This week marks the 25th anniversary of a Nobel Prize winning discovery: the first image of the cosmic microwave background. This image showed the world what the universe looked like shortly after the big bang, and transformed cosmology. Reporter Davide Castelvecchi asks Nobel Laureate John Mather how the iconic image was taken, and investigates what the cosmic microwave background still has to teach us today.
This is a video version of an audio package produced for the Nature Podcast and broadcast on 26 April 2017. You can listen to the full podcast: here.
There are no uncharted lands waiting for ships to find their shores, and few if any untasted fruits waiting for human lips. Many grand mysteries of the Universe have been cracked open by science, from the makeup of matter on Earth to the nature of the stars in the sky. The child who marvels at the adventures of Magellan or wonders about how the Universe works might worry: What is left for me to discover?
While we have made tremendous strides in mapping the planet and the cosmos, there are still vast tracts of unexplored scientific territory. Much of life on Earth, from the ocean’s depths to the microbiome in our guts, remains unknown. And the largest cosmic questions are still unanswered: How big is the Universe? What is 95 percent of the Universe made of? What happened before the Big Bang? Why does time move only forward? Does space have more than three dimensions? Is there life beyond Earth?
Even the tiniest particles inside the atom hold perplexing puzzles that elude today’s greatest thinkers: Why do we have anti-matter? Why does every particle have two heavy cousins? How many particles are there? Is there a single tiny particle (or string) that makes up all of matter?
Almost certainly, intellectual revolutions await us. Thinking back before the past few centuries of progress in scientific understanding, we can wonder: what it was like for people to live in such ignorance about the scale of the Universe, our place within it, the quantum nature of reality, and our own evolutionary history? How can we take history’s greatest thinkers seriously when they were so oblivious to basic facts about the human situation? Future generations will almost certainly think the same of us, while snickering behind their hands at the primitive absurdities that today we believe unquestioningly, and dismissing the silly ideas that we build on top of our grand ignorance.
So when we teach science to children, we should certainly describe what we do know, but there should also be a strong emphasis on what we don’t know, to inspire the next generation of explorers.
As Adam Gopnik wrote in the New Yorker: “Every few weeks or so, in the Science Times, we find out that some basic question of the universe has now been answered—but why, we wonder, weren’t we told about the puzzle until after it was solved?” When we talk about science to the public, we need to explain what we have discovered, but we should also not be afraid to tout our ignorance. When we introduce the grand mysteries, we make the case for the importance of further exploration.
The next Magellan, tomorrow’s Einstein might be more inspired by our ignorance than by our discoveries.
The first memorial to come down was the Liberty Monument, an 1891 obelisk honoring the Crescent City White League.
Workers arrived to begin removing the statue, which commemorates whites who tried to topple a biracial post-Civil War government in New Orleans, around 1:25 a.m. in an attempt to avoid disruption from supporters who want the monuments to stay, some of whom city officials said have made death threats.
The workers inspecting the statue ahead of its removal could be seen wearing flak jackets and helmets. Police officers watched the area from atop the parking garage of a nearby hotel. Meanwhile, a handful of people opposed to the move held a vigil at the statue of Jefferson Davis, who was the president of the Confederacy during the Civil War.
New Orleans Mayor Mitch Landrieu has called the Liberty Monument "the most offensive of the four" to be taken down, adding it was erected to "revere white supremacy."
"If there was ever a statue that needed to be taken down, it's that one," he said in an interview Sunday with The Associated Press.
The Crescent City White League attempted to overthrow a biracial Reconstruction government in New Orleans after the Civil War. That attempt failed, but white supremacist Democrats later took control of the state.
An inscription added in 1932 said the Yankees withdrew federal troops and "recognized white supremacy in the South" after the group challenged Louisiana's biracial government after the Civil War. In 1993, these words were covered by a granite slab with a new inscription, saying the obelisk honors "Americans on both sides" who died and that the conflict "should teach us lessons for the future."
Three other statues to Confederate Generals Robert E. Lee and P.G.T. Beauregard and Confederate States of America President Jefferson Davis will be removed in later days now that legal challenges have been overcome.
The removals are "about showing the whole world that we as a city and as a people are able to acknowledge, understand, reconcile — and most importantly — choose a better future," Landrieu said in a statement released by his office. "We can remember these divisive chapters in our history in a museum or other facility where they can be put in context — and that's where these statues belong."
