Category Archives: Space Travel

The closest star to Earth is Proxima Centauri. It is about 4.25 light-years away, or about 25 trillion miles (40 trillion km). The fastest ever spacecraft, the now- in-space Parker Solar Probe will reach a top speed of 450,000 mph. It would take just 20 seconds to go from Los Angeles to New York City at that speed, but it would take the solar probe about 6,633 years to reach Earths nearest neighboring solar system.

If humanity ever wants to travel easily between stars, people will need to go faster than light. But so far, faster-than-light travel is possible only in science fiction.

In Issac Asimovs Foundation series, humanity can travel from planet to planet, star to star or across the universe using jump drives. As a kid, I read as many of those stories as I could get my hands on. I am now a theoretical physicist and study nanotechnology, but I am still fascinated by the ways humanity could one day travel in space.

Some characters like the astronauts in the movies Interstellar and Thor use wormholes to travel between solar systems in seconds. Another approach familiar to Star Trek fans is warp drive technology. Warp drives are theoretically possible if still far-fetched technology. Two recent papers made headlines in March when researchers claimed to have overcome one of the many challenges that stand between the theory of warp drives and reality.

But how do these theoretical warp drives really work? And will humans be making the jump to warp speed anytime soon?

Physicists current understanding of spacetime comes from Albert Einsteins theory of General Relativity. General Relativity states that space and time are fused and that nothing can travel faster than the speed of light. General relativity also describes how mass and energy warp spacetime hefty objects like stars and black holes curve spacetime around them. This curvature is what you feel as gravity and why many spacefaring heroes worry about getting stuck in or falling into a gravity well. Early science fiction writers John Campbell and Asimov saw this warping as a way to skirt the speed limit.

What if a starship could compress space in front of it while expanding spacetime behind it? Star Trek took this idea and named it the warp drive.

In 1994, Miguel Alcubierre, a Mexican theoretical physicist, showed that compressing spacetime in front of the spaceship while expanding it behind was mathematically possible within the laws of General Relativity. So, what does that mean? Imagine the distance between two points is 10 meters (33 feet). If you are standing at point A and can travel one meter per second, it would take 10 seconds to get to point B. However, lets say you could somehow compress the space between you and point B so that the interval is now just one meter. Then, moving through spacetime at your maximum speed of one meter per second, you would be able to reach point B in about one second. In theory, this approach does not contradict the laws of relativity since you are not moving faster than light in the space around you. Alcubierre showed that the warp drive from Star Trek was in fact theoretically possible.

Proxima Centauri here we come, right? Unfortunately, Alcubierres method of compressing spacetime had one problem: it requires negative energy or negative mass.

Alcubierres warp drive would work by creating a bubble of flat spacetime around the spaceship and curving spacetime around that bubble to reduce distances. The warp drive would require either negative mass a theorized type of matter or a ring of negative energy density to work. Physicists have never observed negative mass, so that leaves negative energy as the only option.

To create negative energy, a warp drive would use a huge amount of mass to create an imbalance between particles and antiparticles. For example, if an electron and an antielectron appear near the warp drive, one of the particles would get trapped by the mass and this results in an imbalance. This imbalance results in negative energy density. Alcubierres warp drive would use this negative energy to create the spacetime bubble.

But for a warp drive to generate enough negative energy, you would need a lot of matter. Alcubierre estimated that a warp drive with a 100-meter bubble would require the mass of the entire visible universe.

In 1999, physicist Chris Van Den Broeck showed that expanding the volume inside the bubble but keeping the surface area constant would reduce the energy requirements significantly, to just about the mass of the sun. A significant improvement, but still far beyond all practical possibilities.

Two recent papers one by Alexey Bobrick and Gianni Martire and another by Erik Lentz provide solutions that seem to bring warp drives closer to reality.

Bobrick and Martire realized that by modifying spacetime within the bubble in a certain way, they could remove the need to use negative energy. This solution, though, does not produce a warp drive that can go faster than light.

[Over 100,000 readers rely on The Conversations newsletter to understand the world. Sign up today.]

Independently, Lentz also proposed a solution that does not require negative energy. He used a different geometric approach to solve the equations of General Relativity, and by doing so, he found that a warp drive wouldnt need to use negative energy. Lentzs solution would allow the bubble to travel faster than the speed of light.

It is essential to point out that these exciting developments are mathematical models. As a physicist, I wont fully trust models until we have experimental proof. Yet, the science of warp drives is coming into view. As a science fiction fan, I welcome all this innovative thinking. In the words of Captain Picard, things are only impossible until they are not.

Read the rest here:

Warp drives: Physicists give chances of faster-than-light space travel a boost - The Conversation US

This article was originally published atThe Conversation.The publication contributed the article to Space.com'sExpert Voices: Op-Ed & Insights.

