Quickie Questions - Humans - Technology

Date Answered Questioner (age, location) Question Answer
May 3, 2010KEVIN (INDIA)why solar cell produce dc supply not ac supply.The basic principle is that when a photon is absorbed, its energy is given to an electron in the crystal of which the cell is made of. The "hole" left by the electron is occupied by another electron, which now leaves a new hole behind, and so on. This is basically, a direct current being generated. (The whole explanation requieres a lot more space. See, for example, this article for more details.
May 19, 2009Daniel (Delaware)why can we not create a zero gravity bubble around a large object the could propel it into space.?because there is no such technology (yet?).
May 19, 2009Clinton (South Africa)Name the different energy wave lenghts used to vorm a picture of the cosmos.Different wavelenghts are used to see the sun, planets and the universe in general. The visible light is just a fraction of the electromagnetic spectrum. For example, the Hubble Space Telescope can observe in visible, infrared and ultraviolet light. Radio waves and infrared radiation are of longer wavelengths (beyond red), while ultraviolet is of shorter wavelenght (beyond violet). When we observe our galaxy under the different wavelenghts, different informations are obtained. for example, gamma ray observations of our galaxy reveal cosmic rays colliding with hot gas, when observed in X-rays galactic 'hot spots' are revealed, under infrared clouds of dust appear, and radio waves come from the centre of the galaxy.
April 21, 2009khawla (saudi arabi)how the junk is being tracked?
and what is your suggested ways of cleaning it up?
If you are asking about the space junk around our planet, there are two main institutions tracking them: The U.S. Space Command, a military agency, catalogues and tracks debris larger than 10 centimeter while NASA's Orbital Debris Program Office uses data collected by radar telescopes and other observatories to detect debris from 10 centimeters (4 inches) down to the size of a pinhead.
February 19, 2009kylie (mansfield)what is a optical telescope and what does it doAn optical telescope is an instrument used to gather and focus light from the visible portion of the electromagnetic spectrum.- There are two types of optical telescopes: Reflecting and Refracting. This page describes both types, and includes diagrams.
August 24, 2008mark (australia)If i'm in a jet flying south to north for two hrs and in that two hrs the earth has rotated 3200kms how then does the jet fly a direct course and not have to fly in a huge arcBy keeping the same height above the Earth surface, the jet is indeed flying in a huge arc!
August 14, 2008vishal (india)"If i want to trasmite signle through parabolic antenna with satelite,it is necessory to rotate our antenna with time changing?It depends on what kind of satellite you are trying to communicate with. If it is a satellite with a geosyncronic orbit, the antenna would be in a fixed position, but if the satellite changes position respect to Earth, the antenna will have to be moved.
March 27, 2008enzo (ontario canada)how does a gps map system work?The satellites from the GPS constellation are continuously transmitting their coordinates along a very exact time reference (using atomic clocks). The GPS receivers receive the signals from all satellites in view and, processing the small time difference between each signal, are able to determine the position where they are at. MOre information can be found here.
February 28, 2008Miami (310 10th Ave. South)What type of rockets do the space shuttle use?The Boeing Company's Delta 4 and Lockheed Martin Corporation's Atlas 5 are two powerful new expendable space rockets introduced in the United States in 2002. This page describes them.
February 7, 2008t-man (New York/United States Of America)Where is the Mauna Kea Space Center located?Mauna Kea’s Onizuka Center for International Astronomy (named Onizuke after the Hawaiian astronaut who perished in the Challenger tragedy) sits atop Hawaii’s tallest peak, Mauna Kea (“white mountain") at 13,800 feet.
February 7, 2008Sophie (UK Lincoln)What is the Chandra X ray observatory?The Chandra X-ray Observatory is a satellite launched by NASA on July 1999. Because X-ray photons would be absorbed by normal mirror surfaces, X-ray telescopes use mirrors with a low grazing angle to reflect them. Chandra uses four pairs of nested iridium mirrors, together with their support structure, called the High Resolution Mirror Assembly (HRMA).
January 31, 2008Luís (Portugal)Do diesel engines have explosions inside the cylinders?
I can find in books 2 answers for this question:
No! Inside a diesel engine there is combustion and no explosion.
Yes! Explosions take place inside a diesel engine, although slower then gasoline engines.
Please I would like to have some help to prove to my colleges (teachers) that in fact diesel engine have explosion inside their cylinders.
Both diesel engines and gasoline engines covert fuel into energy through a series of small explosions (combustions). There are differences between them: Gasoline Engine: fuel is mixed with air, compressed by pistons and ignited by sparks from spark plugs. Diesel Engine, air is compressed first, and then the fuel is injected. Because air heats up when it's compressed, the fuel ignites.
July 20, 2007ZACK (DELHI, INDIA)Name the equipment that keeps a track of aircraft and missiles in the air using radio wavesThe radars are also used to track the weather, animal migrations, etc.
January 3, 2007Michael (Wisconsin/USA)what are carbon nanotubes and what holds them together?Carbon nanotubes (CNTs) are allotropes (different molecular configurations) of carbon. They take the form of cylindrical carbon molecules and have novel properties that make them potentially useful in a wide variety of applications in nanotechnology, electronics, optics and other fields of materials science. For a comprehensive discussion please visit the Wikipedia page Carbon Nanotubes.
March 17, 2003Savanah(USA)If I wanted to make a telescope that could see far away how would I go about doing that?You can make a simple telescope out of lenses and a cardboard tube! Just follow the directions on the Lightwave website. Or, order a kit from Newport Glass Works to help you make your own telescope.
November 22, 2002Angie (California, USA)What is the difference between chart and a graph?The words 'chart' and 'graph' are often used to mean the same thing. They refer to a visual aid that is used to illustrate measurements. For instance, a pie chart, which represents the percentages of a whole, can also be called a pie graph.

