It’s one of the biggest puzzles in cosmology. Why two different methods used to calculate the rate at which the universe is expanding don’t produce the same result. Known as the Hubble tension, the enigma suggests that there could be something wrong with the standard model of cosmology used to explain the forces in the universe.
Now, recent observations using the new James Webb Space Telescope (JWST) are shaking up the debate on how close the mystery is to being resolved.
In this episode of The Conversation Weekly podcast, two professors of astronomy explain why the Hubble tension matters so much for our understanding of the universe.
(The Conversation included two files that one could listen to but they could not be played directly. But I have left them in the post just in case.)
In February, the Nobel prize-winning physicist Adam Reiss, published a new paper. It said that new observations of far-away stars using the JWST matched those obtained by the Hubble Space Telescope.
These stars, called Cepheids, are commonly used in one method of calculating the rate at which the universe is expanding. Known as the local distance ladder, or cosmic distance ladder, this method has been around since observations first made by Edwin Hubble himself in 1929. And it generally produces a rate of expansion of around 73km per second per mega parsec.
But a second method, using predictions of the cosmic microwave background radiation left over by the Big Bang, has constantly arrived at a different number for the rate of expansion of the universe: 67km per second per mega parsec.
Reiss said that when the new data confirmed the earlier observations from the Hubble Space Telescope, the gap between the numbers remains unresolved. “What remains is the real and exciting possibility that we have misunderstood the universe,” he said.
A few months later, however, more data from the JWST, presented by Wendy Freedman, a physicist at the University of Chicago, using observations from a different set of stars, arrived at 69km per second per mega parsec, a number closer to the cosmic microwave background figure of 67. Freedman is excited that the numbers seem to be converging.
Vicent Martínez and Bernard Jones are fascinated by the Hubble tension. Jones is an emeritus professor of astronomy at the University of Groningen in the Netherlands. Martínez, his former student, is now a professor of astronomy and astrophysics at the University of València in Spain.
“The fundamental basis of science, what distinguishes science from science fiction, is our ability to verify the information we are getting,” explains Jones.
That’s why Martinez says the mystery of the Hubble tension is still driving people to:
Research and imagine experiments and organise huge projects with the complicated observation of the cosmos in order to understand what’s going on. At the end, this will affect your idea of the whole universe and probably you will need to change some fundamental ingredient of your cosmological model.
Martinez and Jones have just written a book, along with their co-author Virginia Trimble, about moments in history when scientists realised they’d got something very wrong, and had to readjust their way of thinking. Martínez thinks this could happen again with the Hubble tension:
It could happen that, for example, a new theory of gravity could solve the problem of dark energy or dark matter. We have to be open to those ideas.
Listen to Bernard Jones and Vicent Martínez talk more about the Hubble tension, and how it fits in the wider history of science, on The Conversation Weekly podcast. The episode also features an introduction from Lorena Sánchez, science editor at The Conversation in Spain.
You’ve probably heard people say, “It’s not the heat, it’s the humidity.” There’s a lot of truth to that phrase, and it’s important to understand it as summer temperatures rise.
Humidity doesn’t just make you feel sticky and uncomfortable – it also creates extra dangerous conditions on hot days. Together, too much heat and humidity can make you sick. And in severe cases, it can cause your body to shut down.
Meteorologists talk about the risk of heat and humidity using the heat index, but it can be confusing.
I’m a risk communication researcher. Here’s what you need to know about the heat index and some better ways meteorologists can talk about the risks of extreme heat.
Heat index is the combination of the actual air temperature and relative humidity:
Air temperature is how hot or cold the air is, which depends on factors such as the time of day, season of the year and local weather conditions. It is what your thermometer reads in degrees Celsius or Fahrenheit.
Relative humidity compares how much water vapor is in the air with how much water vapor the air could hold at that temperature. It’s expressed as a percentage.
The heat index tells you what it “feels like” outside when you factor in the humidity. For example, if it’s 98 degrees Fahrenheit (36.7 Celsius) with 55% relative humidity, it might feel more like a scorching 117 F (47.2 C).
