Daily Archives: November 25, 2021

For all of the clamour around Elon Musks prognostications of a human colony on Mars by 2026, experts said that the limiting factor of humanitys aspirations to reach other worlds is still dictated by the frailty of the human body.

At a recent talk organised by the French Embassy and Institut Francais, a panel of authorities pointed out any attempt to reach other planets and celestial bodies is massively challenged by the task of protecting and sustaining astronauts during long-haul space missions.

Among the obstacles are solar radiation, the need for safe habitations plus concocting ways to carry out agriculture or storing food on the austere new world or spacecraft, addressing the fearsome battery of physiological and psychological problems associated with long-term space travel worsened by a sense of disconnect from Earth and even the disposal of food and human waste that 'earthlings' take for granted.

It is this set of challenges that leaves Mathieu J Weiss, Space Counsellor and the Bengaluru representative of the French Space Agency, the National Centre for Space Studies (CNES), convinced that it is not so much the technicality of space technology or even propulsion systems holding back a deluge of human-crewed missions into space, but concern about how humans will survive missions that could take months or years to complete.

The space sector has gone through tremendous changes these last years. Look at reusable technologies, look at sustainable technologies, solutions with artificial intelligence, Weiss said. In fact, the novels we were reading in the 20th century about science fiction are just becoming reality and we, as experts in the field, we are feeling it, living it every day.

At the same time, Weiss cautioned that living on the moon or on Mars presents technical challenges which have never really been addressed by the earlier generations of space travel or even current missions at the International Space Station (ISS).

We are at the cusp of a major leap in human space flight to other celestial bodies but whatever we learned from the fantastic Apollo program and all the work the Russians have done cannot be used for us to live on Mars. We need to now understand the physical limits of sending humans out there, which raises questions such as: How will they rehab from the prolonged flight duration and how will they fare from a physiological point of view and from a psychological point of view? he said.

Physiological changes

What is known is that within four to six hours of a human being going to space, the individual starts to experience changes in the bodys cardiovascular system involving the heart and blood acid, according to Wing Commander Dr Stuti Mishra, a Flight Surgeon and Instructor at the Institute of Aerospace Medicine (IAM) in Bengaluru where the Gaganyaan astronauts are being trained.

The moment we put a human behind a machine for a long duration, the human becomes the limiting factor, she said.

This is because something similar to osteoporosis, the instantaneous fractures which happen to old people, occurs in space and as does muscle wasting in the lower limbs. "Demineralisation in the bones is one issue. The other is radiation because it has a long-term effect on cells, Dr Mishra said, adding that natural sensors in the human body known as vero-receptors also are de-conditioned in low gravity.

This has particular resonance for India, whose long-term aspiration beyond the Gaganyaan-manned missions is to set up a space station in low-earth orbit with the eventual aim of going to the moon.

Gaganyaan is just the foundation of a sustained manned space program and it will act as a stepping stone, said V R Lalithambika, Director of ISROs Human Spaceflight Programme. Beyond this programme, we would be thinking of permanent presence in low-Earth orbit first, and we need to develop a lot of enabling technologies for that, which we do not have at the moment onthe engineering side, docking technologies, on the human side, bio-asthmatics is one area where we do not have any expertise.

We need to develop that expertise and all the associated technology which would be required for a sustained presence in space, she added.

Although data exist, going back some 60 years to the early US and Russian-manned missions showing how space travel impacts the human body, Isro officials told DH that the country would like to collect its own data through space expeditions because it could present new findings on how solar radiation affects Indians on a genetic level.

This is a statement corroborated by Dr Audrey Berthier, Executive Director of Medes (the French Institute for Space Medicine and Physiology at Toulouse) who said that there is still a long way to go before individual susceptibility to solar radiation can be established.

In ongoing French-Australian trials at Sydney, for example, scientists have been using a heavy-ion synchrotron to test new radiation-protective light materials for spaceflight on animal meat samples. In our study, we found out that different people are reacting totally differently to radiation, Weiss added.

New lessons to learn

While there is data accumulated in previous space missions, Dr Berthier stressed that additional data, such as that to be generated by Gaganyaan will help complete the picture. But for some facets of future space travel such as deep-space isolation, there is even less quantifiable data. Where studies at Concordia Station in Antarctica have presented some information on the reaction of people to isolation, deep-space missions remain a wildcard.

