The Dangerous Relationship Between Hurricanes and the Moon

by Rebecca Boyle – source: medium

As Hurricane Florence makes landfall, scientist eyes are looking to the skies

MYRTLE BEACH, SC — Sept. 14: Storm clouds seen over the 2nd Ave. pier. Photo by Joe Raedle/Getty Images News

It may not be visible on the sodden Eastern Seaboard, but far above Hurricane Florence’s lashing winds and rain, the crescent moon is waxing—and that’s bad news for flooding along the Carolina coast.
Through its gravitational tug, the moon is the primary driver of the Earth’s tides—the daily rising and sinking of the oceans and lakes. High tides are higher than usual in the days around a new or full moon. As wind and rain from Hurricane Florence began pelting North Carolina, the moon’s cycle was just four days old, which means higher tides than average for America’s eastern shores. It also means the storm tide—the term for rising waves brought on by rainfall and surging seawater—will be higher too.
“If you could choose when to get hit by a hurricane, you would want it to be at a low tide,” said Brian McNoldy, a hurricane researcher at the University of Miami, who explained that to reduce the storm tide as much as possible, you want hurricanes to hit—if they must—during the first quarter or third quarter moon, “as far opposite of a new or full moon as you can get,” he said. Unfortunately, the recent new moon is still influencing tides in the Carolinas and in the Miami area.

The moon’s influence may not be obvious to most people, especially those who don’t live near coasts. But it shouldn’t be underestimated.

The moon’s shape appears to change in the sky with each consecutive night because of its alignment with respect to the Earth and sun. When the moon sidles in between the two, we can’t see light reflected off the moon’s surface, and it is invisible to us. That’s a new moon. During this phase, the sun and moon line up on the same side of Earth, so the sun amplifies the moon’s gravitational pull. The water on our planet bulges toward the moon more dramatically, and tides can be significantly higher.
Here’s what that means for Florence: As the effects of the hurricane slammed into the coast Thursday, Sept. 13 (the eye of the storm reached the coast on Friday morning), the moon was four days past new and 240,100 miles away, pretty close to its average distance from Earth. The scenario is not great news for the storm surge and storm tide, according to McNoldy.
The last megastorm to besiege the Carolinas was Hurricane Hazel in 1954. That storm had terrible timing, making landfall during a full moon high tide, bringing an 18-foot storm surge. Hurricane Sandy made landfall in New York City in 2012, also during a full moon, which may have contributed to higher than usual storm-surge levels. Hurricane Florence poses an even greater threat because it is expected to stall along the coast, dumping rain on the Carolinas for days on end. If the storm is as slow-moving as predicted, “it’s going to be there for two or three high tides,” McNoldy said.
Scientists are still trying to work out just how high the water will rise, where it will rise, and for how long. Storm surges—the abnormal rise in sea levels and, often, the deadliest effect of a hurricane—depend on numerous things, like a storm’s strength, speed, and direction; the terrain, coastline shape, and inlet size; the warmth of the water; and even the continental shelf on the ocean floor.

If you could choose when to get hit by a hurricane, you would want it to be at a low tide.

While the moon is partly to blame for high tides, there is one very human reason for Florence’s heightened storm surge risk. Average sea levels are higher now than in the past because of human-caused global warming. This ensures that Florence’s storm surge will be correspondingly higher and reach farther inland than it otherwise would. This is evident in sunny-day flooding already taking place in the Carolinas: Flooding projections were about 25 percent above average in the Carolinas for 2017-2018, according to the National Oceanic and Atmospheric Administration (NOAA). In 2016, Wilmington, North Carolina, saw 84 days of high-tide flooding and Charleston, South Carolina, saw 54 days. By contrast, in 1966, Charleston saw only four days of high-tide floods.
“There are a lot of things that affect this baseline upon which the storm travels,” said Ben Hamlington, an atmospheric scientist at NASA’s Jet Propulsion Laboratory, who studies sea-level rise. “The higher that baseline is, the worse your storm surge is going to be.”
Hamlington recently moved to California from Norfolk, Virginia, where municipal authorities are trying to build street-level flood prediction maps. “There’s a compounding effect with all the rainfall and the storm surge. When all this water gets dumped into an area, where does that water go? How does the land respond to that? All those things are very difficult to understand, and it’s a very active research area,” he said.
McNoldy, who was an astronomy major in college and switched to atmospheric science in graduate school, said the moon’s influence may not be obvious to most people, especially those who don’t live near coasts. But it shouldn’t be underestimated.
“It’s uncommon for people to ask about the tides, but it’s a huge factor, honestly,” he said. ”It can make all the difference.”

