1] Mr Chong mentioned about the highly elliptical orbit of comets entering and leaving the inner solar system. This is due to the high change in speed as it speeds towards the sun and then orbiting back towards the Oort Cloud. Comets' tails are composed of ice and other minerals which are ripped off the comet as it encounters the solar wind and radiation. This is why comet tails always face away from the sun, and not facing away from the direction of travel.
2] Mr Chong also talked about the formation of neutron stars. Stars fuse hydrogen atoms into helium, and in the process, lose mass in the form of energy. According to the equation E=mc^2, matter is essentially condensed energy, and hence the small amount of mass can be converted to energy. This energy, in the form of light and heat (radiation). This radiation moves at the speed of light, as do all wavelengths of the electromagnetic spectrum, however, due to extremely dense and hot (15 million degrees kelvin) nature of the particles of the core and to a smaller extent, convective zone, the photons have to do a random walk, reflecting off the particles and increasing the distance travelled greatly. Hence, light absorbed by iris from the sun may have been released million sun of years prior. Larger stars use up their vast amounts of hydrogen more quickly, due to the greater gravitational pressure increasing the rate of fusion at the hotter and denser core. Hence, the hydrogen would eventually be exhausted. Helium would then become the main form of nuclear fusion 'fuel'. This is important as stars are balanced by their immense gravitational force and nuclear pressure from the center. These forces are in balance, and the star is stable. Helium is fused into denser and denser elements, till iron is reached. The last fusion reaction fusing silicon to iron does not produce a fusion pressure. The star implodes, reaching speeds exceeding 25% the speed of light. Now, the size of the star dictates its final form. If the outer layers of the star do not exceed a particular mass and the Schwarzchild radius, the strong nuclear force, one of the 4 fundamental forces of the universe, is not overcome and a black hole cannot be formed. The core resists the collapse further, and the outer layers are catapulted away from the star to form a spectacular supernova, which contains many denser elements formed from the fusion of various elements during the immense pressures of the collapse. The protons and neutrons fuse to form neutrons, which are packed into a tight lattice. A neutron star is born. A neutron star's core's material is largely unknown, with some Scientists dubbing it as superfluid degenerate neutron matter. Neutron stars have the mass of 3 solar masses, packed into a sphere with diameter not exceeding 10km wide. The gravitational field is incredibly strong especially at small distances, with the surface lacking changes in topography more than 3 cm. The star does have an atmosphere of superheated plasma, which is relatively incredibly thin. Neutron star magnetic fields are approximately 1000000000000 times more powerful than the magnetic field of the magnetosphere of earth. Apparently, atoms get 'bent' when it enters its influence. Dr Chong refers to pulsars as fundamentally different to neutron stars, but I think I misinterpreted his meaning. This is due to pulsars being rapidly spinning neutron stars, which hence send out a pulse, detectable by radio observatories. They may be obtaining this high rate of revolution from 'sucking' in matter from a nearby star, and this is how the most rapidly spinning neutron stars reach their speeds, which can be around 1000 revolutions/second. However, if the Schwartzchild radius is exceeded and the strong nuclear force is overcome, all the mass of the star Isner compressed into an infinitely dense point known widely as a singularity. The star has now become a black hole. A black hole still has the same gravitational influence as the star before it, contrary to popular belief. This is due to the black hole retaining the same amount of mass, And hence the same degree of curve of the Space Time. It is just that this mass is compressed into an infinitely dense point, which means that light is not able to escape it once it has passed the event horizon, where even if you were travelling at c, escape would be impossible, proving that light indeed cannot escape a black hole after that point. Something many do not know is that there is a photon sphere around a black hole, where photons do not escape but do not enter, orbiting around the black hole. This means that you would be able to see the back of your head at that point.
3] Dr Chong even touched on the topic of the voyagers and Pioneer probes. These satellites have far passed the planets and for example, the Voyagers used what's known as gravitational assist (slingshotting) to increase their velocity greatly and reach the Kuiper belt faster. They are powered by nuclear decay or radioactive isotopes, which release heat from this relatively slow reaction in the form of thermal energy. Thi said energy is used by mechanisms composed of different alloys which harness the thermal energy and converts it to kinetic energy through their different expansion rates to induce a current, which is use daily to supplement the solar panels, where the sun is only at about 1% of its brightness compared to from 1 A.U. They have expanded man's horizons (wink wink New horizons) by taking the first images of some of the gas and ice giants. They provide details insight about the chemical composition of the atmospheres of the gas giants, notably Jupiter.
4] Dr Chong talked about how easy it is to build and operate a practical telescope anywhere. In extension, a use of telescopes would be spectrometry, where the chemical compositions of incredibly distant objects can be analysed with small margins of error. This allows us to investigate planets' habitability, which is important in allowing us to expand our views on astrobiology and other similar topics. We would then be able to even, locate a reasonably close p, aphabitable planet to relocate the human species after we have ravaged our own Earth.
5]Dr Chong introduced us to a lunar map, where the Maria and mountain ranges are distinctly visible, and named. Earth's moon was created (widely accepted) by a glancingly impact with a mars-sized body and Earth. The debri reached escape velocity and formed a ring, which eventually combined to form a moon. The moon, according to Dr Chong, was once geologically active, hence the lava seas which once flowed across most of it's surface. Due to the moon not possessing a sufficient gravity to create enough pressure to maintain a molten core, geological activity ceased. This has the effect that there are no swirling convection currents of molten rock generating a protective magnetic field. This means that the sun's radiation is able to strip the moon of much of its atmosphere, but induces a charge on the moon's surface. Helium 3 has also been deposited onto the moon's surface in a similar way, And helium 3 is a notable candidate for potential nuclear fusion reactors.
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