Sam Baron, Associate professor, Australian Catholic University

In 1994, physicist Miguel Alcubierreproposeda radical technology that would allow faster than light travel: thewarp drive, a hypothetical way to skirt around the universe's ultimate speed limit by bending the fabric of reality.

It was an intriguing idea even NASA has beenresearchingit at the Eagleworks laboratory but Alcubierres proposal contained problems that seemed insurmountable. Now, a recentpaperby US-based physicists Alexey Bobrick and Gianni Martire has resolved many of those issues andgeneratedalotofbuzz.

But while Bobrick and Martire have managed to substantially demystify warp technology, their work actually suggests that faster-than-light travel will remain out of reach for beings like us, at least for the time being.

There is, however, a silver lining: warp technology may have radical applications beyond space travel.

Related: 'Impossible' EmDrive Space Thruster May Really Be Impossible

The story of warp drives starts with Einstein's crowning achievement: general relativity. The equations of general relativity capture the way in which spacetime the very fabric of reality bends in response to the presence of matter and energy which, in turn, explains how matter and energy move.

General relativity places two constraints on interstellar travel. First, nothing can be accelerated past the speed of light (around 300,000 km per second). Even travelling at this dizzying speed it would still take us four years to arrive at Proxima Centauri, the nearest star to our Sun.

Second, the clock on a spaceship travelling close to the speed of light would slow down relative to a clock on Earth (this is known as time dilation). Assuming a constant state of acceleration, this makes it possible to travel the stars. One can reach a distant star that is 150 light-years away within one's lifetime. The catch, however, is that upon ones return more than 300 years will have passed on Earth.

Related: Warp Speed and the hype of hyperspace

This is where Alcubierre came in. He argued that the mathematics of general relativity allowed for "warp bubbles" regions where matter and energy were arranged in such a way as to bend spacetime in front of the bubble and expand it to the rear in a way that allowed a flat area inside the bubble to travel faster than light.

Read more:Don't stop me now! Superluminal travel in Einstein's universe

To get a sense of what "flat" means in this context, note that spacetime is sort of like a rubber mat. The mat curves in the presence of matter and energy (think of putting a bowling ball on the mat). Gravity is nothing more than the tendency objects have to roll into the the dents created by things like stars and planets. A flat region is like a part of the mat with nothing on it.

Such a drive would also avoid the uncomfortable consequences of time dilation. One could potentially make a round trip into deep space and still be greeted by ones nearest and dearest at home.

How does Alcubierre's device work? Here discussion often relies on analogies, because the maths is so complex.

Imagine a rug with a cup on it. You're on the rug and you want to get to the cup. You could move across the rug, or tug the rug toward you. The warp drive is like tugging on spacetime to bring your destination closer.

But analogies have their limits: a warp drive doesn't really drag your destination toward you. It contracts spacetime to make your path shorter. Theres just less rug between you and the cup when you switch the drive on.

Alcubierres suggestion, while mathematically rigorous, is difficult to understand at an intuitive level. Bobrick and Martire's work is set to change all that.

Bobrick and Martire show that any warp drive must be a shell of material in a constant state of motion, enclosing a flat region of spacetime. The energy of the shell modifies the properties of the spacetime region inside it.

This might not sound like much of a discovery, but until now it was unclear what warp drives might be, physically speaking. Their work tells us that a warp drive is, somewhat surprisingly, like a car. A car is also a shell of energy (in the form of matter) that encloses a flat region of spacetime. The difference is that getting inside a car does not make you age faster. That, however, is the kind of thing a warp drive might do.

Using their simple description, Bobrick and Martire demonstrate a method for using Einsteins general relativity equations to find spacetimes that allow for arrangements of matter and energy that would act as warp bubbles. This gives us a mathematical key for finding and classifying warp technologies.

Their work manages to address one of the core problems for warp drives. To make the equations balance, Alcubierres device runs on negative energy but we are yet to discover any viable sources of negative energy in the real world.

Worse, the negative energy requirements of Alcubierres device are immense. By some estimates, the entire energy in the known universe would be needed (though later work brings the number down a bit).

Bobrick and Martire show a warp drive could be made from positive energy (i.e. normal energy) or from a mixture of negative and positive energy. That said, the energy requirements would still be immense.

If Bobrick and Martire are right, then a warp drive is just like any other object in motion. It would be subject to the universal speed limit enforced by general relativity after all, and it would need some kind of conventional propulsion system to make it accelerate.

The news gets worse. Many kinds of warp drive can only modify the spacetime inside in a certain way: by slowing down the clock of the passenger in exactly the way that makes a trip into deep space a problem.

Bobrick and Martire do show that some warp drives could travel faster than light, but only if they are created already travelling at that speed which is no help for any ordinary human hoping for a bit of interstellar tourism.