NOAA’s heat index chart shows how heat and humidity combine for dangerous temperatures. NOAA
But there’s a catch: Heat index is measured in shady conditions to prevent the sun’s angle from affecting its calculation. This means if you’re in direct sunlight, it will feel even hotter.
Apparent temperature, alerts and wet bulb
“Apparent temperature” is another term you might hear this summer.
Apparent temperature is the “feels like” temperature. It considers not only temperature and humidity but also wind speed. This means it can tell us both the heat index and wind chill – or the combination of the temperature and wind speed. When conditions are humid, it feels hotter, and when it’s windy, it feels colder.
We found that apparent temperature is even less well understood than the heat index, possibly due to the word apparent having various interpretations.
There are a few other ways you may hear meteorologists talk about heat.
Wet bulb globe temperature considers temperature, humidity, wind and sunlight. It’s especially useful for those who spend time outdoors, such as workers and athletes, because it reflects conditions in direct sunlight.
HeatRisk is a new tool developed by the National Weather Service that uses colors and numbers to indicate heat risks for various groups. More research is needed, however, to know whether this type of information helps people make decisions.
Knowing about heat and humidity is important, but my colleagues and I have found that the term heat index is not well understood.
We recently conducted 16 focus groups across the United States, including areas with dry heat, like Phoenix, and more humid areas, like Houston. Many of the people involved didn’t know what the heat index was. Some confused it with the actual air temperature. Most also didn’t understand what the alerts meant, how serious they were or when they should protect themselves.
In our discussions with these groups, we found that meteorologists could get across the risk more clearly if, instead of using terms like heat index, they focus on explaining what it feels like outside and why those conditions are dangerous.
Watches, warnings and advisories could be improved by telling people what temperatures to expect, when and steps they can take to stay safe.
Clear warnings can help residents understand their risk and protect themselves, which is especially important for small children and older adults, who are at greater risk of heat illness. Jason Armond/Los Angeles Times via Getty Images
Climate change is exacerbating heat risks by making extreme heat more common, intense and long-lasting. This means clear communication is necessary to help people understand their risk and how they can protect themselves.
What you can do to protect yourself
With both hot and humid conditions, extra precautions are necessary to protect your health. When you get hot, you sweat. When sweat evaporates, this helps the body cool down. But humidity prevents the sweat from evaporating. If sweat cannot evaporate, the body has trouble lowering or regulating its temperature.
Although everyone is at risk of health issues in high heat, people over 65, pregnant women, infants and young children can have trouble cooling their bodies down or may run a higher risk of becoming dehydrated. Certain health conditions or medications can also increase a person’s risk of heat-related illness, so it’s important to talk to your doctor about your risk.
Heat illnesses, such as heat exhaustion and heat stroke, are preventable if you take the right steps. The U.S. Centers for Disease Control and Prevention focuses on staying cool, hydrated and informed.
Stay cool: Use air conditioning in your home, or spend time in air-conditioned spaces, such as a shopping mall or public library. Limit or reschedule your exercise and other outdoor plans that occur in the middle of the day when it is hottest.
Stay hydrated: Drink more water than you might otherwise, even if you don’t feel thirsty, so your body can regulate its temperature by sweating. But avoid sugary drinks, caffeine or drinks with alcohol, because these can cause you to become dehydrated.
Stay informed: Know the signs of heat illness and symptoms that can occur, such as dizziness, weakness, thirst, heavy sweating and nausea. Know what to do and when to get help, because heat illnesses can be deadly.
The difference between heat exhaustion and heat stroke and the CDC’s advice on how to respond. NOAA, CDC
That last diagram on staying cool, staying hydrated, and staying informed is one element in me choosing this article for publication. Further, if one looks up the website for the Centers for Disease Control and Prevention then immediately one comes across:
Stay cool indoors.Stay in an air-conditioned place as much as possible. If your home does not have air conditioning, go to the shopping mall or public library—even a few hours spent in air conditioning can help your body stay cooler when you go back into the heat.
The Labour Party, led by Keir Starmer, is heavily favored to return to power for the first time since 2010.