How this will play out in a mission going to Mars where all one will see is darkness and blinking stars for six to nine months is anyones guess, added the space entrepreneur, Dr Susmita Mohanty, the founder of Liquefier System Group (LSG), an aerospace architecture and design firm based in Vienna.

Psychological impact

When in isolation, sometimes even fungus or mold can become your pet or friend, she said, pointing to a brief stint in Antarctica where she found the sunlight as having an otherworldly quality. It affects your mind and it starts to disorient you a bit in terms of time and space. Little things happen which have a big psychological impact, she added.

Worse, current behavioural data from the International Space Station is of little help as astronauts in low-earth orbit can see the Earth from the window, which is a source of comfort, added Dr Berthier, who pointed out that the ISS astronauts also have the option of a relatively speedy trip back to an Earth hospital in the event of a serious medical emergency a luxury that deep-space travellers lack.

But even if one survives the perils of spaceflight, there are more to follow on planetary surfaces. Future Indian astronauts who take up station on the moon may encounter problematic living conditions, according to Dr Mohanty.

Because there's no weathering force on the moon, if you pick up dust, it's fine and sharp like glass. It gets into everything. It gets into the creases of your spacesuit, it gets into the mechanical parts of your buggy, if you breathe it and sort of bring it into your habitat it goes into lungs, and it smells like burnt gunpowder, she said.

Ultimately solutions to all these problems will be found, experts said, adding that this will yield advances applicable even on the Earth.

Speaking at the event, Thierry Berthelot, General Consul of France in Bengaluru set the context for where humanity seeks to go. If the Earth was the size of a tennis ball, the farthest astronauts have gone is two meters away from the tennis ball to the moon which would be the size of a marble. Now we are aiming for Mars, which is a golf-ball-sized object three football fields away from our tennis ball. What has to be achieved is tremendous, he said.

But he added that the spin-offs: the benefits for our life on Earth will come in similar spurts - leapfrogging in the medical field, but also technical clues for adapting to climate change, new solutions to the conservation of the living and maybe new societal models. There are intensive hopes in these programs to serve humanity, he said.

Watch the latest DH Videos here:

See original here:

Risks and rewards of human deep-space travel - Deccan Herald

Traveling faster than light and time-travel could be real for tachyons. If one thing science fiction excels at, it's allowing us to marvel at the breaking of the physical laws of the universe. We watch and read in wonder as the warp engines of the starship Enterprise push it to beyond the speed of light, or as Barry or Wally whoever is carrying the name of the Flash at the time does the same in no more than a pair of yellow boots.

Likewise, we enjoy tales of adventurers like the Doctor, or Doc Brown, using weird seemingly antiquated machinery to violate the laws of causality. What if there was a fundamental particle that could do all these things? Moving faster than light like the Flash, and traveling back through time without the need for a TARDIS or a Delorian or yellow boots.

Thats a tachyon. But make no mistake, these particles arent just the idling's of science fiction writers. Tachyons are the stuff of "hard" science.

Related: What would happen if the speed of light was much lower?

Tachyons are one of the most interesting elements arising from Einsteins theory of special relativity. The 1905 theory is based on two postulates, nothing with mass moves faster than the speed of light (c), and physical laws remain the same in all non-inertial reference frames. A significant consequence of special relativity is the fact that space and time are united into a single entity; spacetime. That means a particles journey through speed is linked to its journey through time.

The term "tachyon" first entered scientific literature in 1967, in a paper entitled "Possibility of faster-than-light particles" by Columbia University physicist Gerald Feinberg. Feinberg posited that tachyonic particles would arise from a quantum field with imaginary mass explaining why the first populate of special relativity doesnt restrain their velocity.

This would lead to two types of particles existing in the universe; bradyons that travel slower than light and compose all the matter we see around us, and tachyons traveling faster than light, according to the University of Pittsburgh. One of the key differences between these particle types is as energy is added to bradyons, they speed up. But, with tachyons, as energy is taken away, their speed increases.

One of the most important and meaningful results from Einsteins theory of special relativity is the establishing universal speed limit of c; the speed of light in a vacuum.