Nationally, the debate over Confederate symbols has become heated since nine parishioners were killed at a black church in South Carolina in June 2015. South Carolina removed the Confederate flag from its statehouse grounds in the weeks after, and several Southern cities have since considered removing monuments. The University of Mississippi took down its state flag because it includes the Confederate emblem.
New Orleans is a majority African-American city although the number of black residents has fallen since 2005's Hurricane Katrina drove many people from the city.
The majority black City Council in 2015 voted 6-1 to approve plans to take the statues down, but legal battles over their fate have prevented the removal until now, said Landrieu, who proposed the monuments' removal and rode to victory twice with overwhelming support from the city's black residents.
People who want the Confederate memorials removed say they are offensive artifacts honoring the region's slave-owning past. But others call the monuments part of the city's history and say they should be protected historic structures.
Robert Bonner, 63, who said he is a Civil War re-enactor, was there to protest the statue's removal.
"I think it's a terrible thing," he said. "When you start removing the history of the city, you start losing money. You start losing where you came from and where you've been."
Since officials announced the removals, contractors hired by the city have faced death threats and intimidation in this deep South city where passions about the Civil War still run deep.
Landrieu refused to say who the city would be using to remove the statues because of the intimidation attempts. And the removal will begin at night to ensure police can secure the sites to protect workers, and to ease the burden on traffic for people who live and work in the city, Landrieu said.
"All of what we will do in the next days will be designed to make sure that we protect everybody, that the workers are safe, the folks around the monuments are safe and that nobody gets hurt," Landrieu said.
Landrieu said the memorials don't represent his city as it approaches its 300th anniversary next year. The mayor said the city would remove the monuments, store them and preserve them until an "appropriate" place to display them is determined.
"The monuments are an aberration," he said. "They're actually a denial of our history and they were done in a time when people who still controlled the Confederacy were in charge of this city and it only represents a four-year period in our 1,000-year march to where we are today."
WASHINGTON — Astronomers have found yet another planet that seems to have just the right Goldilocks combination for life: Not so hot and not so cold. It’s not so far away, either.
This new, big, dense planet is rocky, like Earth, and has the right temperatures for water, putting it in the habitable zone for life, according to a study published Wednesday in the journal Nature.
It’s the fifth such life-possible planet outside our solar system revealed in less than a year, and still relatively near Earth. Rocky planets within that habitable zone of a star are considered the best places to find evidence of some form of life.
The first planet outside our solar system was discovered in 1995, but thanks to new techniques and especially NASA’s planet-hunting Kepler telescope, the number of them has exploded in recent years. Astronomers have now identified 52 potentially habitable planets and more than 3,600 planets outside our solar system.
The latest discovery, called LHS 1140b, regularly passes in front of its star, allowing astronomers to measure its size and mass. That makes astronomers more confident that this one is rocky, compared with other recent discoveries.
In the next several years, new telescopes should be able to use the planet’s path to spy its atmosphere in what could be the best-aimed search for signs of life, said Harvard astronomer David Charbonneau, a co-author of the study. If scientists see both oxygen and some carbon in an atmosphere, that’s a promising sign that something could be living.
Outside astronomers have already put this new planet near the top of their must-see lists for new ground and space-based telescopes.
‘‘This is the first one where we actually know it’s rocky,’’ Charbonneau said. ‘‘We found a planet that we can actually study that might be actually Earth-like.’’
Make that super-sized, because it belongs to a class of planets called super-Earths that are more massive than Earth but not quite the size of giants Neptune or Jupiter.
Compared with Earth, the new planet is big, pushing near the size limit for rocky planets. It’s 40 percent wider than Earth but it has 6.6 times Earth’s mass, giving it a gravitational pull three times stronger, Charbonneau said. A person weighing 167 pounds would feel like 500 pounds on this planet.
While many super-Earths are too big to have the right environment for life, 1140b is just small enough to make it a good candidate. Thirty-two of the potentially habitable planets found so far are considered super-Earth sized.
The new planet was found using eight small telescopes in Chile and help from an amateur planet-hunter, Charbonneau said.
In the constellation Cetus, it is 39 light years or 230 trillion miles away. So are a group of seven mostly Earth-sized planets in or near the habitable zone found circling a star called Trappist-1 earlier this year, but it in a different direction. And in August, astronomers found that the nearest planet to Earth outside our solar system, only 25 trillion miles away, also could have the right temperature for life, but astronomers can’t get a peek at its atmosphere.
