Space

I have had lots of questions about this today because of a poorly researched Daily Star sensationalist article based on a many years out of date NASA press release. As usual with Google News this nonsense has gone right to the top of its search results. They really do need to fix this! 

Anyway I am writing this in the hope that it gets into Google News and helps some of the people getting scared by this story. So far I can't see any debunking articles there and the Science 2.0 articles do often get placed high in Google News.

Phil Plait of "Bad Astronomer" fame has a few choice words about this "tabloid fish-wrapper" - in case you don't get it, newspapers are often used to wrap fish and chips - he's suggesting that's all it is good for.

Stephen Hawking tends to exaggerate, using hyperbole - exaggerations for emotional effect. In this talk he takes our exponential population growth and extrapolates it forwards to 2600 and predicts that human beings will cover the globe shoulder to shoulder and that our electricity consumption will turn the surface of Earth red hot through the waste heat. Stephen Hawking hasn't taken account of the fact that our exponential growth has stopped. The same number of children were born in 2005 as in 2017 and our population is currently growing due to increasing lifespans, not through exponential growth. The middle of the range estimate is for it to level off at around 11 billion by 2100.. This story is scaring people and that's my motive for debunking it here. 

When we search the cosmos for evidence we are not the first advanced life form, we look for things that we could share in common. This anthropomorphism is common in culture, in everything from science studies to science-fiction. And it may not be wrong.

Assuming we have any extra-terrestrial neighbors, far less popular is the idea that we will be the advanced civilization new ones are terrified about being invaded by, they will likely have undergone natural selection just like we did. In the video game Spore, almost everyone evolved creatures that were purple and had huge eyes, despite trying to do things randomly, and that may happen on other planets also.

It may not seem to make sense but most of the universe - mass - can really only account for about 6 percent of what is going on. The rest of it can be under just about any umbrella at this point. Some call it the God of the Gaps, scientists call the unknown mass Dark Matter.

What is it? No one knows, when it comes to the very large and the very small, physics does not have all the answers, but something has made the universe at least 100 billion light years in size even though it's only 13 billion years old. As you know, a light year is the distance light will travel in that time. Since nothing can go faster than the speed of light, it's long been time to think about what Nothing is.

That's dark matter. And whatever is propelling it can be called Dark Energy.

The 24.2-day semi-periodicity of KIC 8462852 was first noted in Boyajian et al. (2015) and subsequently generated some interest. ETI enthusiasts apparently interpret it as evidence of artificial planning (e.g. intervals between megastructures that follow a clearance guideline in a shared orbit.) The more skeptical observers seem to either dismiss it as a meaningless chance finding (a view that was justifiable not long ago) or as something that would have to be produced by intrinsic variability.
The WTF paper, Boyajian et al. (2015), made an observation about a peculiar pattern of semi-periodicity in the light curve of KIC 8462852:

Three detectors tracking gravitational waves emitted by a merger of two black holes have brought science a little closer to locating a gravitational wave's birthplace in space. 

Gravitational waves are ripples in space and time created when two massive, compact objects such as black holes merge. The new detections were made on August 14, 2017 by two gravitational-wave detectors in the United States - Hanford and Livingston at the Laser Interferometer Gravitational-Wave Observatory (LIGO), operated by Caltech and MIT - and by the Virgo Gravitational-Wave Observatory in Italy. This marks the fourth detection of a binary black-hole system.

Until recently, we hadn't observed brightening of Boyajian's Star (KIC 8462852) over time. There were documented instances of fading over time, some more convincing than others. It was as though the star is gradually fading until the day it finally disappears from view.


Simon et al. (2017) changed all of that. Using ASAS/ASAS-SN data, the researchers documented two apparent episodes of brightening in the last 11 years. It now seems Boyajian's Star has long-term variability that is likely periodic.

Since the apparent amplitude of the long-term magnitude signal is not small, it's reasonable to expect it should show up in century-long data, despite the noisy nature of this data. I have confirmed this expectation with simulations.

A while back I wrote my article "Can Giant Airships Slowly Accelerate to Orbit Over Several Days" . It lead to a lot of discussion and as usual whenever you discuss John Powell's ideas, there were physicists and aeroengineers saying it is impossible. So anyway as part of this I had an especially interesting online discussion over many days with James Fincannon on the Space Show blog and much of this article comes out of that discussion. Unlike many of those who get involved in these discussions on the topic, he actually did many detailed calculations and shared them on the blog.

The IAU famously decided that Pluto is not a planet any more, calling it a "dwarf planet" instead, along with Ceres. However, their definition works as well as it does only because of a historical accident of our solar system and the bodies we have discovered in it so far. There are good reasons for thinking it has a "use before" date too, as we'll see. We don't know when that date is, but we will probably reach a point where we can't use it any more, at some point in the next two or three decades. The "use before "date may well be sooner than that. So why not change right away?