Are Moon Colonies Possible or the Fantasy of Billionaires?

by Eric Niiler – source: medium

The economy of lunar mining and tourism

Credit: Education Images/Universal Images Group/Getty

Growing up, my brother and I couldn’t get enough of Space: 1999, a mid-’70s series that hypnotized us with cool special effects, the crush-worthy Barbara Bain, who acted alongside her real-life husband Martin Landau, and its portrayal of the Moon as the main character in an action-packed 48-minute weekly episode. The premise of the show is bit far-fetched: an explosion at a moon base knocks the Moon out of Earth’s orbit and into a voyage to explore strange new worlds across the galaxy. The show was set a mere 15 years in the future.
It’s a reminder that in those post-Apollo years, we fully expected NASA or some international space force to be working on space bases in real life. More than four decades later, we’re still waiting for our Moonbase Alpha — though that’s not for a lack of interest. Ex-astronauts, entrepreneurial dreamers and short-lived sci-fi shows like Space: 1999 have kept alive the dream of a moon colony, and now, the confluence of technology, money, and political interest is pushing this idea out of the realm of sci-fi and closer to reality.
In my interviews with space scientists, industry officials, and futurists it appears that there’s an unofficial blueprint that is slowly shaping up for moon colonization. First, private space companies find ways to reduce the cost of launch. Right now, SpaceX says that it costs $62 million every time its Falcon 9 rocket is launched, while the more powerful Falcon Heavy costs an estimated $90 million per launch. Satellite companies and others wanting to get something in orbit get a discount for bulk purchases. SpaceX is bringing food and supplies to the International Space Station, it hopes to ferry U.S. astronauts by sometime in late 2019.
Then come fly-arounds and orbiting platforms. The Chinese plan to launch an Earth-orbiting space station by 2020, while NASA has asked private companies to develop a “Lunar Orbital Platform — Gateway” near the Moon by 2022. This could be NASA’s launch pad of sorts for future expeditions and settlements on both the Moon and Mars.
At the same time, private firms like Moon Express, as well as China, India and the European Space Agency are moving forward with robotic landers and rovers. The final step, supporters say, will be a permanent human presence on the surface. Maybe a government base first, followed by a private Moon resort.
NASA’s long-term involvement in the Moon is key to getting private companies to build on the lunar surface, according to Chris Lewicki, CEO of Planetary Resources, a Redmond, WA, based startup that plans to mine asteroids for rocket fuel and water.
“Government programs are like anchor tenants in a shopping mall,” Lewicki says about NASA and a future moonbase. “Without those big leaseholders, all smaller businesses don’t have a way to make a living. Without NASA it was hard to do itself.”
Some say all this could happen in the next 10 years. Others say it will take at least 20 years before both the technology for routine lunar launches is developed, and the cost comes down so that there’s actually consumer demand.

Single-planet species don’t survive. Living off the planet is probably not a bad strategy for survival. Sooner or later it will be one of the motivations of having bases on the moon.

And while the pace seems glacial, one Moon expert says likens it to the establishment of New World colonies, which didn’t happen overnight. “There’s a lag between discovery, exploration in detail, and exploitation,” says James W. Head III, a planetary scientist at Brown University who started his career at NASA selecting lunar landing sites for the Apollo missions.

So why go?

Supporters believe a moon colony will allow us to better understand how to reach farther out into the solar system. It also might be fun to visit for a once-in-a-lifetime vacation. The Moon is also a whole lot closer than Mars — it would take three days to get there, versus nine months — making it more of destination for lunar car campers than the hardcore astro-backpackers that would eventually reach Mars.
There’s also the idea of Moon mining.
Some Chinese and European researchers believe that the surface contains large quantities of helium-3, a rare element that could be used as a future energy source to fuel rockets traveling from Earth even further out to space. (The downside is that processing helium 3 into something useable takes an enormous amount of energy.) There’s also frozen water on the Moon’s polar regions: split it into hydrogen and oxygen via electrolysis and you have air to breathe — plus another rocket fuel source. That might be a long way off, but leaders of European and Chinese moon programs have said they have plans to explore it on upcoming lunar missions.
There’s another good case for colonies: our survival. James Head remembers what Apollo Cmdr. John Young, who flew in space during the Gemini, Apollo and shuttle programs, often told him when asked why humans should return to the Moon: “Single-planet species don’t survive,” Head remembers him saying. “Living off the planet is probably not a bad strategy for survival. Sooner or later it will be one of the motivations of having bases on the moon.”

How would a Moon economy work?

