Dinosaur tail found in amber at market in Myanmar

The tip of a preserved dinosaur tail section, showing carbon film at its surface exposure, and feathers arranged in keels down both sides of tail.

Source: Royal Saskatchewan Museum (RSM/ R.C. McKellar)
The tip of a preserved dinosaur tail section, showing carbon film at its surface exposure, and feathers arranged in keels down both sides of tail.

Scientists browsing a market in Southeast Asia have uncovered a highly unusual 99-million-year-old feathered dinosaur tail encased in amber.

It is rare to find a feather attached to a dinosaur’s body in an amber sample, and it supports the position among researchers that many dinosaurs had feathers rather than scales, like the birds that have descended from them.

 

This reconstruction depicts a small coelurosaur approaching a resin-coated branch on the forest floor.

Source: Chung-tat Cheung
This reconstruction depicts a small coelurosaur approaching a resin-coated branch on the forest floor.

The study’s lead author, Lida Xing of the China University of Geosciences in Beijing, found the unusual specimen at an amber market in Myanmar in 2015, and urged the Dexu Institute of Palaeontology to buy the piece after recognizing its potential scientific importance.

The team used a CT scan to peer into the fossil, finding that the long and flexible nature of the tail meant it had to belong to a dinosaur, not a bird.

The tail belonged to a dinosaur called Coelurosaur — a dinosaur about the size of a small bird, from the same theropod group of dinosaurs as Tyrannosaurus rex. Despite the feathers, the dinosaur was not able to fly, providing more evidence for the contention that plumage originally began popping up on animals for reasons other than flight — such as for camouflage or attracting mates.

Amber is fossilized tree sap, and it acts as a kind of resin that can preserve organic matter that would otherwise be lost.

“Amber pieces preserve tiny snapshots of ancient ecosystems, but they record microscopic details, three-dimensional arrangements, and labile tissues that are difficult to study in other settings,” one of the study’s authors, Ryan McKellar of the Royal Saskatchewan Museum in Canada, said in a news release. “This is a new source of information that is worth researching with intensity and protecting as a fossil resource.”

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After A Year In Space, The Air Hasn’t Gone Out Of NASA’s Inflated Module

Flight engineer Kate Rubins checks out the Bigelow Expandable Activity Module, which is attached to the International Space Station.

NASA

A prototype of what could be the next generation of space stations is currently in orbit around the Earth.

The prototype is unusual. Instead of arriving in space fully assembled, it was folded up and then expanded to its full size once in orbit.

The module is called BEAM, the Bigelow Expandable Activity Module, and it has been attached to the International Space Station since April last year.

 Beamgif

Expandable modules allow NASA to pack a large volume into a smaller space for launch. They’re not made of metal, but instead use tough materials like the Kevlar found in bulletproof vests.

The station crew used air pressure to unfold and expand the BEAM, but it’s wrong to think about BEAM as expanding like a balloon that could go “pop” if something punctured it.

NASA’s Jason Crusan says there is a better analogy: “It’s much like the tire of your car.”

Even with no air in it, a tire retains its tirelike shape.

When BEAM unfolded in orbit, it adopted its more natural shape, something resembling a stumpy watermelon. Even if it was to lose all its internal air, “it still has structure to it,” says Crusan.

Of course NASA would prefer BEAM not lose all its air, so there are many layers of shielding to prevent things like meteorites or other space debris from poking a hole in BEAM.

“We do believe we’ve taken at least one hit,” says Crusan. “Very small in nature, and actually we can’t even visually see where it’s at.”

Crusan says there was no loss of pressure from the hit.

NASA isn’t actually using BEAM for anything. It’s there just to see how it behaves in space. But Crusan says the space station crew does go inside every once in a while to check sensors inside the module. He says crew members seem to like visiting BEAM.

Astronauts Peggy Whitson and Thomas Pesquet are photographed inside BEAM, which has an interior roughly the size of a medium school bus.