September 23, 2002Michael (Ohio, USA)I have a really good invention, but I do not know where to go to make it?You might try talking to your science teacher or your parents. If it really is a good invention, they would probably be able to point you in the right direction.

September 12, 2002Brad (Alaska, USA)Why does it cost so much to patent your ideas? And I would also like to know where I would go to find money to do scientific research if at all possible.The patent process takes a lot of money because it actually takes a lot of work. To file a patent you need to do a lot of research, then write an application that describes your invention and what you think is unique about it. This usually requires legal help. Once you file a patent, it goes to the patent office, and there examiners check to see how your invention fits in with everything else in their records. Once they're satisfied that your invention is really unique (they also check other things), they can issue the patent. Overall, the process is slow and expensive, but worth it if your invention is really unique!

As for getting money for research, there are a lot of private and government-funded agencies that provide money for research. The application process is actually a lot like applying for a patent, because you have to write a long research proposal that describes what research you will be doing and why it is important. This process is not easy to do, so only the best scientists get money to start new projects.

If you are interested in trying research, I encourage you to contact the colleges and universities around you. Many schools have opportunities for students to do research in all sorts of different fields, and this is the best way to decide if you like it and to get to know the people who can help you take the next step in a research career.

November 30, 2000Kearrie (New York, USA)What has NASA done for humanity?NASA actually sent out an email earlier in October answering just that. Take a look!
September 6, 2000Don Where do I get plans to build my own telescope?To build your own telescope, you should definitely check out the ATM web site...that's the Amateur Telescope Making web site. Good Luck!
July 12, 2000Fran (Arizona, USA )How would you define a planetarium?A planetarium is any building that has a dome and a projector system which can produce an impression of the stars of the night sky. Planetariums are used for education and entertainment. And sometimes they offer star gazers refuge from the cold or the mosquitos!
June 29, 2000Sidney (Washington, USA )If a meteor is the size of a grain of sand, how can they do damage to satellites?Man-made debris orbits at a speed of roughly 17,500 miles/hour! A small speck of paint or a tiny meteor could do a lot of damage to a spacecraft if it hit at such a high speed!
June 19, 2000Susannah (California, USA )What is the future of the Hubble(What Do you think?)?

The Hubble has been going strong since 1990, and will continue to help scientists for many more years. Another telescope will take its place in the years to come.

June 2, 2000Steve (England)Does any one know a good site for setting up a reflecting telescope ?This site is a great reference for telescopes.
May 30, 2000Stephanie (Indiana, USA)I am getting a telescope soon. What are some stars or planets I could look at?

First of all, make sure you get a good look at the Moon. A telescope can provide a great view of our celestial neighbor!