Remember that a warp drive can modify the region of flat spacetime it encloses. It can, in particular, speed up or slow down a clock inside the drive.

Consider what it would mean to have such an object available. Want to put someone with a terminal illness on ice? Stick them in a warp drive and slow their clock down. From their perspective, a few years will pass, while a hundred years will pass on Earth time enough to find a cure.

Read more:The art and beauty of general relativity

Want to grow your crops overnight? Stick them in a warp drive and speed the clock up. A few days will pass for you, and a few weeks will pass for your seedlings.

There are even more exotic possibilities: by rotating the spacetime inside a drive one may be able to produce a battery capable of holding huge amounts of energy.

Faster-than-light travel remains a distant dream. But warp technology would be revolutionary in its own right.

This article is republished fromThe Conversationunder a Creative Commons license. Read theoriginal article.

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New warp drive research dashes faster than light travel dreams, but reveals stranger possibilities - Space.com

After three successful test flights, NASA's Mars helicopter Ingenuity is ready to push the envelope in the skies of the Red Planet.

The small chopper will attempt its fourth flight today (April 29) at its Wright Brothers Field in Mars' Jezero Crater, where it landed with NASA's Perseverance rover, and this one aims to be its biggest and boldest yet.

"When Ingenuitys landing legs touched down after that third flight, we knew we had accumulated more than enough data to help engineers design future generations of Mars helicopters," Ingenuity chief engineer J. "Bob" Balaram of NASA's Jet Propulsion Laboratory in Pasadena, California, said in a statement. "Now we plan to extend our range, speed, and duration to gain further performance insight."

The 4-lb. (1.8 kilograms) Ingenuity is expected to take off at 10:12 a.m. EDT (1412 GMT) to make its fourth aerial sortie. The data from the flight should arrive at JPL at 1:21 p.m. EDT (1721 GMT), NASA officials said.

Video: Zoom in on Ingenuity helicopter's 1st flight on Mars

Ingenuity made history with its first flight on April 19, when it hovered just 10 feet (3 meters) above the ground. Since then, it has made two more flights, each one bigger than the last. The chopper's most recent flight occurred Sunday (April 25), when Ingenuity reached a height of 16 feet (5 m), flew 164 feet (50 m) downrange and reached a top speed of 6.6 feet per second, which is about 4.5 mph (7.2 kph).It also captured a stunning photo of the Perseverance rover from the air.

For Ingenuity's fifth flight, the helicopter's controllers aim to fly faster and longer. If all goes according to plan, Ingenuity will fly up to a height of 16 feet and reach a top speed of 8 mph (12.8 kph) during the flight. It will first fly south for about 276 feet (84 m) to photograph sand ripples, rocks and small craters from above. If no issues pop up, Ingenuity is expected to reach a point 436 feet (133 m) downrange, hover and take photos, and then return to its Wright Brothers Field home.

"To achieve the distance necessary for this scouting flight, we're going to break our own Mars records set during flight three," said Mars Helicopter backup pilot Johnny Lam in the same statement. "Were upping the time airborne from 80 seconds to 117, increasing our max airspeed from 2 meters per second to 3.5 (4.5 mph to 8), and more than doubling our total range."

Related: How NASA's Mars helicopter Ingenuity can fly on the Red Planet

If Ingenuity's fourth flight goes well, the helicopter could attempt an even more audacious fifth and final flight. MiMi Aung, Ingenuity project manager at JPL, said earlier this month that she'd like the helicopter to travel about 2,000 feet (600 m) on that final flight, if it was possible. But plans for the fifth flight will only be finalized after this fourth trip, Ingenuity's handlers said.

NASA's Perseverance rover landed on Mars Feb. 18 to deliver Ingenuity and begin a planned two-year mission to collect samples of the Red Planet and search for signs of past life. Ingenuity's five flights, which are spread out over a month of the mission, are a technology demonstration to prove that flying on Mars is possible and could be useful for future missions. Ingenuity's flight window for its five flights closes in early May.

"From millions of miles away, Ingenuity checked all the technical boxes we had at NASA about the possibility of powered, controlled flight at the Red Planet," said Lori Glaze, director of NASA's Planetary Science Division, said in the statement. "Future Mars exploration missions can now confidently consider the added capability an aerial exploration may bring to a science mission."

Email Tariq Malik at tmalik@space.com or follow him @tariqjmalik. Follow us @Spacedotcom, Facebook and Instagram.

Originally posted here:

NASA's Mars helicopter Ingenuity will attempt its boldest flight yet today - Space.com

For most people, getting to the stars is nothing more than a dream. On April 28, 2001, Dennis Tito achieved that lifelong goal but he wasnt a typical astronaut. Tito, a wealthy businessman, paid US$20 million for a seat on a Russian Soyuz spacecraft to be the first tourist to visit the International Space Station. Only seven people have followed suit in the 20 years since, but that number is poised to double in the next 12 months alone.