NASA

“We’ve actually had up to six crew members at a time inside of it. It’s about 15 to 16 cubic meters inside,” says Crusan. That translates to something like the interior space of a modest-sized school bus.

The original plan was to detach BEAM after two years and let it burn up as it re-enters Earth’s atmosphere. But there has been a change.

“Because of its performance and it’s doing extremely well, there’s really no reason to throw it away,” says Crusan.

Since storage is at a premium aboard the space station, NASA now plans to use BEAM as a kind of storage shed and to keep it in space as long as the station continues to operate.

The company that made BEAM, Bigelow Aerospace, has big plans for expandable modules, including a stand-alone space station called the B330. The B330 will be 20 times larger than BEAM. But company president Robert Bigelow remains cautious despite the good performance of BEAM.

“No, I worry too much,” says Bigelow. The B330 is much, much more complex than BEAM.

“It has two propulsion systems,” he says. “It has very large solar arrays, a full suite of environmental life-support systems.”

These are all things that have to work flawlessly in order to keep a crew alive and happy in space.

“That’s why I walk around perpetually with a frown. It’s just because there’s so much to think about and be concerned about,” says Bigelow.

Despite his concerns, Bigelow says his new space stations may be in orbit before too long. His company plans to have two B330s ready for launch in 2020.

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Weed Hangovers Are Real & The Worst

Image result for weed smoking alien
 Sarah Jacoby
We tend to think of cannabis as a relatively safe medicine — and it is! But there are some possible side effects that aren’t so nice. For instance, the internet is full of cautionary tales that suggest overdoing it can leave you in a pretty unpleasant state the next day. Termed a “weed hangover,” the condition supposedly comes with feelings of fatigue, lack of appetite, irritability, and an overall sense of grogginess. But how much of this is just stoner legend?

“It’s very real, and it as a lot to do with dosage,” confirms Dustin Sulak, DO, a medical cannabis expert based in Maine. So, smoking a little too much can absolutely make your morning miserable.

Plenty of people who use cannabis, either recreationally or medically, approach it with a “more is better” mentality. In truth, “most people will get relief from symptoms at a dose that’s lower than what would cause intoxication,” Dr. Sulak says. So, if you’re using marijuana to treat a health issue, you don’t necessarily need to feel high to get the benefits. And even if you’re using it specifically to enjoy a high, there’s no real need to go ham — you’ll probably be better off the next day if you, well, chill a little bit.

Any time you’re consuming cannabis, your body’s cannabinoid receptors are being activated and, essentially, overstimulated. To counteract that, the receptors are pulled into the cells and become inactive, Dr. Sulak explains. But that doesn’t just make them inactive to the THC you’re inhaling, it also means the endocannabinoid compounds that naturally occur in your body aren’t going to be able to bind to those receptors, either.

Under normal circumstances, your body can balance this out, and there’s no real harm. But, if you ingest enough, you could wake up in a state of cannabinoid withdrawal, Dr. Sulak says. “By using a high dose late in the night, what we’re left with is a feeling of deficiency.” That, combined with weed’s well-documented dehydrating effects, can make you an extremely unhappy camper the next day.

What can you do about it? Treating a weed hangover is a lot like treating a normal one, it turns out. Your first priority is going to be getting rehydrated. After that, you can either wait your symptoms out or, if your life circumstances allow, consume a small dose of cannabis to counteract your withdrawal symptoms. On the other hand, if you wake up and still feel a bit intoxicated, Dr. Sulak suggests taking a some CBD or consuming a high-CBD cannabis strain to counteract the effects.

Beyond that, though, it’s worth taking a good look at your long-term cannabis habits. “If you’re having a weed hangover, it’s a sign you’re not using cannabis optimally,” Dr. Sulak says. So, he recommends new users try using a dose that produces the most minimal (yet noticeable) effects for about three days before upping their consumption. And, for veteran users, he suggests abstaining from weed for two days before finding their minimal dose. Both of these protocols help your body build up a tolerance to the negative side effects of marijuana while also making you more sensitive to the positive effects, Dr. Sulak explains.

