The charge applies to every new plastic bag used at large stores in England – but only shops or chains with 250 or more full-time employees.
BBC political correspondent Ben Wright said there would be a consultation on extending the 5p charge in England.
Chris Noice from the Association of Convenience Stores welcomed the government’s plans as being “good for the environment and good for the retailers taking part”.
He told BBC Radio 4′s Today programme that “approval for carrier bag charging is now very high” among the association’s 33,500 members, and more than a third of the shops it represents have already adopted the idea voluntarily.
He said: “There was a bit of an adjustment period when the initial legislation came in in England. But everyone is pretty comfortable with it now.”
Plastic bags at airport shops or on board trains, planes or ships are currently not included, and neither are paper bags.
More broadly, Prime Minister Theresa May said the government would take a stand against the “profligate” use of natural resources with its 25-year plan.
Last week, she said 50 million trees would be planted in a “Northern Forest” stretching along the M62 corridor between Liverpool and Hull over the coming 25 years, to boost natural habitats and give people access to more woodland.
Fewer than one in 10 engineers in the UK are female – the lowest percentage in Europe, according to the Women’s Engineering Society. Latvia, Bulgaria and Cyprus lead with nearly 30%. Here, two pioneering female engineers at Oxford University explain what drives them.
Priyanka Dhopade was named as one of the top 50 Women in Engineering Under 35 in 2017, as chosen by the Women’s Engineering Society. She grew up in Canada, where she studied for a degree in aerospace engineering. She completed a PhD at Monash University in Melbourne before moving to Oxford in 2013.
As a child I was very interested in aeroplanes, and how things fly in space – I wanted to be an astronaut. My parents suggested engineering, because it’s quite practical. I could use my enthusiasm and my skills to do something that’s real that matters.
My research looks at the thermodynamics and the fluid dynamics of jet engine internal flows. I do a lot of computational fluid dynamics to look at the transfer of heat inside an engine and use those predictions to help design innovative cooling systems for modern jet engines. What that does is it helps to make the engine more efficient and safer as well, and reduces the environmental impact in terms of emissions and fuel consumption. If we help to make jet engines more efficient, that’s going to have a huge environmental impact.
Not just hard hats
The stereotype of an academic is someone who sits at their desk and doesn’t talk to anybody and just scribbles away in their notebook. But I talk to so many experimentalists and work with them to help design these massive test facilities so that we can look at different aspects of the jet engine. I work with industry sponsors and get their input on the real problems that they are facing. I spend some time on the computer as well. I think that’s also another thing that people don’t realise, that in our modern digital world – engineering, a lot of it, is computer-based. It’s not about wearing a hard hat and being on-site – although those roles are still available for those who are attracted to them.
I try not to think about it on a daily basis because I’m quite busy and I’m doing interesting things, but, occasionally, I look around and see that I’m the only woman in the room full of 30 or 40 men and I do find it a bit odd. The cultural, historical connotations of engineering, particularly in Britain, seem to be quite different from other countries, certainly in the culture that I grew up in, which is South Asian. The connotation of an engineering career is something quite prestigious, and boys and girls are encouraged to do it, because it’s seen as a stable, rewarding career, financially as well. So I find it a bit odd coming to Britain and seeing that people aren’t as enthusiastic – it’s not as prestigious or as respected a profession. And, not seeing enough women doing it – it breaks my heart.
I think there’s so many problems that need to be solved and the problems are quite diverse, so the solutions also need to be diverse. We need to be involving as many different members of society as possible, not just women but also different ethnicities and different socioeconomic classes and disabilities – it has to be a combined effort. Making parents and teachers aware that engineering is an interesting, rewarding, successful career choice for girls would go a long way towards increasing the intake of girls. But, at the same time, we have to do things to improve the environment for when they do become engineers.