NASA has long been hesitant to play host to space tourists, so Russia looking for sources of money post-Cold War in the 1990s and 2000s has been the only option available for those looking for this kind of extreme adventure. However, it seems the rise of private space companies is going to make it easier for regular people to experience space.

From my perspective as a space policy analyst, I see the beginning of an era in which more people can experience space. With companies like SpaceX and Blue Origin hoping to build a future for humanity in space, space tourism is a way to demonstrate both the safety and reliability of space travel to the general public.

Dennis Tito, on the left beside two Russian astronauts, was the first private citizen to ever go to space and he spent more than a week on the International Space Station. Image via NASA/Wikimedia Commons

Flights to space like Dennis Titos are expensive for a reason. A rocket must burn a lot of costly fuel to travel high and fast enough to enter Earths orbit.

Another cheaper possibility is a suborbital launch, with the rocket going high enough to reach the edge of space and coming right back down. While passengers on a suborbital trip experience weightlessness and incredible views, these launches are more accessible.

The difficulty and expense of either option has meant that, traditionally, only nation-states have been able to explore space. This began to change in the 1990s as a series of entrepreneurs entered the space arena. Three companies led by billionaire CEOs have emerged as the major players: Virgin Galactic, Blue Origin and SpaceX. Though none have taken paying, private customers to space, all anticipate doing so in the very near future.

British billionaire Richard Branson has built his brand on not just business but also his love of adventure. In pursuing space tourism, Branson has brought both of those to bear. He established Virgin Galactic after buying SpaceShipOne a company that won the Ansari X-Prize by building the first reusable spaceship. Since then, Virgin Galactic has sought to design, build and fly a larger SpaceShipTwo that can carry up to six passengers in a suborbital flight.

Credit: Virgin GalacticThe VSS Unity spacecraft is one of the ships that Virgin Galactic plans to use for space tours.The VSS Unity spacecraft is one of the ships that Virgin Galactic plans to use for space tours.AP Photo/Matt Hartman

The going has been harder than anticipated. While Branson predicted opening the business to tourists in 2009, Virgin Galactic has encountered some significant hurdles including the death of a pilot in a crash in 2014. After the crash, engineers found significant problems with the design of the vehicle, which required modifications.

Elon Musk and Jeff Bezos, respective leaders of SpaceX and Blue Origin, began their own ventures in the early 2000s.

Musk, fearing that a catastrophe of some sort could leave Earth uninhabitable, was frustrated at the lack of progress in making humanity a multiplanetary species. He founded SpaceX in 2002 with the goal of first developing reusable launch technology to decrease the cost of getting to space. Since then, SpaceX has found success with its Falcon 9 rocket and Dragon spacecraft. SpaceXs ultimate goal is human settlement of Mars sending paying customers to space is an intermediate step. Musk says he hopes to show that space travel can be done easily and that tourism might provide a revenue stream to support development of the larger, Mars-focused Starship system.

Bezos, inspired by the vision of physicist Gerard ONeill, wants to expand humanity and industry not to Mars, but to space itself. Blue Origin, established in 2004, has proceeded slowly and quietly in also developing reusable rockets. Its New Shepard rocket, first successfully flown in 2015, will eventually offer tourists a suborbital trip to the edge of space, similar to Virgin Galactics. For Bezos, these launches represent an effort at making space travel routine, reliable and accessible to people as a first step to enabling further space exploration.

SpaceX has already started selling tickets to the public and has future plans to use its Starship rocket, a prototype of which is seen here, to send people to Mars. Image via Jared Krahn/Wikimedia Commons

Now, SpaceX is the only option for someone looking to go into space and orbit the Earth. It currently has two tourist launches planned. The first is scheduled for as early as September 2021, funded by billionaire businessman Jared Isaacman. The other trip, planned for 2022, is being organized by Axiom Space. These trips will be costly, at $55 million for the flight and a stay on the International Space Station. The high cost has led some to warn that space tourism and private access to space more broadly might reinforce inequality between rich and poor.

Blue Origins and Virgin Galactics suborbital trips are far more reasonable in cost, with both priced between $200,000 and $250,000. Blue Origin appears to be the nearest to allowing paying customers on board, saying after a recent launch that crewed missions would be happening soon. Virgin Galactic continues to test SpaceShipTwo, but no specific timetable has been announced for tourist flights.

Though these prices are high, it is worth considering that Dennis Titos $20 million ticket in 2001 could pay for 100 flights on Blue Origin soon. The experience of viewing the Earth from space, though, may prove to be priceless for a whole new generation of space explorers.

[Over 104,000 readers rely on The Conversations newsletter to understand the world.Sign up today.]