“It’s a very forgiving and sustainable medicine,” he says. So it’s worth taking the time to find the way to use it that works the best for you — without feeling like crap the next day.

 no way are we encouraging illegal activity and would like to remind its readers that marijuana usage continues to be an offense under Federal Law, regardless of state marijuana laws.


Stephen Hawking says we have 100 years to colonize a new planet—or die. Could we do it?

Here’s what it would take to survive this particular doomsday prophecy

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Hawking urges Moon landing to ‘elevate humanity’

By Pallab Ghosh

Image result for journey to the moon
Prof Hawking says: “If humanity is to continue for another million years, our future lies in boldly going where no one else has gone before.”
Prof Stephen Hawking has called for leading nations to send astronauts to the Moon by 2020.
They should also aim to build a lunar base in 30 years’ time and send people to Mars by 2025.
Prof Hawking said that the goal would re-ignite the space programme, forge new alliances and give humanity a sense of purpose.
He was speaking at the Starmus Festival celebrating science and the arts, which is being held in Trondheim, Norway.
Spreading out into space will completely change the future of humanity
Prof Stephen Hawking
“Spreading out into space will completely change the future of humanity,” he said.
“I hope it would unite competitive nations in a single goal, to face the common challenge for us all.
“A new and ambitious space programme would excite (young people), and stimulate interest in other areas, such as astrophysics and cosmology”.
Moon LandingsImage copyrightNEIL A. ARMSTRONG
Image caption
Return of the Moon landings would give humanity “a sense of purpose”.
He addressed the concerns of those arguing that it would be better to spend our money on solving the problems of this planet along with a pointed criticism of US President Donald Trump.
“I am not denying the importance of fighting climate change and global warming, unlike Donald Trump, who may just have taken the most serious, and wrong, decision on climate change this world has seen,” he said.
Prof Hawking explained that human space travel is essential for the future of humanity precisely because the Earth was under threat from climate change as well as diminishing natural resources.
“We are running out of space and the only places to go to are other worlds. It is time to explore other solar systems. Spreading out may be the only thing that saves us from ourselves. I am convinced that humans need to leave Earth,” the Cambridge University theoretical physicist explained.
Image result for journey to the moon

The head of the European Space Agency (Esa) Jan Woerner has said he envisages the construction of a Moon base to replace the International Space Station in 2024 and is collaborating with Russia to send a probe to assess a potential site. China has set itself the goal of sending an astronaut to the Moon.
Nasa has no plans to return to the Moon, instead focusing its efforts on sending astronauts to Mars by the 2030s. Though if other space agencies begin to collaborate on constructing a lunar base it would be hard to see Nasa not participating.
Prof Hawking said that there was no long-term future for our species staying on Earth: it would either be hit by an asteroid again or eventually engulfed by our own Sun. He added that travelling to distant worlds would “elevate humanity”.

Media captionIn this European Space Agency video Dr James Carpenter describes the landing site
“Whenever we make a great new leap, such as the Moon landings, we bring people and nations together, usher in new discoveries, and new technologies,” he continued.
“To leave Earth demands a concerted global approach, everyone should join in. We need to rekindle the excitement of the early days of space travel in the sixties.”
He said that the colonisation of other planets was no longer science fiction, though he did pay tribute to the genre in his closing remarks.
“If humanity is to continue for another million years, our future lies in boldly going where no one else has gone before.
“I hope for the best. I have to. We have no other option”.

Monkeys Could Speak If Their Brain Allowed Them To

Avaneesh Pandey


Why Brain Scientists Are Still Obsessed With The Curious Case Of Phineas Gage ?

JON HAMILTON

Image result for images of the brain

It took an explosion and 13 pounds of iron to usher in the modern era of neuroscience.

In 1848, a 25-year-old railroad worker named Phineas Gage was blowing up rocks to clear the way for a new rail line in Cavendish, Vt. He would drill a hole, place an explosive charge, then pack in sand using a 13-pound metal bar known as a tamping iron.