My earliest role model was my dad, who was a mechanical engineer. Growing up I didn’t really have any other engineering role models but when I became a graduate student and started to feel more and more that I was a minority in terms of gender, I started to seek out role models. Now I know all of these amazing female engineers who are definitely huge role models to me, like Dame Ann Dowling, Professor Eleanor Stride at Oxford and Professor Alison Nobel at Oxford. I think they don’t get as much visibility as they deserve. For young girls to look up to someone like Dame Ann Dowling and say, ‘I want to be like her’ – that would make such a huge difference.
Gladys Ngetich grew up in Kenya, where she studied engineering. She came to Oxford as a Rhodes Scholar, and is now studying for her PhD.
My father was an engineer in Kenya. During holidays he would come home with spanners and engineering tools trying to fix things here and there. I think I was introduced to that engineering environment when I was very young.
I’m looking at improving or coming up with new efficient advanced cooling technologies for jet engines. We are filing a patent. That’s actually one of my dreams. To work and to come up with something which is significant, that is going to have uses in the world in terms of making intercontinental travel safe and efficient so we use less fuel, we have less emissions, and just generally helping people all over the world.
Filing a patent
Aerospace is male-dominated. Personally, it’s not been a big problem for me because I was born after four boys and so most of my childhood I spent with boys. I’ve had role models all through my levels of education – grammar school, high school, undergrad and now in Oxford. I think my biggest role model is my supervisor. He’s helped me to write a paper and file a patent. I feel I have already achieved more than I was expecting. In five years, I’m not sure where I will be, but it will either be industry, maybe in Oxford, or I will be teaching.
Gov Scott is reportedly planning to run for an open US Senate seat.
What does the decision mean?
It means some of the Gulf of Mexico on Florida’s western coast will be exempt from drilling, but not all of it.
Florida state waters extend three nautical miles from the shore on the Atlantic, and nine nautical miles on the Gulf side, according to the National Oceanic and Atmospheric Administration (NOAA).
What happens now?
“Such a quick reversal begs the question: Will the Trump administration give equal consideration to all the other coastal governors from both parties who overwhelmingly reject this radical offshore drilling plan?” asked Diane Hoskins, director of the Oceana campaign group, according to Reuters news agency.
Maryland, South Carolina and Massachusetts are among states with Republican governors also known to oppose the Draft Five Year Outer Continental Shelf Oil and Gas Leasing Programme (2019-2024).
California’s attorney general was among several public figures who demanded similar exemptions for their states:
Both the scale and the nature of the plan have attracted criticism – including from a coalition of 60 environmental groups, nearly a dozen attorneys general and more than 100 US lawmakers.
It opens up more than 90% of the national outer continental shelf (OCS) for development – making more than 98% of undiscovered, technically recoverable oil and gas resources in federal offshore areas available to private companies.
At the moment, 94% of the OCS is protected.
Industry regulation was tightened by Barack Obama in the aftermath of BP’s Deepwater Horizon oil spill in the Gulf of Mexico in 2010 – a disaster still fresh in many minds.
Even the Department of Defense has concerns – about how drilling will interact with the military exercises held in the eastern Gulf of Mexico, reports Reuters.
A discovery by citizen scientists has led to the confirmation of a system of five planets orbiting a far-off star.
Furthermore, the planets’ orbits are linked in a mathematical relationship called a resonance chain, with a pattern that is unique among the known planetary systems in our galaxy.
Studying the system could help unlock some mysteries surrounding the formation of planetary systems.
The results were announced at the 231st American Astronomical Society meeting.
The system was found by astronomy enthusiasts using Zooniverse, an online platform for crowdsourcing research.
“People anywhere can log on and learn what real signals from exoplanets look like, and then look through actual data collected from the Kepler telescope to vote on whether or not to classify a given signal as a transit, or just noise,” said co-author Dr Jesse Christiansen, from Caltech in Pasadena.
Since the discovery of four planets in this system was announced last year, Dr Christiansen has been working to shed further light on this distant planetary neighbourhood, dubbed K2-138. This led to the discovery of the fifth planet and hints of a sixth.
