Answer:
The mechanisms used to produce sound vary from one family of cetaceans to another. Marine mammals, such as whales, dolphins, and porpoises, are much more dependent on sound for communication and sensation than are land mammals, because other senses are of limited effectiveness in water. Sight is less effective for marine mammals because of the particulate way in which the ocean scatters light. Smell is also limited, as molecules diffuse more slowly in water than in air, which makes smelling less effective. However, the speed of sound is roughly four times greater in water than in the atmosphere at sea level. As sea mammals are so dependent on hearing to communicate and feed, environmentalists and cetologists are concerned that they are being harmed by the increased ambient noise in the world's oceans caused by ships, sonar and marine seismic surveys.[2]
<span>After the plague was over, times were tough for the Catholic Church. Remember, in medieval times, the Church wielded incredible political power over the lives of many people whether they were kings or peasants. But when the Black Plague hit Europe, the Church was at a loss. Their promises to heal the sick turned out to be empty and people began to lose faith in the Church.</span>
Answer:
The quote means that as an author, your purpose must be made very clear. As a result of that, just pirating or copying other people's work into your own is not ideal and sufficient. The author must clarify and convince the readers how the information he got from outside sources relate to each other and are relevant to his thesis. This can also be achieved by proper referencing of the source materials.
Explanation:
The Norton Field Guide is known to help teachers to teach the way they want to teach. There are color-coded links which help the students to get more detail if the need arises. The Norton Field Guide usually have short chapters with the availability of just
enough detail which can be assigned in any order. With the help of menus, directories, and a glossary/index, finding book is made easy.
Answer: C. get back on the right road
Explanation:
Answer:
No, I guess not. Scientists do not know precisely what happens in a black hole, since no information can return through the event horizon. The accepted theory is that at the center of every black hole lies a singularity - a point where the density rises to infinity - meaning mass exists in zero volume. Consequently the curvature of space also reaches infinity.
The black hole cannot be described in terms of classical physics, where the effect of gravity is modeled as a force. Instead, General Relativity is used in which gravity is the result of curved spacetime. Objects - and light, of course -follow what is known as a ‘geodesic’ through spacetime. Equivalently, it is a path that any particle which is not accelerating would follow. In flat space, the geodesics are straight lines. On a sphere, the geodesics are great circles like the equator. A geodesic is the shortest path between two points. For example, two points on Earth is a curved line because the Earth is a sphere. But apparently, geodesics simply lead to the singularity and disappear instead of being continuous. The singularity breaks this continuity, that’s why, what happens at the center of the black hole is not known.
Light travels at a constant speed - but gravity, like motion, tends to shift its frequency without affecting the speed. Therefore, light streaming towards a black hole will be blue shifted as it approaches. It is, however, doomed upon crossing the event horizon. It will never exit that region of space.
There is no such thing as “new space” or “new time”.
