Author Archives: siming tang

Does time flies?

The clock was invented by human beings to keep track of time. The atomic clock is one of the most accurate clocks in the world,  it will not gain or lose one second in 15 billion years. Therefore, the time will not fly. However, sometimes we do feel that the time pass by quickly when we are having fun. The time seems to crawl when we are having a boring class.

 

Ytterbium Lattice Atomic Clock took by National Institute of Standards and Technology https://commons.wikimedia.org/wiki/File:Ytterbium_Lattice_Atomic_Clock_(10444764266).jpg

Some people suggest that when we are having fun, we are paying attention to what we are doing. Therefore, we can not notice that the time pass by. However, when we are feeling bored, we will focus on time and notice that the time crawls.

 

Dr. Michael Shadlen said that “Every thought has various horizons”.Time flies according to these horizons. When we are really focusing on doing something, our mind can see the near horizons and the distant horizons. This makes the time goes by fast. In contrast, when we feel bored then we can only notice the near horizons and the horizons are not link to each other. As a result, time crawls.

It can also be related to the cells in the brain. Neuroscientist Joe Paton found out the neurons in our brain will release neurotransmitter dopamine which is a type of chemical that impacts how the brain feels about the time. When we are having fun, the neurons will release much more chemicals than usual. These chemicals make us feels that less time goes by. On the other hand, if we release lesser this type of chemicals, the time will go slowly in our mind.

In conclusion, time does not fly in reality. However, it does fly in our mind when we are having fun.

Fast radio burst signals

Artificial Radio waves is one of the most common electromagnetic radiations in the modern world. Nowadays, people use it in broadcasting, radar, and other systems. However, natural radio waves come from the space objects and we will talk about one of these natural radio waves, Fast radio burst(FRB).  On 9 January 2019, it is reported that the astronomers found the second repeating FRB source by using CHIME which is a new radio telescope in Canada. This repeating FRB source was from over 1.5 billion light years away and it was named as FRB 180814. But, what is FRB exactly?

CHIME experiment construction (Mateus A. Fandiño)

FRB is a transient radio pulse and the length of it start from a millisecond to a few milliseconds. Although FRBs is reported for multiple times, the repeating fast radio burst is quite rare and only two of the repeating FRB is FRB 121102 and this FRB 180814. The first signals from FRB 121102 were discovered in 2012 and it was confirmed that it was caused by plasma dispersion. However, FRB 121102 was observed by astronomer Paul Scholz in November 2015 again. He used the Arecibo radio telescope to find 10 repeating fast radio pulses from May 2015 TO June 2015. In the next few years, the FRB 121102 was recorded once again in 2016,2017 and 2018, this showed that it is not a one-time event.

But what are the sources of these FRBs? We are still yet to confirm the source of fast radio burst signals, but it is suggested that it could come from a highly magnetized rotating neutron star(pulsar). A neutron star is the collapsed core of a giant star. Some of the neutron stars will emit electromagnetic radiations such as FRB so that they can be detected by instruments.

Neutron Stars(NASA Goddard)

 

Some scientist suggested that the repeating FRB could come from an unknown extraterrestrial intelligence. They argued that the FRB repeating signals is an artificial stray blast and they are caused by spaceships. However, this is also a hypothesis and it is not be proven.

In conclusion, these “sources” for FRB are all assumptions and the source of FRB signals still remain to be unknown. Scientists are still working on it and looking forward to solving this mystery.

 

Siming tang