To a U.S. audience, many of the top issues in the election campaign will sound familiar: the economy, immigration, health care, Ukraine and Gaza. The choice of date, too, may ring a bell – and political soothsayers are already trying to read into what it means for the U.K. election to fall on Independence Day.
U.K. elections can be an odd affair in which mainstream politicians can rub shoulders with the likes of rival candidates Count Binface and Lord Buckethead. Oli Scarff/AFP via Getty Images
But as to the campaign itself – well, they do things a bit different on the other side of the pond. While Americans may be used to set terms and lengthy campaigns filled with endless advertising, in the U.K. such things are, to use a Britishism, “just not cricket.” Here are three main ways in which the British conduct their elections.
1. Election timeline
U.S. elections follow a predictable schedule. In 1845, Congress passed a law establishing a single day for federal elections to take place on “the Tuesday next after the first Monday in November.” Further, presidents are elected for a fixed four-year term, making the dates for upcoming votes knowable for the foreseeable future.
That isn’t the case in the United Kingdom. By convention, elections have been held on a Thursday since 1935. But the month of the vote has varied considerably. For the most part, they take place in late spring or early summer – but fall and winter elections are not unheard of.
The U.K. Parliament does have a fixed term of five years, with elections automatically scheduled once that time has lapsed. In practice, however, parliaments have rarely gone the full five years.
Indeed, prime ministers in the United Kingdom have the authority to request the dissolution of Parliament at any time. They can do so without the approval of the cabinet, and so prime ministers have taken liberal advantage of their ability to control the timing of the election to try and gain an advantage.
Many thought that Sunak may have been eyeing an election later in the year, but a number of factors, including economic forecasts and not wanting the distraction of a U.S. election, may have factored in to him calling an earlier-than-expected vote.
2. Campaign rules
Besides the shifting timing, the nature and rules of the campaign are also very different in the United Kingdom. This starts with the sheer brevity of the campaign. Once Parliament is dissolved, the election must take place 25 working days later. This means the parties have a mere six weeks to make their case to the public.
And unlike in a presidential system, voters in the United Kingdom do not cast a ballot for the person they want to see lead the country. Instead, the U.K. is divided into 650 distinct constituencies; voters pick their preferred candidate to represent their local constituency in Parliament. The party with the most seats typically wins the election, and the leader of that party has the opportunity to become prime minister and govern as a single-party government or as part of a coalition.
U.K. election campaigns are also subject to strict rules to maintain neutrality. Once the campaign starts, the period of “purdah” kicks in, which imposes certain restrictions on government activities. This involves, for instance, strict prohibitions on government ministers announcing new initiatives to affect the election or using public funds for political purposes.
In the same manner, civil servants – employees of the crown who work for the government but are not political appointees – are required to maintain strict impartiality and not become involved in partisan debates.
Moreover, the Office of Communications, the United Kingdom’s independent media regulatory authority, also enforces strict rules for broadcast media, including television and radio. The 2003 Communications Act requires that all broadcast media must cover the elections in an impartial manner, providing coverage of all parties, even if they do not assign equal time.
Opposition leader Keir Starmer, left, poses on the campaign trail with what the photographer says is a cup of coffee … but which I strongly suspect is actually tea. Leon Neal/Getty Images
Broadcast media is also not allowed, on polling day, to suggest the outcome of the vote before polls are closed.
In a huge departure from the U.S., U.K. political parties are banned from buying television ads, but this rule does not apply to streaming television.
3. The role of money
The limited role of money is another distinct feature in U.K. elections. Even factoring in the different population sizes, U.K. elections are significantly cheaper than their counterparts in the United States.
Indeed, total campaign spending in the 2020 U.S. elections, covering presidential and congressional races, hit more than US$14 billion. That scale completely dwarfs how much parties and candidates will be able to spend in the 2024 United Kingdom election.
Through regulations established by the Electoral Commission, an independent government agency, a British party that competes in all constituencies in the United Kingdom will be allowed to spend just over £34 million (around $43 million) in total to support all candidates.
That figure in itself marks an 80% increase from the allowance at the last election in 2019, so to factor for inflation since limits were set in 2000.
