Q: The phase velocity of an electromagnetic wave, when traveling through a medium, can routinely exceed c, the vacuum velocity of light. For example, this occurs in most glasses at X-ray frequencies. However, the phase velocity of a wave corresponds to the propagation speed of a theoretical single-frequency (purely monochromatic) component of the wave at that frequency. Such a wave component must be infinite in extent and of constant amplitude (otherwise it is not truly monochromatic), and so cannot convey any information. Thus a phase velocity above c does not imply the propagation of signals with a velocity above c.
Can we conclude that can phase velocity be greater than speed of light?
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A: yes
To maintain lactation, a dairy cow must be bred and produce calves. Depending on market conditions, the cow may be bred with a ''dairy bull'' or a ''beef bull.'' Female calves (heifers) with dairy breeding may be kept as replacement cows for the dairy herd. If a replacement cow turns out to be a substandard producer of milk, she then goes to market and can be slaughtered for beef. Male calves can either be used later as a breeding bull or sold and used for veal or beef. Dairy farmers usually begin breeding or artificially inseminating heifers around 13 months of age. A cow's gestation period is approximately nine months. Newborn calves are removed from their mothers quickly, usually within three days, as the mother/calf bond intensifies over time and delayed separation can cause extreme stress on both cow and calf.
do cows need to have babies to produce milk?
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Answer: yes
Status as a natural-born citizen of the United States is one of the eligibility requirements established in the United States Constitution for holding the office of President or Vice President. This requirement was intended to protect the nation from foreign influence.

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can someone not born in us be president?

A: no
Problem: Text: Natural brown sugar, raw sugar or whole cane sugar are sugars that retain a small to large amount of the molasses from the mother liquor (the partially evaporated sugar cane juice). Based upon weight, brown cane sugar when fully refined yields up to 70% white sugar, the degree depending on how much molasses remained in the sugar crystals, which in turn is dependent upon whether the brown sugar was centrifuged or not. As there is more molasses in natural brown sugar, it contains minor nutritional value and mineral content. Some natural brown sugars have particular names and characteristics, and are sold as turbinado, demerara or raw sugar if they have been centrifuged to a large degree. Brown sugars that have been only mildly centrifuged or unrefined (non-centrifuged) retain a much higher degree of molasses and are called various names across the globe according to their country of origin: e.g. panela, rapadura, jaggery, muscovado, piloncillo, etc.

Question: is demera sugar the same as brown sugar?

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A: no
IN: Is it true that did america make it in the world cup?

The United States men's national soccer team is controlled by the United States Soccer Federation and competes in the Confederation of North, Central American and Caribbean Association Football. The team has appeared in ten FIFA World Cups, including the first in 1930, where they reached the semi-finals. The U.S. participated in the 1934 and 1950 World Cups, winning 1--0 against England in the latter. After 1950, the U.S. did not qualify for the World Cup until 1990. The U.S. hosted the 1994 World Cup, where they lost to Brazil in the round of sixteen. They qualified for five more consecutive World Cups after 1990 (for a total of seven straight appearances, a feat shared with only seven other nations), becoming one of the tournament's regular competitors and often advancing to the knockout stage. The U.S. reached the quarter-finals of the 2002 World Cup, where they lost to Germany. In the 2009 Confederations Cup, they eliminated top-ranked Spain in the semi-finals before losing to Brazil in the final, their only appearance in a final. The team failed to qualify for the 2018 World Cup, having been eliminated in continental qualifying, ending the streak of consecutive World Cups at seven.

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OUT: no
IN: Is it true that can you own guns in new york city?

The City of New York has its own set of laws, and requires permits to own any long gun or pistol.

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OUT:
yes