From Micro to Macro: Stars, Dust, Cosmic Rays, and how they Change the Universe 1时6分 2362播放 Explore the origin sources of cosmic rays with multi-messenger 57分钟 1788播放 The multiple stellar populations problem and the role of the Chinese Space Station Telescope 1时7分 867播放 The effe...
Discovery of cosmic rays and positronsAs many great discoveries, the phenomenon of cosmic rays was discovered mainly accidentally, during investigations that sought to answer another question: what are sources of air ionization? This problem became interesting for science about 230years ago in the ...
Cosmic radiation from the Sun and other stars is a source of background radiation on Earth. Other radioactive isotopes are produced by humans via nuclear reactions, which result in unstable combinations of neutrons and protons. One way of artificially inducing nuclear transmutation is by bombarding ...
Hiroyuki Tanaka of the University of Tokyo reasoned that the throat could be "x-rayed" with energetic muons produced in cosmic-ray showers. The number of muons passing through the volcano would depend on the density of intervening rock, so measuring the number of muons passing through various p...
With the pending return to long-duration crewed spaceflights, astronauts will face significant risks from exposure to space radiation. Galactic cosmic rays (GCRs) pose a particular challenge as they are not easily shielded and have dose rates as high as 0.5 mGy/day. ...
We only know 4% of what the universe is made up of. Can we also know what lies beyond our galaxy ... and if there are undiscovered forms of matter? Luckily, we have space messengers — cosmic rays — that bring us physical data from parts of the cosmos b
Cosmic Rays with 50 Joules of Energy: What, How, and from Where?The observation of cosmic ray air showers above 10[sup 20] eV poses three serious challenges for particle astrophysics: (i) how the primary particles are accelerated to these fantastic multi-Joule energies, (ii) how the ...
All of the elements heavier than uranium are artificially produced either inside nuclear reactors or in particle accelerators. So far, none of the synthetic elements have been stable, though some have long half-lives, allowing them to be used for a variety of purposes. ...
The specific decay mode depends on the isotope's characteristics, such as the balance between protons and neutrons in its nucleus and its energy state. In these processes, four different kinds of radioactive rays are produced: Alpha Decay ...
X-rays come from a change in the electron structure of an atom and are mostly machine-produced. They aren't quite as penetrating as gamma rays, and just a few millimeters of lead can stop them. That's why you wear a "lead apron" when receiving medical X-rays. Overexposure to ionizing...