This article byWendy Whitman Cobb, Professor of Strategy and Security Studies, US Air Force School of Advanced Air and Space Studies,is republished from The Conversation under a Creative Commons license. Read the original article.

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Space tourism is now a reality if youre filthy rich - The Next Web

The closest star to Earth is Proxima Centauri. It is about 4.25 light-years away or about 25 trillion miles (40 trillion km). The fastest-ever spacecraft, the now- in-space Parker Solar Probe will reach a top speed of 450,000 mph. It would take just 20 seconds to go from Los Angeles to New York City at that speed, but it would take the solar probe about 6,633 years to reach Earths nearest neighbouring solar system.

If humanity ever wants to travel easily between stars, people will need to go faster than light. But so far, faster-than-light travel is possible only in science fiction.

In Issac Asimovs Foundation series, humanity can travel from planet to planet, star to star or across the universe using jump drives. As a kid, I read as many of those stories as I could get my hands on. I am now a theoretical physicist and study nanotechnology, but I am still fascinated by the ways humanity could one day travel in space.

Some characters like the astronauts in the movies Interstellar and Thor use wormholes to travel between solar systems in seconds. Another approach familiar to Star Trek fans is warp drive technology. Warp drives are theoretically possible if still far-fetched technology. Two recent papers made headlines in March when researchers claimed to have overcome one of the many challenges that stand between the theory of warp drives and reality.

But how do these theoretical warp drives really work? And will humans be making the jump to warp speed anytime soon?

Physicists current understanding of spacetime comes from Albert Einsteins theory of General Relativity. General Relativity states that space and time are fused and that nothing can travel faster than the speed of light. General relativity also describes how mass and energy warp spacetime hefty objects like stars and black holes curve spacetime around them.

This curvature is what you feel as gravity and why many spacefaring heroes worry about getting stuck in or falling into a gravity well. Early science fiction writers John Campbell and Asimov saw this warping as a way to skirt the speed limit.

What if a starship could compress space in front of it while expanding spacetime behind it? Star Trek took this idea and named it the warp drive.

In 1994, Miguel Alcubierre, a Mexican theoretical physicist, showed that compressing spacetime in front of the spaceship while expanding it behind was mathematically possible within the laws of General Relativity. So, what does that mean?

Imagine the distance between two points is 10 meters. If you are standing at point A and can travel one meter per second, it would take 10 seconds to get to point B. However, let us say you could somehow compress the space between you and point B so that the interval is now just one meter. Then, moving through spacetime at your maximum speed of one meter per second, you would be able to reach point B in about one second.

In theory, this approach does not contradict the laws of relativity since you are not moving faster than light in the space around you. Alcubierre showed that the warp drive from Star Trek was, in fact, theoretically possible.

Proxima Centauri here we come, right? Unfortunately, Alcubierres method of compressing spacetime had one problem: it requires negative energy or negative mass.

Alcubierres warp drive would work by creating a bubble of flat spacetime around the spaceship and curving spacetime around that bubble to reduce distances. The warp drive would require either negative mass a theorised type of matter or a ring of negative energy density to work. Physicists have never observed negative mass, so that leaves negative energy as the only option.

To create negative energy, a warp drive would use a huge amount of mass to create an imbalance between particles and antiparticles. For example, if an electron and an antielectron appear near the warp drive, one of the particles would get trapped by the mass and this results in an imbalance. This imbalance results in negative energy density. Alcubierres warp drive would use this negative energy to create the spacetime bubble.

But for a warp drive to generate enough negative energy, you would need a lot of matter. Alcubierre estimated that a warp drive with a 100-meter bubble would require the mass of the entire visible universe.

In 1999, physicist Chris Van Den Broeck showed that expanding the volume inside the bubble but keeping the surface area constant would reduce the energy requirements significantly, to just about the mass of the sun. A significant improvement, but still far beyond all practical possibilities.

Two recent papers one by Alexey Bobrick and Gianni Martire and another by Erik Lentz provide solutions that seem to bring warp drives closer to reality.

Bobrick and Martire realised that by modifying spacetime within the bubble in a certain way, they could remove the need to use negative energy. This solution, though, does not produce a warp drive that can go faster than light.

Independently, Lentz also proposed a solution that does not require negative energy. He used a different geometric approach to solve the equations of General Relativity, and by doing so, he found that a warp drive would not need to use negative energy. Lentzs solution would allow the bubble to travel faster than the speed of light.

It is essential to point out that these exciting developments are mathematical models. As a physicist, I will not fully trust models until we have experimental proof. Yet, the science of warp drives is coming into view. As a science fiction fan, I welcome all this innovative thinking. In the words of Captain Picard, things are only impossible until they are not.

Mario Borunda is an Associate Professor of Physics, Oklahoma State University.

This article first appeared on The Conversation.

