WonderQuest:  On the web since 1997...      

Antimatter:  Are there anti-matter galaxies?
Cold nuclear fusion:  Is cold nuclear fusion possible?
Crashing electrons:  Why do electrons whiz around in their orbits instead of crashing into the nucleus?
Dating, radiometric: When dating ancient objects, how do scientists determine the initial
percentage of parent isotope in a dating sample?
Electromagnetic & strong nuclear force:  What is the difference between the electromagnetic force and the nuclear force?
Electromagnetic & strong nuclear force: What is the reason behind the glow of radium?
Energy:  What is energy?
Energy:  Where does an atom get its energy?
Energy:  It is possible to convert mass into energy, but can we do the reverse?
Neutrino:  What is the fastest moving thing in the universe, other than light or other types of electromagnetic radiation?
Radioactivity of radium: What is the reason behind the glow of radium?

Charge:  Photons carry the electromagnetic force, but don't have a charge. Like charges repel, differing charges attract. So when a photon from an electron approaches another electron, how does it "know" whether to repel or attract, if it is the same kind of photon that would come from a proton?
Electromagnetism:  Your answer about light got me wondering how we "see" other electromagnetic waves — like ultraviolet light, infrared light, and radio waves. Why can’t we see them all?
Electromagnetism:  I wonder what viewing device, in theory, would have high enough resolution to detect the movement of nitrogen and oxygen molecules? Could radar be used or would it take higher frequencies, like X-rays?
EMI: On many electrical cables, particularly those for computers, there is a cylindrical chunk of ferrite material slipped over the end adjacent to the plug. I understand these things somehow filter out undesirable electrical interference but, how do they work?
Energy:  What is energy?
Magnetism:  Why are some things magnetic? What makes them magnetic?
Magnetism:  Is there any material or substance that blocks or interrupts a magnetic field?
Radio waves: Why are AM radio signals coming from a distance much stronger at night?
Radio waves:  What’s the longest radio wave (and, therefore, has the lowest frequency)? Which equation relates the wavelength, frequency, and speed of an electromagnetic wave?
Resistance:  Why does electrical resistance exist?  Why does metal have low resistance?
Speed of electricity:  What speed does electricity travel along a wire?
Surface tension:  What can keep water from falling out of an inverted cup?
Thunder: I see lightning but often hear no thunder. Why is there no thunder?

Balance point:  At what point between the Earth and the Moon will their gravitational fields cancel each other
Black holes: I was taught in school that gravity is a force between two masses. And that the speed of light is the fastest something can travel, because light has no mass. So why can light not escape from a black hole? If it has no mass, how can it be under the influence of gravity?
Earth:  If the earth had twice its present mass, but the same radius what would be the value of g?  
Energy:  What is energy?
Falling candle:  If you place a lighted candle in a sealed jar and drop it, why does the candle go out as soon as someone catches the dropped jar?
Gravitons:  If gravity is nothing but the bumps, depressions and warpings of geometrical space-time, why is anybody talking about ‘gravitons’ to explain gravity? Doesn’t Einstein's General Theory of Relativity do the job?
Hot air rising:  I am an 8-year-old boy and I want to know how and why fire travels upwards.  Why does a candle flame defy gravity?
Space, weightless:  Today on CNN, they reported that the astronaut and cosmonaut at the space station "lost weight" because of a restricted diet. Without gravity effects acting on a space station ("weightless"), how do they determine that the men had "lost weight"?
Weight:  How much would I weigh at the center of the earth?

