Tag: physics

Nobel Prize in Physics Shared by Woman for 1st Time in 55 Years

Members of the Nobel Committee for Physics sit in front of a screen displaying portraits of this year’s Laureates: Arthur Ashkin, Gerard Mourou and Donna Strickland.

Three scientists were awarded the Nobel Prize in physics this morning for their groundbreaking inventions in the field of laser physics.

Donna Strickland and Gérard Mourou were awarded one half of the award, with the other half going to Arthur Ashkin.

Strickland is only the third women to be awarded a Nobel in physics ever. (The other two were Marie Curie in 1903 and Maria Goeppert-Mayer in 1963.)

We need to celebrate women physicists because they’re out there… I’m honored to be one of those women,” Strickland said, according to the Nobel Prize Foundation.

When she received the call this morning telling her about the award, as many Laureates in the past have said, she was in disbelief.

First of all, you have to think it’s crazy. So that was my first thought and you do always wonder if it’s real,” Strickland said during a press briefing this morning at the Royal Swedish Academy of Sciences in Sweden.

Ashkin, of Bell Laboratories in Holmdel, New Jersey, is being honored for his invention of optical tweezers; these laser beam fingers can grab the teensy living cells, including particles, atoms and viruses.

This new tool allowed Ashkin to realize an old dream of science-fiction — using the radiation pressure of light to move physical objects,” the Royal Swedish Academy of Sciences said in a statement.

In 1987, he used the tweezers to grasp living bacteria without harming them, according to the academy statement.

Achievements by Strickland, of the University of Waterloo in Canada, and Morou, of the École Polytechnique, Palaiseau, France, led to the creation of the world’s shortest and most intense laser pulses.

The duo invented what is called chirped pulse amplification, a process in which laser pulses are stretched in time, amplified and then compressed.

When a pulse gets squished in time, becoming shorter, the same amount of light is packed into a tiny space and so the pulse’s intensity skyrockets.

When asked this morning about the groundbreaking discovery, Strickland said, “It’s thinking outside the box to stretch first and then amplify. Most people were amplifying and trying just to compress whatever they had amplified.”

This technique is used in millions of laser eye surgeries every year, according to the academy statement.

Askkin will receive half of the 9 million krona ($1.01 million) Nobel Prize award, and Mourou and Strickland will share the other half.

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Gravitational Wave Detection Is Going Through An Even Tighter Squeeze

A team of researchers from the Max Planck Institute for Gravitational Physics (Albert Einstein Institute; AEI) in Hannover and from the Institute for Gravitational Physics at Leibniz Universität Hannover has developed an advanced squeezed-light source for the gravitational-wave detector Virgo near Pisa.

Now, the Hannover scientists have delivered the setup, installed it, and handed it over to their Virgo colleagues.

Beginning in autumn 2018 Virgo will use the squeezed-light source to listen to Einstein’s gravitational waves together with the worldwide network of detectors with higher sensitivity than ever before.

The German-British gravitational-wave detector GEO600 near Hannover has been routinely using a squeezed-light source since 2010.

“It has increased the part of the Universe that GEO600 listens to by a factor of up to four,” says Prof. Karsten Danzmann, director at the AEI Hannover and director of the Institute for Gravitational Physics at Leibniz Universität Hannover.

“The development and perfection of the cutting-edge technology is another successful chapter in the history of GEO600 as think thank of gravitational-wave research.”

Both US LIGO instruments and the Virgo detector based in Tuscany are currently being upgraded and improved in preparation of the next joint observation run “O3” which is planned to commence in autumn 2018.

O3 is expected to usher in full-scale gravitational-wave astronomy through a large number of further gravitational-wave detections from merging binary black holes and additional signals from merging neutron star pairs.

For this purpose, Virgo has now received a valuable addition from Hannover: A setup called a squeezed-light source is expected to significantly increase Virgo’s sensitivity from the beginning of O3.

The custom-made device is a permanent loan of the AEI to Virgo and is worth about 400,000 Euros.

The sensitivity of all interferometric gravitational-wave detectors (LIGO, Virgo, and GEO600) to the ripples of space-time from large cosmic events is fundamentally limited by quantum mechanical effects.

They cause a background noise which overlaps with the gravitational-wave signal that is measured with laser light.

The sensitivity of all interferometric gravitational-wave detectors can only be further increased in the future through the use of similar squeezed-light sources.

Planned third-generation detectors like the Einstein Telescope will also depend on this technology.

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Science Tackles The Hard Questions At Last: How To Create A Perfect Bubble

Blowing soap bubbles is child’s play, but surprisingly, physicists haven’t worked out the details of the phenomenon.

Now researchers have performed experiments and developed a complete theory of the process of soap bubble formation.

