Tag Archives: Physics

Crucial Difference Between Truth and Meaning


The Life of the Mind, Author: Hannah Arendt.

By Maria Popova – While our thirst for knowledge may be unquenchable because of the immensity of the unknown, the activity itself leaves behind a growing treasure of knowledge that is retained and kept in store by every civilization as part and parcel of its world.

The loss of this accumulation and of the technical expertise required to conserve and increase it inevitably spells the end of this particular world. more> http://tinyurl.com/pcg6m9w

Moving silicon atoms in graphene with atomic precision

ScienceDaily – Richard Feynman [2, 3, 4, 5] famously posed the question in 1959: is it possible to see and manipulate individual atoms in materials?

For a time his vision seemed more science fiction than science, but starting with groundbreaking experiments in the late 1980s and more recent developments in electron microscopy instrumentation it has become scientific reality. However, damage caused by the electron beam is often an issue in such experiments.

Besides being beautiful physics, the findings open promising possibilities for atomic-scale engineering: “What makes our results truly intriguing is that the bond flip is directional — the silicon moves to take the place of the carbon atom that was hit by a probe electron,” explains Toma Susi, physicist and FWF Lise Meitner Fellow at the University of Vienna. more> http://tinyurl.com/phra9ao

Fluid mechanics suggests alternative to quantum orthodoxy

ScienceDaily – The system by Yves Couder and Emmanuel Fort consists of a bath of fluid vibrating at a rate just below the threshold at which waves would start to form on its surface. A droplet of the same fluid is released above the bath; where it strikes the surface, it causes waves to radiate outward. The droplet then begins moving across the bath, propelled by the very waves it creates.

“This system is undoubtedly quantitatively different from quantum mechanics,” John Bush says.

“It’s also qualitatively different: There are some features of quantum mechanics that we can’t capture, some features of this system that we know aren’t present in quantum mechanics. But are they philosophically distinct?” more> http://tinyurl.com/o4kcmpf

Atomically thin material opens door for integrated nanophotonic circuits

R&D – A new combination of materials can efficiently guide electricity and light along the same tiny wire, a finding that could be a step towards building computer chips capable of transporting digital information at the speed of light.

Using a laser to excite electromagnetic waves called plasmons at the surface of the wire, the researchers found that the MoS2 (molybdenum disulfide) flake at the far end of the wire generated strong light emission.

Going in the other direction, as the excited electrons relaxed, they were collected by the wire and converted back into plasmons, which emitted light of the same wavelength. more> http://tinyurl.com/pttr3h8

Can our computers continue to get smaller and more powerful?

R&D – Limits relating to time and space can be felt in practice.

The speed of light, while a very large number, limits how fast data can travel. Traveling through copper wires and silicon transistors, a signal can no longer traverse a chip in one clock cycle today.

A formula limiting parallel computation in terms of device size, communication speed and the number of available dimensions has been known for more than 20 years, but only recently has it become important now that transistors are faster than interconnections.

This is why alternatives to conventional wires are being developed, but in the meantime mathematical optimization can be used to reduce the length of wires by rearranging transistors and other components. more> http://tinyurl.com/qav9bsn