As a result, both Sunak and Starmer will have only a short time – and limited funds – to make their case to voters. Whoever wins will face a very challenging situation at home and abroad, with little to no respite. According to the think tank Institute for Fiscal Studies, the state of public finances is “a dark cloud that hangs over the election.” And then there is the delicate matter of maintaining a special relationship with the U.S. – a country that may itself have a very different political landscape after it goes to the polls later in the year.
As I have frequently said, I feel English and love the fact that I speak with an English accent. Yet I adore, along with Jean, where we live just outside Merlin in Southern Oregon. I wouldn’t want to live anywhere else in the world.
Politically we are in very strange times, as was said right at the end of this article.
There is quite a long introduction but it helps enormously in explaining the background to the photographs.
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This image is released as part of the Early Release Observations from ESA’s Euclid space mission. All data from these initial observations are made public on 23 May 2024 – including a handful of unprecedented new views of the nearby Universe.
The Dorado Group of galaxies is one of the richest galaxy groups in the southern hemisphere. Here, Euclid captures signs of galaxies evolving and merging ‘in action’, with beautiful tidal tails and shells visible as a result of ongoing interactions. As Dorado is a lot younger than other clusters (like Fornax), several of its constituent galaxies are still forming stars and remain in the stage of interacting with one another, while others show signs of having merged relatively recently. In size, it sits between larger galaxy clusters and smaller galaxy groups, making it a useful and fascinating object to study with Euclid.
This dataset is enabling scientists to study how galaxies evolve and collide over time in order to improve our models of cosmic history and understand how galaxies form within halos of dark matter, with this new image being a true testament to Euclid’s immense versatility. A wide array of galaxies is visible here, from very bright to very faint. Thanks to Euclid’s unique combination of large field-of-view and high spatial resolution, for the first time we can use the same instrument and observations to deeply study tiny (small objects the size of star clusters), wider (the central parts of a galaxy) and extended (tidal merger tails) features over a large part of the sky.
Scientists are also using Euclid observations of the Dorado Group to answer questions that previously could only be explored using painstakingly small snippets of data. This includes compiling a full list of the individual clusters of stars (globular clusters) around the galaxies seen here. Once we know where these clusters are, we can use them to trace how the galaxies formed and study their history and contents. Scientists will also use these data to hunt for new dwarf galaxies around the Group, as it did previously with the Perseus cluster.
The Dorado Group lies 62 million light-years away in the constellation of Dorado.
All images are: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi
Composite image of five astronomical views, three at the top, two at the bottom. All are dotted with stars and galaxies against a black background. Striking features are three bright glowing structures in the first image. The second image has an orange veil-like structure spanning across. In the third we see a stunning spiral galaxy with many arms. The fourth image features light from galaxies lying behind a bright cluster distorted into arcs. And the fifth image shows a variety of galaxies in all shapes and sizes
An elongated bright cloudy ellipse, tilted at a 45-degree angle in front a black background dotted with small white stars and galaxies. Above the ellipse floats a smaller, cloudy ellipsoid.
A dark orange filamentary structure seems to enclose stars. Centrally, three bright star-forming regions shine brightly through the orange veil in a traffic-light like formation.
The image shows hundreds of stars, some brighter than others. The stars seem to light up their cloud-like surroundings in purple. A darker structure spans the image in an arch from upper left to bottom right. The bottom of this arch runs into dense clouds forming the darkest part of the image.
This breathtaking image features Messier 78 (the central and brightest region), a vibrant nursery of star formation enveloped in a shroud of interstellar dust. This image is unprecedented – it is the first shot of this young star-forming region at this width and depth.
Today, (May 23rd, 2024) ESA’s Euclid space mission releases five unprecedented new views of the Universe. The never-before-seen images demonstrate Euclid’s ability to unravel the secrets of the cosmos and enable scientists to hunt for rogue planets, use lensed galaxies to study mysterious matter, and explore the evolution of the Universe.
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Fabulous. It is an example of just how clever the science is getting!