‘‘If you picture the Milky Way as the size of the United States, then these systems are all within the size of Central Park,’’ Charbonneau said. ‘‘These are your neighbors.’’
The latest discoveries have their founders at odds over which of the planets are the most promising. Charbonneau said recent studies show that the Trappist planets may not be rocky like Earth, while Trappist discoverer Michael Gillon said the newest planet has such intense gravity that its atmosphere may be smooshed down so telescopes can’t get a good look at it.
Seven outside astronomers said the Milky Way is big enough for all the discoveries to be exciting, requiring more exploring.
Yale astronomer Greg Laughlin, who wasn’t part of any of the teams, praised all the new findings but said the Trappist planets seem too light and the new one too dense for his taste. ‘‘I wouldn’t book a trip to any of these planets,’’ he said.
Galaxy formed like a firecracker in just 100 million years at start of cosmic time
The 'red and dead' galaxy had three times more stars than our Milky Way today
This discovery sets a new record for the earliest massive red galaxy
Astronomers have discovered a massive, inactive galaxy from a time when the Universe was only 1.65 billion years old.
Within a short time period this massive galaxy formed all its stars through an extreme star-burst event, researchers found.
But it stopped forming stars only a billion years after the Big Seed, to become a quiescent or 'red and dead' galaxy – the first found to exist at this ancient epoch.
An international team of astronomers found the 'monster' galaxy which has 300 billion stars crammed into a region of space about the same size as the distance from the Sun to the nearby Orion Nebula.
Astronomers expect most galaxies from this epoch to be low-mass minnows, busily forming stars, but this galaxy, known as ZF-COSMOS-20115, stayed as an inactive super galaxy.
'This discovery sets a new record for the earliest massive red galaxy', said Professor Glazebrook, Director of Swinburne's Centre for Astrophysics and Supercomputing, who led the team.
'This huge galaxy formed like a firecracker in less than 100 million years, right at the start of cosmic history', he said.
'This fast life and death so early in the Universe is not predicted by our modern galaxy formation theories'.
Until recently, models suggested dead galaxies or 'red nuggets' such as this should only exist from around three billion years after the Big Bang.
'It quickly made a monstrous object, then just as suddenly it quenched and turned itself off. As to how it did this we can only speculate', said Dr. Glazebrook.
Astronomers used the W M Keck telescopes in Hawaii to find these galaxies.
They took deep spectra at near-infrared wavelengths to find the presence of old stars and a lack of active star formation.
'It is an incredibly rare find that poses a new challenge to galaxy evolution models to accommodate the existence of such galaxies much earlier in the Universe', said Dr. Glazebrook.
Astrophysicists are still debating just how galaxies stop forming stars.
This research builds on an earlier study that suggested such dead galaxies could exist based on finding dim red objects in extremely deep near-infrared images.
'We used the most powerful telescope in the world, but we still needed to stare at this galaxy for more than two nights to reveal its remarkable nature,' co-author Professor Vy Tran, from Texas A&M University said.
'By collecting enough light to measure this galaxy's spectrum, we decipher the cosmic narrative of what stars and elements are present in these galaxies and construct a timeline of when they formed their stars,' Dr. Tran said.
For the first time, scientists have detected an atmosphere around a planet beyond our solar system that's just a little bit larger than Earth.
The exoplanet GJ 1132b, which orbits the dwarf star GJ 1132, is located about 39 light-years away from Earth. It has a radius about 1.4 times that of Earth and is 1.6 times Earth's mass, according to the new study. When the planet was first discovered, researchers called it a potential Venus twin because it's a rocky world with a very high surface temperature — and now, they've found that the planet and Venus might have a thick atmosphere in common, too (although it would have a different composition).
While observers have pinpointed atmospheres around much larger, Jupiter-like gas giants orbiting other stars — and a larger super-Earth, about eight times Earth's mass — this is the first evidence of an atmosphere around an exoplanet that's near Earth's size, the study's researchers said. Researchers can use planets' atmospheres to try and determine if these worlds are suitable for life as we know it on Earth, or even to identify potential traces of life recorded there.
"While this is not the detection of life on another planet, it's an important step in the right direction: The detection of an atmosphere around the super-Earth GJ 1132b marks the first time that an atmosphere has been detected around an Earth-like planet other than Earth itself," John Southworth, a researcher at Keele University in the United Kingdom and first author on the new work, said in a statement from the university.