The team aimed a jet of gas at a soap film and observed that bubbles appear only above a threshold gas speed.

By measuring this threshold under varying conditions, the team showed that bubbles result from a competition between the pressure of the gas jet and the surface tension of the soap film.

Understanding the physics of bubbles is important for a variety of industrial processes and scientific fields, from cosmology to foam science, and the new experiments may also be useful in the classroom.

Researchers have studied related processes, such as the popping of bubbles, and examined soap films being pierced by pellets or liquid droplets.

But bubble blowing has mostly been overlooked, say Laurent Courbin and Pascal Panizza, both of the French National Centre for Scientific Research (CNRS) and the University of Rennes 1.

While watching children blowing bubbles in a local park, they realized that the phenomenon hadn’t been studied before and hurried back to the lab to tinker with soapsuds.

Following the example of previous soap film research on fluid flows and turbulence, Courbin, Panizza, and their colleagues built a large apparatus capable of creating a meter-tall, long-lived, vertical sheet of soap solution.

In this system, the soap film continually flows downward—unlike the stationary film in a standard bubble wand—and the liquid is collected at the bottom and pumped back to the top.

This laboratory setup allows the film to remain stable indefinitely, and its thickness can be adjusted, as can the speed with which it falls.

The team placed a gas nozzle at the surface of the soap film and used a high-speed camera to capture the results. At low gas jet speeds, only a small dimple appeared in the soap film.

The dimple became deeper as the team increased the jet’s speed, until bubbles finally formed.

The phenomenon, the researchers found, can be explained as a contest between the pressure the gas jet exerts on the film and the surface tension of the film, which resists any increase in curvature.

Bubbles form when the jet’s pressure is large enough to deform the film into a hemispheric dimple of the same width as the jet.

At that point, the film has reached its maximum curvature, and the bubble can fill with gas and float away.

The researchers found that wider jets, which produce larger bubbles, create them at lower gas speeds than narrower jets. These larger bubbles have less curvature, making it easier to overcome surface tension’s pull.

Repeating the study with a simple bubble wand gave similar results, suggesting that the laboratory setup is a passable proxy for real-world bubble blowing.

The thickness of the soap film had no effect on the gas speed at which bubbles formed.

Understanding how bubbles form is important for certain industrial processes, like those involving foam production, and avoiding bubble formation is necessary in glassmaking and coating solids with liquids, says Courbin.

But “this paper is really about explaining an everyday-life experiment,” rather than real-world applications, he says.

Still, says Hamid Kellay of the University of Bordeaux in France, “it’s the first time that these types of ideas can be tested correctly, because of the well-controlled experiments.

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Astronomers Might Have Finally Detected Where Mysterious, Extra-Galactic Neutrinos Are Coming From

Just over three years ago, physicists working in Antarctica announced they’d detected the first evidence of mysterious subatomic particles, known as neutrinos, coming from outside our galaxy.

It was a huge moment for astrophysics, but since then, no one’s quite been able to figure out where those particles are coming from, and what’s sending them hurtling our way.

Until now, that is – a team of astronomers has just identified the possible source of one these extragalactic visitors, and it appears that it started its journey to us nearly 10 billion years ago, when a massive explosion erupted in a galaxy far, far away.

Let’s step back for a second here though and explain why this is a big deal. Neutrinos are arguably the weirdest of the fundamental subatomic particles.

They don’t have any mass, they’re incredibly fast, and they’re pretty much invisible, because they hardly ever interact with matter.

Like tiny ghosts, billions of neutrinos per second are constantly flowing through us, and we never even know about it.

In order to detect them, researchers have step up extravagant labs, like the IceCube Neutrino Observatory at the South Pole, where they wait patiently to capture glimpses of neutrinos streaking through the planet, and measure how energetic they are, to try to work out where they came from.

Usually that source is radioactive decay here on Earth or inside the Sun, or maybe from the black hole at the centre of our galaxy.

But in 2013, the IceCube researchers announced they’d detected a couple of neutrinos so unimaginably energetic, they knew they must have come from outside our galaxy.

These neutrinos were named ‘Bert’ and ‘Ernie‘ (seriously) and they were the first evidence of extragalactic neutrinos.

Their discovery was followed by the detection of a couple of dozen more, slightly less energetic, extragalactic neutrinos over the coming months.

Then at the end of 2012, they spotted ‘Big Bird‘.

At the time it was the most energetic neutrino ever detected, with energy exceeding 2 quadrillion electron volts – that’s more than a million million times greater than the energy of a dental X-ray.

Not bad for a massless ghost particle.

Since then, teams across the world have been working to figure out where the hell this anomaly had come from. And now we might finally have a suspect.

