Photo Researchers ftp March 2011

Wolf (Canis lupus) in winter, Minnesota.

Wolf (Canis lupus) in winter, Minnesota.

Wolf (Canis lupus) in winter, Minnesota.

Wolf (Canis lupus) in winter, Minnesota.

Wolf (Canis lupus) in winter, Minnesota.

Wolf (Canis lupus) in winter, Minnesota.

Wolf (Canis lupus) in winter, Minnesota.

Wolf (Canis lupus) in winter, Minnesota.

Water heating and boiling, Photo 1 of 5. An immersion heater is used to heat and boil water. In this sequence, the heater is put into the water at roo...

Water heating and boiling, Photo 2 of 5. An immersion heater is used to heat and boil water. In this sequence, the heater is put into the water at roo...

Water heating and boiling, Photo 3 of 5. An immersion heater is used to heat and boil water. In this sequence, the heater is put into the water at roo...

Water heating and boiling, Photo 4 of 5. An immersion heater is used to heat and boil water. In this sequence, the heater is put into the water at roo...

Water heating and boiling, Photo 5 of 5. An immersion heater is used to heat and boil water. In this sequence, the heater is put into the water at roo...

Refraction. When light is incident from the air on an acrylic block it refracts (bends) toward the normal to the surface. When light exits the block t...

Refraction. When light is incident from the air on an acrylic block it refracts (bends) toward the normal to the surface. When light exits the block t...

An ALNICO bar magnet attracting steel paper clips.

An ALNICO bar magnet separates steel screws from brass screws.

An ALNICO bar magnet deflects the compass needle so that it aligns along the magnetic field produced by the magnet.

An ALNICO bar magnet deflects the compass needle so that it aligns along the magnetic field produced by the magnet.

Airy disk, Photo 1 of 2. A pinhole (small round aperture) is placed in a beam produced by either a Helium-Neon laser operating at 632.8 nm (red, Photo...

Airy disk, Photo 2 of 2. A pinhole (small round aperture) is placed in a beam produced by either a Helium-Neon laser operating at 632.8 nm (red, Photo...

Diffraction on a screw, Photo 1 of 4. A small screw is placed in a beam produced by either a Helium-Neon laser operating at 632.8 nm (red, Photos 1 an...

Diffraction on a screw, Photo 2 of 4. Stylized photo. A small screw is placed in a beam produced by either a Helium-Neon laser operating at 632.8 nm (...

Diffraction on a screw, Photo 3 of 4. A small screw is placed in a beam produced by either a Helium-Neon laser operating at 632.8 nm (red, Photos 1 an...

Diffraction on a screw, Photo 4 of 4. Stylized photo. A small screw is placed in a beam produced by either a Helium-Neon laser operating at 632.8 nm (...

Diffraction on a needle, Photo 1 of 2. A needle is placed in a beam produced by either a Helium-Neon laser operating at 632.8 nm (red, Photo 1) or a H...

Diffraction on a needle, Photo 2 of 2. A needle is placed in a beam produced by either a Helium-Neon laser operating at 632.8 nm (red, Photo 1) or a H...

Diffraction on a slit. A narrow slit is placed in the path of a laser beam and the resulting diffraction pattern is observed some distance away. Two d...

Diffraction on a slit.A narrow slit is placed in the path of a Helium-Neon laser (632.8 nm) beam and the resulting diffraction pattern is observed som...

Diffraction on a slit, Photo 1 of 3. A narrow slit is placed in the path of a laser beam and the resulting diffraction pattern is observed some distan...

Diffraction on a slit, Photo 2 of 3. A narrow slit is placed in the path of a laser beam and the resulting diffraction pattern is observed some distan...

Diffraction on a slit, Photo 3 of 3. A narrow slit is placed in the path of a laser beam and the resulting diffraction pattern is observed some distan...

Double-slit experiment. Interference patterns observed in a modern-day replica of Thomas Young's double-slit experiment. A coherent beam from either a...

Double-slit experiment. Interference patterns observed in a modern-day replica of Thomas Young's double-slit experiment. A coherent beam from a red He...

Double-slit experiment, Photo 1 of 3. Interference pattern observed in a modern-day replica of Thomas Young's double-slit experiment. A coherent beam...

Double-slit experiment, Photo 2 of 3. Interference pattern observed in a modern-day replica of Thomas Young's double-slit experiment. A coherent beam...

Double-slit experiment, Photo 3 of 3. Interference pattern observed in a modern-day replica of Thomas Young's double-slit experiment. A coherent beam...

Laser beam split by a diffraction grating. Diffraction grating is an optical element whose properties are periodically modulated in one dimension. Lig...

Laser beam split by a diffraction grating.Diffraction grating is an optical element whose properties are periodically modulated in one dimension. Ligh...

Laser beam split by a diffraction grating, Photo 1 of 3. Diffraction grating is an optical element whose properties are periodically modulated in one...

Laser beam split by a diffraction grating, Photo 2 of 3. Diffraction grating is an optical element whose properties are periodically modulated in one...

Laser beam split by a diffraction grating, Photo 3 of 3. Diffraction grating is an optical element whose properties are periodically modulated in one...

Queen's Delight (Stillingia sylvatica) photographed on a sandhill along the Arkansas River near Geuda Springs, Kansas.

Fruit of Queen's Delight, Stillingia sylvatica, on a sandhill, along the Arkansas River near Geuda Springs, Kansas. This plant is used to treat liver,...

Fruit of Queen's Delight, Stillingia sylvatica, on a sandhill, along the Arkansas River near Geuda Springs, Kansas. This plant is used to treat liver,...

Cocklebur (Xanthium strumarium) on sandbar near Arkansas River near Geuda Springs, Kansas.

Monarch butterfly larva (Danaus plexippus)feeding on Tropical Milkweed or Mexican Butterfly Weed (Asclepias curassavica) in garden. Lawrence, Kansas.

Arrowhead Spider (Verrucosa arenata) Lawrence, Kansas.

An Alnico bar magnet attracting iron filings.

An Alnico bar magnet attracting iron filings.