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PPPL physicist Lan Gao

Physicists create stable, strongly magnetized plasma jet in laboratory

When you peer into the night sky, much of what you see is plasma, a soupy amalgam of ultra-hot atomic particles. Studying plasma in the stars and various forms in outer space requires a telescope, but scientists can recreate it in the laboratory to examine it more closely.

Now, a team of scientists led by physicists Lan Gao of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) and Edison Liang of Rice University, has for the first time created a particular form of coherent and magnetized plasma jet that could deepen the understanding of the workings of much larger jets that stream from newborn stars and possibly black holes — stellar objects so massive that they trap light and warp both space and time.

“We are now creating stable, supersonic, and strongly magnetized plasma jets in a laboratory that might allow us to study astrophysical objects light years away,” said astrophysicist Liang, co-author of the paper reporting the results in The Astrophysical Journal Letters.

The team created the jets using the OMEGA Laser Facility at the University of Rochester’s Laboratory for Laser Energetics (LLE). The researchers aimed 20 of OMEGA’s individual laser beams into a ring-shaped area on a plastic target. Each laser created a tiny puff of plasma; as the puffs expanded, they put pressure on the inner region of the ring. That pressure then squeezed out a plasma jet reaching over four millimeters in length and created a magnetic field that had a strength of over 100 tesla.

“This is the first step in studying plasma jets in a laboratory,” said Gao, who was the primary author of the paper. “I’m excited because we not only created a jet. We also successfully used advanced diagnostics on OMEGA to confirm the jet’s formation and characterize its properties.”

The diagnostic tools, developed with teams from LLE and the Massachusetts Institute of Technology (MIT), measured the jet’s density, temperature, length, how well it stayed together as it grew through space, and the shape of the magnetic field around it. The measurements help scientists determine how the laboratory phenomena compare to jets in outer space. They also provide a baseline that scientists can tinker with to observe how the plasma behaves under different conditions.

“This is groundbreaking research because no other team has successfully launched a supersonic, narrowly beamed jet that carries such a strong magnetic field, extending to significant distances,” said Liang. “This is the first time that scientists have demonstrated that the magnetic field does not just wrap around the jet, but also extends parallel to the jet’s axis,” he said.

The researchers hope to expand their research with larger laser facilities and investigate other types of phenomena. “The next step involves seeing whether an external magnetic field could make the jet longer and more collimated,” Gao said.

“We would also like to replicate the experiment using the National Ignition Facility at Lawrence Livermore National Laboratory, which has 192 laser beams, half of which could be used to create our plasma ring. It would have a larger radius and thus produce a longer jet than that produced using OMEGA. This process would help us figure out under which conditions the plasma jet is strongest.”

The team included scientists from PPPL, Rice, LLE, MIT, and the University of Chicago. The research was supported by the DOE’s National Nuclear Security Administration, the National Science Foundation, and Los Alamos National Laboratory. Computer simulations were performed on the Extreme Science and Engineering Discovery Environment (XSEDE), a collaborative partnership of 19 institutions, and the Argonne Leadership Computing Facility, a DOE Office of Science user facility.

Materials provided by Princeton Plasma Physics Laboratory

A calorimeter designed by UBC researchers that is capable of detecting anomalous heat at high temperatures and high pressures. Photo credit: Phil Schauer

Scientists revisit the cold case of cold fusion

Four academic laboratories partner with Google to explore how materials science can help make fusion more accessible

Scientists from the University of British Columbia, the Massachusetts Institute of Technology, the University of Maryland, the Lawrence Berkeley National Laboratory, and Google are conducting a multi-year investigation into cold fusion, a type of benign nuclear reaction hypothesized to occur in benchtop apparatus at room temperature.

A progress report published today in Nature publicly discloses the group’s collaboration for the first time.

The group, which included about 30 graduate students, postdoctoral researchers and staff scientists, has not yet found any evidence of the phenomenon, but they did find important new insights into metal-hydrogen interactions that could impact low-energy nuclear reactions. The team remains excited about investigating this area of science and hopes their ongoing journey will inspire others in the scientific community to contribute data to this intriguing field.

Operating as a “peer group” with a stringent internal review process, the team started out by vetting previous claims of cold fusion, which have not been pursued in mainstream academic research for the past 30 years. If cold fusion could be realized, the heat released by this process might offer an attractive option for decarbonizing the global energy system.

The collaborative effort has produced nine peer reviewed publications and three arXiv posts. The team continues to search for a reproducible reference experiment for cold fusion.

Read the full perspective in Nature“Revisiting the cold case of cold fusion,” Curtis P. Berlinguette (UBC), Yet-Ming Chiang (MIT), Jeremy N. Munday (UMD), Thomas Schenkel (Berkeley Lab), David K. Fork, Ross Koningstein and Matthew D. Trevithick (Google).

