“Alien” Signals, Dark Energy, and SpaceX Investing in Solar | Vol. 2 / No. 23

"It is important to note that we did not “optimize” this fit." ; Image: Hippke, Domainko, and Learned.
“It is important to note that we did not “optimize” this
fit.” ; Image: Hippke, Domainko, and Learned.

187.5 cm-3

Fast Radio Bursts, or FRBs, have been a bit of a mystery since their discovery in 2001 (the dates of all eleven on the above graph are given YYMMDD). They’re only milliseconds long and intensely powerful — New Scientist describes them as having “as much energy as the Sun gives off in a month” — and we don’t know what causes them. But now we know something else about them, and it’s a little odd. In a new paper that’s gone up on arxiv.org, Michael Hippke, Wilfried Domainko, and John Learned have revealed that one measurement, their “dispersion measure.” DM is used by astronomers to tell how far away pulsars are: as the brief pulse comes at us through nearly-empty space, different wavelengths interact more or less with free-floating electrons, slowing down the lower frequency photons more than the higher frequency ones. Without getting into the peculiarity of the units (parsec cm-3) it’s basically counting how many electrons are between us and the source. And for all eleven we’ve seen so far, that number is almost exactly a multiple of 187.5. Which is odd. Now, some people are getting their tin-foil hats ready, because the likelihood of this being chance is somewhere in the “5 in 10,000” range and they want it to be aliens. Heck, I’d love for it to be something like, I don’t know, a “warp signature” or something equally science-fictiony, but even if it’s not, this is still very cool. If it’s not some new spy satellite screwing with our data, then this is the most likely to be an alien signal since pulsars were discovered. And so what if it’s not aliens? Last time we got pulsars. That’s pretty exciting news any way you shake it. Check out New Scientist for an explanatory rundown, or else check out the paper itself at arxiv.org.

Looking for dark energy at home vs. looking for it in space; photos: Paul Hamilton et al. (left), UCL Mathematical and Physical Science -- Dark Energy Survey (right)
Looking for dark energy at home vs. looking for it in space; photos: Paul Hamilton et al. (left), UCL Mathematical and Physical Science — Dark Energy Survey (right)

Dark Energy Close to Home

When you think of scientists looking for dark energy, the mysterious repulsive force causing the increasing expansion of the universe, chances are you probably picture them doing it with a telescope. But it turns out that’s not the only way to go looking. One theory of the stuff is something called a “chameleon” field — basically instead of a universal value for dark energy throughout the cosmos, the value would be more like temperature, varying from place to place. And in this case, the value would be higher the further away from matter you got. So to test this, a team at UC Berkeley looked at the way individual atoms passed through a vacuum at different distances from a central sphere, and managed to rule out a lot of possibilities. But hey, negative data are still data: when we know all the things dark energy isn’t, we’ll have a better idea of what it could be. Check out this article at Quanta for more detailed explanation, or the paper “Atom-interferometry constraints on dark energy” at arxiv.org for more.

Photo: Flickr user (ノ◕ヮ◕)ノ*:・゚✧, CC BY 2.0
Photo: Flickr user (ノ◕ヮ◕)ノ*:・゚✧, CC BY 2.0

SpaceX and Solar Bonds

This week solar electricity company SolarCity announced that SpaceX is investing $90million in their solar bonds program. It’s an interesting way to raise capital without going to venture capitalists or to a bank: just like a government savings bond, they promise certain interest yields for certain term lengths. They’re open to anyone who can part with $1000 for at least a year, but it’s a little less secure than a governmental bond, because if the company goes under, well, that’s about it (the same could be said for governments, but they’re at least a little less likely to go under… a little). That said, SpaceX’s investment is a good vote of confidence — if nothing else a vote of confidence in Elon Musk’s commitment to his empire growing. Check out the SolarCity press release for more.

Pick a colour? Photo: Flickr user Michael Pardo, CC BY 2.0 (modified)
Pick a colour? Photo: Flickr user Michael Pardo, CC BY 2.0 (modified)

Designer Chlorophyll

Get ready for blue and orange salad, at least, if you’re willing to believe this article over at Gizmodo. The long and short of it is that a team of researchers seem to have found a controllable way to alter the wavelengths absorbed by chlorophyll, the (often) green stuff in plant leaves that harvests the energy of the sun. In a paper published in the Journal of Physical Chemistry B (not A or C, mind you — I love chemists), they claim to be able to expand the infrared wavelengths absorbed during photosynthesis, thereby making the process more efficient. Whether this will lead to plants of different colours is, of course, up in the air, although it does make sense we should be able to, but it’s still a pretty important breakthrough and one that may come in handy as our population grows beyond all reasonable levels. Check out the article at Gizmodo or the paper itself at JPCB.


In surprising news out of the Mayo Clinic this week, researchers studying the brains of deceased patients with Alzheimer’s Disease have claimed that, rather than the amyloid plaque buildup in the brain associated with the disease, the culprit behind the cognitive decline is in fact something else: a misfolded protein known simply as Tau. By studying thousands of brains at differing stages of the disease, they found that the process of Tau buildup mirrored the processes of cognitive decline, starting in the hippocampus and moving outward to the cortex — a better fit than amyloid plaque which starts in the cortex and moves on from there. While both proteins certainly play a role in the disease, the team is now advocating a push toward targeting Tau in future therapeutics for the disease. Check out the press release from the Mayo Clinic for more.

Testing Drones in Canada

Turns out that Amazon’s gotten tired of waiting for the FAA to make things easier for its path to drone delivery, so in the meantime they’re testing their drones in Canada. This week Ed Pilkington over at the Guardian got access to Amazon’s “secret” drone testing site in British Columbia just a couple thousand feet from the US border. The plan is to use the airspace between 200 feet and 500 feet (above most buildings and below most aircraft) to deliver their goods in a timely manner. That is, timelier than free 2-day delivery, which is what the company promises (and delivers on) for its US “Prime” customers. As of this week, the US government is only allowing Amazon to test its drones indoors, which, the company says, isn’t helpful. The FAA’s new rules — under which some outdoor work will be allowed — won’t come into effect for another two years. Amazon’s not interested in waiting. Check out the Guardian article for more.

Best of the Rest

So much more happened this week. Here’s a super-quick rundown:

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That’s all for today. Have a great week.