What is the part on a sundial that casts the shadow from the sun?
86908
The Gnomon;\nPicture at this link.\nhttp://www.rnzih.org.nz/pages/sundial2.htm
239104
There are two types of eclipses. Solar and lunar. A solar eclipse occurs when the moon passes between the Earth and the sun.  A lunar eclipse is when the Earth casts it's shadow on the moon, basically the Earth passes between the sun and the moon.
190329
A sunspot is a region on the Sun's surface (photosphere) that is marked by a lower temperature than its surroundings and intense magnetic activity, which inhibits convection, forming areas of low surface temperature. Although they are blindingly bright, at temperatures of roughly 4000-4500 K, the contrast with the surrounding material at some 5700 K leaves them clearly visible as dark spots. Next year is expected to be a cyclical peak in the sunspot cycle
1114860
when sun is some what perpendicular(not exactly) to it there will a shadow.measure it using the ruler(since it will be smaller).now measure the length of the shadow of the ruler.comparing the length of shadow of ruler and the building we can find the height..
350565
Lunar: the earth gets between the sun and the moon and so it projects its shadow on the moon and it dissapears for a moment.\nSolar: The moo gets between the earth and the sun and you stop seeing the sun or a part of it during some moments, a complete solar eclipse you still see a ring of sun around the moon due to size difference. This doesn't happen on the lunar one as the projected shadow of the earth is much bigger than the moon (and the earth itself) so the moon can disappear for several minutes...
796172
Equinox means equal night......the two days a year ( March and September) when the sun at noon is directly overhead at the Equator. The two solstices are Summer when the sun is directly overhead at 23N and the Winter when its directly overhead at 23S...so your shadow would point south everyday of the year at 23S except on the Winter Solstice when there would be, in theory, no shadow at all since the sun is 90 degrees overhead
1026089
1) the rheostat (that little knob that increases or decreases the light coming from the light source)\n\n2) the iris diaphram (works like the iris of the eye, making bigger or smaller circles for the light to pass through)--this is usually part of the condenser
3690
The ones i've seen are a diode with 1 or 2 little arrows pointing out, indicating radiant light.  The circle is optional.\n\nSimilarly, photodiodes have the arrows pointing in.
329266
Plasma does not cast a shadow. Plasma is the extreme for of matter. Its the core of the sun but Plasma cannot cast a shadow.
484262
A circle with a cross within it.\nRefer to: http://www.earth.uni.edu/~morgan/astro/course/Notes/section4/new17.html
180612
On Wednesday, 2006 March 29, a total eclipse of the Sun will be visible from within a narrow corridor which traverses half the Earth. The path of the Moon's umbral shadow begins in Brazil and extends across the Atlantic, northern Africa, and central Asia where it ends at sunset in western Mongolia. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes the northern two thirds of Africa, Europe, and central Asia.\n----------------------------------------------\nMaps and tables for 7000 years of lunar and solar eclipses, eclipse photographs, observing tips, and eye safety information.... then follow the link....\nhttp://sunearth.gsfc.nasa.gov/eclipse/eclipse.html
237617
Think of three balls in a gym.  a Basket ball, a golf ball, and a tennis ball.  Now think of the basket ball as being lit, its the biggest so we will pretend its the sun.  the earth would be the tennis ball, and the golf ball would be the moon.  well when the golf ball got between the sun and the earth it would create a cast shadow on the tennis ball, but its not big enough to put the entire tennis ball in shadow... that is why only part of the earth can see the eclipse.
61894
I know this as light mill or photon mill. There is a vacuum inside. The vanes are black on one side and metallic on the other side, the metallic side reflecting photons while the black side will absorb it. The pulse exchanged is twice as high on the metallic side of the vanes as on the black side, causing the device to set in motion.
452393
The link to Howstuffworks has good illustrations for a pendulum clock.  You may be able to improvise the parts for a project if you understand what is involved.  I know, a sundial would be easier.  Good luck.
258869
In a dark(ened) room.\nUse a smal lamp. Move it up and down. Choose one pupil and let the other ones see how the length of his shadow changes with the altitude of the lamp.
171969
In a solar eclipse, we see a shadow pass over the face of the sun. In a lunar eclipse, we see a shadow pass over the face of the moon.
367371
Found this explaination for your question:\n\n"Shadows cast on the lunar surface should be parallel. Some shadows in the Apollo photos are not parallel indicating more than one light source, thus the photos are fakes. \n\nAgain there is a sound explanation; it is a simple a matter of perspective. A photo is a two-dimensional representation of a three-dimensional world, hence parallel lines may not appear as such on film. We all know how lines on a highway appear to diverge as they approach the observer, yet we know they are parallel. Another important factor that comes into play here is the slope of the ground. Let's consider two shadows - one cast on an upward slope and the other on a downward slope. If viewed from the side, these shadows would appear to go off in different directions. However, if viewed from high above, they would be seen as parallel. In other words, looks can be deceiving. There is no evidence of NASA trickery here. \n\nThis photograph [see photo], taken on Earth, is an excellent example illustrating how perspective causes shadows to appear non-parallel when seen on film. In this example [see photo] the astronaut on the right is standing on a small rise. The sloping ground has caused his shadow to elongate and appear at a different angle than the shadow of the astronaut on the left. Also note, if two spotlights produced the shadows then each astronaut would have two shadows." \n\nFor more information debunking "fake" moon landing follow link