I can only look at these images in awe. For example, Messier 78 is part of the Orion constellation, has a radius of five light-years, and is only 1,600 light-years from Planet Earth. (Using the figure from below of the distance of a single light-year, that puts Messier 78 as 1,600 times 6 trillion miles from our planet or 9,600 trillion miles.)
And in case you forgot it, one light year is:
The light-year is a measure of distance, not time. It is the total distance that a beam of light, moving in a straight line, travels in one year. To obtain an idea of the size of a light-year, take the circumference of the earth (24,900 miles), lay it out in a straight line, multiply the length of the line by 7.5 (the corresponding distance is one light-second), then place 31.6 million similar lines end to end. The resulting distance is almost 6 trillion (6,000,000,000,000) miles!
“This is far ahead of my knowledge of science. I applaud you for writing this despite me not understanding it”
So it may seem a little strange that I now publish the following. It was published originally on Skeptic. It is quite a long video but, please, settle down and watch it.
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Sean Carroll is creating a profoundly new approach to sharing physics with a broad audience, one that goes beyond analogies to show how physicists really think. He cuts to the bare mathematical essence of our most profound theories, explaining every step in a uniquely accessible way.
Quantum field theory is how modern physics describes nature at its most profound level. Starting with the basics of quantum mechanics itself, Sean Carroll explains measurement and entanglement before explaining how the world is really made of fields. You will finally understand why matter is solid, why there is antimatter, where the sizes of atoms come from, and why the predictions of quantum field theory are so spectacularly successful. Fundamental ideas like spin, symmetry, Feynman diagrams, and the Higgs mechanism are explained for real, not just through amusing stories. Beyond Newton, beyond Einstein, and all the intuitive notions that have guided homo sapiens for millennia, this book is a journey to a once unimaginable truth about what our universe is.
Sean Carroll is Homewood Professor of Natural Philosophy at Johns Hopkins University, and Fractal Faculty at the Santa Fe Institute. He is host of the Mindscape podcast, and author of From Eternity to Here, The Particle at the End of the Universe, The Big Picture, and Something Deeply Hidden. He has been awarded prizes and fellowships by the National Science Foundation, NASA, the American Institute of Physics, the Royal Society of London, and many others. He lives in Baltimore with his wife, writer Jennifer Ouellette. His new book series, The Biggest Ideas in the Universe, includes one volume on Space, Time, and Motion, and this new volume on Quanta and Fields.
Shermer and Carroll discuss:
the measurement problem in physics
wave functions
entanglement
fields
interactions
scale
symmetry
gauge theory
phases
matter
atoms
What is time?
Is math all there is? Is math universal?
double-slit experiment
superposition
metaphors in science
limitations of models and theories of reality
What banged the Big Bang?
Why is there something rather than nothing?
Second Laws of Thermodynamics and directionality in nature
Is there a place for God in scientific epistemology?
many interpretations of quantum mechanics
multiple dimensions and the multiverse
string theory and the multiverse
known unknowables: Are there things we can never know, even in principle?
God
hard problem of consciousness
free will/determinism.
ooOOoo
I’m assuming you have watched the video because in a world that is pre-occupied with the trivial this is just the opposite. Sean shares his physics in a profoundly different and powerful way!
EVENT: A coronal mass ejection (CME) is an eruption of solar material. When they arrive at Earth, a geomagnetic storm can result. Watches at this level are very rare. TIMING: Several CMEs are anticipated to merge and arrive at Earth on May 12th. EFFECTS: The general public should visit our webpage to keep properly informed. The aurora mav become visible over much of the northern half of the country, and maybe as far south as Alabama to northern California.
Meanwhile, Earth.com presented the following (and it is a long but extremely interesting report):
Update: New solar flare, secondary peak today in this “Extreme” solar storm
The Sun released another powerful burst of energy today, known as a solar flare, reaching its peak intensity at 12:26 p.m. Eastern Time. The flare originated from a region on the Sun’s surface called sunspot Region 3664, which has been quite active lately.
NASA’s Solar Dynamics Observatory, a spacecraft that keeps a constant eye on our nearest star, was able to capture a striking image of this latest solar outburst.
