Category: Space & Physics

The Demise of a Discovery: BICEP2 and Gravitational Waves

By Sarah Scoles | February 2, 2015 11:28 am
The BICEP2 telescope at twilight. Credit Steffen Richter, Harvard University

The sun sets on the BICEP2 telescope in Antarctica. Credit Steffen Richter, Harvard University

Last week, BICEP2 scientists — who in March announced evidence of cosmic inflation, a potentially Nobel-worthy find — threw handfuls of dust on the grave of their own results. The official paper [pdf], just published on the BICEP website, tells the story of how they mistook cosmic dust for “primordial gravitational waves,” and why everybody needs to calm down and stop trying to bury inflation, too.

What’s inflation?

Just 10-35 seconds after the Big Bang, cosmologists (or at least most of them) believe the universe expanded in hyperdrive — faster than it ever has since and faster than it ever will again. This ballooning, called inflation, smoothed everything out. It turned the cosmos into the roughly homogenous place we see today, and perhaps created other universes that add up to the sci-fi-sounding “multiverse.”

But it’s difficult to find direct evidence that inflation actually happened (after all, it was a long time ago). That’s where B-modes, which the BICEP2 team saw, come in.

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CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: Big Bang, cosmology

BICEP2 Was Wrong, But Publicly Sharing the Results Was Right

By Shannon Hall | January 30, 2015 3:58 pm
This Planck image shows that dust emission is strongest along the plane of the Galaxy, in the upper part of the image, but that it cannot be neglected even in other regions of the sky. Credit: ESA/Planck Collaboration

This Planck image shows that dust emission is strongest along the plane of the galaxy, in the upper part of the image, but that it cannot be neglected even in other regions of the sky. Credit: ESA/Planck Collaboration

The claim made headlines worldwide, hailing one of the biggest scientific discoveries in decades. After 35 years of research, astronomers said in March, they had found evidence that the universe underwent a brief but ultra-fast expansion when it was roughly a trillionth of a trillionth of a trillionth of a second old. The research team could see a Nobel Prize looming in the distance. So they popped bottles of bubbly in celebration and shared their excitement with the world.

But results confirmed today indicate that the fizz has long gone out of those findings. A second team of astronomers, which includes the initial BICEP2 team itself, used the European Space Agency’s Planck satellite to show that the twisting patterns did not come from the cosmic microwave background at all. They’re nothing but swirling patterns of dust.

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CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: Big Bang, cosmology

What Does Space Sound Like?

By Trevor Cox | January 28, 2015 3:40 pm

earth from space

“Space, the final frontier,” announces James T. Kirk at the start of the first Star Trek episode. As the spaceship Enterprise flies past the screen, the voice sounds as though it was recorded in a very reverberant cathedral. I know space is a big place, but where are the reflections meant to be coming from? And anyway, space is silent or, to quote the catchy tag line from the 1979 movie Alien, “in space, no one can hear you scream.”

For an astronaut unfortunate enough to be caught outside the spaceship without a space suit, screaming to occupy the moments before asphyxiation would be pointless, as there are no air molecules to carry the sound waves. But Hollywood does not let anything as trivial as physics get in the way of a compelling soundtrack. The latest Star Trek film showed the outside of the soaring Enterprise accompanied by lots of powerful engine noises; the photon torpedoes sounded pretty impressive as well.

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CATEGORIZED UNDER: Space & Physics, Top Posts

Where Will We Live After Earth?

shutterstock_164724506

This article originally appeared on The Conversation.

Some climatologists argue it may be too late to reverse climate change, and it’s just a matter of time before the Earth becomes uninhabitable – if hundreds of years from now. The recent movie Interstellar raised the notion that we may one day have to escape a dying planet. As astrophysicists and avid science fiction fans, we naturally find the prospect of interstellar colonization intriguing and exciting. But is it practical, or even possible? Or is there a better solution?