Quotes

“We need a fundamentally new energy technology that can be scaled within the span of a human lifetime. Achieving this goal requires scientists to be afforded the opportunity to do daring work. This program provided us with a safe environment to take the long shot – given the profound impact this could have on society, we should remain open to it even if there is an unknown probability of success.”

Curtis Berlinguette, principal investigator and professor of chemistry and chemical and biological engineering at the University of British Columbia (UBC).

“If any research project ever met the definition of high-risk, high-reward, this would be the one. Electrochemistry can create interesting states of matter. If those states of matter help us in the search for new clean energy sources, all the better.”

Yet-Ming Chiang, principal investigator and Kyocera professor of materials science and engineering at the Massachusetts Institute of Technology (MIT).

“This program explores several intriguing and overlooked problems with the potential for significant impact. Even if we do not find a better way to produce clean energy, our discoveries along the way will still shed new light onto a variety of areas in science and engineering.”

Jeremy Munday, principal investigator and associate professor of electrical and computer engineering at the University of Maryland (UMD).

“We shouldn’t shy away from looking into areas that may have been written off. Not frivolously – but with new ideas and a recognition that there are things we don’t know and that we should be curious about.”

Thomas Schenkel, principal investigator and interim director of the Accelerator Technology and Applied Physics Division at the Lawrence Berkeley National Laboratory (Berkeley Lab).

“Google cares deeply about data and sustainability. When we looked into the scientific record of cold fusion, we found some bold claims, but not a lot of current, credible data. Given the positive impact cold fusion could have if true, we saw an opportunity to help the situation. We are impressed with the research team that rose to this challenge, and are pleased with what has been accomplished so far.”

Matt Trevithick, senior program manager at Google Research.

Materials provided by University of British Columbia

What If Time Travel Was Possible?

What if the dimension of time was no different from the three dimensions of space we live in? What if you could travel to the past and to the future…. the same way you can move right or left, up or down? Would you be able to change your past? And if you did, would it create a time paradox? What kind of time machine would you need to build, anyway?

Want to read more about time travel and understand the physics behind time travel, want to know about the paradoxes and problems behind time travel, Read the below blog to get a good understanding

 

Is Time Travel Possible? Physics Behind Time Travel | ScienceHook

We all travel in time, don’t we? From the last year, we’ve moved up one year. Another way to say this is that we all are travelling forward at the same speed. But our topic at hand is, can we travel faster or slower? Or can we travel backwards or forward in time?

Is Time Travel Possible

Is Time Travel Possible? Physics Behind Time Travel

We all travel in time, don’t we? From the last year, we’ve moved up one year. Another way to say this is that we all are travelling forward at the same speed. But our topic at hand is, can we travel faster or slower? Or can we travel backwards or forward in time? It is indeed kind of mind-boggling to wrap our whole head around that concept. And there are countless imaginative theories. What if time-travel was possible? Would we be able to prevent something bad from happening? But if so, then what’s the guarantee that something more ominous might not happen? Let us dive deep into the depth of it all. Is all of this science fiction or is it truly possible?

Content

  1. Physics behind time travel
  2. Is time travel possible?
  3. Some paradoxes and facts about Time-Travel
  4. Wrapping up!

Physics behind time travel

To understand the concepts of time travel you need to understand a few theories and about a few hypothetical things.

The first name we get to our mind while talking about Time Travel is Albert Einstein and his Theory of Relativity. Understanding these theories completely is very difficult and there are very less people in the world who understand it completely. But this theory proves two special things with which we can travel in time. They are

1. If we travel with speeds closer to the speed of light, time will move slower for us (by the Special Theory of Relativity). But achieving such speed is very difficult and the reason again comes from Einstein. Einstein gave a mass velocity relation which tells that our inertial mass increases with velocity. The equation is

einsteins mass velocity relation

Einstein’s Mass Velocity Equation

Where,

  • is the magnitude of the velocity
  • is the speed of light
  • m0 is the rest mass of the body
  • m is the relativistic mass

2. Gravity distorts space and time and time moves slower in places with high gravitation (by the General Theory of Relativity). Know more about Gravity time dilation.

The Theory of General Relativity predicts the existence of something called Wormholes. A wormhole is a special solution to Einstein’s Field Equation. Wormholes are like passages or shortcuts between two points in space. Physicists say that we can travel in time through Wormholes but there are serious problems. We will discuss the problems in the next section.

One more hypothetical thing one needs to know is Exotic Matter. Exotic Matter is such a matter which have negative mass and repels the mass we see. At first, scientists believed that exotic matter cannot exist as it contradicts Einstein’s theories but some of the researchers have claimed that they have found a solution to Einsteins General theory of relativity which allows the existence of negative mass.

Is time travel possible?