Solar flares are immense explosions on the Sun that send energy, light and high speed particles into space. They occur when the magnetic fields in and around the Sun reconnect, releasing huge amounts of stored magnetic energy. Flares are our solar system’s most powerful explosive events.
The NOAA’s Space Weather Prediction Center (SWPC) has extended the Geomagnetic Storm Warning until the afternoon of May 13, 2024.
Understanding different classes of solar flares
Today’s flare was classified as an X1.0 flare. Solar flares are categorized into classes based on their strength, with X-class flares being the most intense. The number provides additional information about the flare’s strength within that class. An X1 flare is ten times more powerful than an M1 flare.
These energetic solar eruptions can significantly impact Earth’s upper atmosphere and near-Earth space environment. Strong flares can disrupt high-frequency radio communications and GPS navigation signals. The particle radiation and X-rays from flares can also pose potential risks to astronauts in space.
Additionally, the magnetic disturbances from flares, if particularly strong, have the ability to affect electric power grids on Earth, sometimes causing long-lasting blackouts.
However, power grid problems are more commonly caused by coronal mass ejections (CMEs), another type of powerful solar eruption often associated with strong flares.
Scientists are always on alert, monitoring the Sun for these explosive events so that any potential impacts can be anticipated and prepared for. NASA’s Solar Dynamics Observatory, along with several other spacecraft, help provide this early warning system.
Stay tuned to Earth.com and the Space Weather Prediction Center (SWPC) for updates.
Update — May 12, 2024 at 9:41 AM EDT
The ongoing geomagnetic storm is expected to intensify later today, Sunday, May 12, 2024. Several intense Coronal Mass Ejections (CMEs), traveling from the Sun at speeds up to 1,200 miles per second, are anticipated to reach the Earth’s outer atmosphere by late afternoon.
Over the past two days, preliminary reports have surfaced regarding power grid irregularities, degradation of high-frequency communications, GPS outages, and satellite navigation issues. These disruptions are likely to persist as the geomagnetic storm strengthens.
Auroras visible across the continental United States
Weather permitting, auroras will be visible again tonight over most of the continental United States. This spectacular display of lights is a direct result of the ongoing geomagnetic storm.
The threat of additional strong solar flares and CMEs, which ultimately result in spectacular aurora displays, will persist until the large and magnetically complex sunspot cluster, NOAA Region 3664, rotates out of view of the Earth. This is expected to occur by Tuesday, May 14, 2024.
Solar activity remains at moderate to high levels
Solar activity has been at moderate levels over the past 24 hours. Region 3664 produced an M8.8/2b flare, the strongest of the period, on May 11 at 15:25 UTC. A CME signature was observed, but an Earth-directed component is not suspected.
Solar activity is expected to remain at high levels from May 12-14, with M-class and X-class flares anticipated, primarily due to the flare potential of Region 3664.
Energetic particle flux and solar wind enhancements
The greater than 10 MeV proton flux reached minor to moderate storm levels on May 10. Additional proton enhancements are likely on May 13-14 due to the flare potential and location of Region 3664.
The solar wind environment has been strongly enhanced due to continued CME activity. Solar wind speeds reached a peak of around 620 miles/second on May 12 at 00:55 UTC.
A strongly enhanced solar wind environment and continued CME influences are expected to persist on May 12-13, and begin to wane by May 14.
Geomagnetic field reaches G4 “Severe” storm levels
The geomagnetic field reached G4 (Severe) geomagnetic storm levels in the past 24 hours due to continued CME activity.
Periods of G3 (Strong) geomagnetic storms are likely, with isolated G4 levels possible, on May 12. Periods of G1-G3 (Minor-Strong) storming are likely on May 13, and periods of G1 (Minor) storms are likely on May 14.
Stay informed and enjoy the light show
As the geomagnetic storm rages on, we must remain vigilant and prepared for the potential consequences. Monitor official sources for updates on the storm’s progress and any further disruptions to our technological infrastructure.
Take a moment to step outside tonight and marvel at the incredible auroras painting the night sky — a stunning reminder of the raw power and beauty of our Sun.
While these solar storms can cause temporary inconveniences, they also provide us with an opportunity to reflect on our place in the universe and the awe-inspiring forces that shape our world.