But in this instance, the metal bar created a spark that touched off the charge. That, in turn, “drove this tamping iron up and out of the hole, through his left cheek, behind his eye socket, and out of the top of his head,” says Jack Van Horn, an associate professor of neurology at the Keck School of Medicine at the University of Southern California.

Gage didn’t die. But the tamping iron destroyed much of his brain’s left frontal lobe, and Gage’s once even-tempered personality changed dramatically.

“He is fitful, irreverent, indulging at times in the grossest profanity, which was not previously his custom,” wrote John Martyn Harlow, the physician who treated Gage after the accident.

This sudden personality transformation is why Gage shows up in so many medical textbooks, says Malcolm Macmillan, an honorary professor at the Melbourne School of Psychological Sciences and the author of An Odd Kind of Fame: Stories of Phineas Gage.

“He was the first case where you could say fairly definitely that injury to the brain produced some kind of change in personality,” Macmillan says.

And that was a big deal in the mid-1800s, when the brain’s purpose and inner workings were largely a mystery. At the time, phrenologists were still assessing people’s personalities by measuring bumps on their skull.

Gage’s famous case would help establish brain science as a field, says Allan Ropper, a neurologist at Harvard Medical School and Brigham and Women’s Hospital.

One Account Of Gage’s Personality Shift

Dr. John Harlow, who treated Gage following the accident, noted his personality change in an 1851 edition of the American Phrenological Journal and Repository of Science.

“If you talk about hard core neurology and the relationship between structural damage to the brain and particular changes in behavior, this is ground zero,” Ropper says. It was an ideal case because “it’s one region [of the brain], it’s really obvious, and the changes in personality were stunning.”

So, perhaps it’s not surprising that every generation of brain scientists seems compelled to revisit Gage’s case.

For example:

  • In the 1940s, a famous neurologist named Stanley Cobb diagrammed the skull in an effort to determine the exact path of the tamping iron.
  • In the 1980s, scientists repeated the exercise using CT scans.
  • In the 1990s, researchers applied 3-D computer modeling to the problem.

And, in 2012, Van Horn led a team that combined CT scans of Gage’s skull with MRI scans of typical brains to show how the wiring of Gage’s brain could have been affected.

“Neuroscientists like to always go back and say, ‘we’re relating our work in the present day to these older famous cases which really defined the field,’ ” Van Horn says.

And it’s not just researchers who keep coming back to Gage. Medical and psychology students still learn his story. And neurosurgeons and neurologists still sometimes reference Gage when assessing certain patients, Van Horn says.

“Every six months or so you’ll see something like that, where somebody has been shot in the head with an arrow, or falls off a ladder and lands on a piece of rebar,” Van Horn says. “So you do have these modern kind of Phineas Gage-like cases.”

Two renderings of Gage’s skull show the likely path of the iron rod and the nerve fibers that were probably damaged as it passed through.

Van Horn JD, Irimia A, Torgerson CM, Chambers MC, Kikinis R, et al./Wikimedia

There is something about Gage that most people don’t know, Macmillan says. “That personality change, which undoubtedly occurred, did not last much longer than about two to three years.”

Gage went on to work as a long-distance stagecoach driver in Chile, a job that required considerable planning skills and focus, Macmillan says.

This chapter of Gage’s life offers a powerful message for present day patients, he says. “Even in cases of massive brain damage and massive incapacity, rehabilitation is always possible.”

Gage lived for a dozen years after his accident. But ultimately, the brain damage he’d sustained probably led to his death.

He died on May 21, 1860, of an epileptic seizure that was almost certainly related to his brain injury.

Gage’s skull, and the tamping iron that passed through it, are on display at the Warren Anatomical Museum in Boston, Mass.

Scientists say your “mind” isn’t confined to your brain, or even your body

FREE YOUR MIND

Image result for mind blown gif

You might wonder, at some point today, what’s going on in another person’s mind. You may compliment someone’s great mind, or say they are out of their mind. You may even try to expand or free your own mind.

