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Archive for the ‘particle physics’ category: Page 486

Nov 6, 2018

Airglow in Earth’s upper atmosphere shines in red, green, purple and yellow in this view from the International Space Station

Posted by in categories: particle physics, satellites

Turbulence in this sea of charged particles can interfere with satellites 🛰 as well as communication 📡 and navigation 📶 signals. When it launches tomorrow, our #NASAICON mission will watch and image airglow, helping scientists better understand the extreme variability of the region where Earth meets space.

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Nov 6, 2018

In materials hit with light, individual atoms and vibrations take disorderly paths

Posted by in categories: materials, particle physics

‘’Until now, scientists assumed this all happened in a smooth, coordinated way. ‘’… silly scientists 🤔🙈🤦‍♂️.


Hitting a material with laser light sends vibrations rippling through its latticework of atoms, and at the same time can nudge the lattice into a new configuration with potentially useful properties – turning an insulator into a metal, for instance.

Until now, scientists assumed this all happened in a smooth, coordinated way. But two new studies show it doesn’t: When you look beyond the average response of atoms and vibrations to see what they do individually, the response, they found, is disorderly.

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Nov 5, 2018

Scientists Are About to Redefine the Kilogram

Posted by in categories: engineering, particle physics, transportation

The kilogram is one of the most important and widely used units of measure in the world — unless you live in the US. For everyone else, having an accurate reading on what a kilogram is can be vitally important in fields like manufacturing, engineering, and transportation. Of course, a kilogram is 1,000 grams or 2.2 pounds if you want to get imperial. That doesn’t help you define a kilogram, though. The kilogram is currently controlled by a metal slug in a French vault, but its days of importance are numbered. Scientists are preparing to re define the kilogram using science.

It’s actually harder than you’d expect to know when a measurement matches the intended standard, even when it’s one of the well–define d Systéme International (SI) units. For example, the meter was originally define d in 1793 as one ten-millionth the distance from the equator to the north pole. That value was wrong, but the meter has since been re define d in more exact terms like krypton-86 wavelength emissions and most recently the speed of light in a vacuum. The second was previously define d as a tiny fraction of how long it takes the Earth to orbit the sun. Now, it’s pegged to the amount of time it takes a cesium-133 atom to oscillate 9,192,631,770 times. Again, this is immutable and extremely precise.

That brings us to the kilogram, which is a measurement of mass. Weight is different and changes based on gravity, but a kilogram is always a kilogram because it comes from measurements of density and volume. The definition of the kilogram is tied to the International Prototype of the Kilogram (IPK, see above), a small cylinder of platinum and iridium kept at the International Bureau of Weights and Measures in France. Scientists have created dozens of copies of the IPK so individual nations can standardize their measurements, but that’s a dangerous way to go about it. If anything happened to the IPK, we wouldn’t have a standard kilogram anymore.

Continue reading “Scientists Are About to Redefine the Kilogram” »

Nov 5, 2018

Scientists Do Too Much Research on the Old Instead of the New

Posted by in categories: innovation, particle physics

Spending billions on a huge particle collider won’t give us the breakthrough discoveries we need.

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Nov 5, 2018

Physicists measured Earth’s mass using neutrinos for the first time

Posted by in category: particle physics

Counting tiny particles that can zip straight through the Earth reveals what the planet is like on the inside.

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Nov 5, 2018

Mystery particle spotted? Discovery would require physics so weird that nobody has even thought of it

Posted by in category: particle physics

Scientists at Cern’s Large Hadron Collider have seen something that may force us to abandon everything we thought we knew about the world on the level of particles.

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Nov 5, 2018

Why Physics Needs a Post-LHC Collider

Posted by in category: particle physics

The Large Hadron Collider is the most powerful particle accelerator ever built by humanity. By achieving higher energies and greater numbers of collisions at those energies than ever before, we’ve pushed the frontiers of particle physics past their old boundaries.

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Nov 3, 2018

Manta rays feed using ricochet separation, a novel nonclogging filtration mechanism

Posted by in categories: biological, engineering, particle physics

Solid-liquid filtration is a ubiquitous process found in industrial and biological systems. Although implementations vary widely, almost all filtration systems are based on a small set of fundamental separation mechanisms, including sieve, cross-flow, hydrosol, and cyclonic separation. Anatomical studies showed that manta rays have a highly specialized filter-feeding apparatus that does not resemble previously described filtration systems. We examined the fluid flow around the manta filter-feeding apparatus using a combination of physical modeling and computational fluid dynamics. Our results indicate that manta rays use a unique solid-fluid separation mechanism in which direct interception of particles with wing-like structures causes particles to “ricochet” away from the filter pores. This filtration mechanism separates particles smaller than the pore size, allows high flow rates, and resists clogging.

Several fundamental mechanisms for solid-fluid separation have been described in the biological and engineering literature, including sieve (1, 2), cross-flow (3–6), hydrosol , and cyclonic separation. Sieve filtration passes a mixture of particles and fluid through a structure with regularly sized pores, causing the particles to be retained while the fluid is drained. Although effective, sieve filters must have pore sizes smaller than the particle size, and they inevitably clog in use (2, 8, 9). Cross-flow filtration is similar to sieving, except that the incoming flow runs parallel rather than perpendicular to the filter. This configuration shears captured particles off the filter’s surface, which reduces but does not eliminate clogging (5, 6). Unlike sieve and cross-flow filters, hydrosol and cyclonic filtration do not require regularly sized pores.

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Nov 2, 2018

What shape are subatomic particles?

Posted by in category: particle physics

Peanuts, rugby ball, bagels and spheres — now that’s an odd menu!

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Nov 1, 2018

‘Ask a Spaceman’ Seeks Out the Elusive Quark Star in Finale

Posted by in categories: cosmology, particle physics

After guiding us across the universe, astrophysicist and Space.com columnist Paul Sutter closes his basic astronomy series this week by looking at the arguments for and against the existence of quark stars.

In Episode 12 of the Facebook Watch series “Ask a Spaceman,” Sutter continues to explore the topic of these stars, finishing a miniseries that began with Episode 10 and Episode 11. Scientists haven’t observed quark stars yet, but the objects may exist. Such a star would be a leftover remnant of a star that exploded and would be packed even more densely than a neutron star; the quark star would have such strong gravity that fundamental particles in the core, such as protons and neutrons, would break down into their constituent parts, called quarks.

“Is there any astrophysical scenario at all that enables them [quark stars] to appear in our universe?” Sutter asks in the new episode. At first, he suggests there might be some things we categorized a dwarf stars that are more dense and massive than what physics would suggest. So, maybe we have seen quark stars, but we can’t tell the difference between a quark star and a neutron star — they look too much alike, Sutter says. [Supernova Fail: Giant Dying Star Collapses Straight into Black Hole].

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