Einstein suggested that as an object approaches c its mass becomes near-infinite, as does the energy required to accelerate it. This should mean that nothing can travel faster than light. But, imagine an anti-mass particle like a tachyon, its lowest energy state would see it speeding at c. But, why would this lead to backward time travel?

That all hinges on the concept that puts the "relative" into "special relativity."

A common tool used to explain special relativity is the spacetime diagram.

Spacetime is filled with events ranging from the cosmically powerful and violent, like the supernova explosion of a distant star, or the mundane, such as the cracking of an egg on your kitchen floor. And these are mapped onto the spacetime diagram. This diagram shows as a particle whizzes through spacetime, it traces out a worldline that maps its progress.

Also filling spacetime are observers, each of whom has their own reference frame. These observers may see the events that fill spacetime occurring in different orders. Observer 1 may see event A, the supernova, occur before event B the egg crack. Observer 2 however may see event B happening before event A.

Each event has a light cone associated with it. If event B falls within the lightcone of event A then the two could be causally linked. The supernova could have knocked the egg off the kitchen counter or maybe the falling breakfast item caused the complete gravitational collapse of a dying star, somehow.Thats because in the light cone a signal traveling slower than light can link the events. The edges of the light cone represent the speed of light. Linking an event outside the light cone with one inside it requires a signal that travels faster than light.

If event A is in the light cone and event B is outside it, then the supernova and egg-related tragedy can't be causally related. But, a tachyon traveling at a speed greater than the speed of light could violate causality by linking these events.

To see why this is a problem, consider it like this. Image event A is the sending of a signal, and event B is the receiving of that signal. If that signal is traveling at the speed of light, or slower all observers in different reference frames agree that A preceded B.

But, if that signal is carried by a tachyon and thus moves faster than light, there will be reference frames that say the signal was received before it was sent. Thus, to an observer in this frame, the tachyon traveled backward in time.

One of the fundamental postulates of special relativity is that the laws of physics should be the same in all non-accelerating reference frames. That means if tachyons can violate causality and move backward in time in one reference frame, it can do it in them all.

To see how this leads to problems called paradoxes, consider two observers, Stella aboard a spacecraft orbiting Earth, and Terra based on the surface of the planet. The two are communicating by sending messages with tachyons.

This means that if Stella sends a signal to Terra which moves faster than light in Stellas frame but backward in time in Terras frame. Terra then sends a reply as ordered which moves faster than light in her frame but backward in time in Stellas frame, Stella could receive the reply before sending the original signal.

What if this response signal from Terra says "do not send any signals"? Then Stella does not send the original signal, and Terra then has nothing to respond to and never sends the tachyon signal that says "dont send any signals."

So not only do tachyons violate causality in every frame they open the door to severe logical paradoxes.

There are suggestions as to how these paradoxes could be avoided. Of course, the most simple solution is that tachyons dont exist.

A less draconian suggestion is that observers in different reference frames cant tell the difference between the emission and absorption of tachyons.

That means a tachyon traveling back in time could always be interpreted as a tachyon moving forward in time because receiving a tachyon from the future always creates the same tachyon and sends it forwards in time.

Another suggestion is that tachyons arent like any other particle we know of, in that they don't interact and can never be detected or observed. Meaning that the tachyon communication system used by Stella and Terra in the above example cant exist.

Along similar lines, other researchers say that tachyons cant be controlled. The receipt and emission of tachyons just happen at random. Thus, theres no way to send a tachyon with a causality violating message.

Aside from the fact that like other particles, they are likely incomprehensibly tiny, because tachyons always travel faster than light it isnt possible to detect one on its approach. Thats because its moving faster than any associated photons.

After it passes, an observer would see the image of the tachyon split into two distinct images. These would show it simultaneously arriving in one direction and disappearing in the opposite direction.

If detecting tachyons, at least of their approach, with light is out of the picture, is there another way we could detect these faster than light particles?

Possibly. Tachyons are proposed to have an "anti-mass" but this still constitutes mass energy. That means these particles should still have some gravitational effect. Its possible highly sensitive detectors could spot this effect.

An alternative detection method could arise from their faster-than-light nature.

While the speed of light in a vacuum c is a universal speed limit, particles have been made to travel faster than light in other mediums. When electrically charged particles are accelerated up to and beyond the speed of light in certain mediums like water, they release a form of radiation called Cherenkov radiation, according to the International Atomic Energy Agency.

