Lifeboat Foundation

A new design for solar cells that uses inexpensive, commonly available materials could rival and even outperform conventional cells made of silicon.

Writing in the Oct. 21 edition of Science, researchers from Stanford and Oxford describe using tin and other abundant elements to create novel forms of perovskite — a photovoltaic crystalline material that’s thinner, more flexible and easier to manufacture than silicon crystals.

“Perovskite semiconductors have shown great promise for making high-efficiency solar cells at low cost,” said study co-author Michael McGehee, a professor of materials science and engineering at Stanford. “We have designed a robust, all-perovskite device that converts sunlight into electricity with an efficiency of 20.3 percent, a rate comparable to silicon solar cells on the market today.”

How, then, could we tell a gravastar from a black hole? It would be almost impossible to “see” a gravastar, because of the same effect that makes a black hole “black”: any light would be so deflected by the gravitational field that it would never reach us. However, where photons would fail, gravitational waves can succeed! It has long since been known that when black holes are perturbed, they “vibrate” emitting gravitational waves. Indeed, they behave as “bells”, that is with a signal that progressively fades away, or “ringsdown”. The tone and fading of these waves depends on the only two properties of the black hole: its mass and spin. Gravastars also emit gravitational waves when they are perturbed, but, interestingly, the tones and fading of these waves are different from those of black holes. This is a fact that was alreadyknown soon after gravastars were proposed.

After the first direct detection of gravitational waves that was announced last February by the LIGO Scientific Collaboration and made news all over the world, Luciano Rezzolla (Goethe University Frankfurt, Germany) and Cecilia Chirenti (Federal University of ABC in Santo André, Brazil) set out to test whether the observed signal could have been a gravastar or not.

When considering the strongest of the signals detected so far, i.e. GW150914, the LIGO team has shown convincingly that the signal was consistent with the a collision of two black holes that formed a bigger black hole. The last part of the signal, which is indeed the ringdown, is the fingerprint that could identify the result of the collision. “The frequencies in the ringdown are the signature of the source of gravitational waves, like different bells ring with different sound”, explains Professor Chirenti.

Continue reading “‘Dark-Energy Star’ or ‘Black Hole’ --Scientists Question Source of LIGO Detection of Gravitational Waves” »

https://youtube.com/watch?v=v-qVBko0r0U

Mars colonization — getting there is only a small part of the equation. The bigger problem is how to survive. Synthetic biology may be able to help.

Bactéria Cyborg

Pesquisadores do Departamento de Ciência e Engenharia Biosystems (D-BSSE) da ETH Zurich em Basileia criaram um ciborgue — uma criatura híbrida que é máquina e parte organismo vivo.

Bactérias em que o crescimento pode ser totalmente controlado automaticamente por um computador. A interface entre o computador e bactérias é baseada na luz vermelha e verde. A abordagem poderia ajudar a otimizar a produção biotecnológica de moléculas.

Continue reading “First cyborg bacteria developed” »

Yossi Ovadya Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel & Valery Krizhanovsky Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel Correspondence [email protected]

Concerns that artificial intelligence will pose a danger if it develops consciousness are misplaced, says Jim Davies.

The Mars lander touched down late on Wednesday night but was emitting no signal, ground controllers have announced. It was not known whether the craft was intact.

“The lander touched down, that is certain,” Thierry Blancquaert, manager of the European Space Agency’s “Schiaparelli” lander told AFP.

“Whether it landed intact, whether it hit a rock or a crater or whether it simply cannot communicate, that I don’t know.”

Continue reading “ExoMars: British scientists face ‘six minutes of terror’ as Mars probe plunges to surface of Red Planet” »

In Tokyo, you can park your bike in underground vaults, and retrieve it in just 8 seconds. http://cnn.it/2evfkBL

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