But what is a mind? Defining the concept is a surprisingly slippery task. The mind is the seat of consciousness, the essence of your being. Without a mind, you cannot be considered meaningfully alive. So what exactly, and where precisely, is it?

Traditionally, scientists have tried to define the mind as the product of brain activity: The brain is the physical substance, and the mind is the conscious product of those firing neurons, according to the classic argument. But growing evidence shows that the mind goes far beyond the physical workings of your brain.

No doubt, the brain plays an incredibly important role. But our mind cannot be confined to what’s inside our skull, or even our body, according to a definition first put forward by Dan Siegel, a professor of psychiatry at UCLA School of Medicine and the author of a recently published book, Mind: A Journey to the Heart of Being Human.

He first came up with the definition more than two decades ago, at a meeting of 40 scientists across disciplines, including neuroscientists, physicists, sociologists, and anthropologists. The aim was to come to an understanding of the mind that would appeal to common ground and satisfy those wrestling with the question across these fields.

After much discussion, they decided that a key component of the mind is: “the emergent self-organizing process, both embodied and relational, that regulates energy and information flow within and among us.” It’s not catchy. But it is interesting, and with meaningful implications.

The most immediately shocking element of this definition is that our mind extends beyond our physical selves. In other words, our mind is not simply our perception of experiences, but those experiences themselves. Siegel argues that it’s impossible to completely disentangle our subjective view of the world from our interactions.

“I realized if someone asked me to define the shoreline but insisted, is it the water or the sand, I would have to say the shore is both sand and sea,” says Siegel. “You can’t limit our understanding of the coastline to insist it’s one or the other. I started thinking, maybe the mind is like the coastline—some inner and inter process. Mental life for an anthropologist or sociologist is profoundly social. Your thoughts, feelings, memories, attention, what you experience in this subjective world is part of mind.”

The definition has since been supported by research across the sciences, but much of the original idea came from mathematics. Siegel realized the mind meets the mathematical definition of a complex system in that it’s open (can influence things outside itself), chaos capable (which simply means it’s roughly randomly distributed), and non-linear (which means a small input leads to large and difficult to predict result).

In math, complex systems are self-organizing, and Siegel believes this idea is the foundation to mental health. Again borrowing from the mathematics, optimal self-organization is: flexible, adaptive, coherent, energized, and stable. This means that without optimal self-organization, you arrive at either chaos or rigidity—a notion that, Siegel says, fits the range of symptoms of mental health disorders.

Finally, self-organization demands linking together differentiated ideas or, essentially, integration. And Siegel says integration—whether that’s within the brain or within society—is the foundation of a healthy mind.

Siegel says he wrote his book now because he sees so much misery in society, and he believes this is partly shaped by how we perceive our own minds. He talks of doing research in Namibia, where people he spoke to attributed their happiness to a sense of belonging.

When Siegel was asked in return whether he belonged in America, his answer was less upbeat: “I thought how isolated we all are and how disconnected we feel,” he says. “In our modern society we have this belief that mind is brain activity and this means the self, which comes from the mind, is separate and we don’t really belong. But we’re all part of each others’ lives. The mind is not just brain activity. When we realize it’s this relational process, there’s this huge shift in this sense of belonging.”

In other words, even perceiving our mind as simply a product of our brain, rather than relations, can make us feel more isolated. And to appreciate the benefits of interrelations, you simply have to open your mind.


Flying cars under development vary significantly

Spurred by technology advances and demand for transportation alternatives in increasingly congested cities, entrepreneurs around the globe are vying to become the first to develop a commercially viable “flying car.” The designs vary greatly, and most aren’t actually cars capable of driving on roads. Here are some examples:

Vahana

European aircraft manufacturer Airbus is working at its Silicon Valley research center on a driverless flying taxi that at first will have a pilot, but will later be autonomous. The vertical takeoff-landing, all-electric aircraft is a cockpit mounted on a sled and flanked by propellers in front and back. Airbus plans to test a prototype before the end of 2017, and to have the first Vahanas ready for production by 2020.

