Mystery of the Missing Mini-Galaxies
Like moths about a flame, thousands of tiny satellite galaxies flutter about our Milky Way. For astronomers this is a dream scenario, fitting perfectly with the established models of how our galaxy’s cosmic neighbourhood should be. Unfortunately, it’s a dream in more ways than one and the reality could hardly be more different.
As far as we can tell, barely 25 straggly satellites loiter forlornly around the outskirts of the Milky Way. “We see only about 1 per cent of the predicted number of satellite galaxies,” says Pavel Kroupa of the University of Bonn in Germany. “It is the cleanest case in which we can see there is something badly wrong with our standard picture of the origin of galaxies.”
It isn’t just the apparent dearth of galaxies that is causing consternation. At a conference earlier this year in the German town of Bad Honnef, Kroupa and his colleagues presented an analysis of the location and motion of the known satellite galaxies. They reported that most of those galaxies orbit the Milky Way in an unexpected manner and that, taken together, their results are at odds with mainstream cosmology. There is “only one way” to explain the results, says Kroupa: “Gravity has to be stronger than predicted by Newton.”
Challenging Newton’s description of gravity is controversial. But regardless of where the truth lies, the Milky Way’s satellite galaxies have become the latest battleground between the proponents of dark matter and theories of modified gravity.
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Overheard...
- 40-something suit on cell: Wait, why do I have to be the girl?
Kseniya Simonova does “sand animation” on Ukraine’s Got Talent.
This is stunning.
So while I haven’t found a new game to get addicted to in awhile, I have found something else. I always knew about the Facebook application called Graffiti. You draw a little something that you can then send to a friend.
What I didn’t know was how many people have mastered this app and created some truly astonishing artwork. Being able to view each and every step with the “replay” button is a big plus. Check out the public gallery here.
PS, this is my favorite one.
Song of the day: “No Woman, No Cry” (Cover) by Xavier Rudd
How LED Tattoos Could Make Your Skin a Screen
The title character of Ray Bradbury’s book The Illustrated Man is covered with moving, shifting tattoos. If you look at them, they will tell you a story.
New LED tattoos from the University of Pennsylvania could make the Illustrated Man real (minus the creepy stories, of course). Researchers there are developing silicon-and-silk implantable devices which sit under the skin like a tattoo. Already implanted into mice, these tattoos could carry LEDs, turning your skin into a screen.
The silk substrate onto which the chips are mounted eventually dissolves away inside the body, leaving just the electronics behind. The silicon chips are around the length of a small grain of rice — about 1 millimeter, and just 250 nanometers thick. The sheet of silk will keep them in place, molding to the shape of the skin when saline solution is added.
These displays could be hooked up to any kind of electronic device, also inside the body. Medical uses are being explored, from blood-sugar sensors that show their readouts on the skin itself to neurodevices that tie into the body’s nervous system — hooking chips to particular nerves to control a prosthetic hand, for example.
Chips are already used inside bodies, most notably the tiny RFID tags injected into pets. But the flexible nature of these “tattooed” circuits means they can move elastically with the body, sitting in places that a rigid circuit board couldn’t.
The first displays are sure to be primitive, but likely very useful for the patients that receive them. You won’t be getting the full-color, hi-res images that come with ink, but functional displays. This doesn’t mean that the commercial and artistic possibilities are being ignored.
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Woah, if that’s not futuristic, I don’t know what is.
Alanis Morissette
Each HP cast member recalls their role in each film in 60 seconds.