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Its theoretically possible to travel faster than light using the warp drives seen in Star Trek - Scroll.in

Mario Borunda is an associate professor of Physics at Oklahoma State University. This story originally featured in The Conversation.

The closest star to Earth is Proxima Centauri. It is about 4.25 light-years away, or about 25 trillion miles (40 trillion km). The fastest ever spacecraft, the now- in-space Parker Solar Probe will reach a top speed of 450,000 mph. It would take just 20 seconds to go from Los Angeles to New York City at that speed, but it would take the solar probe about 6,633 years to reach Earths nearest neighboring solar system.

If humanity ever wants to travel easily between stars, people will need to go faster than light. But so far, faster-than-light travel is possible only in science fiction.

In Issac Asimovs Foundation series, humanity can travel from planet to planet, star to star or across the universe using jump drives. As a kid, I read as many of those stories as I could get my hands on. I am now a theoretical physicist and study nanotechnology, but I am still fascinated by the ways humanity could one day travel in space.

Some characterslike the astronauts in the movies Interstellar and Thoruse wormholes to travel between solar systems in seconds. Another approachfamiliar to Star Trek fansis warp drive technology. Warp drives are theoretically possible if still far-fetched technology. Two recent papers made headlines in March when researchers claimed to have overcome one of the many challenges that stand between the theory of warp drives and reality.

But how do these theoretical warp drives really work? And will humans be making the jump to warp speed anytime soon?

Physicists current understanding of spacetime comes from Albert Einsteins theory of General Relativity. General Relativity states that space and time are fused and that nothing can travel faster than the speed of light. General relativity also describes how mass and energy warp spacetime hefty objects like stars and black holes curve spacetime around them. This curvature is what you feel as gravity and why many spacefaring heroes worry about getting stuck in or falling into a gravity well. Early science fiction writers John Campbell and Asimov saw this warping as a way to skirt the speed limit.

What if a starship could compress space in front of it while expanding spacetime behind it? Star Trek took this idea and named it the warp drive.

In 1994, Miguel Alcubierre, a Mexican theoretical physicist, showed that compressing spacetime in front of the spaceship while expanding it behind was mathematically possible within the laws of General Relativity. So, what does that mean? Imagine the distance between two points is 10 meters (33 feet). If you are standing at point A and can travel one meter per second, it would take 10 seconds to get to point B. However, lets say you could somehow compress the space between you and point B so that the interval is now just one meter. Then, moving through spacetime at your maximum speed of one meter per second, you would be able to reach point B in about one second. In theory, this approach does not contradict the laws of relativity since you are not moving faster than light in the space around you. Alcubierre showed that the warp drive from Star Trek was in fact theoretically possible.

Alcubierre estimated that a warp drive with a 100-meter bubble would require the mass of the entire visible universe.

Proxima Centauri here we come, right? Unfortunately, Alcubierres method of compressing spacetime had one problem: It requires negative energy or negative mass.

Alcubierres warp drive would work by creating a bubble of flat spacetime around the spaceship and curving spacetime around that bubble to reduce distances. The warp drive would require either negative massa theorized type of matteror a ring of negative energy density to work. Physicists have never observed negative mass, so that leaves negative energy as the only option.

To create negative energy, a warp drive would use a huge amount of mass to create an imbalance between particles and antiparticles. For example, if an electron and an antielectron appear near the warp drive, one of the particles would get trapped by the mass and this results in an imbalance. This imbalance results in negative energy density. Alcubierres warp drive would use this negative energy to create the spacetime bubble.

But for a warp drive to generate enough negative energy, you would need a lot of matter. Alcubierre estimated that a warp drive with a 100-meter bubble would require the mass of the entire visible universe.

In 1999, physicist Chris Van Den Broeck showed that expanding the volume inside the bubble but keeping the surface area constant would reduce the energy requirements significantly, to just about the mass of the sun. A significant improvement, but still far beyond all practical possibilities.

Two recent papersone by Alexey Bobrick and Gianni Martire and another by Erik Lentzprovide solutions that seem to bring warp drives closer to reality.

Bobrick and Martire realized that by modifying spacetime within the bubble in a certain way, they could remove the need to use negative energy. This solution, though, does not produce a warp drive that can go faster than light.

Independently, Lentz also proposed a solution that does not require negative energy. He used a different geometric approach to solve the equations of General Relativity, and by doing so, he found that a warp drive wouldnt need to use negative energy. Lentzs solution would allow the bubble to travel faster than the speed of light.

It is essential to point out that these exciting developments are mathematical models. As a physicist, I wont fully trust models until we have experimental proof. Yet, the science of warp drives is coming into view. As a science fiction fan, I welcome all this innovative thinking. In the words of Captain Picard, things are only impossible until they are not.

