Month: April, 2018

What Came Before The Big Bang?

It is difficult enough to imagine a time, roughly 13.7 billion years ago, when the entire universe existed as a singularity.

According to the big bang theory, one of the main contenders vying to explain how the universe came to be, all the matter in the cosmos – all of space itself – existed in a form smaller than a subatomic particle.

Once you think about that, an even more difficult question arises: What existed just before the big bang occurred?

The question itself predates modern cosmology by at least 1,600 years. Fourth-century theologian St. Augustine wrestled with the nature of God before the creation of the universe.




His answer? Time was part of God’s creation, and there simply was no “before” that a deity could call home.

Armed with the best physics of the 20th century, Albert Einstein came to very similar conclusions with his theory of relativity.

Just consider the effect of mass on time. A planet’s hefty mass warps time — making time run a tiny bit slower for a human on Earth’s surface than a satellite in orbit.

The difference is too small to notice, but time even runs more slowly for someone standing next to a large boulder than it does for a person standing alone in a field.

The pre-big bang singularity possessed all the mass in the universe, effectively bringing time to a standstill.

Following this line of logic, the title of this article is fundamentally flawed.

According to Einstein’s theory of relativity, time only came into being as that primordial singularity expanded toward its current size and shape.

Case closed? Far from it. This is one cosmological quandary that won’t stay dead.

In the decades following Einstein’s death, the advent of quantum physics and a host of new theories resurrected questions about the pre-big bang universe. Keep reading to learn about some of them.

Here’s a thought: What if our universe is but the offspring of another, older universe? Some astrophysicists speculate that this story is written in the relic radiation left over from the big bang: the cosmic microwave background (CMB).

Astronomers first observed the CMB in 1965, and it quickly created problems for the big bang theory — problems that were subsequently addressed (for a while) in 1981 with the inflation theory.

This theory entails an extremely rapid expansion of the universe in the first few moments of its existence.

It also accounts for temperature and density fluctuations in the CMB, but dictates that those fluctuations should be uniform.

In chaotic inflation theory, this concept goes even deeper: an endless progression of inflationary bubbles, each becoming a universe, and each of these birthing even more inflationary bubbles in an immeasurable multiverse.

Other scientists place the formation of the singularity inside a cycle called the big bounce in which our expanding universe will eventually collapse back in on itself in an event called the big crunch.

A singularity once more, the universe will then expand in another big bang.

This process would be eternal and, as such, every big bang and big crunch the universe ever experiences would be nothing but a rebirth into another phase of existence.

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Pass it on: Popular Science

Gaia Mission Releases Map Of More Than A Billion Stars – Here’s What It Can Teach Us

Most of us have looked up at the night sky and wondered how far away the stars are or in what direction they are moving.

The truth is, scientists don’t know the exact positions or velocities of the vast majority of the stars in the Milky Way.

But now a new tranche of data from the European Space Agency’s Gaia satellite, aiming to map stars in our galaxy in unprecedented detail, has come in to shed light on the issue.

The Gaia Archive opened on April 25, making public Gaia’s second data release to everyone.

To quote the character Dave Bowman in the sci-fi classic 2001: A Space Odyssey: “It’s full of stars”. In fact, it contains data on the distances to more than 1.3 billion stars.

The Gaia satellite was launched in 2013 and has been scanning the sky with its two telescopes continuously ever since, with the aim of deciphering how our Milky Way galaxy formed and evolved.




To do this, it is measuring something called parallax. If you hold a finger at arms length and look at it with one eye and then the other, your finger appears to shift position compared to the background.

The angular change is called parallax.

Being in space allows Gaia to see similar tiny shifts in star positions. Observations at different locations six months apart (half way of its orbit around the Earth) are akin to looking at your finger with one eye and then the other.

When you know the parallax as well as the distance from Gaia to the sun (or the distance from your nose to your eye), you can use simple trigonometry to work out the distance to each star (or your finger).

Gaia also sees stars move in the plane of the sky over time. These units of “angle per time” can be converted to a physical unit of speed (for example kilometres per second) if we know the distance to the stars.

However, to know how a star is moving in three dimensions in space requires that we also measure the speed perpendicular to the sky along the line-of-sight. This requires a galactic speed camera!