Also look for Venus, Mars, Jupiter and Saturn. They should all stick out in the night sky.

May 17, 2000Carlene (Canada)What is hydro-electricity and how does it operate?Hydro-electricity is electricity produced by water! Power plants use the energy produced from flowing water.

Sometimes dams are set up along rivers. The water flows through the dam and pushed on a large turbine, which spins on a generator and makes electricity!

February 5, 2000Carl (Texas, USA)Why can't balloons travel in space?One of the major constraints on sending balloons to space is the amount of time a balloon can stay aloft. However, NASA has been working on this, and is working on an Ultra Long Duration Balloon which will be able to remain in the upper atmosphere for up to 100 days.
January 25, 2000Nicole (Arizona, USA)In year 2025 what would be most high tech space craft?It's hard to say exactly what will be the most advanced spacecraft 25 years from now, simply because out technology is changing so quickly.

However, in the near future space shuttles will be obsolete, thanks to a new spacecraft NASA has been working on. The VentureStar will be a reusable spacecraft that costs much less than the current space shuttles.

Read more about the VentureStar and it's prototype, the X-33, here.

July 12, 1999Annabelle (Ghana)What is the fastest spaceship and its speed?The fastest space craft in operation is the Ulysses mission to study the poles of the Sun. It travels at up to 11.3 km/s, which is 40680 km/hr. To put that in perspective, its over one-hundred football fields endzone to endzone per second! The Galileo probe was traveling at 47 km/s when it plunged into Jupiter's atmosphere, but it was destroyed shortly after entering the atmosphere.
June 30, 1999Josh (Minnesota)How long would it take to get to Grandma and Grandpa's house (Minneapolis to Tucson) aboard the space shuttle?Good question! I guess it depends if you are going to use highways, or just go straight there (avoiding construction delays). The distance between the two cities is about 1,800 miles by highway, and 1,300 miles as the crow flies (in a straight line). The shuttle has an orbital speed of about 17,500 mi/hr - so it would take about six minutes and six seconds with highways, and a little less than four and a half minutes if you go in a straight line. Barely enough time to even fall asleep in the back seat!
June 7, 1999Nichole (Idaho)Will the Y2K computer bug have any effect on the NASA's Cassini mission to Saturn?NASA is very carefully checking all their computers, hardware and software, to be absolutely sure nothing will go wrong as the new year begins.
May 24, 1999Nicholas (United Kingdom)What are the uses of resonance in modern day life ? What is Nuclear Magnetic Resonance?Magnetic resonance imaging (MRI) is an imaging technique used primarily in medical settings to produce high quality images of the inside of the human body.MRI is a painless technology used to view inside the body without using X-rays. It can produce two- or three-dimensional images using a large magnet, radiowaves, and a computer. The magnetic fields MRI uses are not known to be harmful and are painless. You can learn more about MRI at this site.
May 21, 1999Jordan (Ontario, Canada)How does a machine gun keep firing when you only press the trigger to fire once? How does this work?Machine guns are really clever. The original single-barreled machine gun used its own recoil energy to keep firing. The force of the fired bullet ejected the spent cartridge and loaded the next.
May 18, 1999MikeDo all visible artificial satellites travel from West to East?All visible artificial satellites do not travel from west to east. Many polar satellites occupy low orbits so are visible and travel north-south.

For more information on satellites you can look at the Windows satellite page.