The BBC’s long-running science-fiction series Doctor Who, celebrating its fiftieth day of remembrance on twenty-three Nov, centres on its name character’s adventures through time and house. However, he may extremely skip between totally different periods of history at will?

Travelling forwards in time is amazingly simple. Einstein’s special theory of relativity, developed in 1905, made it clear that if we can travel at speeds close to the speed of light, we can travel into the future. Thanks to Einstein

Time travel used to be thought of as just science fiction, but Einstein's general theory of relativity allows for the possibility that we could warp space-time so much that you could go off in a rocket and return before you set… Click To Tweet

If one were to go away from Earth inside a spacecraft moving at a considerable fraction of light speed, and is available back, solely a number of years may need to be passed on board however many years may have gone along on Earth. This leads to the “twins paradox“. What is twins paradox? Suppose one of a twin goes on the above-mentioned spacecraft and comes back, he would find himself much younger than his twin.

There’s just one drawback, once after you travel into future, coming back to the time where you started is difficult. There is a possibility of travelling back in time if traversable wormholes exist in reality. Wormholes are known to exist at microscopic levels and even if traversable wormholes exist they would collapse in seconds because of gravity. To keep Wormholes open we would need Exotic matter which is still hypothetical.

Assuming exotic matter exists and wormholes also do, even then we can’t go to any point in past. First of all, we need to have a machine to travel through a wormhole and with that machine we can travel back only to the time when the machine was created. Even if we create machines which have no effect with time and if could travel back to any point in time, we still have problems like the Grandfather paradox.

More restrictively still, theoretical work by Kip Thorne of Caltech employing a partial unification of general theory of relativity with natural philosophy recommended that any hole that enables time travel would collapse as before long because it fashioned.
Thorne did, however, resolve a noticeable issue that might arise because of my time travel (within the orbit of general relativity). The “grandfather paradox” involves going back in time and accidentally killing one’s grandfather before one’s father is planned – preventing one’s own birth.

Not only that, if time travel becomes possible anyone could go into the past and change the future randomly which is very dangerous.

Some paradoxes and facts about Time-Travel

Time Travel

Time Travel (Credi: Pixabay)

  1. Infinite Loop Paradox

A man travels back into the past and marries a woman. After that, he returns to the present. The woman whom he married gets pregnant and has a son. After a few years, that son becomes the time traveller who goes to the past and marries the woman.

So who is the son and who is the father?

  1. Stephen Hawking once believed that time travel is impossible

Stephen Hawking used to think that time travel is impossible. He claimed there would be some physical law which would prevent time travel and he even named it as “chronology protection conjecture”. But in the following years, unable to find any such physical law, he changed his statement and he stated as below

“Time travel may be possible, but it is not practical.”--Stephen Hawking Click To Tweet

3. Many of us are time travellers

Many researches have proved that time flows quickly on higher altitudes on earth. Scientists have compared time from two atomic clocks, one was on a mountain and one was at sea level. The clock on the mountain was faster by 90 Billionths of a second.

So if you want to add a few billionths of a second to your life, stay in basements.

4. End of Humans Paradox

If someone travels back in time and kills the first human, there should be no life and the human who went there should disappear. What? These paradoxes really sound terrific.

There are many other paradoxes and theories, people say that

  • All great scientists could probably be time travels and didn’t know how  to go back
  • All the amazing structures like the Pyramids, Kailashnath Temple etc might be built by the time travellers and the list goes on

Space and time are two sides of the same coin

Space And Time are simultaneous phenomena (like mass and energy), and together form the fabric of the universe known as space-time. A demonstration of four-dimensional space-time’s inseparability is the fact that, as astronomers often remind us, we cannot look into space without looking back into time. We see the Moon as it was 1.2 seconds ago and the Sun as it was 8 minutes ago.

Also, in accordance with Einstein’s general theory of relativity, a massive object in space stretches the fabric of both the space and time around it. For example, our Sun’s mass bends its surrounding space so that the Earth moves in a straight line but also circles within the Sun’s curvature in space. The Sun’s effect on time is to slow it down, so time runs slower for those objects close to the massive object. Interestingly, gravity is the result of mass stretching the fabric of the space-time around it. Gravity also has an infinite range such that no matter how far apart two masses are in space they will always experience some gravitational pull towards each other. Theoretical physicists have tried to explain this phenomenon in terms of gravitons, S-Theory, and M-Theory, but even today a successful quantum theory of gravity is yet to be found.

Wrapping up!

While time travel does not appear possible — at least, possible in the sense that the humans would survive it — with the physics that we use today, the field is constantly changing. Advances in quantum theories could perhaps provide some understanding of how to overcome time travel paradoxes.

One possibility, although it would not necessarily lead to time travel, is solving the mystery of how certain particles can communicate instantaneously with each other faster than the speed of light.

In the meantime, however, interested time travellers can at least experience it vicariously through movies, television and books.