A normal radar speed camera uses the Doppler effect – the stretching or squashing of waves because of motion – by measuring the change in the radio frequency from signals bounced off cars to measure their speed.

Similarly, Gaia measures the change in frequency in the light from stars to check their speed. The star light is bluer if the star is moving towards us or redder if the star is moving away from us. This is called radial velocity.

Gaia’s first data release in 2016 published the distances of around two million stars but did not include any radial velocities.

However we already knew the radial velocity of less than 400,000 of these stars – measured from the ground by many different surveys.

Gaia’s second data release includes information on sky positions and brightness for nearly 1.7 billion stars and more than seven million radial velocities.

Not only does this make Gaia the largest radial velocity survey ever – it increases the number of stars with accurate 3D space velocities by a factor of 18.

A series of Gaia science demonstration papers have also been published alongside the star catalogue. I was involved in the research behind one of these papers, constructing the most detailed map ever of 3D space velocities to date.

The next data release by Gaia will be in 2020. This is expected to boost the numbers of stars with known radial velocities from seven million today to around 30m – keeping our team busy for several years yet.

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Learn To Be An Astronaut Online With Chris Hadfield

The more you know, the less you fear.” The former International Space Station commander wants to teach you all about space exploration with this MasterClass.

With 21 years as an astronaut under his belt, there’s bound to be a few valuable lessons Chris Hadfield can teach us all even if we never plan to leave orbit.

The former astronaut shares his knowledge about space exploration in an online course at MasterClass.

Hadfield spent six months in orbit as the commander of the International Space Station (ISS).




He has flown on three space missions, made two spacewalks, and has logged almost 4,000 hours in space, which also includes singing a David Bowie song while playing his guitar.

So if anyone is qualified to teach us all about being an astronaut, it’s Hadfield.

The reason I wanted to do this MasterClass is to share the hidden depths of purpose that are behind space exploration,” Hadfield said in the preview video.

In 28 video lessons, Hadfield covers the full scope of an astronaut’s training from leadership qualities to survival skills.

This also includes extensive lesson plans to help students learn all about how rockets work, atmospheric drag, fuels, capsule design, navigation systems, life support systems and more.

Hadfield also offers a head-to-toe tour of a spacesuit, referred to as an Extra-vehicular Mobility Unit (EMU).

It’s not really a suit, it’s more like a one-person spaceship,” Hadfield explains in the spacesuit lesson. “The suit has to protect you from big temperature extremes.

“You’re also subject to getting hit by all the little tiny particles of the universe, like you’re being sandblasted the whole time you’re outside. This suit has to protect you from that.”

While Hadfield plans on covering the ins and outs of everything from orbital mechanics to rocket propulsion, it’s his stories about exploring mars and commanding the International Space Station that will likely keep most of us on the edge of our seats.

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Disney Made A Jacket To Simulate Physical Experiences, Like A Snake Slithering Across Your Body

Disney Research, MIT Media Lab, and Carnegie Mellon University have unveiled a new conceptual haptic “force jacket” that simulates physical experiences to people wearing the device.

The force jacket is lined with airbags controlled by a computer that inflates and deflates the bags.

Disney envisions the jacket will be used with VR headsets for more immersive experiences, given its ability to simulate hugs, being hit or punched, and peculiarly, the sensation of a snake slithering across your body.

The jacket is made up of airbags with sensors attached that direct force and vibrations to specific locations on your body.




The software-controlled jacket weighs about five pounds and has a valve system that inflates and deflates 26 air compartments.

It has adjustable sleeves, and the vest is made of a repurposed life vest with the inside foam replaced with the air bags. The air compartments are located on the jacket’s front, back, arms, and sides.

The speed, force, and duration of inflation and deflation can be controlled using a haptic effects software editor.

In their paper, researchers on the project from Disney, MIT, and Carnegie Mellon wrote: “At this stage of work, the goal is to develop core technology for the Force Jacket that will be sufficient for basic psychophysical assessment and to design and test an initial set of effects.

So far, those effects include: a racing heartbeat, light or heavy rain, snowball hit to the chest, a hand tap on the shoulder, slime dripping on your back, a bug crawling up your arm, and motorcycle vibrations.

There are further refining parameters, like controlling the feeling of how fast that bug is crawling.