That means that if tachyons are electrically charged, one way of detecting them would be measuring Cherenkov radiation in the near-vacuum of space.

What tachyons really demonstrate is the importance of imagination in our ongoing quest to understand the universe. They may not exist, and if they do we may have no hope of ever measuring one.

But what our technology cant capture, our minds can. We can consider the possibility of a particle that journeys back through time and what that says about the nature of time, and the Universe, and the events that fill them.

In an interview with George Sylvester Viereck published in "The Saturday Evening Post" in 1929, Albert Einstein is believed to have said: "Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world."

Read more from the original source:

Tachyons: Facts about these faster-than-light particles - Space.com

If you're hunting for a telescope that's able to reveal a plethora of deep-sky targets such as far-flung galaxies and nebulas with ease, then look no further than the Unistellar eVscope eQuinox. What's more, this smart device which is the world's newest telescope is a little over 10% off this Black Friday from Unistellar's dedicated site.

The Unistellar eVscope eQuinox is a breeze to set up, allowing the skywatcher to get observing within moments. Packed with a database of millions of stars, the eQuinox makes use of an autonomous field detection software, which enables its computerized system to recognize the targets in its field of view in less than a minute: no more complicated calibrating and the skywatcher is also provided with snippets of information about the target their observing, making this one of the most user-friendly telescopes on the market.

Digital magnification can be pushed to 400x, but we recommend no more than about 150x, while optical magnification won't exceed 50x due to the lack of an eyepiece. The eQuinox makes use of a Sony Exmor IMX224 CMOS in the way of sensor technology. At a modest weight of 9 kilograms (19.8 lbs.), it's portable enough for travel to dark-sky parks and moving around your backyard without too much hassle.

Being observers of the night sky ourselves, we are particularly impressed with the eQuinox's revolutionary technology that's able to reduce the effects of light pollution; interference from street lamps that often limits urban skywatchers to the bright deep-sky targets, the planets and surface of the moon. This smart telescope enables observations to be made from inner-city environments by identifying interfering light and making use of in-built filters to remove it, leaving the user with views of excellent quality and contrast. The eQuinox is also able to reduce pesky moonlight for uninterrupted, dazzling deep-space observations.

And that's not all, thrown into the cost is the eQuinox's capability of enabling citizen science, so whether you're looking to protect the planet against near-earth asteroids or track down the next undiscovered exoplanet, you can join the global Unistellar Network to contribute valuable observations alongside a community of thousands of citizen astronomers.

Just like many telescopes on the market, the eQuinox is also supplied with a free download of a dedicated app, which not only recommends the best targets to observe from your location out of a catalog of 5,000 objects, but also allows for group observing and remote control whether you prefer observing from the comfort of your sofa or under the night sky.

Be sure to check out Space.com's Black Friday Space deals, or our guide to the Best telescopes. If you're looking for a telescope for a young skywatcher or beginner, then read our guides on the best telescopes for kids or best telescopes for beginners.

Today's best telescope deals

Here is the original post:

Get $300 off the Unistellar eVscope eQuinox smart telescope this Black Friday - Space.com

Its December 11, 1972, and Houston has a problem. The lunar rover on the Apollo 17 mission, LRV-3, has lost its right rear fender. Not a huge deal on earth, but on the moon, its potentially catastrophic. Fenderless driving kicks up a flume of lunar regolith that coats the rovers navigation and communication instruments in fine, wave-blocking silt. Its a silt that insinuates itself into the aluminum rings that hold the astronauts helmets and gloves in place, and it cant be wiped off.

NASA comes up with a solution: Take four laminated pages from the survey maps, tape them together into a 15-by-10-inch slat, and marry that piece to the shorn fender. It works. Outer-limit engineering fixed with tape.

This story originally appeared in Volume 8 of Road & Track.

SIGN UP FOR THE TRACK CLUB BY R&T FOR MORE EXCLUSIVE STORIES

As the alphanumerics imply, the LRV-3 was NASAs third lunar rover. It was, in its most utilitarian sense, a tool for collecting geological samples. But in another, it was a perilous transport to the edge of the knowable. The rockets may have taken us to the moon, but the rovers allowed us to interrogate it.