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The Mystery Of How Easter Island Statues Got Their Colossal Hats Might Finally Be Solved

It’s a towering problem, one to stump the most determined of milliners. You’ve carved almost 1,000 immense statues standing up to 10 metres (33 ft) tall. And now you want to put their hats on.

There’s just one problem. The hats, like the graven colossi themselves, are hewn out of solid rock, and weigh several tonnes a piece. How on Earth could you ever lift and fit this hulking headwear?

This ancient puzzle is just one of many posed by the strange stone legacy of Easter Island, whose unflinching moai statues maintain their silent vigil long centuries after the mysterious collapse of the Polynesian Rapa Nui society that erected them.

Of the many questions that surround the island’s past, two tend to stand out,” explains anthropologist Carl Lipo from Binghamton University.

How did people of the past move such massive statues, and how did they place such massive stone hats (pukao) on top of their heads?

Researchers already solved the first part of the puzzle. For decades, archaeologists have experimented with various methods of ‘walking’ the moai – rocking replica statues from side to side along prepared paths, ever slowly inching the towering figures forward.

It’s kind of like shuffling a fridge into a new kitchen (although decidedly more epic).

But what about the world’s heaviest hats?

In a new study, Lipo and his team suggest that the cylindrical pukao – with diameters up to 2 metres (6.5 feet) and weighing 12 tonnes – may have been rolled across the island from the red scoria quarries they were cut from.

A diagram of how the pukao might have been placed.

That’s how they were transported to the moai, but to lift them onto the statues’ elevated heads, props – and a little physics trickery – would be needed, with a ramp-and-ropes technique called parbuckling.

The solution may seem simple in hindsight, but to show that the hypothetical rig would have been workable for Rapa Nui islanders required building detailed 3D models of 50 pukao and 13 red scoria cylinders found on the island, and calculating how the huge hats may have been pulled up the inclined ahu platforms.

“Transport equations based on Newtonian physics, human strength estimates, and estimates of moai height and pukao mass at four different ahu verify that pukao transport by rolling up a ramp is physically feasible with 15 or fewer people,” the researchers write, “even in the case of the most massive pukao (about 12 metric tonnes).”

This technique means it wouldn’t have required huge number of peoples or resources to construct and assemble the moai and pukao, which helps discredit the view that the Rapa Nui may somehow have helped destroy their own civilisation through overpopulation taxing the island’s natural resources.

And yet, for all that ingenuity and coordinated effort, most of the pukao are sadly no longer affixed to the moai heads.

Centuries of weather, erosion, and animal activity have seen the majority of these rock hats fall back to Earth, where they rest crumbled and damaged around the island surface – which is one of the reasons you rarely see this monumental headwear in photos of the iconic statues.

Something to think about next time your hat blows off on a windy day.

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Do Black Holes Die?

There are some things in the universe that you simply can’t escape. Death. Taxes. Black holes. If you time it right, you can even experience all three at once.

Black holes are made out to be uncompromising monsters, roaming the galaxies, voraciously consuming anything in their path.

And their name is rightly deserved: once you fall in, once you cross the terminator line of the event horizon, you don’t come out. Not even light can escape their clutches.

But in movies, the scary monster has a weakness, and if black holes are the galactic monsters, then surely they have a vulnerability. Right?

In the 1970s, theoretical physicist Stephen Hawking made a remarkable discovery buried under the complex mathematical intersection of gravity and quantum mechanics: Black holes glow, ever so slightly, and, given enough time, they eventually dissolve.

Wow! Fantastic news! The monster can be slain! But how? How does this so-called Hawking Radiation work?

Well, general relativity is a super-complicated mathematical theory. Quantum mechanics is just as complicated.

It’s a little unsatisfying to respond to “How?” with “A bunch of math,” so here’s the standard explanation: the vacuum of space is filled with virtual particles, little effervescent pairs of particles that pop into and out of existence, stealing some energy from the vacuum to exist for the briefest of moments, only to collide with each other and return to nothingness.

Every once in a while, a pair of these particles pops into existence near an event horizon, with one partner falling in and the other free to escape.

Unable to collide and evaporate, the escapee goes on its merry way as a normal non-virtual particle.

Here’s the thing: I don’t find that answer especially satisfying, either.

For one, it has absolutely nothing to do with Hawking’s original 1974 paper, and for another, it’s just a bunch of jargon words that fill up a couple of paragraphs but don’t really go a long way to explaining this behavior.

It’s not necessarily wrong, just…incomplete.

One way or the other, as far as we can tell, black holes do dissolve. I emphasize the “as far as we can tell” bit because, like I said at the beginning, generality is all sorts of hard, and quantum field theory is a beast.

Put the two together and there’s bound to be some mathematical misunderstanding.