All the worlds are a bit bigger than our own planet, ranging between 1.6 and 3.3 times the radius of Earth.
The collected findings have now been accepted for publication in the Astrophysical Journal.
The raw data used in the discovery was provided by Nasa’s Kepler space telescope, which identifies potential planets around other stars by looking for dips in the brightness of those stars when planets pass across their face – or transit them.
Links in a chain
Being in a resonance chain means each planet takes almost 50% longer to orbit the star than the next planet further in.
Intriguingly, the sixth planet skips two slots in that resonance chain – taking much longer to orbit the star than it should if it was simply the next planet up from number five.
“If you keep going with the resonance chain, you skip 19 days, you skip 27 days and you end up at about 43 days,” said Dr Christiansen.
“That’s a really tantalising clue that we may be missing more planets in this system. If this chain continues, there’s a gap.”
It’s not the only system to exhibit resonances. The orbital motions of seven planets in the Trappist-1 system are linked in a complex chain. In the time that it takes for the innermost planet to make eight orbits, the second, third and fourth planets revolve five, three and two times around the star, respectively.
But the way the chain is configured in K2-138 is different to Trappist-1 and unique among exoplanetary neighbourhoods. The near-resonant chain in Trappist-1 is thought to have formed as the planets migrated inwards toward their parent star after formation, early in the system’s history.
So K2-138 could yield further clues to the process by which planets form and then migrate from their original positions. This is a particularly contested area, with several competing ideas.
“Some current theories suggest that planets form by a chaotic scattering of rock and gas and other material in the early stages of the planetary system’s life. However, these theories are unlikely to result in such a closely packed, orderly system as K2-138,” said Dr Christiansen.
“What’s exciting is that we found this unusual system with the help of the general public.”
The small, low-cost UK mission was one of 31 payloads riding on the Indian Polar Satellite Launch Vehicle.
It lifted off from the Satish Dhawan spaceport in Andhra Pradesh.
Controllers made first contact with the UK satellite as planned within a few hours.
The spacecraft is a pre-production model. If it performs well over the coming months, its manufacturer, SSTL, also in Guildford, will proceed with Earth-i’s first batch of five operational spacecraft.
The contract for these platforms was signed in November.
Start-up’s radical space radar solution
US firm picks UK for weather satellites
Mega-constellation production begins
The forthcoming constellation – which will be known as Vivid-i – will be the first of its kind to provide hi-def, full-colour video.
Short movies of the Earth’s surface have been acquired from orbit before, but not on the envisaged scale.
The demonstrator will circle the globe at an altitude of 505km.
It has the ability to point and stare at a particular location. It can take a still picture or gather two-minute movie sequences.
“We can collect up to 50 frames per second which is a lot of information,” explained Earth-i CEO Richard Blain.
“That allows us to stack the individual images and increase our effective resolution, achieving somewhere around 65cm to 75cm,” he told BBC News.
This is more than sharp enough to see moving objects like cars and ships. Image analysts could use such views to monitor and model traffic flow around cities, and in and out of ports.
But the system can also be configured to generate slightly offset images of a target which can then be assembled into 3D models of surface elevation.
This approach could be used to make urgent maps for relief teams entering an earthquake disaster zone, for example.
However, the key capability being sought by Earth-i is frequent re-visits to locations.
Detecting changes in near real-time is expected to be a burgeoning market for space data and this is only possible when you have a train of spacecraft constantly passing overhead.
At the moment, Earth-i’s plan is to put up additional batches of five spacecraft every year or so after the initial quintet have been launched at the end of 2019.
With a 15-satellite constellation, Earth-i could image a particular place at least three times a day, cloud permitting.
Networks of satellites are all the vogue at the moment.
Indeed, on Friday’s PSLV flight there were two other fascinating demonstrators that will trial technologies for future space constellations.
