Why are astronomers using radio telescopes looking for far stars instead of a telescope?

First of all, what is a radio telescope? The first non-visual spectral region that was used extensively for astronomical observations was the radio frequency band. Telescopes observing at these wavelengths are commonly called radio telescopes. Radio telescopes may be made much larger than optical/infrared telescopes because the wavelengths of radio waves are much longer than wavelengths of optical light. A rule of thumb is that the reflecting surface must not have irregularities larger than about 1/5 the wavelength of light that is being focused.

By that criterion a radio telescope is several hundred thousand times easier to figure than an optical telescope of the same size In the movie “Contact,” astronomer Ellie Arroway, played by actress Jodie Foster, searches for signs of extraterrestrial life using massive, Earth-bound radio telescopes. Much of Contact’s scientific intrigue, based on Carl Sagan’s 1985 bestseller, unfolds at two National Science Foundation-supported radio astronomy facilities where real-life astronomical mysteries continue to be probed.

Scientists use the government-supported telescopes to detect radio waves not from distant civilizations but from planets, stars, galaxies and other objects in space. Radio observations extend astronomers’ reach into space and time, letting them “see” through gas and dust in space to detect celestial objects whose visible light cannot be seen from Earth. In “Contact,” Foster hears the first guttural, throbbing message transmitted by other-worldly life using the world’s most powerful radio telescope, the Very Large Array in Socorro, New Mexico, a collection of 27 antennas spread in a three-armed configuration across the desert.

NSF’s National Radio Astronomy Observatory runs the huge dishes, which Foster manipulates in the film from her laptop computer like a high-tech, movable Stonehenge, in reality. Electronically linked to simulate a single radio telescope up to 20 miles in diameter, the antennas can be bunched together or moved apart along railroad tracks into different configurations. About 700 astronomers visit the VLA each year to observe the universe.

In “Contact,” Foster gets her scientific start at another NSF-supported facility, the Arecibo Observatory, a huge, stationary radio dish operated by Cornell University in the lush mountain setting of Puerto Rico. The 1000-foot reflector dish, also featured in the James Bond film, “Goldeneye,” is the largest stationary radio telescope and most powerful radar in the world. Russell Hulse and Joseph Taylor of Princeton University earned a Nobel Prize by using the dish in the 1970s to discover the first pulsar in a binary system, confirming a prediction of Einstein’s theory of general relativity.

In the early 1990s, Arecibo was used to detect the first planets outside the solar system. The dish recently received a facelift in a $27-million upgrade which makes it four times more sensitive to radio emissions from distant galaxies. The dish was used in the 1960s to chart accurately for the first time the rate at which the planet Mercury rotates. More recently it studied ice in Mercury’s polar craters, the chemistry of Earth’s upper atmosphere and rotating pulsars.

The new upgrade will let astronomers “hear” signals from much greater distances, and further back in time, than before. d) What is VLA? How does it work? The VLA is an interferometer; this means that it operates by multiplying the data from each pair of telescopes together to form interference patterns. The structure of those interference patterns, and how they change with time as the earth rotates, reflect the structure of radio sources on the sky: we can take these patterns and use a mathematical technique called the Fourier transform to make maps.

The VLA was used to detect the first radio emission from a gamma-ray burster shedding light on the cause and locations of these explosions, one of the great mysteries of astrophysics. In a 1994 discovery, the VLA revealed an object within the Milky Way Galaxy–a double-star system with a black hole or neutron star as one partner–ejecting jets of particles at nearly the speed of light, a process thought to mirror the dynamics at work in the centers of galaxies. ) What would be the implications to Earth’s religion, beliefs, society, and science if indeed we were able to establish that life exists beyond our planet? f) Why is multi-dimensional travel represented as the plausible way of going to another planet (or point in space) instead of other means? The problems involved in reaching the stars are almost impossible to understate. Scientists have sent probes to eight of the nine planets in our solar system and have developed the fastest moving man made objects in the process.

If those same probes were to be launched to the stars, however, they would take thousands of years to reach them! The distances to the stars are huge So huge, in fact, that the light from the nearest star to the Sun, a triple star system known as Alpha, Beta and Proxima Centauri, takes over four and a quarter years to get here. Since, according to special relativity, nothing in the universe can travel faster than the speed of light, it would seem that travel times with even the most advanced starships are going to be extremely long indeed.

There are also highly exotic ideas, which lie on the tantalizing fringes of modern theoretical physics. If the universe is a multidimensional place with human beings only able to perceive three dimensions, perhaps a way can be found to shortcut through the ‘higher’ dimensions. These so-called wormholes are currently having their mathematics calculated by the theorists but if they can be utilized for travel then perhaps the entire universe will become accessible to us. Traveling to different planets may take no more time than traveling to different countries does now!


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