Read the original post:

The explanation behind warp speed Popular Science - Popular Science

Few moments are as iconic in mankinds collective memory as Neil Armstrong and Buzz Aldrins landing on the moon. But what was a unique sight is likely to become a slightly more regular one in the future, with lunar space missions in the works to reach the moon once again.

But reaching the moon is fraught with numerous technical challenges, one of them being the fact that it takes huge amounts of oxygen to launch rockets and spaceships and to get them back to Earth.

Since oxygen isnt available in outer space like it is here on Earth, delivering all this oxygen to the moon is a tricky and expensive business. An ultimate solution would be to manufacture oxygen for space travel right on the moon itself and this is where Israeli startup Helios comes in.

Manning bases on the moon

As opposed to what happened 50-odd years ago, this time were going to travel there not only to put up a flag and come back, but to stay there and man bases on the moon in a way similar to the International Space Station, which has been continually manned for the past 20 years, explains Helios co-founder and CEO Jonathan Geifman.

Were working toward being able to set up by the end of the decade a usable system that will be able to supply oxygen and fuel this whole endeavor of establishing permanent infrastructure on the moon and later on also on Mars, he says.

A rendering of an induction furnace extracting oxygen from lunar soil. Photo by Haya Gold

Established in 2018, Helios is focused on scaling up an existing technology called molten regolith electrolysis that enables the separation of oxygen and metals found in lunar soil and making it work in a lunar environment.

The technology involves heating up the lunar soil which is comprised of between 40 and 50 percent of oxygen to a temperature of almost 3,000 F and then passing an electric current through it.

As a result, we on the one hand receive oxygen that bubbles out, and on the other a usable by-product in the form of metals such iron, silicon and aluminum that remain at the bottom, Geifman says.

The high temperatures and the challenging environment make this a complex technological challenge, he adds.Making it work on a lab level is not the issue. The challenge is to scale it up. We need to be able to produce hundreds of tons of oxygen.

Helios co-founder and CEO Jonathan Geifman. Photo by Haya Gold

Helios, which has received funding from the Israel Innovation Authority, the Israel Space Agency and the Energy Ministry, has already achieved its proof of concept, and is busy developing and optimizing the system.

Luckily, its an inspiring field, and you can recruit very good people our team really is amazing and super professional, Geifmannotes.

Missions into space

Helios, he adds, is not directly cooperating with either NASA or SpaceX that are leading the world of space travel, but it is planning to send two missions into space within the next few years as part of its work. Unfortunately, I cant expand on that, he says.

And yet, when Helios launches its product into space, it will bring expanded space exploration a step or two closer.

For me, personally, its a field that has always fascinated me and I knew that I wanted to pursue it, Geifman says. The idea really was to think what part of the puzzle we could work on to complete the value chain and enable the establishment of permanent bases on the moon and Mars.

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Meet the startup reaching for the moon to make oxygen - ISRAEL21c

Space and humans are not a perfect mix. Scientists are constantly discovering new kinds of health risks associated with space, related to how factors like microgravity and cosmic radiationaffect our bones and organs.

But prolonged exposure to the environment of space isn't just a concern for our bodies. What about our minds?

The psychological effects of extreme isolation and confinement during long-term space travel and missions to other planets still represent a big unknown.

If we're ever going to successfully travel through space and even colonize other worlds, we need to understand much more about what happens to people stuck in unforgiving places for long periods, while very, very far from home.

As it happens, there is a scientific name for these hostile habitats:isolated, confined, extreme (ICE) environments. There is even a field of research in which scientists probe the psychological impacts of living in conditions analogous to long jaunts in space.

Of all the places on Earth to run ICE experiments, one in particular stands out.

"The Antarctic is regarded as an ideal analog for space because its extreme environment is characterized by numerous stressors that mirror those present during long-duration space exploration," a team of researchers led by psychologist Candice Alfano from the University of Houston wrote in a new study.

"In addition to small crews and limited communication during Antarctic winter months, the environment offers little sensory stimulation and extended periods of darkness and harsh weather conditions restrict outdoor activity. Evacuation is difficult if not impossible," the study authors added.

Alfano and her team leveraged the natural hardship of Antarctica's difficult conditions, monitoring the psychological health and development of personnel living and working at two remote Antarctic research stations during the nine-month study period.

The psychologists devised a monthly self-reporting tool called the Mental Health Checklist, designed to measure personnel's emotional states and mental health, including positive adaptation (feelings of control and inspiration), poor self-regulation (feelings of restlessness, inattentiveness, and tiredness), and anxious apprehension (feelings of worry and obsessing over things).

The study also monitored and rated Antarctic personnel's physical symptoms of illness, and Alfano's team collected saliva samples to assess the personnel's cortisol levels a biomarker of stress.

Ultimately, the study results showed that the participants' positive adaptations decreased over the course of their Antarctic mission, while poor self-regulation emotions increased.

