The NIST-F1 Cesium fountain clock is in Colorado. It is the standard for primary time and frequency in measuring time.
The NIST laboratories in Boulder, Colorado, developed the cesium fountain atomic clock NIST-F1, which serves as the country's primary time and frequency standard. NIST-F1 is a member of the global network of atomic clocks that establishes Coordinated Universal Time (UTC), the recognized global time.
The NIST-F1 is known as a fountain clock because it measures frequency and time intervals by using the atoms' fountain-like movement. Atomic clocks are the most precise means of measuring time intervals, or the amount of time that separates two events.
Atoms in the clocks leap from one energy level to another due to the precise frequency at which these clocks emit electromagnetic radiation, such as microwaves.
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Answer:
The correct answer is A - They allow us to see distant objects as they were long in the past.
Explanation:
A telescope is an optical instrument. It helps in magnifying distant objects usually stars and planetary bodies through the use of various lenses and mirrors. A time machine is a hypothetical device that transports an object/matter between different time frames.
When we view objects with a telescope, what we are seeing through the lenses have already occurred, especially when viewing distant objects. This is because of light. Light travels.
For example, if you are looking at the sun directly, you are seeing the sun as it was about 8mins 20secs ago. Now imagine viewing distant objects, you are actually looking at the past.
Distance of two points can be calculaetd using formula:
![d= \sqrt{ ( x_{2}- x_{1} )^{2}+ ( y_{2}- y_{1} )^{2} }](https://tex.z-dn.net/?f=d%3D%20%5Csqrt%7B%20%28%20x_%7B2%7D-%20x_%7B1%7D%20%20%29%5E%7B2%7D%2B%20%28%20y_%7B2%7D-%20y_%7B1%7D%20%20%29%5E%7B2%7D%20%7D%20)
Here x1 and y1 are coordinates of point A and x2 and y2 are coordinates of point B.
Now we insert numbers into formula:
D the NWS has reported a severe hurricane in the neighborhood
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