In his meticulously researched and masterfully written new book, Across the Airless Wilds, Earl Swift tells the story of the lunar-vehicle program from its inception in the mind of ex-Nazi Wernher von Braun to the three rover excursions.

It is unfair to suggest that challenges facing the lunar-rover program were as steep as those posed by a lunar landing itself, but they were not insignificant. NASA had to come up with an electric vehicle that could report back to our planet, withstand extreme temperatures (plus or minus 250 degrees Fahrenheit), operate in one-sixth gravity, fold up into and deploy from the tiny moon lander, and traverse unknown lunar terrain.

NASA put the contract out for bids, and the job went to Boeing. General Motors became the major subcontractor based in part on its wire-mesh wheel design. One somewhat hilarious thing detailed in Swifts book is NASAs frustration with Boeing and GM. NASA worked to the very highest standards of testing, engineering, and process, predicated on the reputational and human risks posed by its missions. Boeing worked to slightly laxer standards, in keeping with the only marginally less dire stakes it encountered in its usual course of business. GM, on the other hand, worked to the safety standards of the Corvair.

Despite the development periods many thrown slide rules and dislodged pocket protectors, the partners delivered the first lunar rover just 22 months after the project got the green light. It would cost the taxpayers $38 million, roughly a quarter of a billion dollars in todays money.

Apollo 15 held the first rover, LRV-1, in its lander. After four days of space travel to get up to the Hadley Rille, astronauts David Scott and James Irwin drove LRV-1 a total of 17.25 miles over three excursions. Dave and Jims first drive, of 6.3 miles, surpassed all previous missions travels combined.

On their next jaunt, they hit pay dirta nugget of four-billion-year-old white anorthosite dubbed Genesis Rock. From Swifts book: This was the consummation of all the missions that had come before. . . . Until now, most missions had been built around testing equipment and sorting out procedures. Apollo 15s moonwalkers were conducting real science.

We left three cars on the moon. But this is no space junk, no off-loaded, off-brand detritus from a pot-metal superpower. This is Grade A American equipment. The LRVs are what NASA decided to create when its moonshots had grown prosaic to the American public and perhaps even to itself. The rovers were the moonshots moonshot.

Go here to see the original:

The Lunar Rovers Went to the Edge and Kept Going - RoadandTrack.com

If youve ever visited the site of the six-year-old, London-based direct-to-consumer clothing company Vollebak, youve likely marveled at the exaggerated descriptions of clothing it sells, including a jacket designed for a world of megastorms, where waterproof is not enough, a hoodie that promises to repel rain, wind, snow and fire; and and an ice age fleece designed to recreate the feeling and performance of the soft hides worn by prehistoric man.

That marketing genius comes directly from CEO Steve Tidball, who co-founded the outfit with his twin, Nick Tidball both of whom worked in advertising previously and both of whom are active outdoorsmen, though their families and the growth of Vollebak have kept them closer to home in recent years. Indeed, Steve Tidball writes the copy himself, he revealed last week in an interview about Vollebak, a brand that prides itself on making clothes for the future.

During that chat, he also answered our questions about how much tech is actually involved in the clothings production. And he let us know that Vollebak has so far raised around $10 million in outside funding, including through a Series A round that is about to close, led by the London-based venture firm Venrex, with participation from Airbnb co-founder Joe Gebbia, and Headspace CFO Sean Brecker, among others. Our chat has been edited for length and clarity.

TC: You started this company with your twin, Nick. So much of its genius seems to be in how your clothing is marketed. Tell us a bit about how it came together.

ST: We launched the company five years ago. Before that, wed been working together in advertising for 15 years, so I think one of the reasons the marketing is more fun than it might otherwise be is that was our job.

Weve operated by an incredibly simple rule from a marketing perspective, which is basically: spend as little money as humanly possible. So, for instance, a couple years ago, we created our first piece of clothing for space, which was a deep sleep cocoon. And in marketing, youre always [asking] whos your audience, and really, our audience was one person here, which was Elon [Musk], so we found a billboard [space] opposite SpaceX, and we just took out a poster there, and it said, Our jackets are ready. Hows your rocket going? It doesnt cost much money, but it was really great fun, and NASA called the next week, and then we got [to] chatting to them.