The researchers built three VR apps in testing the jacket, including a snowball fight game, a simulation of a snake crawling around, and a simulation of “growing muscles” — like turning into the Hulk. They wrote:

“The overall system set-up is very bulky and confining for the user. Also, with the surround body effects that the wearable can achieve, a 360 degree virtual reality experience is possible; however, the user’s ability to rotate or move in the VR space is limited by the tubing that tethers them to the air and vacuum supply.”

The researchers believe with more development the jacket could be more viable in VR use.

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Gene Editing Fixes Harmful Mutation In Human Embryos

GENE

Scientists have successfully edited the DNA of human embryos to erase a heritable heart condition that is known for causing sudden death in young competitive athletes, cracking open the doors to a controversial new era in medicine.

This is the first time gene editing on human embryos has been conducted in the United States. Researchers said in interviews this week that they consider their work very basic.




The embryos were allowed to grow for only a few days, and there was never any intention to implant them to create a pregnancy.

But they also acknowledged that they will continue to move forward with the science, with the ultimate goal of being able to “correct” disease-causing genes in embryos that will develop into babies.

News of the remarkable experiment began to circulate last week, but details became public Wednesday with a paper in the journal Nature.

The experiment is the latest example of how the laboratory tool known as CRISPR (or Clustered Regularly Interspaced Short Palindromic Repeats), a type of “molecular scissors,” is pushing the boundaries of our ability to manipulate life, and it has been received with both excitement and horror.

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NASA Brings Out The Big Gun For Asteroid Impact Science

A top-down view of the Ames Vertical Gun Range.

Just before he gets ready to fire a projectile down the 14-foot barrel of a vertical gun, planetary scientist Peter Schultz turns to me and gives an apologetic smile.

There’s something you have to do,” he says, as his graduate student snickers. “You have to assume the Gault position.

The Gault position, it turns out, involves crossing your index finger over your middle, your ring finger over your pinkie, then crossing your two arms over one another and finally crossing your legs (while standing).

Schultz assumes it, explaining that it serves as a good luck measure, as does his graduate student and the other engineers in the gun control room.

We’re armed,” someone calls. “Voltage looks good.” A klaxon buzzes and, seconds later, there’s the sound of a powerful explosion from the next room over.

A burst of flame and sand appears on the computer screen in front of us and, just like that, the NASA Ames Vertical Gun range has provided a new data point for science.

The gun is a fantastic tool for studying the effects of meteorite impacts on different places in the solar system. You see, Earth is something of an anomaly.




Most other rocky bodies are covered in countless craters ranging from the size of continents down to the size of sand grains.

The active tectonics of our planet recycle its crust, erasing the long-term scars that come from living in a solar system full of debris.

But just about every other terrestrial planet, moon, asteroid, and comet is coated in pockmarks, a testament to how pervasive and important impacts have been in our solar system’s history.

Over the course of its nearly 50-year career, the gun range been used to figure out why the scars of an impact look different on Mars than they do on Venus.

It has helped explain how the man on the moon could have gotten his face. And it has provided key data for many NASA missions, in particular the Deep Impact spacecraft, which shot a projectile into an asteroid.

Peter Schultz, who teaches geoscience at Brown University, has done much of this research. He’s worked at the gun range for 33 years, becoming its principal investigator in 2012, and he knows a great deal about its history and lore.

Planetary scientist Peter Schultz, principal investigator at the Ames Vertical Gun Range.

Though it’s called a gun, the facility doesn’t look much like any firearm you’ve ever seen. The main chassis is a long metal barrel as thick as a cannon mounted on an enormous red pole that forks at the end into two legs.

The red pole was once used to hold MIM-14 Nike-Hercules missiles that served as an anti-ballistic defense against Soviet nuclear warheads, Schultz explains.

This complex is pointed at a huge rotund cylinder and can be moved up and down in 15-degree increments to simulate a meteorite strike at different angles.

The entire machine is housed in a 3-story industrial building here at NASA’s Ames campus.

At the far end of the barrel, a gunpowder explosion is used to compress hydrogen gas to as much as 1 million times atmospheric pressure.

The compressed gas gets released and sent down the launch tube, firing a projectile pellet at speeds between 7,000 and 15,000 mph.