One of these, the Phase 1 LEO satellite, was also manufactured by SSTL in Britain. It is a prototype for more than 100 follow-on platforms that Telesat of Canada wants to launch to deliver broadband across the globe.
The other PSLV passenger of note in this context was a small radar-imaging satellite for Finnish start-up ICEYE.
What all these proposed constellations have in common is that they are exploiting the use of cheap electronics normally found in consumer products – rather than the expensive, “space qualified” parts built into traditional spacecraft designs.
This makes the manufacture and launch of multiple platforms much more affordable.
“And the change comes both in cost and in size because COTS components have been miniaturised to fit inside your phone, literally. We are using the same components.”
Friday’s PSLV launch was the first since the rocket failed to jettison its nose cone on an ascent to orbit last August. The navigation satellite being carried on that occasion was lost because it could not get off the vehicle.
The PSLV is India’s workhorse rocket, so the country will be delighted to have it back in action. Its primary payload for the latest flight was another imaging and mapping spacecraft in the nation’s long-running Cartosat series.
Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos
The first FRB was discovered in 2007, in archived data from the Parkes Radio Telescope in Australia. Astronomers were searching for new examples of magnetised neutron stars called pulsars, but found a new phenomenon – a radio burst from 2001.
Since then, 18 FRBs – also referred to as “flashes” or “sizzles” – have been found in total.
The mystery surrounding their nature has spawned a variety of different possible explanations, from black holes to extra-terrestrial intelligence.
Only one of these sources of radio energy has erupted more than once – a so-called burster catalogued as FRB 121102. This FRB has sent out around 150 flashes since its discovery in 2012.
Now, in the journal Nature, a team of scientists explains how the emission might come from a neutron star, perhaps one near a black hole or one embedded in a nebula.
The researchers found something interesting about the polarisation of the radio waves – which describes the direction in which they vibrate. When polarised radio waves pass through a region with a magnetic field, the polarisation gets “twisted” by an effect known as Faraday rotation. And the stronger the magnetic field, the greater the twisting.
“The only sources in the Milky Way that are twisted as much as FRB121102 are in the galactic centre, which is a dynamic region near a massive black hole. Maybe FRB121102 is in a similar environment in its host galaxy,” said Daniele Michilli, a co-author from the University of Amsterdam.
“However, the twisting of the radio bursts could also be explained if the source is located in a powerful nebula or supernova remnant,” he added.
Vishal Gajjar, from the Breakthrough Listen project and the Berkeley SETI Research Center, commented: “At this point, we don’t really know the mechanism. There are many questions, such as, how can a rotating neutron star produce the high amount of energy typical of an FRB?”
The team used the Arecibo radio observatory in Puerto Rico and the Green Bank telescope in West Virginia to probe the source at higher frequencies than ever before.
Andrew Seymour, a staff astronomer at the Arecibo Observatory, said: “The polarisation properties and shapes of these bursts are similar to radio emission from young, energetic neutron stars in our galaxy. This provides support to the models that the radio bursts are produced by a neutron star.”
A year ago, the research team pinpointed the location of FRB121102 and reported that it lies in a star-forming region of a dwarf galaxy at a distance of more than three billion light-years from Earth.
The enormous distance to the source implies that it releases a monstrous amount of energy in each burst – roughly as much energy in a single burst of one millisecond as the Sun releases in an entire day.
Theresa May has defended her 25-year plan to protect the environment as campaigners called for “emergency” action now.
The prime minister said her long-term strategy, including eradicating all avoidable plastic waste in the UK by 2042, would allow future generations to “enjoy a beautiful environment”.
Green groups said the proposals should have legal force.
Labour’s Jeremy Corbyn said 25 years was “far too long” to take action.
Unveiling the proposals at London Wetlands Centre, Mrs May vowed that Brexit would not lead to environmental standards being lowered, and promised her government would “leave the natural environment in a better state than we found it”.