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Cormorant

Israeli tech firm Urban Aeronautics originally designed its people-carrying drone as an “air mule” for military use. It takes off vertically and has a standard helicopter engine, but no large main rotor. Its lift comes from two fans buried inside the fuselage. Two smaller ducted “fans” mounted in the rear provide forward movement. It can fly between buildings and below power lines, attain speeds up to 115 mph, stay aloft for an hour and carry up to 1,100 pounds

___This image provided by Urban Aeronautics/Tactical Robotics shows an Israeli-made flying car. Urban Aeronautics conducted flight tests of its passenger-carrying drone call the Cormorant in Megiddo, Israel, late in 2016. (Urban Aeronautics/Tactical Robotics via AP)

Lilium Jet

German technology company Lilium Aviation is working on a two-seater aircraft that will take off vertically using 36 electric fan engines arrayed along its wings. The aircraft will hover and climb until the fans are turned backward slowly. After that, it flies forward like a plane using electric jet engines. The company has been flight-testing small scale models. The aircraft will have an estimated cruising speed of up to 190 mph and a range of 190 miles.

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AeroMobil 3.0

The Slovakian company AeroMobil has developed a car with wings that unfold for flight. It uses regular gasoline and fits into standard parking spaces. It can also take off from airports or “any grass strip or paved surface just a few hundred meters long,” according to the company’s website. Driver and pilot licenses will be required.

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EHang 184

Chinese drone maker EHang has been flight-testing a person-carrying drone in Nevada. The vehicle is a cockpit with four arms equipped with rotors. Takeoff and landing targets are pre-programmed. A command station in China will be able to monitor and control the aircraft anywhere in the world, company officials say.

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S2

Joby Aviation of Santa Cruz, California is developing a two-seat, all-electric plane with 12 tilt rotors arrayed along its wings and tail. The aircraft takes off and lands vertically and can achieve speeds up to 200 mph, according to the company’s website.

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Transition/TF-X

Terrafugia, based in Woburn, Massachusetts, began working a decade ago on a car folding wings that can fly or be driven on roads that’s called the Transition. The company says it plans to begin production of the Transition in 2019. Terrafugia is also working on a “flying car” called the TF-X — a car with folding arms and rotors for vertical takeoff and landing.

___This image provided by Urban Aeronautics/Tactical Robotics shows an Israeli-made flying car. Urban Aeronautics conducted flight tests of its passenger-carrying drone call the Cormorant in Megiddo, Israel, late in 2016. (Urban Aeronautics/Tactical Robotics via AP)

Volocopter

This two-seater, electric multicopter from German company e-volo has 18-rotors and looks like a cross between a helicopter and a drone. It is controlled from the ground, eliminating the need for a pilot license.

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Zee

This Mountain View, California, aircraft developer bankrolled by Google co-founder Larry Page says on its webpage that it is working on a “revolutionary new form of transportation” at the “intersection of aerodynamics, advanced manufacturing and electric propulsion.” Company officials declined to provide details about Zee’s projects.

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This image provided by Urban Aeronautics/Tactical Robotics shows an Israeli-made flying car. Urban Aeronautics conducted flight tests of its passenger-carrying drone call the Cormorant in Megiddo,… (Urban Aeronautics/Tactical Robotics via AP) More


Evidence shows that marijuana works for pain, the medical reason most people want it — but doctors still have questions

Kevin Loria,Business Insider

marijuana cannabis pot weed bud nug(Shutterstock)

The most common reason that people seek out medical marijuana is for chronic pain.

According to a report released earlier in January by the National Academies of Sciences, Engineering, and Medicine (NASEM), that makes a lot of sense.

One of the strongest conclusions of the report, which provides basically the most comprehensive, up-to-date look at what all available research on cannabis tell us, is that there is conclusive or substantial evidence (in general, enough to make a firm conclusion) that cannabis or cannabinoids, found in the marijuana plant, can be an effective treatment for chronic pain.