Absolute zero:  What happens at absolute zero?  Do atoms and electrons stop moving?
Bubbles (supersaturation):  Why do little bubbles form along the bottom and the sides of a cup when carbonated drinks are poured into it?
Bubbles:  Why does beer fizzle when you add salt?
Bubbles:  Why does soda pop spew out violently when shaken and opened?
Burning candle:  If I put a small burning candle on the middle of a plate, cover it with a jar and then fill the plate with water, why does the candle go out and the water seep into the jar? 
Contrails: Why do jets leave white streaks in the sky?
Boiling water:  Is it true that distilled water won't boil?
Boiling water:  Why — when water gets to its boiling point, does its temperature not change anymore??!  Is that just a characteristic, or is there a real explanation?
Boiling water:  How long does it take to soft boil an egg on top of Mt. Everest?
Energy:  What is energy?
Fahrenheit: Why did Fahrenheit develop such an awkward thermometer: 32 degrees for the water freezing point and 212 degrees for its boiling point?
Fire:  In my science class we have learned about mass, and I'm just wondering, does fire have any mass? It has stumped all the teachers I asked (even my science teacher), and I would really like to know.
Fire and fog: Does fire burn in fog?
Ice:  Why do the ice cubes in my ice tray occasionally have spikes on them? Why would they defy gravity and spike upwards?
Ice: why do ice cubes shrink by 25% over time in the refrigeration?
Ice:  Why do the ice cubes in my ice tray occasional have spikes on them? Why would they defy gravity and spike upwards?
Ice:  Will water always expand if frozen or are there any exceptions?
Ice: why is some ice blue?
Ice:  Which freezes faster — cold water or boiling water?
Salty water:  Explain why salty water does not freeze even though the temperature falls below zero.
Salty water:  Why do we add salt both to melt road ice and also to freeze ice cream?
Salty water: Why and how does salt affect the boiling point of water?
Shaking water:  If you put water in a bottle and keep shaking it, does the water temperature go up?
Sun:  If I put hot soup into a vacuum bottle, "Thermos", it will stay hot inside due to the vacuum and the outside will stay cool since heat is not transmitted in a vacuum. There is 93 million miles of vacuum between us and the sun. How come it feels hot when I go outside?

Blue mountains:  Why do distant mountains look blue?
Color:  What is the colour of a red flower when it is exposed to blue light?
Darker:  Why is the ground darker after a rain?
Deep-Water Colors: why do some colors appear black in the water?
Energy:  What is energy?
Ice: why is some ice blue?
Glow-in-dark:  Why do phosphors glow?  What substances have phosphors?  Do phosphors glow longer if you hold them in the light longer?
Mirrors:  Is the image we see of ourselves in the mirror really what we look like?
Lasers:  Can a magnetic field interrupt the path of a laser?  Can a magnet bend light?
Lasers:  White light contains all wavelengths. But, I understand a laser is created from just one wavelength. So, is it possible to create a White Laser?
Light:  What is light made of, if anything at all? Is it actually radiating from its source, or do we just see the source?
Light bends:  White light is composed of all wavelengths, right? So what causes dispersion if all colors travel at the same speed? Why does violet bend more than red in a prism or a transparent medium?
Light speed:  How long does it take to reach the speed of light?
Light speed:  The speed of light is 300,000 km/s. How was it determined?
Light speed:  A man on Earth clocks a distant rocket ship going close to the speed of light. A woman on the spacecraft fires a missile that leaves her ship at near light speed, relative to the ship. She sees a missile shooting forward of the craft and traveling at near light speed. What will the Earthman see?
Light speed:  The nearest star from Earth is Proxima Centauri, which is 4 light years from Earth. So, is it true the stars that we see in the sky at any instant are not the stars exactly at that instant but more than 4 years old, which we see now due to the sluggishness of light? (P.S. Can we see asteroids with the naked eye?)
Light speed:  Using a telescope, if I could look into a mirror located far away from the earth, would the reflection I see be in the past?
Light speed, faster than light:  Is there anything faster then the speed of light?
Light speed, faster than light: How fast is warp speed?
Light speed, faster than light:  Why is it impossible to go faster than light?
Light and Sound Waves: how are they different?
Light, black light: How does black light illuminate white T-shirts?
Mirages: What causes a mirage?
Mirrors: If the color of a mirror is the light it reflects, what color is a mirror?
Luminescence:  I got an ice cube tray out of the freezer one night without turning on the kitchen light. Much to my surprise, when I twisted the tray to get the cubes out, a streak of light went through the ice. What causes the quick spark of light in the ice?
Primary colors: Why are red, green, and blue the primary colors?
Primary colors: I thought red, yellow, and blue were the primary colors. Am I wrong?
Rainbows:  I saw a lovely rainbow recently. The sky just inside the bow seemed brighter than the sky outside the bow. Why?
Shadows:  Do airplanes have the same size shadow, no matter how far they are from the earth, and, if so, why?
Transparency / absorption:  If both electric and magnetic fields can pass through paper why not light?
Transparency / absorption:  Why is glass transparent even though it is made of sand?
X-rays: How do x-rays let you see inside something?