Key to this is a crackdown on throwaway plastics. Under the government’s plan, supermarkets will be urged to introduce “plastic-free” aisles while taxes and charges on single-use items such as takeaway containers will be considered.
Mrs May’s announcements also include:
Confirmation of the extension of the 5p charge for plastic carrier bags to all retailers in England
Government funding for plastics innovation
A commitment to help developing nations tackle pollution and reduce plastic waste, including through UK aid
She said: “We look back in horror at some of the damage done to our environment in the past and wonder how anyone could have thought that, for example, dumping toxic chemicals into rivers was ever the right thing to do.”
She called plastic waste “one of the great environmental scourges of our time”, adding: “In the UK alone, the amount of single-use plastic wasted every year would fill 1,000 Royal Albert Halls.”
Asked after her speech about calls for more urgent action, the PM said the government had already reduced plastic bag usage by nine billion and legislated to ban plastic microbeads used in cosmetics and cleaning products.
And asked about her own environmental credentials, she revealed she had put owl and bat boxes in her garden.
Some campaigners have warned about the loss of European environmental standards once the UK leaves the EU, but Mrs May promised a new “world leading” body to hold the government to account on environmental issues.
However the chairwoman of the Commons Environmental Audit Committee, Labour’s Mary Creagh, said a new Act of Parliament was needed after Brexit.
“We don’t want to go back to being the ‘dirty man of Europe’,” she added.
Analysis by the BBC’s Roger Harrabin
Thursday’s announcements are the culmination of an environmental week for the government. On Sunday, Mrs May promised a clampdown on plastic waste. On Wednesday, plans emerged to extend the 5p plastic bag charge to include corner shops in England.
Ministers have been under political pressure to do more for the environment after it was identified by the Tory think-tank Bright Blue as the key issue for young voters, who failed to back the party in large numbers at the 2017 general election.
Environmentalists agree that the government’s plan to restore nature – not just safeguard nature – is genuinely radical.
Many of the UK’s landscapes have been ravaged by development, intensive farming and sheep grazing. Only 2% of wildflower meadows have survived.
I understand that the document will cover many policy areas, including: managing land sustainably; enhancing nature and recovering wildlife; increasing people’s health and well-being through nature; resource efficiency, reduction of pollution and waste and protecting and improving the global environment.
But there is scepticism about how far the environment department Defra will be able to carry out its plans.
There are huge pressures on the natural world from urgently needed house-building; HS2 threatens scores of ancient woodlands; and the Department for Transport has a major road-building programme.
Green campaigners said Mrs May’s plans could simply be shelved if they become inconvenient and the promise to stop “avoidable” plastic waste is too vague.
“Britain’s natural environment needs a 25-month emergency plan more than it needs a 25-year vision,” said Greenpeace UK’s executive director John Sauven.
“If the government’s aim is to get through to young voters, they need to offer change that happens before these youths turn middle-aged.”
Greenpeace questioned why there was no mention of deposit return schemes for bottles – which the government has said it will consider – while Friends of the Earth said a “clear timetable” not “woolly promises” was needed.
Sue Hayman, Labour’s environment spokeswoman, said the Conservatives had a record of “failure and broken promises” on the environment.
She said the “weak” proposals would mean the problem with plastic waste was “kicked into the long grass”.
The Liberal Democrats said it “beggared belief” that a target of 2042 had been set for removing plastic waste and that action was needed now.
Astronomers have caught a massive black hole letting out a ‘double burp’ after binging on hot gas.
When cosmic gas comes near one of these sinkholes, it gets sucked it in – but some of the energy is released back into space in the form of a burp.
Now, the Hubble and Chandra space telescopes have detected a new belch emerging from a black hole located about 800 million light-years away.
But they saw a remnant of another belch that occurred 100,000 years earlier.
“Black holes are voracious eaters, but it turns out they don’t have very good table manners,” Julie Comerford, from the University of Colorado, Boulder, told the 231st American Astronomical Society meeting in Washington DC.