But with that caveat, we can still look at the numbers, and those numbers tell us we don’t have to worry about black holes dying anytime soon.

A black hole with the mass of the sun will last a wizened 10^67 years. Considering that the current age of our universe is a paltry 13.8 times 10^9 years, that’s a good amount of time.

But if you happened to turn the Eiffel Tower into a black hole, it would evaporate in only about a day. I don’t know why you would, but there you go.

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Elon Musk Says We’re Probably Characters In Some Advanced Civilization’s Video Game

I don’t want to freak you out here, but there’s a chance you’re not the only ‘you’ in existence.

I’m not talking about the possibility that you might actually have two different brains, which means it’s virtually impossible to tell which one is ‘you’.

I’m talking about the fact that there could well be countless parallel universes, and each one contains a slightly different version of you.

Within that parallel universe construct, our own reality might not be as ‘real’ as you think. Are some of the most massive objects in our Universe nothing but holograms?

Is our Universe itself a hologram? Is this whole thing one giant simulation and we’re just characters in the most advanced video game ever? I swear I’m not high.

Everything I just mentioned is part of actual thought experiments that have been devised and debated over by the world’s best thinkers for years now, because one way or another, we have to make sense of this very strange and incredibly unlikely reality we’ve found ourselves in.

At Recode’s annual Code Conference this week in California, billionaire tech genius Elon Musk was asked about the possibility of us humans being unwitting participants in a giant simulation built by some alien civilization that’s far more advanced than our own.

His argument is pretty simple, if we look at our own history of video games. Forty years ago, video games meant stuff like Pong and Space Invaders.

Now we have photorealistic, three-dimensional stuff that looks like this, and we could have millions, potentially even billions, of people all playing the same game online at the same time.

Sure, there’s a certain ‘uncanny valley‘ quality to our video game counterparts right now, but think of what things are going to look like in another 40, or even 20 years’ time, with virtual and augmented reality already trying to inch its way into our living rooms.

Musk explains:

“If you assume any rate of improvement at all, then the games will become indistinguishable from reality, even if that rate of advancement drops by a thousand from what it is now. Then you just say, okay, let’s imagine it’s 10,000 years in the future, which is nothing on the evolutionary scale.

So given that we’re clearly on a trajectory to have games that are indistinguishable from reality, and those games could be played on any set-top box or on a PC or whatever, and there would probably be billions of such computers or set-top boxes, it would seem to follow that the odds that we’re in base reality is one in billions.”

It might not be the most comforting thing in the world to think about – our reality isn’t at all what we think it is – but Musk says all of this being one big video game is about the best option we could hope for, given the alternatives.

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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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How Physics Can Help You Achieve The Perfect Egg Crack

cracked egg

What’s the best way to crack an egg?

Physicists explain that we’re predisposed to hit the egg against a hard surface where the egg is flattest, or, its center, where its oblong shape widens; that’s the point at which an egg is weakest.

The egg puts up more of a fight at its round, arched ends. This curvature creates an even distribution of pressure, which may explain why it’s all but impossible to crack an egg when it’s held lengthwise between your fingers.

To game this correctly, then, you should create an initial crack in the center of your egg that opens a cavity small enough to fit your thumb through.


What comes next requires quick, careful precision: You expand this ripple ever so slightly with your hands so that the egg’s yolk tumbles out. Go too fast and the shell will collapse in your hands.

So, there you go. Now you’ve got some new vocabulary, borrowed from the wild world of fracture mechanics, to apply to a deceptively simple cooking act. If this registers as completely useless information, consider that egg-cracking is a difficult art to master for the less dexterous among us.

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The Physics Of Hitting A Baseball

Hitting the “sweet spot” is something that baseball players strive for. This is the location of the bat that is generally regarded as the best spot for hitting the ball.

It minimizes vibration of the bat and results in the maximum energy delivered to the ball, meaning it travels the farthest.

The “sweet spot” is a special point on the bat which minimizes stinging of the hands when the ball strikes there. Baseball players say that hitting the ball in this location “feels” the best, and results in the most solid hit.

If the baseball strikes outside of the sweet spot a painful stinging sensation is felt in the hands, due to bat vibration. In addition, this undesirable vibration reduces the energy that is delivered to the ball, so it doesn’t travel as far.

Here we are using physics to confirm what baseball players already know from experience.

It’s not easy to hit the sweet spot. For best results, contact with the ball must be made within 1/8″ of this special point. It is the main “good hit” criterion of players.

But it is one of the biggest challenges in Major League sports, where a round ball traveling at 90 mph has to hit a round bat swinging at 80 mph, at precisely this location.

The result is the ball flying off the bat at 110 mph, enough for a home run.

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