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Archive for the ‘cosmology’ category: Page 198

Jul 2, 2022

Ask Astro: What are the differences between supernovae, kilonovae, and hypernovae?

Posted by in categories: cosmology, nuclear energy

In Latin, nova means “new.” In astronomy, that refers to a temporary bright “star” in the night sky. But the causes of these brief but brilliant stars are varied.

Classical novae occur in a binary star system with a white dwarf and a star close enough together that the white dwarf pulls, or accretes, material from its companion. The material — mostly hydrogen — sits on the surface of the white dwarf until enough has been gathered to kick-start a nuclear fusion reaction, the same process that powers the Sun. As the hydrogen is converted into heavier elements, the temperature increases, which in turn increases the rate of hydrogen burning. At this point, the white dwarf experiences a runaway thermonuclear reaction, ejecting the unburnt hydrogen, which releases 10,000 to 100,000 times the energy our Sun emits in a year. Because the white dwarf remains intact after blowing away this excess, a stellar system can experience multiple classical novae.

Kilonovae occur when two compact objects, like binary neutron stars or a neutron star and a black hole, collide. These mergers, as their name suggest, are about 1,000 times brighter than a classical nova, but not as bright as a supernova, which is 10 to 100 times brighter than a kilonova.

Jul 1, 2022

What If We Could Harness the Energy of a Black Hole?

Posted by in categories: cosmology, physics

What would happen if you put a couple of physicists in a room with a rope, a box and a black hole? They might come up with a plan to power the Earth for centuries. Black holes aren’t something you come across every day. To make a black hole of your own, you’d have to squeeze a star ten times bigger than our Sun into a sphere the diameter of New York City.

Transcript and sources: https://whatif.show/what-if-we-could-harness-the-energy-of-a-black-hole/
Music: http://bit.ly/whatif-music.

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Jul 1, 2022

Lab denies opening portals into parallel universes despite everyone thinking so

Posted by in categories: cosmology, government, nuclear energy, particle physics

A lab in Tennesee that does research in neutron, nuclear and clean energy had to debunk the myth that they were somehow attempting to open portals to other dimensions. Though if I ever learned anything from popular science fiction, if a research lab says they aren’t opening portals to parallel universes, my instinct tells me that they are totally opening portals to other dimensions. So you can imagine why folks would be skeptical.

Research scientist Leah Broussard explains in the video above that the experiments they are doing at the Oak Ridge National Laboratory (which is managed by the US Department of Energy) aren’t exactly about building portals to other dimensions. Instead, they involved “looking for new ways that matter we know and understand, that makes up our universe, might interact with the dark matter that makes up the majority of our universe, which we don’t understand.”

Broussard also explains when a particle physicist says portal, they mean it in a figurative sense. All this talk of parallel universes came when her research was released and people started making connections to the Netflix show, Stranger Things. A show that, coincidentally, features kids stumbling across a shady government agency opening portals to other dimensions full of monsters, in the ’80s.

Jul 1, 2022

The struggle to find the origins of time

Posted by in categories: cosmology, mathematics, quantum physics

What is time? Why is it so different from space? And where did it come from? Scientists are still stumped by these questions — but working harder than ever to answer them.


St. Augustine said of time, “If no one asks me, I know what it is. If I wish to explain to him who asks, I don’t know.” Time is an elusive concept: We all experience it, and yet, the challenge of defining it has tested philosophers and scientists for millennia.

It wasn’t until Albert Einstein that we developed a more sophisticated mathematical understanding of time and space that allowed physicists to probe deeper into the connections between them. In their endeavors, physicists also discovered that seeking the origin of time forces us to confront the origins of the universe itself.

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Jun 28, 2022

Physicists confront the neutron lifetime puzzle

Posted by in categories: chemistry, cosmology, internet, particle physics

To solve a long-standing puzzle about how long a neutron can “live” outside an atomic nucleus, physicists entertained a wild but testable theory positing the existence of a right-handed version of our left-handed universe. They designed a mind-bending experiment at the Department of Energy’s Oak Ridge National Laboratory to try to detect a particle that has been speculated but not spotted. If found, the theorized “mirror neutron”—a dark-matter twin to the neutron—could explain a discrepancy between answers from two types of neutron lifetime experiments and provide the first observation of dark matter.

“Dark matter remains one of the most important and puzzling questions in science—clear evidence we don’t understand all matter in nature,” said ORNL’s Leah Broussard, who led the study published in Physical Review Letters.

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Jun 28, 2022

Spacecraft in ‘warp bubble’ could travel faster than light

Posted by in categories: cosmology, information science, space travel

Special relativity famously dictates that no known object can travel faster than the speed of light in a vacuum – making it unlikely that humans will ever send spacecraft to explore beyond our local area of the Milky Way. However, new research by Erik Lentz at the University of Göttingen suggests there could be a way beyond this limit. The only catch is that his scheme requires vast amounts of energy and so may never actually be able to propel a spacecraft (Class. Quant. Grav. 38 075015).

Lentz proposes that conventional energy sources could arrange the structure of space–time in the form of a soliton – a robust singular wave. This soliton would act like a “warp bubble’”, contracting space in front of it and expanding space behind. Unlike objects within it, space–time itself can bend, expand or warp at any speed. A spacecraft contained in a hyperfast bubble could therefore arrive at its destination faster than light would in normal space without breaking any physical laws.

It had been thought that the only way to produce a warp drive was by generating vast amounts of negative energy – perhaps by using some sort of undiscovered exotic matter or by manipulating dark energy. To get around this problem, Lentz constructed an unexplored geometric structure of space–time to derive a new family of solutions to Einstein’s general relativity equations called positive-energy solitons. Though Lentz’s solitons appear to conform to Einstein’s general theory of relativity and remove the need to create negative energy, space agencies will not be building warp drives any time soon, if ever. Part of the reason is that Lentz’s positive-energy warp drive requires a huge amount of energy. According to Lentz, a 100 m radius spacecraft would require the energy equivalent to “hundreds of times the mass of Jupiter”.

Jun 23, 2022

In a Parallel Universe, Another You

Posted by in category: cosmology

As they probe the secrets of the cosmos, scientists question whether our reality is but one in a multiverse.

Jun 22, 2022

Gravitational Wave Events With Split Personalities

Posted by in categories: cosmology, physics

Deep Follow-up of GW151226 — an ordinary binary or a low-mass ratio merger?

Now that we’ve been detecting gravitational waves.

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Jun 21, 2022

Researcher uses math to investigate possibility of time travel

Posted by in categories: cosmology, education, mathematics, physics, time travel

After some serious number crunching, a UBC researcher has come up with a mathematical model for a viable time machine.

Ben Tippett, a mathematics and physics instructor at UBC’s Okanagan campus, recently published a study about the feasibility of . Tippett, whose field of expertise is Einstein’s theory of general relativity, studies black holes and science fiction when he’s not teaching. Using math and physics, he has created a formula that describes a method for time travel.

“People think of time travel as something as fiction,” says Tippett. “And we tend to think it’s not possible because we don’t actually do it. But, mathematically, it is possible.”

Jun 21, 2022

Can wormholes act like time machines?

Posted by in categories: cosmology, physics, time travel

https://youtube.com/watch?v=V9Id-Ayy12g

Time travel into the past is a tricky thing. We know of no single law of physics that absolutely forbids it, and yet we can’t find a way to do it, and if we could do it, the possibility opens up all sorts of uncomfortable paradoxes (like what would happen if you killed your own grandfather).

But there could be a way to do it. We just need to find a wormhole first.

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