“There are a lot of examples of black holes with single burps emanating out, but we discovered a galaxy with a supermassive black hole that has not one but two burps.”
Supermassive black holes are the largest type and are found at the centres of nearly all big galaxies. X-ray emission from the galaxy in question – called SDSS J1354+1327 – was picked up by the Chandra telescope, allowing researchers to pinpoint the location of its central black hole.
Hubble was able to show them that a cloud of blue-green gas extending away from the black hole represented the aftermath of an earlier burp. They found that electrons had been stripped from atoms in the cone of gas and surmise that this was caused by a burst of radiation from the vicinity of the black hole.
In the meantime, it had expanded 30,000 light-years away from the black hole itself.
But the astronomers found a little loop in the images; the sign of a new belch emerging from the cosmic sinkhole.
“This new burp is actually moving like a shockwave that is coming out very fast,” said Dr Comerford.
“I thought of an analogy for this and I was debating whether to use it or whether it’s a little too gross… imagine someone eating dinner at their kitchen table and they’re eating and burping, eating and burping.
“You walk in the room and you notice there’s an old burp still hanging in the air from the appetiser course. Meanwhile, they’re eating the main course and they let out a new burp that’s rocking the kitchen table.”
She said the black hole was going through a cycle of feasting, burping and napping, before starting over.
The observations are important because they support previous theories – not demonstrated until now – that black holes should go through these cycles. The black holes were expected to become very bright in the process of feasting and burping and then go dark during the nap phase.
“Theory predicted that black holes should flicker on and off very quickly and this galaxy’s evidence of black holes does flicker on timescales of 100,000 years – which is long in human timescales, but in cosmological timescales is very fast,” said Julie Comerford.
The researchers think the black hole erupted twice because it consumed two separate meals. The reason for this might lie with the fact that the galaxy it’s in had collided with another galaxy nearby. This would provide plenty of cosmic gas on which a black hole could feast.
“There’s a stream of stars and gas connecting these two galaxies. That collision led gas to stream towards the supermassive black hole and feed it two separate meals that led to these two separate burps,” said the University of Colorado researcher.
The results are published in the Astrophysical Journal.
Newly discovered fossils show that moths and butterflies have been on the planet for at least 200 million years.
Scientists found fossilised butterfly scales the size of a speck of dust inside ancient rock from Germany.
The find pushes back the date for the origins of the Lepidoptera, one of the most prized and studied insect groups.
Researchers say they can learn more about the conservation of butterflies and moths by studying their early evolution.
They used acid to dissolve ancient rocks, leaving behind small fragments, including “perfectly preserved” scales that covered the wings of early moths and butterflies.
“We found the microscopic remains of these organisms in the form of these scales,” said Dr Bas van de Schootbrugge from Utrecht University in the Netherlands.
Intriguingly, they show that some of the moths and butterflies belonged to a group still alive today that have long straw-like tongues for sucking up nectar.
“These finds push back the evolution of this group with proboscises – with a tongue – by about 70 million years,” said Dr van de Schootbrugge.
“Our finds show that the group that was supposed to co-evolve with flowers is actually much older.”
The Jurassic was a world dominated by gymnosperm plants, such as conifers, which produced sugary nectar to capture pollen from the air. The primitive insects may have fed on this nectar, before flowering plants came along around 130 million years ago.
Dr Russell Garwood of the University of Manchester, who is not connected with the study, said it had always been assumed that coiled mouthparts had evolved alongside the flowers that these animals pollinate.
“This new evidence suggests that perhaps the coiled mouthparts had another role, before flowering plants evolved,” he said.
The study, published in the journal Science Advances, gives clues to how butterflies and moths became so widespread, thriving on every continent except Antarctica.
The early Lepidopterans survived the mass extinction at the end of the Triassic, which wiped out many other living things.
This knowledge will help inform modern conservation efforts, said Dr Timo van Eldijk, also of Utrecht University, the lead researcher on the study.