The Ames Vertical Gun Range as it looked in the 1960’s. The gun (center) is used to fire tiny pellets into a surface at speeds resembling a collision between asteroids.

The shot enters the cylinder, in which low pressure or even a vacuum is maintained, and hits a dish filled with different material that simulates whatever planetary body researchers are studying.

High-speed cameras mounted on windows around the cylinder record the impact aftermath at up to 1 million frames per second.

Using data from the gun, Gault helped figure out that the Apollo astronauts weren’t going to die by lunar quicksand.

After NASA finished its goal of safely landing and returning astronauts, Gault continued using the gun range to study the formation of craters on the moon.

When he retired, NASA planned to mothball the gun but an outcry from the planetary science community re-opened the firing range as a national facility.

It was during this time that Schultz, who had worked with Gault as a post-doc, was hired to take over as science coordinator for the gun range.

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Meet The Russian Biologist Who Is Also A Pioneer Of Modern Genetics

Nikolai Konstantinovich Koltsov was a Russian biologist and a pioneer of modern genetics.

Koltsov graduated from Moscow University in 1894 and was a professor there (1895-1911).

He established and directed the Institute of Experimental Biology in the middle of 1917, just before the October revolution and was a member of the Agricultural Academy.

In 1920, Koltsov was arrested as a member of the non-existent “Anti-Soviet Tactical Center” invented by the VCheKa.

Prosecutor Nikolai Krylenko demanded the death sentence for Koltsov (67 of around 1000 arrested people were executed).

However, after a personal appeal to Vladimir Lenin by Maxim Gorky Koltsov was released and was restored to his position as the head of the Koltsov Institute of Experimental Biology.




Nikolai Koltsov worked on cytology and vertebrate anatomy. In 1903 Koltsov proposed that the shape of cells was determined by a network of tubules which he termed the cytoskeleton.

In 1927 Koltsov proposed that inherited traits would be inherited via a “giant hereditary molecule” which would be made up of “two mirror strands that would replicate in a semi-conservative fashion using each strand as a template“.

These ideas were confirmed to have been accurate in 1953 when James D. Watson and Francis Crick described the structure of DNA.

Watson and Crick had apparently not heard of Koltsov. US geneticist Richard Goldschmidt wrote about him: “There was the brilliant Nikolai Koltsov, probably the best Russian zoologist of the last generation, an enviable, unbelievably cultured, clear-thinking scholar, admired by everybody who knew him“.

In 1937 and 1939, the supporters of Trofim Lysenko published a series of propaganda articles against Nikolai Koltsov and Nikolai Vavilov.

They wrote: “The Institute of Genetics of the Academy of Sciences not only did not criticize Professor Koltsov’s fascistic nonsense, but even did not dissociate itself from his “theories” which support the racial theories of fascists“.

His death in 1940 was claimed to have been due to a stroke. However, the biochemist Ilya Zbarsky revealed that the unexpected death of Koltsov was a result of his poisoning by the NKVD, the secret police of the Soviet Union.

The same day his wife, the scientist Maria Sadovnikova Koltsova, committed suicide.

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Pass it on: New Scientist

Growing Human Brain Cells In The Lab

When researchers like Gan find potential new drugs, they must be tested on human cells to confirm they can benefit patients. Historically, these tests have been conducted in cancer cells, which often don’t match the biology of human brain cells.

The problem is that brain cells from actual people can’t survive in a dish, so we need to engineer human cells in the lab,” explained Gan, senior investigator at the Gladstone Institutes. “But, that’s not as simple as it may sound.”

Many scientists use induced pluripotent stem cells (iPSCs) to address this issue. IPSCs are made by reprogramming skin cells to become stem cells, which can then be transformed into any type of cell in the body.

Gan uses iPSCs to produce brain cells, such as neurons or glial cells, because they are relevant to neurodegenerative disease.




Human brain cells derived from iPSCs offer great potential for drug screening. Yet, the process for producing them can be complicated, expensive, and highly variable.

Many of the current methods produce cells that are heterogeneous, or different from one another, and this can lead to inconsistent results in drug screening.

In addition, producing a large number of cells is very costly, so it’s difficult to scale up for big experiments.

