, Archaeology, etc.) -Degrees in Aviation, Aviation Management, or similar fields.

September 26, 2008Sean (age 13, California) How do I create a continuous electric arc? I was thinking something along the lines of running an electric current through a controlled stream of a highly conductive gas. This method is one of the most commonly used today. See, for example, this article.
September 25, 2008kali (age 11, goergia) are minerals compound or mixture Minerals can be found in both forms. A compound is when the materials are chemically bonded (for example, salt is a compound of sodium and chlorine), while mixture is when the materials are intermingled but still keep their individual properties (granite is an example).
September 18, 2008PATRICIA (age 40, CALIFORNIA) IS THE ECLIPSE DANGER FOR HUMANS No, eclipses, from the earth point of view, are just the partial or total apparent darkening of the sun when the moon comes between the sun and the Earth (solar eclipse), or the darkening of the moon when the Earth is placed between the Sun and the moon. The only related danger is to look directly to the Sun during eclipses without eyes protection.
September 17, 2008Sarah (age 9, Victoria) How do scientists discover their discoveries? After a lot of work and using the scientifc method.
September 17, 2008cya (age 13, india) if bubble gum sticks on our face why dosen't it sticks on our teeth? There are two main factors that differentiate one from the other, teeth are covered by a very polished, non-porous material and are always wet, the skin don't.
September 17, 2008cya (age 13, india) sir,what is the normal iq of a normal person? sir
Einstine's and sir newton's iq was more than a normal person?
The average IQ of the population as a whole is, by definition, 100. IQs range from 0 to above 200, and among children, to above 250. However, about 50% of the population have IQs between 89 and 111, and about 80% of the population have IQs ranging between 80 and 120, with 10% lying below 80, and 10% falling above 120. Adapted from What Does "IQ" Stand For, and What Does It Mean?.
September 16, 2008Molly (age 25, West Virginia) Can astronauts see asteroids, meteors or comets when they are on space missions? Although I haven't read about a specific case, I would expect astronauts to see them with more clarity because the lack of atmosphere at those heights.
September 16, 2008Devon (age 15, Ohio) A Scientist, examining a set of data, finds a single break in an otherwise strong trend or pattern in the data. Would the single break invalidate the trend or pattern? Why? No,a data point outside the main trend (known as an outlayer) could be due to many factors, like normal variability of the system, natural or artificial noise, etc. This is a extremely comun finding when working with "real" data. The use of error bars takes care of the variability.
September 15, 2008darryl (age 14, Illinois) Is the lake Geneva WI lake a crater? The second paragraph on this link describes the origin of the lake, and the rest that of the city of the same name.
September 15, 2008darryl (age 14, Illinois) Is the lake Geneva WI lake a crater? The second paragraph on this link describes the origin of the lake, and the city of the same name.
September 12, 2008Min (age 11, Myanmar) What is mean Dwarfs? These are the meanings of dwarf from wordnet.princeton.edu/perl/webwn: - a person who is markedly small - gnome: a legendary creature resembling a tiny old man; lives in the depths of the earth and guards buried treasure - shadow: make appear small by comparison; "This year's debt dwarfs that of last year" - a plant or animal that is atypically small - check the growth of; "the lack of sunlight dwarfed these pines" Currently is also used to identify the smallest (dwarf) planets in our solar system.
September 8, 2008Bears class (age 5, United Kingdom) How do rockets land? Rockets are not designed to land. Once all the combustible in them is used, they are released from the space ship and burn during re-entry in the atmosphere.
September 8, 2008Bears class (age 5, United Kingdom) How do rockets land? Rockets are not designed to land. Once they are released from the ship, they burn during re-entry in to the atmosphere.
September 4, 2008priyanka (age 15, NEPAL/kathmandu) What we have to know at first to become a scientist There are as many answers to your questions as scientists are, but I am sure we all agree in several common things -a love for learning, a big pasion for discovery, curiosity, math, and literal skills are basic factors over which a scientific carrer could be built.
September 1, 2008Amir (age 25, Pakistan) When a helicopter is placed on earth, its motion alongwith earth can be understood but when the helicopter is above earth (in air) why not it is displaced simply because of earth's rotation?
Which force binds helicopter to move alongwith earth when it is in air? (because gravity can only force it to come down not to move alongwith earth.)
The controlled motion of helicopters is a complex topic beyond the reach of this section. Let's only say that the combined, controlled motion of both rotors, including the pitch angle, is what keeps the helicopter in the right direction.
August 24, 2008Julia (age 13, Australia) How does Climate change relate to social justice and equity? You can find the answer to your question on Climate change, vulnerability and social justice, a paper published by Harvard scientists.
August 20, 2008Roy (age 60, North Carolina, USA) Is the oil that we are using up so quickly a form of insulation from the Earths molten core, Most of the oil is quite close to the surface, and I don't think it is enough, or well-distributed to be thought as a form of insulation.
August 20, 2008kav (age 15, trinidad) why is a flat tyre not considered to have zero atmospheres when flat? A flat tire still has air in the interior, only that it is not enough to use the tire as intended.
August 19, 2008brenda (age 10, nc) What is the most likely reason cars are designed with smooth surfaces I would say to minimize air friction.
July 2, 2008Darius (age 11, Baltimore) What is the hardness of the mineral cobalt (not cobaltite) on Mohs hardness scale? Cobalt has a hardness of 5.5 on the Mohs scale of mineral hardness.
July 2, 2008Keejhontai (age 12, u.s) were does the word metamorphic come from? The word metamorphic has Greek origins. Meta means change, and morphic means structure.
July 2, 2008emma (age 73, Michigan USA) What is an electrical surge that surge plugs protect against. An electrical surge is the short-lived, intense peak of electrical current that can reach our homes due to short-circuits, atmospheric electric discharges, etc. They could be quite damaging for common household appliances.
July 2, 2008Janice (age 47, San Antonio, Texas, USA) My nephew wants to know: If you throw a boomerang on the moon, will it come back to you? Or, just keep going straight? Bommerangs motion involves aerodynamic laws. It needs air to fly. See this website for more information.
June 30, 2008Timothy (age 9, Texas, US) How the moon is able to follow you when you are in a car ride? The average distance from Earth to moon is about 384 401 km. A normal car trip (for example, the distance between San Francisco and New York is 4125.91 km) is too short to be considered a change of position against the moon.
June 30, 2008Yu (age 9, Singapore) How many planets are there in the whole Universe? It is impossible to say. We don't have enough observational power to reach all corners of the universe.
June 30, 2008Yu Ci (age 9, Singapore) How many planets are there in the whole Universe? It is impossible to say. We don't have enough observational power to reach all corners of the universe.
June 27, 2008Haley (age 11, Massachusetts/USA) A person who studies and collects rocks for fun A person who studies and collects rocks for fun is called a Rockhound. People that study rocks professionally are called Geologists.
June 25, 2008Saffron (age , ) Due to the lack of breathable atmosphere it would be impossible without building an enclosed city or after a terra-forming process (the modification of the environment of a planet to make it more Earth-like and habitable by humans. Definition adapted from drernestmaurer.com/glossary.htm).
June 20, 2008Mark (age , ) It is commonly used to identify approximate values.
June 20, 2008Mark (age , ) It is commonly used to mark approximate values.

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