To make a moon base work, an economic foundation would be necessary. There’s already a growing “Low-Earth Orbit” economy (LEO for short) of U.S. companies that are putting satellites into space, servicing them and preparing to build places for people to live in work in Earth orbit.
The LEO economy numbers keep growing. Since 2000, more than 180 startup space ventures have attracted over $18.4 billion of investment, according to a May 2018 report by Bryce Space and Technology, an Alexandria, Virginia-based consulting firm. At $28 billion in valuation, SpaceX is the behemoth of the commercial space industry, and CEO Elon Musk wants to do it all: launch a constellation of Earth-orbiting satellites, send people around the Moon, and eventually establish a Mars base.
Musk has a history of missing deadlines, whether it’s delivery of the Tesla Model 3 or his ambitious space plans. But the frequency of SpaceX rocket launches — 28 since the beginning of 2017 — has made it one of the world’s most successful commercial space launch companies.
As it figures out how to use reusable rockets, SpaceX is driving down the cost of launches. That might open the door to a new set of zero-G pit-stops around the Earth and perhaps the Moon. These private rest stops would eventually replace the International Space Station, a $100 billion, 20-year-old NASA-funded mission that is now on its last legs. The White House says it wants someone else to run it after 2024 so that NASA can set its sights on putting people back on the Moon and Mars, although for now, Congress doesn’t agree.
The transition from a low-Earth economy to a moon economy is realistic, says Jeffrey Manber, CEO of Nanoracks, a Houston-based firm that operates its own laboratory space on the space station and launches tiny 10-inch square satellites, known as “cube-sats,” for commercial and university clients from ISS.
“We will have LEO hotels within five years and a decade from now you will see a growing infrastructure,” says Mander. “There will be hotels scattered throughout the frontier along with warehouses, fuel depots, then commercial modules or lunar colonies.”

“The key to having a Heinlein-esque future is that it has to get cheaper to get out of Earth’s gravity, once you do that, it all comes into place.”

Call Manber crazy, but many of the things he’s talking about are actually happening. Bigelow Aerospace, a space tech startup, built an inflatable astronaut work module on the space station in 2016 and plans to put one in orbit around the moon by 2022. The company is owned by Robert Bigelow, the billionaire founder of Budget Suites of America hotels, and an avowed believer in UFO visitations to Earth. Bigelow is one of several billionaires who are competing in the race for the Moon, including Jeff Bezos, with Blue Origin (Amazon founder), Musk, with SpaceX, and Richard Branson, with Virgin Galactic.
Their deep pockets and freedom from quarterly earnings returns are helping push technology forward in decadal leaps. They are building rockets that can get companies like Bigelow and Nanoracks off Earth and over to the Moon. Only NASA during the go-go Apollo years could match the burn rate of folks like Bezos, who said recently that he sells a billion dollars a year in Amazon stock to keep Blue Origin going.
Blue Origin is developing the Blue Moon lander, which could carry cargo to the lunar surface in preparation for a base and its own New Glenn rocket, which has a successful test in July.

How realistic are the colonies?

Getting the economics of rocket launching just right may be the tipping point for landing people — and things — on the Moon, according to Andy Weir. He wrote The Martian, a sci-fi novel about a stranded astronaut that became the blockbuster 2015 Matt Damon movie. As a follow-up, Weir wrote Artemisabout a moon colony that was subject to a heist and extortion plan involving competing mining interests. Weir places Artemis in the 2080s. He believes a real-life moon base is possible.
“The key to having a Heinlein-esque future,” says Weir, referring to the 1950s era sci-fi author Robert Heinlein, “is that it has to get cheaper to get out of Earth’s gravity, once you do that, it all comes into place.”
Weir crunched the numbers to figure out what it would take to get well-heeled space tourists to take a $70,000 vacation at a Moon resort. His rough estimateis that the cost of a rocket launch has to drop from its current rate of $4,635 per kilogram (in 2015 dollars) to about $35 per kilogram. That’s a big drop, but it may not be as long as we think before the figures add up.
Once that problem is solved, Weir believes, the moon already has the natural resources available for building a city.
“Even in a world when you’ve driven the price to LEO down, you still need to use resources locally,” Weir said. “The early pioneers didn’t bring pallets of lumber to build their houses,” Weir said the Moon is extremely rich in exactly the things you need to build a Moon base, for example, anorthite rock, which covers vast areas of the lunar surface, can be separated into aluminum, oxygen, calcium, and silicon (used in glass).
But after all his research, Weir realized that the seafloor, the Earth’s polar regions, and the Sahara are all easier to colonize than the Moon. You have to bring breathable oxygen, protection against space radiation and all your own food and water, he points out.
“The problem is that you still don’t want to send humans to the moon,” Weir said. “You want to send robots. Humans are soft and squishy and they die. Robots are hard and nobody gets upset when they die.”
China’s already working on this. China plans to launch a lander and rover in December to the far side of the moon. The country’s leaders have also talked about putting astronauts on the Moon by 2036 while the White House says it wants NASA to return to the moon but without giving a firm commitment date.
Head, the planetary scientist who works with the Chinese, believes the Chinese government has the ultimate deep pockets needed for such an expensive technological enterprise. China’s space program doesn’t have to worry about justifying its expenses to Congress, like NASA does, or running out of company stock to sell to finance the money-losing space companies.
“For them, the ultimate goal is to have astronauts on the moon, and they are definitely moving in that direction,” Head said. “It’s possible they could get back to the Moon with humans before we do.”