Science fiction has painted a certain picture of space travel in popular culture. Drawing on stories of exploration from an age of tall ships, with a good helping of anachronisms and fantastical science, space exploration is often depicted in a romantic style: a crew of human travelers in high-tech ships wandering the galaxy, making discoveries and reporting back home. Perhaps they even find habitable words, some teeming with life (typically humans with different-colored skin), and they trade, colonize, conquer or are conquered. Pretty much, they do as humans have always done since the dawn of their time on Earth.

How closely do these ideas resemble what we may be able to achieve in the next few hundred years? The laws of physics and the principles of engineering will go a long way to helping us answer this question.

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MORE ABOUT: space exploration

The “Pillars of Creation” Have Been, Are Being, and Will Be Destroyed

By Sarah Scoles | January 6, 2015 12:00 pm

pillars of creation

The “Pillars of Creation,” a photograph of part of the Eagle Nebula, is one of the most iconic images ever taken by the Hubble telescope. Yesterday, astronomers released a bigger, better, sharper version of the pillars, taken almost two decades after the first.

But an ironic twist – and what we didn’t know twenty years ago – is that the Pillars might have been long ago torn apart by a distant explosion. The photos we snap of them today are high-tech and modern but their subject is clouded by thousands of light-years of remove. Like the post-mortem photography of the Victorian era, the resulting images are lifelike, and beautiful, and sad.

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CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: stars

Three Totally Mind-bending Implications of a Multidimensional Universe

By David Warmflash | December 4, 2014 1:38 pm
universes

Image by Juergen Faelchle / Shutterstock

Nearly a century ago, Edwin Hubble’s discovery of red-shifting of light from galaxies in all directions from our own suggested that space itself was getting bigger. Combined with insights from a handful of proposed non-Euclidean geometries, Hubble’s discovery implied that the cosmos exists in more than the three dimensions we’re familiar with in everyday life.

That’s because parts of the cosmos were moving further apart, yet with no physical center, no origin point in three-dimensional space. Just think of an inflating balloon seen only from the perspective of its growing two-dimensional surface, and extrapolate to four-dimensional inflation perceived in the three-dimensional space that we can see. That perspective suggests that three-dimensional space could be curved, folded, or warped into a 4th dimension the way that the two dimensional surface of a balloon is warped into a 3rd dimension.

We don’t see or feel more dimensions; nevertheless, theoretical physics predicts that they should exist. Interesting, but are there any practical implications? Can they become part of applied physics?

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CATEGORIZED UNDER: Space & Physics, Top Posts

If Mars Once Hosted Life, How Would We Know?

By Sarah Scoles | November 5, 2014 9:00 am

mars

Despite a few press-stopping false alarms and a long-standing sci-fi fascination, there’s no evidence of biology — microscopic, trilobitish, or creepily humanoid — on Mars.

But that hasn’t stopped the Curiosity rover from running around saying “This spot would have been habitable” and “That spot definitely has water.” And it hasn’t stopped astronomer Nathalie Cabrol from searching for the ever-elusive “biosignatures”: evidence, like geological graffiti, that proclaims “LIFE WUZ HERE.”

But it isn’t as easy as finding a spray-painted tag. First of all, the life almost certainly isn’t alive anymore. And second of all, it probably hasn’t been alive for a long time. Around 3.5 billion years ago, Mars changed from being a relatively nice place into the frozen radiation-zapped desert it is today. It was never San Juan, but it does seem to have had a milder climate, water oceans, and a thick, protective atmosphere. If this young sub-Caribbean Mars was home to life, that life may have left its mark. The problem is that we aren’t totally sure what that mark might look like.

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CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: Mars

What It Was Like to Capture the Hubble Space Telescope

By K. Megan McArthur | November 3, 2014 10:00 am
astronaut Megan McArthur in the 3rd floor suit-up facility (located in the O&C building) about four hours from launch: 11 May 2009

Astronaut Megan McArthur in the suit-up facility about four hours from launch, 11 May 2009. Image by Michael Soluri, Infinite Worlds

It’s a beautiful October morning in Houston, but I am grumpy and bleary-eyed as I make my way into Mission Control. I’ve just come off a string of Orbit 1 shifts (midnight to 0800) working as CAPCOM in the International Space Station Mission Control Center. (CAPCOM is the call sign for the astronaut on the ground who speaks to the crews that are in space.) Now I’ve slam-shifted back to daylight hours to work as CAPCOM during a simulation of the rendezvous planned for an upcoming shuttle mission.