To overcome these constraints, Michael Ward, MD, PhD, had an idea.

A New Technique Is Born

I came across a new method to produce iPSCs that was developed at Stanford,” said Ward, a former postdoctoral scholar in Gan’s lab who is now an investigator at the National Institutes of Health.

I thought that if we could find a way to simplify and better control that approach, we might be able to improve the way we engineer human brain cells in the lab.”

Ward and his colleague Chao Wang, PhD, discovered a way to manipulate the genetic makeup of cells to produce thousands of neurons from a single iPSC. This meant that every engineered brain cell was now identical.

The team further improved the technique to create a simplified, two-step process. This allows scientists to precisely control how many brain cells they produce and makes it easier to replicate their results from one experiment to the next.

Their technique also greatly accelerates the process.

While it would normally take several months to produce brain cells, Gan and her team can now engineer large quantities of them within 1 or 2 weeks, and have functionally active neurons within 1 month.

The researchers realized this new approach had tremendous potential to screen drugs and to study disease mechanisms. To prove it, they tested it on their own research.

They applied their technique to produce human neurons by using iPSCs. Then, they developed a drug discovery platform and screened 1,280 compounds.

Their goal is to identify the compounds that could lower levels of the protein tau in the brain, which is considered one of the most promising approaches in Alzheimer’s research and could potentially lead to new drugs to treat the disease.

A Powerful Tool for the Entire Scientific Community

We have developed a cost-effective technology to produce large quantities of human brain cells in two simple steps,” summarized Gan.

By surmounting major challenges in human neuron-based drug discovery, we believe this technique will be adopted widely in both basic science and industry.

Word of this useful new technology has already spread, and people from different scientific sectors have come knocking on Gan’s door to learn about it.

Her team has shared the new method with scores of academic colleagues, some of whom had no experience with cell culture.

So far, they all successfully repeated the two-step process to produce their own cells and facilitate scientific discoveries.

Details of this new technique were also published on October 10, 2017, in the scientific journal Stem Cell Reports.

With some of the roadblocks out of the way, Gan hopes more discoveries will soon help the millions who suffer from Alzheimer’s disease.

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Are You High? There’s An App To Help You Tell For Sure

There’s no breathalyzer for cannabis on the market, but the fine folks over at NORML have created My Canary, an app that measures how high you are based on a series of simple tests.

While a disclaimer states it shouldn’t be used to determine fitness to drive or engage in other high-risk activities, it sure is fun to test out.

The creators of My Canary “examined thousands of peer-reviewed studies on the influence of fatigue, and legal and illegal substances […] and over 20,000 studies specifically focusing on the influence of marijuana on functioning.” 

Backed by that research, the app tests the following areas of cognitive and psychomotor abilities, then tells you whether you’re significantly impaired.

You’d better set aside at least 15 minutes if you want to do this right.




Individual Baseline

Everyone’s different. “Normal” reaction time, for example, is approximately 0.75 seconds, but many people might be considerably faster or slower.

Doing the test sober first establishes your norm as a point of comparison for your high self, which it can then use anytime.

Memory

Six random numbers appear, spin around, and slowly disappear: your job is to remember them. The test taps into your so-called “verbal working memory,” a.k.a. the “phonological loop.”

It’s the combination of verbal storage and a rehearsal system that your brain uses to remember the digit string.

Changes in the brain that affect memory eventually affect driving ability.

Balance

You’re asked to stand on one leg, raise your dominant foot a few inches off the ground, and stay steady – just like a roadside test (note: we found this tricky even while not under the influence.)

It then detects any shaking or wavering that could affect skills like driving.

Reaction Time and Divided Attention

Different-colored buttons appear at random locations on the screen: you’re asked to tap the correct color button as soon as it appears.

Unlike a test for normal, simple reaction time, My Canary takes into account the “perception-reaction time” – an important factor in crash-avoidance research.

Results

After you’re finished, My Canary scores your performance compared to your baseline.

Obviously, most people know it when they’re high, but after My Canary’s battery of tests, you have some objective perspective on how, specifically, the stuff’s treating you.

You can purchase My Canary (which isn’t to be confused with the now-shuttered cannabis delivery service, Canary) for $4.99 in the Apple App Store.

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Pass it on: New Scientist