The Path to Galactic Colonization

by Tony Deller – source: medium

The foundation for humanity’s future must be built by our generation


Using the newest data from the European Space Agency’s GAIA spacecraft, the ESA created the above map of our galaxy that pinpoints the brightness and positions of nearly 1.7 billion stars.
Our Milky Way is roughly 100,000 light years across. To cross our galaxy end-to-end would take 100K years moving at light speed. Ridiculous. That’s just to cross it in a straight line. Covering the actual volume of space enclosed by the Milky Way in our fictional “U.S.S. Enterprise” would require hundreds of millions of years.
And yet, despite our galaxy’s immense scale, the future of life on Earth ultimately depends on the human race taking to the stars and colonizing other worlds.
If we don’t undertake this fateful mission, it is only a matter of time before man made or cosmic threats kill most or all of humanity and all other living things on Earth. Whether nuclear war or biological plague, major asteroid impact, supernova explosion or gamma ray burst, some disaster WILL befall our planet sometime between now and a few thousand years in the future.
Humanity needs to prepare for this inevitability now, before something terrible occurs that reduces our capacity to do so, like a high energy solar flare or series of supervolcano eruptions.

One Small Step

We began, with that first “small step”, on July 20th, 1969, when the Apollo 11 lunar module fell into our Moon’s gravity well. Buzz Aldrin and Neil Armstrong became the first human beings to land on another celestial body. Today, several plans are underways to take the next steps in our journey outward into the cosmos. These primarily involve setting up bases, and eventually cities, on Mars.
Colonizing Mars will be the test case that allows us to prove we can live on a world significantly different than Earth. The two organizations that are likely to be the first to send humans to Mars are NASA and the private corporation SpaceX. SpaceX, led by entrepreneur Elon Musk, plans to place the first humans on Mars by 2030, with the hope that a permanent colony will be thriving by 2100.

Photo by SpaceX on Unsplash

Looking to the stars for humanity’s ultimate salvation has many detractors, people who believe we should focus solely on solving the problems we face on Earth before we consider the enormity of outer space. While these problems are indeed terrible and need the attention of great minds and philanthropists (such as Bill and Melinda Gates’ work), we cannot entirely ignore the long-term promise of expanding the presence of humanity across multiple locations in the galaxy.
For those who believe we should be stewards of the rest of Earth’s life, since we have presided over so much of its devastation, colonizing the galaxy offers a chance to also save ALL other life on Earth. Humans will not go alone into the depths of space. We will take with us many, if not most, of our companions on Earth, in the form of DNA samples, embryos and seeds. Some day, perhaps 100,000 years from now, there may be a dozen other very Earth-like planets safely distributed throughout the Milky Way, locations chosen specifically to ensure that any single cosmic catastrophe could never devastate them all at once.
In order to reach such a point, we will need to drastically advance our space technology. This will take money and time. As we proceed, every step of the way must result in the creation of a new economy in the place of colonization, since trading actual material goods back and forth between planets will be incredibly costly in every way.

How Do We Go Further?

As new bases are established, ever further from the Solar System, only information will be relatively cheap to transfer. New inventions and thought that results from our explorations and adaptations will benefit everyone, but every successive colony will need to be able to survive on its own.
One way we can help ourselves in this course is to build and program a fleet of smart robots to pave a path for us into the stars. These would be similar to the the idea of Von Neumann machines, named after 20th century Hungarian physicist Jon von Neumann. Such machines would be robust AI-driven creations whose programming sends them to worlds which have the highest possible compatibility with Earth life. For now, we refer to such worlds as being located in a star’s habitable, or “Goldilocks”, zone: Orbiting at just the right distance from its sun to allow the existence of liquid water.
After arrival on such a world, the Von Neumann machine would begin mining the planet for raw materials and then use the most advanced 3D printing technology to turn those materials into fuels and more machines. These resources, in turn, would go about building bases for humans and starting the long process of terraforming the planet.
Later, perhaps a century or a millennium after the Von Neumann machine had begun its work, a starship containing humans held in cryonic suspension, or perhaps just human embryos, would arrive to populate the new world.

How long might a process like this take?
Based on data from NASA’s Kepler spacecraft, there may be as many as 40 billion Earth-sized planets orbiting inside their star’s habitable zone in our galaxy.
If exponential growth could be applied to colonizing the galaxy, complete colonization of every habitable exoplanet may happen within the next 500,000 to 10 million years. However, according to Seth Baum, current Director of the Global Catastrophic Risk Institute:

The problem is that this kind of growth may not be possible, and they look at Earth as an example. For any expansion to be sustainable, the growth in resource consumption cannot exceed the growth in resource production. And since Earth’s resources are finite, and it has a finite mass and receives solar radiation at a constant rate, human civilization cannot sustain an indefinite, exponential growth.

The better question may be: How long will it take for humanity to place a stable population on enough planets to ensure the existence of Earth-originated life for a million years?

