Are there time machines? Yes, but they are not the science-fiction Hollywood time machines we see in movies. The real time machines are space telescopes. Why? Because what they look at, namely stars, galaxies, supernovas and so on, are so far away that it takes time for their light to get to Earth. What telescopes show us is not what the stars, galaxies or supernovas look like now, but what they looked like years, centuries, even millions of years ago.
There have been many time-space telescopes. The most memorable one for the public is the Hubble. The images it showed were astounding. But Hubble is near the end of its science voyage. Other telescopes are in the design stages and will do more and show more than the Hubble space telescope was able to show.
The Giant Magellan Telescope
Building the Giant Magellan Telescope (GMT) will take place in Las Campanas, Chile by 2018. This is a segmented mirror telescope employing seven of the largest stiff monolith mirrors as segments. Surrounding a central on-axis segment are six off-axis 8.4-meter, or 27-foot, segments, which together form a single optical surface with a collecting area of 24.5 meters, or 80 feet, in diameter. What this means for astronomers it that the GMT will have a resolving power 10 times greater than the Hubble Space Telescope.
By way of comparison, the world’s largest optical and infrared telescopes today have primary mirrors that measure about 10 meters (32 feet) across. The Giant Magellan Telescope, on the other hand, will more than double that diameter, with a primary mirror that spans almost 25 meters (80 feet).
The Mauna Kea 30-Meter Telescope
The design of large Big Bang telescopes is proceeding with another large telescope. This one, put together with a consortium of organizations and universities, is preparing to construct the 30-Meter Telescope on the Mauna Kea summit in Hawaii, also scheduled for completion in 2018.
It will have a 30-meter, f1 mirror, 492, 1.45 meter mirror segments, and 20 arcminute field of view. TMT will contain a fully integrated adaptive optics (AO) with a Nasmyth-mounted suite of powerful instruments. This will provide the ability to switch rapidly, in less than 10 minutes, between different instruments, which then gives astronomers the observational flexibility and the ability to respond to changes in scientific requirements. For example, when time critical observations are required, multi-instrument observations must take place, or to respond to weather conditions, the flexibility will be there.
The European Extremely Large Telescope (E-ELT)
The European Extremely Large Telescope is an optical to mid-infrared telescope. Some astronomers have dubbed it “the world’s biggest eye on the sky” with a primary mirror 42 meters (137 feet) in diameter. It will start operations in 2018 in Cerro Armazones, Chile.
The structure of the telescope is a 10 arcminute diameter field of view. The optical design is a five-mirror design with three-mirror on-axis anastigmat plus two folds mirrors used for adaptive optics. The wavelength range is blue atmospheric cut-off (300 nm) to mid-infrared (24 microns). The primary mirror consists of almost 1,000 segments, where each segment is 1.4 meters wide, but only 50 mm thick. The optical design will have a very large secondary mirror that is 4.2 meters in diameter.
With a capability of the telescope to observe over a wide range of wavelengths from the standard optical to the mid-infrared provides scientists with the ability to exploit the telescope’s size fully.
James Webb Space Telescope
There is one more telescope planned for deployment in 2018, the James Webb Space Telescope. However, that is expected to be out in space about 1.5 million miles from Earth. It will replace the Hubble Space Telescope.
With these telescopes, searching for data near the occurrence of the time of the Big Bang will be their operational goal. Hubble and other telescopes have laid the foundation for exploring space to the near beginnings of time. A new dimension of science information and data will be available from these massive telescopes after they are deployed.