Stay tuned to Earth.com and the Space Weather Prediction Center (SWPC) for updates.
Understanding geomagnetic solar storms
Geomagnetic storms are disturbances in the Earth’s magnetic field caused by the interaction between the solar wind and the planet’s magnetosphere. These storms can have significant impacts on technology, infrastructure, and even human health.
Causes of geomagnetic storms
Geomagnetic storms typically originate from the Sun. They are caused by two main phenomena:
Coronal Mass Ejections (CMEs): Massive bursts of plasma and magnetic fields ejected from the Sun’s surface.
Solar Flares: Intense eruptions of electromagnetic radiation from the Sun’s surface.
When these events occur, they send charged particles streaming towards Earth at high speeds, which can take anywhere from one to five days to reach our planet.
Effects on Earth’s magnetic field
As the charged particles from CMEs and solar flares reach Earth, they interact with the planet’s magnetic field. This interaction causes the magnetic field lines to become distorted and compressed, leading to fluctuations in the strength and direction of the magnetic field.
Impacts on technology and infrastructure
Geomagnetic storms can have significant impacts on various aspects of modern technology and infrastructure:
Power Grids: Strong geomagnetic storms can induce currents in power lines, causing transformers to overheat and potentially leading to widespread power outages.
Satellite Communications: Charged particles can damage satellite electronics and disrupt communication signals.
GPS and Navigation Systems: Geomagnetic disturbances can interfere with the accuracy of GPS and other navigation systems.
Radio Communications: Storms can disrupt radio signals, affecting communication systems that rely on HF, VHF, and UHF bands.
As charged particles collide with Earth’s upper atmosphere, they excite oxygen and nitrogen atoms, causing them to emit light in various colors.
Monitoring and forecasting
Scientists continuously monitor the Sun’s activity and use various instruments to detect and measure CMEs and solar flares.
This data helps them forecast the timing and intensity of geomagnetic storms, allowing for better preparedness and mitigation of potential impacts.
Historical geomagnetic storms
Some of the most notable geomagnetic storms in history include:
The Carrington Event (1859): The most powerful geomagnetic storm on record, which caused widespread telegraph system failures and auroras visible as far south as the Caribbean.
The Halloween Storms (2003): A series of powerful geomagnetic storms that caused power outages in Sweden and damaged transformers in South Africa.
The Quebec Blackout (1989): A geomagnetic storm that caused a massive power outage affecting millions of people in Quebec, Canada.
Understanding geomagnetic storms is crucial for protecting our technology-dependent world and mitigating the potential risks associated with these powerful space weather events.
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I have no excuse for not being better at looking after my teeth, for one of my elder sisters, Corinne, was a dental assistant and when I was in my mid-fifties I moved down to South-West England and bought a home just a few miles from Corinne’s home. Thereafter she looked after my teeth at the dental practice in Totnes.
But I was careless in following Corinne’s advice and it wasn’t until in my seventies, and living in Merlin, Oregon, that I saw the light; so to speak!
Read this!
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Healthy teeth are wondrous and priceless – a dentist explains why and how best to protect them
Yet, in a society where 1 out of 5 Americans ages 75 and up live without their teeth, many people may not realize that teeth are designed to stay with us for a lifetime.
In the process, I have developed reverence for natural teeth and for the complex beauty of these biological and mechanical masterpieces.
Designed for lifelong function
The secret of teeth longevity lies in their durability as well as in how they are anchored to the jaw – picture a hammer and its hand grip. For each tooth, durability and anchorage are functions of the complex interface between six different tissues; each alone is a biological marvel.
For anchorage, the cementum, ligament and bone grip the tooth at its root portion that is buried under the gum. The ligament, a soft tissue that is about 0.2 millimeters wide (about the diameter of four hairs), attaches the cementum of the root on one end to the bone of the jaw on the other end. It serves to anchor the tooth as well as to cushion its movement during chewing.
For durability, however, the secret lies in the enamel, dentin and pulp – our focus in this discussion.