Preserving Humanity and Earth Life for Eternity

Outside of Mars, the best bets for a sustainable colonies in our own solar system are long shots at best: our Moon, and various moons of Jupiter and Saturn. However, those locations are not amenable to terraforming, which is what is needed to truly preserve human and other Earth life.
The nearest rocky exoplanet that orbits within the habitable zone of its star is Proxima Centauri B, at 4.2 light years away. This world would be our first candidate for colonization and terraforming outside of our Solar System. If we can reach speeds of even 1/10th C (the speed of light, 186,000 miles/second, as in E = MC²), getting any spacecraft to Proxima Centauri B would take 42 years.

The Breakthrough Starshot project is an initiative to propel a small fleet of one-gram nanospacecraft the size of a postage stamp — what they’re calling a “starchip that is really just a super-miniature computer — to 1/5th C (100 million mph) on a journey to Proxima Centauri B and other planets in the Alpha Centauri system. This acceleration will be accomplished via directed light beams at solar sails, allowing the speeds to be reached without any onboard engine of any kind.
We are very limited with how we get into space and continue accelerating currently. Propellent technology only gets us so far. At our present pace, it would take ~30,000 years to reach Proxima Centauri B. The trifecta of fusion, fission and antimatter propulsion are the focus at this point, all believed to be capable of getting us to the 10% C mark. As speeds increase, so do the inherent dangers of space travel, such as radiation and micrometeoroids, which makes 10% of light speed both a safety limit as well as a practical limit on how fast we might be able to travel in the near future.
There are just under 50 exoplanet candidates known right now that could be sites for colonies, and also be in the habitable zone and therefore allow for eventual terraforming. The distances from Earth range the gamut between Proxima Centauri B’s 4.2 light years to Kepler 443b’s 2540 light years. These are only worlds that we’ve discovered up until now: There is no doubt we will discover more potentially habitable exoplanets on the nearer side of that range within the next few decades.
If we want to make certain humanity cannot be completely wiped out in any one cosmic disaster, we need to eventually have colonized worlds that are at a sufficient distance from one another to avoid such possibility. To this end, we look at the largest scale cosmic event we know of: a supernova explosion. According to this article, a minimum safe distance from a supernova is 30 light years, though the size and effects of such an event can vary so much that in order to be certain we should include a buffer of 150%…so let’s say 45 light years.
Aside from a catastrophe on a galactic scale that we could never defend against, this means that we need to reach a point where humanity has colonized at least 45 light years from Earth. The closest candidate world that fits this case is Gliese 163c, at 49 light years away. A journey of 49 light years, at an average speed of 10% C, would take approximately 490 years.
Out of our list of ~50 known potentially habitable exoplanets, about 20 of them are within that 45 light year range of Earth. A few are contained in the same star system, most notably 4 worlds in the Trappist-1 system 39 light years away.

Could this be a scene on a world 50 light years away and a thousand years in the future? Photo by Shot by Cerqueira on Unsplash

Without a doubt, our first goal must be to create a second home for humanity and Earth life on Mars. The world’s close proximity, gravity and water offer our best bet for a sustainable colony and eventual terraforming. Establishing a stable colony on Mars may take until 2100, while a truly thriving population that is no longer dependent on Earth might take another century to develop.
During the middle centuries of this millenium, humanity will be focused on building smaller human stations on moons of Jupiter and Saturn, as well as perhaps on the massive Ceres asteroid in the Asteroid Belt. This time will be one of advancement in our ability to survive for long periods in space without many negative side effects, learning how to terraform Mars, and also developing true starships and medical technology that will empower us to make the jump to Alpha Centauri.
By 3000 AD, humanity should be established on Proxima Centauri B, and dozens, if not hundreds, of other ships should be on their way to the other 50-odd potential colony worlds, all much farther away, containing either humans and other Earth life in suspended animation or in the form of embryos and seeds.
By 12000 AD, humanity should be firmly rooted on a dozen worlds, some of them separated by enough distance from Earth to ensure that a single supernova could never drive Earth life into complete extinction.
At this point, the children of Earth, all life born here, will have a true chance at immortality: The rest of the Milky Way galaxy awaits.
Thank you for reading and sharing!

Can We Create Wormholes?

by Ella Alderson – source: medium

A look into the popular sci-fi method of travel

Imagine you want to get from point A to point B. Point A in this case is Earth, and point B is our nearest exoplanet, Alpha Centauri Bb at 4.24 light years away. Because the laws of physics prevent anything from traveling faster than the speed of light, that means the minimum number of years it’ll take to reach point B is a little over 4 years. However, for now — and for many more years to come — we don’t have the means to travel anywhere near the speed of light. What we can do with our current technology is travel at around 20,000 miles per hour or 0.003% the speed of light. At this rate it will take us 142,000 years to reach Alpha Centauri Bb.
To send anyone to the exoplanet would take either incredible advancements in human preservation or sending generations of people to live onboard a spaceship, somehow overcoming the problems of reproduction in space, as well as the physical and psychological strain it would put on the families. Then there’s also ship design. What material will hold up for hundreds of thousands of years? How will that many resources — food, water, fuel — fit onto the craft? How will communication work across such a vast distance?
So there is no way to get from point A to point B. Not unless there was some kind of shortcut that would drastically reduce the time and distance needed to reach the other planet.

