Coming to the end of 2016, I thought I would use my last post of the year, to reflect on some of the amazing physics and space/astronomy stories that have infused this year with so much excitement and intrigue. From the confirmation of the detection of gravitational waves (100 years after the famous general relativity publication) to a whole new raft of confirmed exoplanets to NASA having a probe in orbit around Jupiter for the first time in over two decades. We’ve seen a series of successful landings of Space X’s falcon rockets either on hard landing pads, or their floating drone ships. Elon Musk also outlined his extremely ambitious plan to get humans to Mars around the 2020’s. Could we be seeing the start of a new ‘private’ space race?
The detection of gravitational waves, as I mentioned in a previous post, has proven to be one of the most important discoveries in physics, perhaps of the century (excluding GR obviously). It opens up a whole new world of observational astronomy, one which eventually may allow us to peer back behind the curtain of the cosmic microwave background, further back in time than any astronomer has ever seen. The CMB is a view of the universe around 380,000 years after the big bang, a kind of baby picture of the universe. This time is known as the ‘Epoch of Reionization’ a time where the temperature of the universe dropped to such a state that ions could form into atoms, making the universe transparent in a flood of light. To peer back beyond this time requires radiation which isn’t dependent on the transparency of the medium through which it travels. In coming years, we may see gravitational observatories such as advanced LIGO & LISA discovering as of yet unknown physics.
Exoplanets are never too far away from the news, and this year has been an exceptional year for the field. The announcement of the discovery of an exoplanet around Earth’s closest star Proxima, by the Pale Red Dot Project, that potentially sits within its parent stars habitable zone. The distance and its orbital location makes it a prime target for exploration. Physicist Stephen Hawking and Russian Billionaire Yuri Milner announced the plans for their ‘Breakthrough Starshot’ project which would see a small cubesat accelerated to a significant percentage of the speed of light (about 20%) which would allow the small craft to make the journey to Proxima in around 20 years rather than the current 20,000+ years of conventional chemical propulsion.
The plucky little Kepler Space Telescope is also still working hard, even after the near disaster with its reaction wheels, its main method of steering to its targets. As of the time of writing, the number of confirmed transiting exoplanets sits at 3,439 with another 4,696 candidates awaiting validation. The patch of sky being monitored by Kepler is tiny, and transiting exoplanets account of only 10% of the exoplanet population, so its pretty safe to say that our solar system is definitely not unique in its existence.
This year has also seen some really odd discoveries. The story of Tabby’s Star, is one which I have been following with great interest. KIC 8462852 (AKA the ‘WTF star’) lies in the constellation of Cygnus, and got the attention of astronomers because of its irregular changes in brightness. The majority of observations of the star have come from the aforementioned Kepler Telescope, though it has been observed as early as 1890. The star is observed to drop in brightness in non-periodic frequency, and has been observed to have two long drops in brightness separated roughly 750 days apart. The drops being a reduction of 15% and 22% respectively. This is pretty significant for a star! Some of the current explanations for the irregular light curves range from the mundane – ‘Young star with proto-planetary disc’ to the ridiculous – ‘Alien Mega-structure’ or ‘Dyson Sphere’. Either way, astronomers are baffled. Observations continue, and there was even a crowd funding campaign to raise money to pay for further telescope time.
Which would be a more interesting outcome, proto-planetary disc or alien mega-structure……I know which I would pick!
These are just some of the physics/space/astronomy stories that have captured my imagination this year. There have certainly been many more, and fingers crossed that 2017 is as fruitful.
Happy New Year!