To Find Life on Mars, Follow the...Salt?

When it comes to finding life on Mars, NASA has had a strategy: follow the water. It makes sense, life as we know it requires liquid water, so it would make sense that if liquid water could be found, that would be the logical place to look for any Martian life. We've even managed to find some liquid water in the form of the recurring slope lineae. However, some new research suggests that following the water may not be the best strategy. Their suggestion? Look for life in the driest, saltiest places.

This sounds very counter-intuitive, but it does make a certain amount of sense, considering how microbial life has adapted to the driest conditions here on Earth. In these hyperarid regions, life survives by going underground, living underneath salty crusts that absorb water directly from the air. There is a possibility that as Mars dried up and microbes huddled together in the last bits of liquid brine just below the surface, they evolved in a similar fashion to Earth microbes in a similar situation, subsisting on the small amount of water in the Martian atmosphere. The researchers also suggest that these environments probably dried up for the last time recently, and perhaps some still exist. It's not the most dignified way for life to get by, but to go for so long in such a hostile place would be impressive nonetheless.

Discovery of Gravitational Waves Announced

It really doesn't sound like very much, does it? The existence of gravitational waves, first theorized by Albert Einstein, is accepted by pretty much everyone. But for the past 100 years, we've never been able to detect them. We've tried, but gravity, as it turns out, is ridiculously weak.

Perfect, now just stuff that in a water bottle

Let's do a little comparison between gravity and the other 3 fundamental forces, just to demonstrate gravity's weakness. Imagine the force of gravity represented as a 1 kilogram object sitting on a table. A big bottle of water that holds 1 liter weighs a kilogram, if you need a visualization. It's not a problem to pick up, right? Everyone can pick up a bottle of water. That bottle represents gravity's comparative force. Now, let's replace gravity with a similarly sized bottle with the comparative weight of the weak nuclear force, the next weakest fundamental force. That bottle, previously 1 kilogram now weighs nearly as much as Earth and Venus combined. It would then turn into a black hole. As it turns out, the weak nuclear force is stronger than gravity by a factor of 1 * 10²⁵. Try picking that up.

The story only gets worse with the other 2 forces. Let's move on to electromagnetism, which along with gravity is the fundamental force we all know. It's stronger than gravity by a factor of 1 * 10³⁶. For reference, the Sun weighs about 2 * 10³⁰ kg. Our bottle would weigh about as much as 500,000 Suns. This is nearly as heavy as Segue 2, a dwarf galaxy and Milky Way satellite which is (according to Wikipedia) the least massive galaxy known; but far, far more than the most massive stars, which weigh in at around 200-250 solar masses. Again, it would then become a black hole. The strong nuclear force is only 100 times stronger than electromagnetism, so our bottle now weighs 50 million solar masses. For comparison, the supermassive black hole at the center of the Milky Way is only about 4.5 million solar masses. At that mass, our bottle actually would not become a black hole...yes it would.

Credit: LIGO

It would clearly be no easy task then to detect gravitational waves. But today, scientists with the Laser Interferometer Gravitational-Wave Observatory announced that they had finally managed to do it. The project used a pair of detectors 2,000 miles apart to detect the waves, which compress a laser in one arm of a detector and stretch the laser of the other arm. 2 detectors are necessary to confirm the result, and to triangulate the location of the gravitational wave. It's an incredibly sensitive experiment, but it has to be. Even the largest gravitational waves, emanating from sources such as supernovas and black hole collisions, cause a change in laser length measured at the subatomic level.

On one hand, this isn't exactly the most exciting news. Gravitational waves have been observed indirectly before, and like I said before, very few doubted that they existed. But on the other hand, direct observation is a lot better than indirect. While we can't rule out an error in the experiment (and verifying this observation will be very difficult, since LIGO is the only detector powerful enough to detect gravitational waves), it seems that this announcement will likely be the real deal. It represents a powerful confirmation of general relativity, and now that we know how to detect gravitational waves, we can take the process further, learning much more about the universe. It really is a bigger deal than it sounds.

Random Thoughts 2/7/16

Currently working on a very long and extensive piece for the blog here, and I don't want to go too long without posting. So, here's a collection of news and random thoughts.

Astronomers have come up with a new theory to address the Fermi Paradox. Unless life can form reasonably quickly after a planet forms to stabilize the environment, the planet will likely become uninhabitable after about a billion years. It does make some sense, Venus and Mars were likely habitable at some point in the early solar system, but became less hospitable very quickly.

I recently finished watching the 2008 Clone Wars animated TV show. I don't want to call it a cartoon, because it didn't really look like one, and there already was a Clone Wars cartoon back in 2003. I really liked the 2003 cartoon, and I was pleasantly surprised that the 2008 show was actually pretty good in its own right. If you get past the 2008 animated movie and the first season, the show does pick up, and there's some surprising compelling stuff in there.

Remember the gigantic snowstorm that barreled right through the Mid-Atlantic a couple weeks ago? It dumped more than 2 feet of snow? Yeah, of course you do. That snow's pretty much all gone. It didn't last very long. What a disappointment. I don't like snow.

Nobody may remember him because he got overshadowed by Alan Shepard and his golfing, but Edgar Mitchell, sixth man to walk on the moon, died on February 4th. One less person alive who's walked on another world, which means there are now seven left.

I feel like there was some sort of significant event tonight, but for the life of me, I can't think of what it could be. Maybe some sort of sporting event? No, that can't be right. I don't know, but if I can't remember, it must not be that important. Oh well.