Copper: Does copper corrode in sea water?
Diamonds: What substances are harder than diamonds? Can anything scratch diamonds?
Diamonds:  If no substance is harder than a diamond and no other material can scratch a diamond then how do they cut a diamond for jewelry?
Water:  Why is air lighter when moisture is added to it?
Wood:  Why can't wood melt?

Acceleration:  Which ball hits a wall harder — plastic or clay?
Energy:  What is energy?
Falling raindrops: What is the speed of a falling raindrop?
Falling through air: Is there a terminal velocity when people sky dive?
Falling & Skydiving: Doesn't terminal velocity of a skydiver also depend on his altitude? I remember seeing a skydiver who jumped from the edge of the earth's atmosphere (in a space suit) and broke the speed of sound.
Falling & skydiving:  What is an estimate of the time it takes for a falling person to go from 0 to 60?
Fastest moving thing:  What is the fastest moving thing in the universe, other than light or other types of electromagnetic radiation?
Flame, leaning: If you light a candle and set it on the dashboard of your car, which way will it lean as you accelerate and why?
Flying weight: Does a trailer weigh less when its load of birds takes off?
Inertia and momentum:  I'm trying to explain to my 14-year old daughter the difference between inertia and momentum; can you give any good examples?
Kites: How do kites fly?
Momentum:  In making a long jump, a competitor has to take a longer run for a longer jump. Is this due to momentum or inertia? My son told his teacher, momentum, but she says it is due to inertia. Who is right?
Rain:  Do you get wetter dashing to your car in the rain or walking there?
Water pressure: Is the water pressure of falling water greater at the bottom?
Water pressure:  If you have a 1 inch pipe 20 feet tall and a 4 inch pipe 20 feet tall filled with standing water will the downward pressure be the same or different at the bottom of each pipe and why?

Energy:  What is energy?
Glow-in-dark:  Why do phosphors glow?  What substances have phosphors?  Do phosphors glow longer if you hold them in the light longer?
St. Elmo's fire:  Why would a lightning-struck tree glow after being hit? It is not on fire and does not give off heat, but gives off a very visible glow.
Vacuum:  What is Vacuum?

Energy:  What is energy?
Headlights on at near-light speed: do your headlights light up what's in front of you when you're traveling almost as fast as light?
International Space Station (ISS): Since time and speed is relative, according to Einstein's theory of relativity, will an atomic clock on the International Space Station be slower than a synchronized atomic clock on the ground?
Light speed:  A man on Earth clocks a distant rocket ship going close to the speed of light. A woman on the spacecraft fires a missile that leaves her ship at near light speed, relative to the ship. She sees a missile shooting forward of the craft and traveling at near light speed. What will the Earthman see?
Light speed:  Q: Your answer about the car traveling at "near-light speed" made me wonder about two, no three, more things. Ok, the light from the car travels at light speed relative to the car. But, doesn't this then mean that the light from the car is traveling faster than the speed of light relative to the rest of the universe outside the car? And if this is possibly true, does an object traveling at near-light speed create its own universe? And can the speed of light in this universe be exceeded in another universe, relative to this one?
Light speed mirrors:   If you are traveling at the speed of light, and you hold up a mirror that is also traveling that fast will you be able to see yourself?
Speed, faster than light:  Is there anything faster then the speed of light?
Time travel: Do the recent experiments showing that light can be slowed, have any theoretical implications for time travel
Time travel: If we time travel, will we experience events in the past (or future) or just be observers?

Energy:  What is energy?
Light and Sound Waves: how are they different?
Singing goblets: What causes crystal water goblets to "sing" when you run a wet fingertip around their rim?
Sound in space: Why is there no sound when spaceships fly?
Thunder: I see lightning but often hear no thunder. Why is there no thunder? 
Voice:  Why does helium change people’s voices after being inhaled?