An explanation of wormholes from the movie Interstellar. The movie is known to have some of the most accurate representations of wormholes and black holes, having worked closely with theoretical physicist Kip Thorne.

That’s where the wormhole comes in. They’re bridges in hyperspace (higher dimensions) from one place to another, whether it be 4 light years away or 100,000 light years away. You take the fabric of spacetime, fold it in on itself, and create a hole from the origin to the place you want to go, bypassing the vast area you would have originally had to travel. This shortcut could cut your travel time significantly; in some cases you’d arrive at your destination immediately after entering the wormhole.

If two wormhole ends were connected to time instead of space, one could theoretically travel in time.

When they were first proposed as a solution to the equations of general relativity, they were called Einstein-Rosen bridges after Einstein and Nathan Rosen who collaborated on the solution. General relativity says that gravity works by bending spacetime. If spacetime can be bent by mass, then surely it can be twisted and manipulated in other ways. The math does check out — wormholes do not in anyway violate the laws of physics. But the same laws that say wormholes are possible also tell us they wouldn’t be useful.
Inside the wormhole, the walls of the tunnel would be completely unstable. Each side would be attracted to the other so that it would collapse and kill any passenger during travel. Not only that but destabilizing a wormhole would create a supernova explosion, wreaking havoc on any nearby solar system.
To keep it open would require something that repels gravitationally — that is, it has to have negative energy. Negative energy is essentially taking energy from a vacuum. Exotic matter could have the antigravity properties we need if we could just find it. Curiously enough, dark energy has been causing an increase in the expansion of the universe, overcoming gravity just like the particle we’d need to act as a gravitational repellent. But even if this turns out to be the key to keeping the tunnels open, there would need to be too much of it for it to occur naturally and only a civilization much more advanced than ours could hope to gather enough of it to introduce the two artificially.

A hole in 3 dimensional space is a sphere. Approaching the wormhole from the movie Interstellar, dir. Christopher Nolan.

Not that we’d survive the journey even then.
According to quantum mechanics, the inside of the tunnel would be full of strange new particles and an immense amount of radiation that would severely burn anything attempting to go through. Assuming you can fit. And assuming the wormhole does end up being a shortcut and not, in fact, a longer path than the original.
Stephen Hawking theorizes that wormholes already exist, only they’re on a scale so small that we can’t see them. Just like zooming in on any seemingly flat surface will reveal its gaps and roughness and holes, so too does zooming in on time reveal that it’s not completely smooth. Wormholes are constantly appearing, disappearing, and reappearing at the quantum level. It’s possible in this theory to somehow enlarge a primordial wormhole and make it big enough for a person or a spaceship to go through. One might also enlarge naturally as the universe continues to expand. Smaller ones could be used to send information.
Whether on a huge scale or a subatomic one, to date we haven’t detected any wormholes in our universe. According to some researchers, this might be because they’re hiding behind black holes. This would be in line with general relativity which says that wormholes could have black holes at each end. It would also be more consistent with quantum mechanics, where black holes are still mysterious anomalies that would make more sense if they ended up concealing a wormhole.
Like wormholes, white holes are predicted to exist by general relativity but have never been detected. It’s possible that there is a black hole on one end concealing a wormhole, and a white hole on the other where a traveler can exit. Some wormholes even allow for multiple exit points, like a subway train. There’s intra-universe wormholes that stay within one universe and then there’s inter-universe wormholes that connect multiple universes. There’s one way wormholes, two way wormholes, wormholes that are traversable and non-traversable. Really the design for these elusive tunnels is always changing.

“Since we do not yet have a theory that reliably unifies general relativity with quantum mechanics, we do not know of the entire zoo of possible spacetime structures that could accommodate wormholes.”
– Avi Loeb, Harvard-Smithsonian Center for Astrophysics

So much depends on facts we still don’t have and physics we’ve yet to understand. Before being able to say confidently whether wormholes do or don’t exist, we must first better understand the history and geometry of our universe. It’s true that they most likely don’t exist in nature, but there’s also not much proof — if any — that a wormhole will collapse each time it’s traversed. A lot of the evidence points to these bridges as being nothing more than science fiction but at the same time we don’t have enough math to disprove them altogether. Some scientists still propose looking for them by checking how their gravity might distort the light behind them. Others say wormholes provide an answer to the fascinating black hole paradox. For now, we just don’t know. They must continue to live only inside the realm of science fiction.

