Where is the single port diameter of the 500-meter spherical radio telescope (FAST)?

The 500-meter spherical radio telescope (FAST) is very famous, which is also an epoch-making project in astronomy in recent years. Located in the deep mountains of Guizhou, the surrounding environment is very quiet, and the air is fresh and quiet. It can detect the farthest signal of the universe, and even trace back to the landscape at the moment of creation. This is the diameter of the single port of the 500-meter spherical radio telescope (FAST).

What is the diameter of the single port of the 500-meter spherical radio telescope (FAST)?

500 meters

Where is the 500m spherical radio telescope (FAST)?

Dawodang Cave, Pingtang County, Qiannan Buyi and Miao Autonomous Prefecture, Guizhou Province

In the past two days, a hot topic in science has been brushed-"Six pulsars were discovered by the 500-meter spherical radio telescope (FAST)".

I don't want to join the fun, but think about it. After all, this is the transcript of FAST's first show. Plus, readers keep sending me private letters, so read it quickly. So in this issue, let's take a look at the self-evident/ambiguous attitude of mainstream news.

Let's talk about why FAST can be called "500-meter spherical radio telescope (FAST)". 500-meter spherical radio telescope (fast), full name is "500-meter spherical radio telescope", referred to as FAST (people want FAST! This is an acronym based on a five-suspended-meter spherical telescope.

This big MAC looks like a cauldron, with a total diameter of 500 meters (488 meters to be exact) and 4,450 panels, which is about the size of 30 football fields. It takes 40 minutes to walk around the edge of the cauldron!

Therefore, people dare to say that they are the largest radio telescope in the world! More precisely, it is the largest single aperture and the most sensitive radio telescope.

Why is it so big? Why dare you say it is the most sensitive? You know, a radio telescope is like an antenna pot that receives satellite signals. The bigger the better! Because the larger the area, the stronger the receiving ability!

This giant pot cost $654.38+800 million, took five years to build, and officially opened in only one year.

Because FAST needs an absolutely quiet environment, it is located not only in the Yunnan-Guizhou Plateau in Dashanli (Qiannan Prefecture), but also in the radio silent zone with a radius of 5 kilometers in Fiona Fang. As a result, another $269 million was used to resettle immigrants.

This high price is paid for the miracle of monitoring. Compared with the Arecibo 300-meter telescope in the United States and the Bonn 100-meter telescope in Germany, the sensitivity and comprehensive performance of FAST have been greatly improved.

How high is it?

For example, FAST has the ability to monitor how active hydrogen atoms produced by BIGBANG are; Electromagnetic waves emitted by some organic molecules in the universe can also be monitored by others; If you encounter intelligent life, alien signals or something, it is not a problem. Therefore, people in the industry call it "500-meter spherical radio telescope (FAST)".

After talking about the superb skills of FAST, let's talk about the "pulsar" discovered this time.

What is a pulsar? Pulsar is a neutron star that can rotate at high speed, but not all neutron stars are pulsars.

The famous "Hand of God" (PSRB 1509-58) is actually a typical pulsar.

What is a neutron star?

Simply put, there are three final destinations for all stars in the universe: white dwarfs, neutron stars and black holes.

1.44 times the mass of the sun will become a white dwarf (which is also the destination of our sun);

1.5~3 times the mass of the sun will eventually collapse into neutron stars. This planet is so dense that even the nucleus can be crushed, leaving only neutrons, hence the name neutron star. A cube-sized substance on a neutron star has a mass of 1 100 million tons! What is this concept? Small enough to compress the whole Mount Everest into a cube of sugar!

Stars three times the mass of the sun will eventually become black holes. It can be said that neutron star is the highest density celestial body except black hole in the universe. Together with black holes, it was praised by astronomers as one of the four major astronomical discoveries of mankind in the 1960s.

Coincidentally, pulsar, a high-speed rotating neutron star, was also discovered in the 1960s. More importantly, however, I thought it was an alien signal when I shot.

Being rigorous in her work, she accidentally found that some pulse signals are very regular, with a period of 1.337 seconds, just like a human pulse.

So she immediately reported to Professor hewish. The astronomer was so excited that his heart was beating. Did I really find the legendary "alien little green men"? You know, throughout the 1960s, the taste of space races and alien science fiction filled the West. This association is also natural.

Fortunately, scientists are quite calm. In the next less than half a year, teachers and students found several such pulse signals.

Later, I finally figured out that this strange "call signal" is not an alien signal, but a pulse signal from a special star-pulsar, which is only theoretically derived.

It is necessary to interrupt here: 1974 The Nobel Prize in Physics was awarded to only one professor, because he completely ignored the contribution of the student Bell when nominating, which became a major scandal in the history of science.

Until 1993, the Nobel Committee specially invited Bell to attend the award ceremony of two American astronomers, who won the prize for discovering pulsar binary stars. Is this a kind of compensation? Or is it deliberately stimulating?

Fortunately, in the past 40 years, Bell not only won the Nobel Prize, but also won more than a dozen world-class scientific awards.

After the episode, continue

Pulsars, like searchlights on lighthouses, are regularly launched into space. If it sweeps to the earth and happens to be intercepted by humans, this is the so-called pulsar signal.

The six pulsars newly discovered by FAST are actually behind this principle.

However, these six new pulsars are all in the Milky Way. At present, more than 2,700 pulsars have been discovered in the Milky Way. China has just started in this field.

The two released J1859-0131and J1931kloc-0/are separated from us 165000 light years and 41respectively.

What's more commendable is that the research on pulsar, an extreme physical environment, is extremely wonderful.

In 1980s, astronomers began to discover millisecond pulsars, whose rotation period is only milliseconds.

Ten years ago in 2007, ESA discovered the fastest pulsar so far, with 1 122 revolutions per second!

In contrast, FAST's new discovery takes 0.59 seconds and 1.83 seconds to turn a corner, which is nothing.

Why pay attention to the rotation period? What is the significance of studying pulsars? In fact, these two questions are both an answer. As I said just now, pulsars with extremely stable rotation periods are like accurate clocks in the universe. The shorter the rotation period, the more accurate the clock signal can be provided, and the greater the value of natural research. This is of great forward-looking significance for future deep space navigation interstellar unmanned spacecraft and manned space exploration.

Moreover, pulsars are celestial bodies under extreme physical conditions, with extremely high density and extremely strong magnetic field. In the eyes of astrophysicists, pulsars are ideal natural laboratories, which can extend many space exploration topics, such as detecting gravitational waves and black holes.

In any case, this is the first achievement of the national scientific heavyweight FAST, which is necessary, especially when it has just rushed out of the starting line.

Of course, this is also the best comfort for "the father of the 500-meter spherical radio telescope (FAST)".

On September 15 this year, Nan, the most important founder of the FAST project, passed away.

Just like Fast raised his children by himself, when the children got back their excellent report cards, the old man had already left.