The astronomers captured images of the planet's star using a telescope at the European Southern Observatory (ESO) in Chile. The researchers measured the star system with seven different wavelengths and used small dips in the star's brightness to determine the radius of the planet passing by during its 1.6-day orbits, according to a statement from the Max Planck Institute for Astronomy, which collaborated on the research. They were able to further clarify the planet's radius.
But the researchers also found something strange, they said: One of the wavelengths showed a larger dip in brightness than the others each time the planet passed by. This world, for some reason, appeared larger at that wavelength than at others, suggesting that the planet had a surrounding atmosphere that this wavelength couldn't penetrate, the researchers said.
While Earth's atmosphere is mostly nitrogen with a large oxygen component, and Venus' is a thick shroud of carbon dioxide, the researchers said that GJ 1132b's atmosphere is likely rich in water vapor or methane, based on their measurements. (It could be "a 'water world' with an atmosphere of hot steam," Southworth said.)
Going forward, GJ 1132b's atmosphere will be a high-priority target for study with the Hubble Space Telescope, ESO's Very Large Telescope and the future James Webb Space Telescope, launching in 2018, the researchers added.
The German cabinet has backed proposals to hit social media firms with fines of up to €50 million if they fail to promptly remove illegal hate speech from their platforms — within 24 hours after a complaint has been made for 👉 “obviously criminal content”, 👈 and within seven days for other illegal content.
The draft law would also see individuals from companies facing fines of up to €5M for any criminal content removal failures.
In a statement today [translated via Google Translate], German Justice Minister Heiko Maas said: “The providers of social networks are responsible when their platforms are abused to spread hate criminality and criminal false news. There can be just as little space on social networks for criminal acts as on the street. To do better, we owe the victims of hate criminality. The Internet is characterized by the debate culture and the social climate in our country. Verbal radicalization is often the precursor to physical violence.”
Germany has specific hate speech laws which criminalize certain types of speech, such as incitement to racial violence. But Maas is also agitating for a European-level approach to tackling the spread of hate speech by online platforms, saying now that he will present the government’s proposals for regulation to colleagues in the European Council of Justice and Home Affairs Ministers.
“We want to continue the process at European level,” he said.
The EU currently has 28 Member States, including Germany, and in May last year its executive body, the European Commission, unveiled a code of conduct for handling hate speech on social platforms, securing agreement on this initiative from Facebook, Twitter, Google and Microsoft. It remains to be seen whether the EC will feel the need to push for a tougher stance across the region.
The German government has been cranking up the pressure on social media companies to tackle a surge in hate speech sentiments spreading via their platforms for several years now, following the refugee crisis in Europe.
In December 2015 it secured an agreement from Facebook, Google and Twitter they would delete hate speech on their platforms within 24 hours. But it’s been unhappy with their performance — calling out Facebook and Twitter for poor complaint handling earlier this month, when it also proposed the new law that’s now been approved by the cabinet.
The government is clearly hoping the threat of fines will enforce better handling of complaints and faster removal of illegal content than political pressure and verbal agreements from social media giants to ‘do more’ has thus far achieved.
A recent analysis of the performance of the three firms at handling hate speech complaints in Germany, conducted by local youth protection organization jugendschutz.net, found that Facebook only deleted 39 per cent of reported criminal content, while Twitter only removed one in a hundred reported messages. (Although Facebook disputed those results — saying its own analysis showed it was performing better.)
Google was judged to have faired better at swiftly nixing hate speech from its social sharing platform YouTube. (Although the company has recently faced a separate backlash from advertisers concerned that their marketing messages are ending up alongside extremist content.)
Maas said today the cabinet backing for the draft law paves the way for it to be adopted in Germany within the current legislative period.
We’ve reached out to Facebook, Twitter and Google for comment and will update this story with any response. Update: A Facebook spokesperson has now provided the following statement: “We work very hard to remove illegal content from our platform and are determined to work with others to solve this problem. As experts have pointed out, this legislation would force private companies rather than the courts to become the judges of what is illegal in Germany.”
Facebook previously told us it will have more than 700 people working on content review for it in Berlin by the end of the year, adding: “We are committed to working with the government and our partners to address this societal issue.”
On the fake news front, the company has been trialling new tools to flag disputed content in Germany since January, as well as working with a local third party fact checking organization.
Twitter has also made recent changes aimed at reducing the spread of abusive content on its platform — which a spokesman previously told us may not have been in place at the time jugendschutz.net was monitoring its performance.