The story of Jocelyn Bell Burnell

Jocelyn Bell at Cambridge’s Mullard Radio Astronomy Observatory in 1968. (Daily Herald Archive/SSPL/Getty Images)

via Timeline

In the winter of 1967, Jocelyn Bell Burnell pored over the near-frozen dials of a radio telescope. Between curses, she breathed on the instruments hoping to thaw them when, suddenly, the telescope’s recording chart sputtered to life and began transmitting a series of regularly spaced ticks.
This was the second time Bell Burnell had observed the puzzling metronomic space signals as a doctoral student working with the Cambridge astronomer Antony Hewish. Initially unsure what could cause such a measured celestial blink, Bell Burnell and her colleagues jokingly called the beating emissions “LGM” for Little Green Men.
The second time the telescope picked up a similar signal, she knew it wasn’t a quirk in the equipment or an extraterrestrial invitation. Bell Burnett had discovered pulsars—and astrophysics would never be the same.
In 1974, however, it was Antony Hewish whose “decisive role in the discovery of pulsars” would be honored with a Nobel Prize. In later years, Hewish would diminish, with defensive bluster, Bell Burnell’s contribution. “It’s a bit like an analogy I make — who discovered America? Was it Columbus or was it the lookout? Her contribution was very useful, but it wasn’t creative,” Hewish told interviewers in 2007.
But Bell Burnell was always more than a lookout. Susan Jocelyn Bell was born in Northern Ireland in 1943 and encouraged by her parents to pursue a clear propensity for understanding things. She and her family protested fiercely when, on the first Wednesday of secondary school, the girls were segregated for training in the art of “domestic science,” while their male peers pored over Bunsen burners and beakers.
She went on to study at the University of Glasgow, where she again found herself defined by her gender rather than her brain. For two years, whenever Bell Burnell entered a lecture hall her male peers whooped, cat-called, and banged their desks. “It was a little isolating. I had to work very much on my own,” she recalled during a TEDx talk in 2013.
After enduring years of the simian ritual, Bell Burnell made haste for Cambridge in 1965 to pursue a PhD studying under the radio astronomer Antony Hewish. Clad in cat-eye glasses, she spent two years constructing a radio telescope of Hewish’s design — a four-acre affair consisting of wires and pylons with galactic radiation receptors. This vineyard-like tessellation was originally built to study quasars — scintillating deep-space objects discovered in the early 1960s.
The first time the telescope’s radio-frequency needle recorded a regularly timed radiation signal, the team was convinced a glitch had befallen their equipment. What aside from human interference or some intelligent messenger could account for the clockwork pulses of energy? The Cambridge researchers were plagued by the Little Green Men mystery for weeks until Bell Burnell detected a second — and later a third and fourth — percussive signal from separate corners of the heavens.
As the probability of detecting multiple galactic dispatches from distant, intelligent civilizations was near zero, the scientists sought a solution consistent with the laws of physics and the scope of the universe. Hewish interpreted the data as the result of neutron stars or pulsars: superdense dead stars that emit radiation from their magnetic poles like strobe lights.
Before Bell Burnell divined the cosmic transmissions, it was believed that when stars died they simply exploded, releasing their energy in volatile displays we call supernovae. But her discovery suggested that a supernova may not lead to the wholesale destruction of a star — that something might stick around. Pulsars, Hewish and Bell Burnell would establish, were the neutron-rich cores of dead stars emitting radio waves as they rotated around a highly magnetized axis. Pandora’s box was open to all sorts of stellar post-mortem possibilities, most notably the theories of a young astrophysicist named Stephen Hawking, whose ravings about black holes were suddenly taken seriously.

Burnell’s pulsar discovery changed the field of astrophysics forever. SXP 1062 (right) is between 10,000 and 40,000 years old. (NASA)

Bell Burnell would go on to receive her PhD in 1968, sans Nobel, despite co-authoring the article in Nature that would lead to Hewish’s nomination. But it wasn’t just the Nobel committee in Stockholm who were guilty of a double standard. Following the discovery of pulsars, Bell Burnell faced casual sexism from the media and public as well.
“When the press found out I was a woman, we were bombarded with inquiries,” she said. “My male supervisor was asked the astrophysical questions while I was the human interest,” she recalled in an interview with the Belfast Telegraph in 2015. “Photographers asked me to unbutton my blouse lower, whilst journalists wanted to know my vital statistics and whether I was taller than Princess Margaret.”
In the years since the discovery of pulsars Bell Burnell has been a vocal critic of the traditional white male power structure that dominates Western scientific thought and academia. When she was appointed the chair of the physics department at Open University in 1991, Bell Burnell was one of only two female physics professors in the U.K. “Throughout my working life, I’ve been either one of very few women or the most senior woman in the place,” she told the TEDx audience.
After obtaining her PhD, Bell Burnell worked part time for many years while raising a family and following the career of a “peripatetic” husband. “I am very conscious that having worked part time, having had a rather disrupted career, my research record is a good deal patchier than any man’s of a comparable age,” she said in a 1996 interview with the Institute of Physics.
Still, Bell Burnell has continued to advance, earning visiting professorships at Oxford and Princeton. She is currently the president of the Royal Society of Edinburgh, Scotland’s national academy of science and the arts.
In public forums, she often repeats the fundamental truth so many people fail to grasp: that the small number of women in STEM in the West is the result of social restrictions and expectations. “The limiting factor,” she points out, “is culture, not women’s brains, and I regret that its still necessary to say that.”