This matters because it has implications for how we treat pain and how we assess the value of medical marijuana. It also helps illustrate how — despite its DEA Schedule I status that declares it has “no currently accepted medical use” — most research indicates there are indeed potentially important medical uses for cannabis.

But at the same time, doctors still want more research to help them decide when marijuana might help a patient and when something else is a better idea.

How marijuana can help

Pain itself is a weird and complex thing. It’s subjective and personal and can’t be precisely measured with a test. That’s because even when it’s pain associated with a part of your body, it’s really your brain that’s telling you to hurt. If a pinched nerve in your spine is causing your back to spasm, your brain’s way of telling you that something is wrong is to make you feel an ache that might throb constantly or make you feel an explosive jolt if you worsen the pinch with certain movements.

But all those sensations are coming from your brain, telling you to take action to deal with some part of your body. And everyone reacts to these stimuli in different ways.

That’s why there are so many different ways to treat pain. Anti-inflammatory drugs reduce inflammation by blocking the chemicals your body creates in response to an injury that cause that inflammation. Opioids bond to opioid receptors you already have in your body, which can cause feelings of euphoria and block sensations of pain. We know that acetaminophen (Tylenol) can treat some forms of pain, but we don’t know how it works or why. Even non-pharmacological treatments can stop your brain from telling you to feel hurt, with interesting research showing that meditation and virtual reality can both effectively treat pain.

According to the NASEM report, studies show that both inhaled marijuana (vaporized or smoked) and cannabinoid compounds that come from the cannabis plant (like THC, mostly responsible for the high, or cannabidiol, CBD, one of the most medically promising of the hundreds of chemical compounds found in marijuana) work for pain. This is likely largely related to natural cannabinoid receptors that we already have in our body and that doctors think play a role in pain control. But the exact mechanisms showing how marijuana relieves pain are not fully understood yet.

marijuana pot weed flower bud dispensary store(John Locher/AP)

It’s no surprise that people seek out cannabis for chronic pain, as it’s incredibly — in some ways disturbingly — common. About 100 million Americans suffer from chronic pain, about one-third of the population, and it’s difficult to treat, especially in cases where the cause is unclear. Such pain is the leading cause of long-term disability. In some cases, opioids may be the best treatment for this pain, but the rapid rise in opioid addiction over the years makes many people want to find safer solutions.

With that in mind, cannabis seems like a good option. In states that have legalized medical marijuana for pain, addiction and opioid overdose rates have dropped.

But doctors still have questions.

Why some doctors are still hesitant to suggest marijuana

“Usually when you make decisions about which drug you are going to take for pain, you make that decision based on the type of pain you have and the relative risks for side effects,” says Ryan Vandrey, an associate professor of psychiatry who researches marijuana at Johns Hopkins Medicine.

When it comes to marijuana, “millions of people are using different types of cannabis products for supposedly therapeutic purposes,” says Vandrey. That introduces a lot of uncertainty to the equation. The marijuana bought at one dispensary in California is going to be very different from an oil bought at another Colorado medical marijuana shop; both will be different from a cannabinoid drug designed to help with pain. All of these substances fall under the cannabis umbrella, but depending on their specific cannabinoid content and the means through which they are ingested, they’re going to have different effects. All those people using those products for therapeutic purposes are “lacking information about which types of products to choose, what doses to use, and how cannabis compares to other medications,” according to Vandrey.

There’s already uncertainty over whether the pain relief from marijuana is on the scale of an over-the-counter drug like ibuprofen, or, more powerful, able to relieve the same pain as an opioid. Different sorts of cannabis products might fill different roles. With all of these questions, it’s hard for doctors to know when recommending marijuana makes the most sense, even if studies indicate that it works.

More research will be needed before we have answers to those questions, and as the NASEM report, Vandrey, and other researchers Business Insider has interviewed all point out, there are obstacles that make it hard to study marijuana.

But clearly, if it’s effective — especially if it can replace more dangerous drugs like opioids — that research is important.