Your clothing is a reflection of the stuff that you think is going to happen to people over the next century, from space travel to sustainability. You have a solar charge jacket that you say can glow like a firefly in the dark, for example. You have a black squid jacket that you say recreates one of natures most brilliant solutions to high visibility, the adaptive camouflage of the squid. How much tech is really involved here?

Over the last five years, the angle of tech we focused on is material science. Thats the one thing that, as a startup, weve had access to, because if youre going to look at much [complex] technologies like AI or exoskeletons, you need a really huge amount of funding to go tackle those, whereas any startup can really go and look at material science. So thats the angle were really fascinated with . ..[because] thats typically not been explored, how much material science could go into a product.

One of the most interesting things we ever launched was the worlds first graphene jacket. Even the scientists who isolated graphene for the first time cant actually tell you what graphene is going to do. . . .[So] we said, well, one side has graphene and the other side doesnt. Why dont you go out and test it and tell us what it does? We had a theory that it could store and redistribute heat because graphene behaves in a very surprising way and theres no limit to how much heat it can store. What came back were two particularly amazing stories, one of a U.S. doctor whod been freezing at night in the Gobi Desert and who wrapped his graphene jacket around a camel, and after it absorbed the heat of the camel, he put his jacket back on and stayed warm through the night.

Another friend of ours, a Russian guy who was out in the Nepalese mountains and was in danger of freezing to death, used the graphene jacket to absorb the last rays of sun. It warmed up, and he put it on as his inner layer and credits it with keeping him warm through the night.

How do you manufacture a graphene shirt or ceramic shirt? Do you have a special loom? Do you make it out of a 3D printer? Whats the process?

You manufacture it with great difficulty is the answer, which is why our stuff costs more than regular clothing. What you really end up with is very specialist factories, typically in Europe, with really high-tech machinery that very few people have access to.

Do you typically do short production runs for your merchandise?

Yes, and at the start, that was really just a function of capital, meaning we didnt have much, so we just made as many clothes as we could, they sold out really quickly, and we tried to make some more as the business has grown. Theres definitely stuff where its so complicated or so experimental, it would be reckless to make 10,000 of them. So yeah, weve made short runs of some of our most experimental stuff, just to see: Does it work? Could it be improved?

One of those experimental new products is the Mars jacket and pants. Where does one wear that?

Of the funny things about making anything for Mars is that the irony, of course, that you have to test it on Earth. But the reality of going to Mars or any space travel is theres going to be an exponential increase in the number of people going there and the number of jobs they need to do when they go there. Youre going to need scientists, biologists, builders, engineers, architects, theyre gonna have to wear something. And so the reality is, we want to start working on it early, so what were doing is were starting to think about some of the tasks that need to be carried out, whether its on the moon or Mars or lower orbit stuff, and about: What are the jobs? What are some of the challenges that were going to face? This is why the jacket comes with a vomit pocket, because your vestibular system is thrown into disarray as soon as you encounter a lack of gravity.

How do you know about the vestibular system? Youre a marketing genius. Are you also a scientist?

Im a pretend scientist [laughs]. But we have a lot of really interesting people around us, whether its people who think about the future of warfare, or people who think about the future of space travel, we often joke that our business is run on WhatsApp.

Where do you receive most of your customer feedback? Certain D2C brands are very active on social and Instagram and have Slack channels. How do things work over there?

I had this really early thought that if you could combine really cool innovative technology with really friendly people on the end of email, that could be a really cool thing.

You only sell directly through the Vollebak site. Will that ever change?

Not in the near-term future. One of the things thats been absolutely central to the brand is getting that feedback, and I really worry about losing that connection to the customers. Lets say someone has a cool experience with one of our shirts or one of our jackets, and they bought it at some wholesale store, and they have no real connection to us. I feel thats lost information.

We will be doing more stuff in the metaverse space very, very soon, because I just find it so exciting, the idea that theres going to be this competition or integration between the virtual world and real world. So were currently building some fairly crazy stuff in that space. Were currently on the hunt for some supercomputers powerful enough to process some of the stuff were working on. But yes, basically, anything that we think is going to define the future, well plow pretty heavily into.

(You can hear this conversation in its entirety, including about Vollebaks plans to eventually launch a womens line and its funding situation, here.)

Read the original:

Vollebak, which makes clothes for the future, is closing its Series A round - TechCrunch