Bouncing ball’s trajectory in general relativity and newtonian gravity

Source: Animation Principles

by Paul Mainwood on Quora

This is a conceptually simple and fun piece of work that has been let down by an appalling write-up on
Reading the paper itself, what the authors have done is to put together two fascinating phenomena from 20th Century physics.

  1. At low speeds and with weak gravitational fields, the predictions of Newtonian Physics and General Relativity approach one another, giving rise to dynamics that are so similar that they can be treated as identical.
  2. There are some types of system — chaotic systems — where very small differences can give rise to unexpectedly huge differences in future dynamics.(1)

With these two phenomena written next to one another, there is an obvious path to explore. Why don’t we see if we can come up with a chaotic system whose dynamics can distinguish between the tiny differences between the predictions of GR and NP, even at low speeds and in a weak gravitational field?
And that’s exactly what the authors: Shiuan-Ni Liang and Boon Leong Lan have done, claiming to have found such a desktop system that can distinguish between the predictions of GR and NP when its dynamics becomes chaotic. Fun!
But the write-up of this simple concept veers all over the place, making it sound as though the paper is claiming to contradict General Relativity (it says the opposite). Worse, after happily taking a logically labyrinthine tour through some out-of-context quotes that the authors may have said on the phone, the write-up triumphantly ends with a crashing non-sequitur: “Explore further: Doubly Special Relativity”. (Doubly Special Relativity is a speculative theory with zero connection to anything in the paper.)
So, which one of General Relativity or Newtonian Physics is right? The authors of the paper could not be clearer:

When the predictions are different, general-relativistic mechanics must therefore be used, instead of special-relativistic mechanics (Newtonian mechanics), to correctly study the dynamics of a weak-gravity system (a low-speed weak-gravity system).

(1) Usually in the study of chaotic systems, these small differences are differences in initial conditions: that is, you keep the dynamical laws the same but alter the initial conditions slightly. But you could equally ask what happens if you keep the initial conditions the same and slightly alter the dynamics, which is what they are effectively doing here.

Extragalactic origin confirmed

Cosmic rays — fast-moving, high-energy nuclei — pervade the Universe. We know that the lower-energy variety that we detect on Earth is funnelled by the solar wind. However, higher-energy cosmic rays have an isotropic distribution due to scattering that makes it difficult to identify their source, although they are likely to be generated by high-energy phenomena like supernova explosions and jets from active galactic nuclei. By looking at the ultrahigh-energy end of the cosmic ray spectrum (on the order of exa-electron volts and higher, where cosmic rays are not scattered by solar-scale magnetic fields), the Pierre Auger Collaboration detected an anisotropy in their arrival directions that indicates an extragalactic origin.
Ultrahigh-energy cosmic rays are rare: typically one cosmic ray with an energy > 10 EeV hits each square kilometre of the Earth’s surface per year. The Pierre Auger Observatory in Argentina detects cosmic rays using two combined techniques: telescopes to detect fluorescence from cosmic-ray-generated air showers, and a network of 12-tonne containers of ultrapure water, spread over an area of 3,000 square kilometres. Photomultiplier detectors in the containers observe the faint Cherenkov radiation generated when cosmic-ray-generated muons encounter water molecules. By reconstructing the cone of emission of the muon (analogous to an aircraft’s sonic boom) an incident direction can be derived. By analysing 32,187 cosmic rays detected over 12.75 years, a map of the sky was produced (pictured), showing evidence of an enhancement (5.2 σ significance) in a region away from the Galactic Centre (marked with an asterisk; the dashed line indicates the Galactic plane). The distance of this hotspot from the Galactic Centre (~125°) points towards an extragalactic origin of ultrahigh-energy cosmic rays, reinforcing previous (less conclusive) results from the Collaboration at lower energies.

Paul Woods, doi:10.1038/s41550-017-0304-0

Martian dust blower

by Bart Verberck, Nature Physics 13, 623 (2017) doi:10.1038/nphys4207 (sci-hub)

Your Earthly carpet sweeper won’t do the job in the low-pressure, CO2-dominant atmosphere on Mars. But Catalin Ticoş and colleagues have now shown how to build a Mars-proof dirt broom, which can be used for removing sand and dust from equipment stationed on the Martian surface.
The authors’ experimental setup involved a coaxial plasma gun, capable of producing dense pulsed plasma jets, directed perpendicularly to the area to be cleaned. As a test surface, they used an array of photovoltaic cells, covered with a powder retrieved from volcanic ash, which mimicked Martian surface soil.
Ticoş et al. measured the efficiency of their cleaning method in terms of how the voltage delivered by the cells increased during operation. An analysis of the plasma jets in a CO2 environment at the same pressure as that on Mars’s surface revealed an average plasma plume speed several orders larger than the planet’s typical wind speeds — implying that the plasma broom would indeed succeed in the Martian environment.