May 1, 1999Mark (Nebraska, USA)What is the most powerful telescope you have there.Here at the University of Michigan, we have a 0.4 meter reflecting telescope. As far as the rest of the world goes, the Keck telescopes are some of the largest, with mirrors of 85 meters!< /td>
April 5, 1999Matthew (Australia)What is an infrared spectroscope and how does it work.I think maybe you are looking for information on an Infrared Spectrometer. This is the instrument used in infrared spectroscopy.
February 5, 1999Grant How long does it take for an object to orbit the earth? For example the space shuttle.How long it takes depends upon the object. But satellites such as the Space Shuttle circle the Earth once every 90 minutes. Since the orbit covers about 40,000 kilometers, the speed is about 26,000 km/hr or 17,000 mi/hr.
February 3, 1999Ben a. How does RADAR work?
b. How does 'stealth' technology work?
Here are a couple good pages...one for RADAR (click on 'First Time Visitors', then at the bottom on 'What is imaging radar.') and one for stealt h technology.
January 21, 1999David (Colorado, USA)When will the 'Space Plane' (X-33) take its first flight and what is the power source?The X-33 is scheduled to take its first flight in March. It will be launched using linear aerospike engines, and has fuel tanks holding liquid hydrogen and oxygen.
September 30, 1998Elizabeth(Florida, USA)If an air plane goes up in the clouds to the high level ones will it get ice on its wings?It's possible! At a certain temperature and pressure, called the dewpoint, the water in the air will change from a gas to a liquid. If the dewpoint is reached and the temperature at that altitude is freezing, then yes ice could develop on the wings of an airplane. Another important thing is the temperature of the wing surface. If the wing surface temperature is below freezing then the water can freeze on the wing surface in a process called sublimation. This process takes water as a vapor and turns it directly to a solid. Most airplanes that can go up that high have heaters in the wings to make sure that the wing surface is above freezing.
September 24, 1998DavidThanks to give me this chance to ask something about the space and our earth.I want to ask to what is the biosphere2 and is it the space colony of our future?Biosphere 2 is a large glass structure. It has seven ecosystems inside, and can be completely controlled. It is possible that someday we will build space colonies similar to this. At this time, it is important to learn as much as possible about how our Earth environment works in order to extend it to outer space.
May 16, 1998Deana (Missouri, USA) What substance(s) can neither be melted by extreme heat or frozen beyond use in the coldest temperatures, and is also lightweight? Can this substance withstand without being crushed by extreme pressure?NASA is still experimenting with a truly remarkable material called aerogel. It is the closest material I have heard of that fits your description. Aerogel is the world's lightest solid made principally from silica. It also is the strongest, lighte st and only transparent building material. Weighing as little as 3 times that of air, a single inch thickness of this silica-based material has the internal surface area of a basketball court and can protect a human hand from the heat of a blowtorch! Ch eck out some more info on aerogel...
April 6, 1998Sylvester (Sabah/Malaysia) What has space technology contributed to mankind's daily life?It would take a full book (or a full thesis!) to fully answer this! Let's see --computer design, electronic miniaturization, medical equipment, and international communications have all benefited from space technology. One of many practical examples is the system that is used to heat the faceplate of space helmets has also been used to keep burn victims warm since they can't tolerate blankets. And there are more intangible benefits. As astronaut William Pogue wrote, "I believe the most important a re the subtle and intangible benefits that have occurred within the minds and spirits of people. Among these benefits are aroused curiousity, the intellectual stimulation that attends exploration, and appreciation of the importance of goals, the virtue o f dedication, the necessity of commitment, and belief in one's ability to accomplish."
March 27, 1998Steve (Kansas, USA) I have been told that the Hubble Space Telescope has taken a picture of the actual 'Big Bang'. If this is true would you please guide me to some links and images.There are no pictures of the Big Bang. There have been observations of background radiation at radio frequencies which may be associated with the Big Bang, but there are no pictures.
February 20, 1998Aaron (Michigan, USA) What kind of a telescope must be used in order to see, if possible, the American Flag placed on the moon by the Apollo 11 astronauts?The Hubble Space Telescope can see farther with more clarity than any other telescope, but I don't think even the Hubble can see such tiny detail as the flag on the moon.
January 16, 1998Kory (Idaho, USA)Can you explain how a refractor works?Refraction telescopes use lenses, as opposed to mirrors as do reflective telescopes. Refractors have two lenses, and work by bending light. When light enters the telescope, it passes through the first lens and bent so it is focused down to a point. As the light passes through the second lens, it is again bent, this time magnifying it so the eye can see it.
January 8, 1998Kevin (USA)How far can the Hubble Space Telescope see?When the HST was first sent into orbit, the telescope was nearsighted! Its mirror was improperly curved, allowing it to see only one third as clearly as it should have. Now, however, the problem has been co rrected. The distance the HST is able to see depends upon how big and bright the object is. However, it can see with about ten times the clarity of telescopes on Earth.
December 9, 1997Great Scott (Kentucky, USA)When was the Keck telescope invented?Today Caltech and the University of California operate two Keck telescopes. They premiered in 1995. Both are located in Hawaii. It took 14.4 tons of glass to make the mirrors within just one telescope! These things are big!

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