I see my friend Ray J in the parking lot, and he waves me over. Ray J is a pilot in the astronaut class ahead of mine. We’ve flown dozens of training flights together in the T-38, and he is a good friend and mentor. And he is always smiling, even at 0645. We chat for a minute, which mainly involves me complaining about my schedule, and then he asks, “So, have you talked to Scooter lately?” I raise my eyebrows at him. Scooter is way senior to me, a flown guy, a space shuttle commander. Of course I haven’t talked to Scooter. Scooter sometimes stops by the office I share with Mike Massimino because they flew on the last Hubble mission together, but it’s not like he’s coming there to shoot the breeze with me. So I say, “No. Why do you ask?” “Oh,” says Ray J nonchalantly, “I was just wondering how he’s doing.”

That was weird, I think as I head into Mission Control. But then I forget all about it and spend the next ten hours working the simulation. That evening, as I’m propped up on the couch at home trying to stay awake until a reasonable bedtime, my phone rings. It’s Steve Lindsey, the chief of the Astronaut Office. This is definitely weird. Why is he calling me at home? This can’t be good.

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CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: space exploration

What It Will Take to Become an Interstellar Civilization

By Sarah Scoles | October 28, 2014 1:07 pm

starship

The new movie “Interstellar” is set in a not-so-distant future, but distant enough that they’ve managed to build something still elusive in 2014: a spaceship that can travel between solar systems. Such starships have been a technological mainstay in science fiction for decades, but they remain a crazily complicated proposition in everything from propulsion to human reproduction.

Still, that hasn’t stopped researchers from trying. Last month, a bunch of rocket scientists, microbiologists and entrepreneurs gathered in Houston’s George R. Brown Convention Center to discuss—in level and serious tones—how to become a spacefaring civilization. The meeting is called the 100-Year Starship symposium, and it’s brought brains together once a year since 2011 to figure out what we need to do now if we want to have an interstellar spacerocket a century from now.

The group has made progress defining the challenges and pointing their noses toward solutions, but much work remains (like, say, building a starship). To quote Contact, it “sounds less like science and more like science fiction.”

Nonetheless, the 100-Year Starship adherents—backed by NASA and the Defense Advanced Research Projects Agency (DARPA)—keep plugging away. At their most recent gathering, 7 major hurdles emerged from their three days of discussion. Read More

CATEGORIZED UNDER: Space & Physics, Top Posts

How Close Are We to Star Trek Propulsion?

By David Warmflash | September 17, 2014 8:30 am

warpdrive

It’s popular to talk about how the original Star Trek, set in the 23rd century, predicted many devices that we’re using already here in 2014. It started with communicators that manifested as flip-open cell phones that many already consider too primitive, moved through computers that talk and recognize human voices and provide instant translation (all of which are constantly improving), to medical applications such as needle-free injection, anti-radiation drugs, and a medical tricorder.

But looking at the more exotic Star Trek technologies, it’s harder to find credible reports that we’re close to a Trek-like world. This is true for Star Trek’s transporter: Despite some success in “quantum teleportation,” which could have applications for computers and possibly communication technology, no experts are saying that this is about to lead to a technology for beaming humans or any other objects from place to place.

It’s also true for space travel. Star Trek depicted a world where people would move between planets and star systems (at least nearby systems) frequently and very swiftly. The United Federation of Planets contains worlds separated by dozens of light-years, which ordinary Earthlings regularly traverse over time periods measured in days to weeks.

Clearly that’s one aspect of Star Trek technology that is far from being a reality in the present day. But the topic isn’t just in the realm of sci-fi: Scientists are taking various approaches to try to create the next generation of space propulsion, beyond the chemical rockets that require most of the mass of the ship to be fuel.

If we want spaceflight to become routine for humans as aviation did, we’ll need major innovations. Are any just around the corner?

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CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: space exploration
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