The information is “paramount to help us piece together how current manmade climate change might affect insects and their evolution in the future”, he said.
Butterflies and moths are fragile creatures, meaning fossil evidence is rare.
Scientists have relied largely on DNA evidence from modern butterflies and moths, which can be used to make an evolutionary tree of life.
A mathematical discrepancy in the expansion rate of the Universe is now “pretty serious”, and could point the way to a major discovery in physics, says a Nobel laureate.
The most recent results suggest the inconsistency is not going away.
Prof Adam Riess told BBC News that an unknown phenomenon, such as a new particle, might explain the deviation.
The difference is found when comparing precise measurements of the rate obtained in different ways.
However, the statistics are not yet at the threshold for claiming a discovery,
Prof Riess, who is based at Johns Hopkins University in Baltimore, Maryland, was one of three scientists who shared the 2011 Nobel Prize in Physics for discovering that the expansion rate of the Universe is accelerating.
This phenomenon was widely attributed to a mysterious, unexplained “dark energy” filling the cosmos.
The unit of measurement used to describe the expansion is called the Hubble Constant, after 20th Century astronomer Edwin Hubble – after whom the orbiting space observatory is named.
Appropriately, Prof Riess has been using the Wide Field Camera 3 instrument on the Hubble telescope (installed during the last servicing mission to the iconic observatory) to help refine his measurements of the constant.
“The answer we get is 73.24. This is not very different to what people have gotten before measuring the Hubble constant. What is different is that the uncertainty has gotten quite a bit smaller,” he said here at the 231st American Astronomical Society meeting in National Harbor, just outside Washington DC.
“The uncertainty has been dropping progressively over time, while the value has not been changing very much.”
To calculate the Hubble Constant, Prof Riess and others use the “cosmic ladder” approach, which relies on known quantities – so-called “standard candles” – such as the brightness of certain types of supernova to calibrate distances across space.
However, a different approach uses a combination of the afterglow of the Big Bang, known as the Cosmic Microwave Background (CMB), as measured by the Planck spacecraft and a cosmological model known as Lambda-CDM.
The Hubble Constant obtained using these data is 66.9 kilometres per second per megaparsec. (A megaparsec is 3.26 million light-years, so it follows that cosmic expansion increases by 66.9km/second for every 3.26 million light-years we look further out into space).
The gap between the two is now at a confidence level of about 3.4 sigma. The sigma level describes the probability that a particular finding is not down to chance. For example, three sigma is often described as the equivalent of repeatedly tossing a coin and getting nine heads in a row.
A level of five sigma is usually considered the threshold for claiming a discovery.
However, Prof Riess said that at the three sigma level “this starts to get pretty serious I would say”.
“In fact, in both cases of measurements, these are very mature measurements… both projects have done their utmost to reduce systematic errors,” he added.
Indeed, a recent measurement of time delays in quasars that is completely independent of the cosmic distance ladder data gets very similar results to Prof Riess’s late Universe Hubble Constant. For the early Universe, a 2017 analysis using the density of baryonic (normal) matter in the cosmos yields a very similar value as the one obtained by the Planck team.
What this all suggested, he said, was that the Universe is now expanding 9% faster than expected based on the data – a result he described as “remarkable”.
One way to bridge the divide is to invoke new phenomena in physics.
There are various ways to account for it, including the addition of a new particle, called a sterile neutrino, to the Standard Model – the best tested theory of particle physics.
The sterile neutrino would represent the fourth type – or flavour – of neutrino; but while the other three are well known to physicists, attempts to detect a fourth with experiments have not come up with much.
Another possibility is that dark energy behaves in a different way now compared with how it did in the early history of the cosmos.
“One promising way is if we don’t have dark matter be so perfectly ‘collision-less’ but it could interact with radiation in the early Universe,” Prof Riess said.
He has submitted a paper with his latest analysis of the Hubble Constant for publication in a journal.