For a long time it was thought that there was no water on the moon. The Apollo missions found none and for a long time the data collected and minerals retrieved were all the evidence we had to go on. But for the last couple of years, due to new findings, it is believed there is water but much deeper down towards the Moon’s centre. Assuming this to be true the question is: How did the moon get hydrated?
The most well championed theory is that water from comets may have been the main source. Since comets are relatively indistinguishable in composition the comets we’ve observed should be very similar to the comets that crashed into the moon. So,f by looking at the isotope ratios in the water from comets and comparing them to the predicted isotope ratio from the lunar samples, the proof that the water comes from comets can be found. But it doesn’t. Because it turns out the isotopes don’t match. In fact at most 20% of all the water on the moon could have come from comets and realistically a lot less.
So we still don’t know what caused the water pocket to develop and we may not know for quite some time. But that just means it’ll be even more pleasing when we do.
On this day in 1966, the Surveyor 1 was launched. It was the first human made object to perform a controlled landing on a celestial body (crashing isn’t that impressive). It was a massive undertaking and proved it was possible to slow descent enough for a soft landing. The idea of getting a man on the moon was now very possible.
Skip on fifty years and you have the international space station attempting to blow up an inflatable room on the side of the satellite. As with everything in space it was done excruciatingly slowly to make sure nothing went wrong. It took three days for the massive bubble room to get to the correct pressure. This entire project called the Bigelow Expandable Activity Module (BEAM) has been planned for some time. Having been fixed to the space station it is planned to remain there for two years, although with no full time inhabitant. This device could also act as a containment of supplies as well as people. This is actually one of NASA’s marked steps on what they describe as the “path to mars.” Though it is clearly going to take a very long time, the idea that there is some long reaching plan already in place is reassuring and I’m certain that the designers of the Surveyor would be happy to know their work continued past the goal they had in mind.
Quantum mechanics has been the main focus of this week with some input coming from astrophysics and biophysics. On the topic of quantum physics comes one of the strangest scientific stories I’ve ever read. There is currently speculation that a fifth fundamental force of nature might have been discovered. The original four are gravity, electromagnetism, strong nuclear and weak interacting and these have been known about since the 1960s. This idea has come about because some American scientists at the University of California were looking through data collected by the Hungarian Nuclear Research Academy and pointed out that the particle the Hungarian physicists had discovered could not have been what they concluded it to be. Instead, they asserted, it must have been created by a force acting over a range smaller that the radius of a nucleus. The research has yet to be repeated so it is best to remain skeptical until some more solid evidence appears.
Anyway, goodbye until tomorrow.
In crystals it is possible to excite the lattice into creating phonons by exposing it to different frequency photons. This light and matter interaction is very useful and would find a wide range of applications if it could be mastered. The problem is that the exact phonons produced depend greatly on the structure of the crystal which is hard to control and is very easy to manipulate incorrectly. But researchers believe they have found a way around this problem. Phase change materials are materials that have a very large latent heat capacity. To get water from 97°C to 98°C takes the same amount of energy as getting it from 98°C to 99°C. But to get from 99°C to 100°C, to boil the water, this takes many multiples more. The energy stored in this stage is called latent heat and by using materials that can store a lot of energy this way an insulator that can be polarised with an electric field. This means that electrical manipulation can be used instead of the chemical kind to produce these materials.
Light travels very fast. It would take about 0.15 seconds for light to travel across the surface of the Earth. But attoseconds (1×10-18) are very small. So in one attosecond light travels across about one helium atom. It takes about 400 attoseconds for electrons to rearrange and a chemical reaction to take place. This means if we really want to probe the quantum landscape then producing pulses that are a few tens of attoseconds would be a brilliant start. The idea that has just been proposed is to use lasers on ionised gasses that should produce photons in the low X-Ray to high ultraviolet spectrum. These bursts would be emitted in the space of hundreds of attoseconds and so could be used to look at quantum systems. The lasers they use when focused would produce intensities of 1015 watt per centimetre cubed, an extreme power output. Research still needs to be done to help focus the X-Rays given off as currently the photons emitted by different laser pulses are flung off in different directions.
Gauge mechanics and gauge theory is an offshoot of quantum and particle physics that describes in detail the way in which all particles are affected by forces; all forces are fields; and all fields are particles. It has been very effective in describing and predicting both the discovery of new particles and the way these particles act on the quantum scale. Spin ice is the name for a substance that has no real ground state and so is constantly excited. It is formed from multiple tetrahedrally arranged ions and since this is the same structure as solid water they were called spin ices. The idea now being presented is that at cold temperatures local coalescing occurs with the spin ice terbium titanate – Tb2Ti2O7.Calculations, models and experiments have revealed that this pinching is an inherent part of the spin ice and will likely transfer over to their cousins the spin liquids. It is still possible that minute magnetic fields begin being generated at even lower temperatures according to classical theory and so there is still a lot of work to be done studying how these vector fields can describe the quantum behaviors of materials.
Quiescent or dormant galaxies are ones where there is close enough to no new star formation happening within them. If a galaxy is as big as the Milky Way or bigger it is likely to be a quiescent galaxy and in the last ten billion years the number of quiescent galaxies has grown to over twenty times its original number. There are currently two main theories about how these galaxies come to be. It is generally accepted as fact that when the black hole forms at the centre of a galaxy the rate of star production decreases. What stops it returning to original speed is what scientists argue about. The first idea is that the hydrogen that would form the stars is removed by some method before the stars can form; the other is that the hydrogen is constantly kept hot which prevents it cooling and coalescing. The first idea is very hand wavy and the second has yet to be observed. But new evidence has c0me leading to a suggestion of what could heat this hydrogen. The idea is that the black hole in the centre could release enough streams of particles with sufficient kinetic energy (they are getting shot off a black hole) to warm the gas. This could explain why quiescent galaxies are all quite large as only a big galaxy could have a black hole capable of heating it.