"We observed significant changes in psychological functioning, but patterns of change for specific aspects of mental health differed,"Alfano said in a press release.

"The most marked alterations were observed for positive emotions such that we saw continuous declines from the start to the end of the mission, without evidence of a 'bounce-back effect' as participants were preparing to return home," she added.

According to the researchers, much previous research in this area has focused on negative emotional states triggered by the conditions of isolated, confined, and extreme environments.

But it's possible we've been missing out on another simultaneous problem. Diminishing positive feelings over long stays in difficult places appeared to be an almost universal response to the ICE conditions, whereas changes in negative emotion levels were more varied between individuals.

"Positive emotions such as satisfaction, enthusiasm, and awe are essential features for thriving in high-pressure settings,"Alfano said. "Interventions and countermeasures aimed at enhancing positive emotions may, therefore, be critical in reducing psychological risk in extreme settings."

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Experts Study People Working in Antarctica As a Proxy for Astronauts - Business Insider

ANU cosmologist and astrophysicist Dr Brad Tucker said the successful experiment on Mars converting carbon dioxide into breathable oxygen is a big step in the right direction for space exploration.It really has been one of the key instruments on Perseverance, weve heard a lot about Ingenuity and this drone but Perseverance has really got on with this job, he told Sky News.Dr Tucker said the majority of Mars atmosphere is carbon dioxide which can support plant life but not human life and it is not possible to bring required amounts through space travel.We obviously need oxygen to breathe and you dont want to bring all of the oxygen you need to support humans to Mars with us, its too complicated and too expensive.If you can convert it into oxygen that is amazing and so they are able to produce five grams of oxygen which doesnt sound like a lot but its enough for about a human to breathe for 15 minutes.Dr Tucker said the oxygen conversion would also help in rocket fuel and energy creation and was not just limited to sustaining human life. The fact that it did work and they were able to do it relatively quickly and successfully is going to pave the way for it to do it more and longer.

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Successful carbon dioxide into oxygen conversion 'is the key' to space travel - Sky News Australia

Australian aerospace firm Hypersonix Launch Systems is joining the space race and its using hydrogen to power its entry.

Helping to fuel its dreams, the Queensland-based company today (21st April) unveiled a new partnership with BOC, a subsidiary of Linde, for the supply of green hydrogen fuel.

The hydrogen fuel will be used for the re-usable SPARTAN scramjet engines, which can take small satellite payloads to lower earth orbit (LEO).

Just last year, Hypersonix secured a Department of Industry, Science, Energy and Resources Accelerating Commercialisation Grant, for the design and build of a re-usable satellite launch vehicle scramjet engine.

Read more:Hydrogen-fuelled rocket engine completes final acceptance test

Our deep-tech solution will ensure that our precious oceans do not become dumping grounds for single use rockets and boosters, and that our SPARTAN scramjet engines do not add further CO2 or methane emissions to the atmosphere, said Michael Smart Head of Research and Development at Hypersonix.

Hydrogen is our fuel of choice because of its proven versatility and performance compared to fossil fuels. Its environmental credentials are hard to beat, with the only emission being water vapour, added David Waterhouse.

Focusing on the new BOC partnership, David Waterhouse, CEO and Co-Founder of Hypersonix, said, Were very pleased to have found a strong clean hydrogen partner in BOC.

We both share a desire to bring the principles of the green space to the small satellite launch market, and this is something that sets us apart. We are determined to go to space, but in a way that is sustainable for our planet by design.

Chris Dolman, Business Development Manager for Clean Hydrogen at BOC, added, Both the automotive and the aviation sectors are well along the path to making the use of hydrogen fuel as a clean fuel option for day-to- day use.

BOC is set to produce green hydrogen for both local and in export use.

Hydrogen refuelling on the moon

In August last year (2020), Connecticut-based clean energy products company Skyre and cryogenic technology specialist Eta Space confirmed their continued development on the Moons first hydrogen fuelling plant.

To find out more about the ambitious mission, how the new plant will work, what the new innovation will refuel and when refuelling on the Moon will become a reality, H2 View sat down with Dr. Trent Molter, CEO and Founder of Skyre to find out more.

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Of course its a big deal to have the first hydrogen fuelling station the Moon but more importantly, its paving the way for the infrastructure needed here on Earth, Molter told H2 View.

After this hydrogen station is built and launched, we anticipate that there will be refuelling bases and other infrastructure provided to the Moon as we prepare ourselves for extended space missions.

The fact is, manned space travel has been using hydrogen for a very long time since the Gemini era in the early 60s. The lunar refuelling station is just a new advancement and application of one of the worlds most ubiquitous and useful elements.

Catch the full exclusive here.

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Hypersonix joins the space race with hydrogen fuel - H2 View