The enamel is the protective shell that covers the visible part of the tooth above the gum. Thanks to its high mineral content, enamel is the hardest tissue in the body. It needs to be, since it acts as a shield against the constant impact of chewing.
Enamel does not contain cells, blood vessels or nerves, so it is nonliving and nonsensitive. Enamel is also non-regenerating. Once destroyed by decay or broken by misuse such as ice chewing, nail biting or bottle opening – or touched by the dental drill – that part of our priceless enamel is gone for good.
Because it interfaces with a germ-laden world, the enamel is also where decay starts. When acid-generating bacteria accumulate on unbrushed or poorly brushed teeth, they readily dissolve the minerals in the enamel.
How bacteria invade the teeth and cause cavities.
Like hair or fingernails, the non-innervated enamel is not sensitive. The decay advances through the 2.5-millimeter thick (tenth of an inch) layer of enamel painlessly. When caught at that phase during a dental checkup visit, the dentist can treat the decay with a relatively conservative filling that hardly compromises the tooth’s structural integrity.
Because of its high mineral content, enamel is stiff. Its lifelong support is provided by the more resilient infrastructure – the dentin.
Dentin and pulp – body and heart
With less mineral content than enamel, dentin is the resilient body of the tooth. It is a living tissue formed of parallel tiny tubes housing fluid and cellular extensions. Both originate from the pulp.
The pulp is the tooth’s soft tissue core. Vastly rich in cells, blood vessels and nerves, it is the life source of the tooth – its heart – and the key to its longevity.
Like smoke detectors communicating with a remote fire station, the cellular extensions within the dentin sense decay as soon as it breaks through the nonsensitive layer of enamel into dentin. Once the extensions communicate the danger signal to the pulp, our tooth sensitivity alarm goes off: The tooth heart is in flames.
The inflamed pulp initiates two protective actions. The first is to secrete an additional layer of dentin to delay the approaching attack. The second is toothache, a call to visit the dentist.
The earlier the visit, the less the drilling and the smaller the filling. If caught in time, most of the tooth’s natural tissues will be preserved and the pulp will likely regain its healthy state. If caught too late, the pulp slowly dies out.
Without its heart, a nonliving tooth has no defense against further decay invasion. Without a hydration source, a dried-out dentin will sooner or later break under the forces of constant chewing. Besides, a tooth that has already lost a significant portion of its natural structure to decay, cavity preparation or root canal instrumentation becomes weak, with limited longevity.
In other words, the tooth is never the same without its heart. Pulpless, the tooth loses its womb-to-tomb endurance and mother nature’s lifelong warranty.
The tooth coming together
More complex – and more precious – than a pearl within an oyster, the formation of a tooth within our jawbone involves layered mineral deposition. As tooth development progresses in a process of ultimate cellular engineering, the cells of the six aforementioned tissues – enamel, dentin, pulp, cementum, ligament and bone – multiply, specialize and mineralize synchronously with each other to form uniquely interlocking interfaces: enamel to dentin, dentin to pulp, cementum to dentin and cementum to ligament to bone.
In a progress akin to 3D printing, the tooth crown grows vertically to full formation. Simultaneously, the root continues its elongation to eventually launch off the crown from within the bone across the gum to appear in the mouth – the event known as teething. It is about that time, around 12 years of age, that our set of adult teeth is complete. These pearls are set to endure a lifetime and are undoubtedly worth preserving.
Save your teeth, visit the dentist
Tooth decay, the most prevalent disease in humans, is both predictable and preventable. The earlier it is caught, the more the tooth integrity can be preserved. Since the process starts painlessly, it is imperative to visit the dentist regularly to keep those insidious germs in check.
During your checkup visit, the dental professional will clean your teeth and check for early decay. If you are diligent with your daily preventive measures, the good news for you will be no news – enough to make anyone smile.
Although I was born in London in 1944, as a result of an affair between my father and mother, my father had two daughters with his wife, Maud, and Rhona and Corinne, for they were their names, took me under their wing. In the 50s Maud, Rhona and Corinne all moved to Devon and I started going regularly to Totnes. When I started driving I usually stopped for a break close by Stonehenge so the site has a special interest to me.
So when I saw this article in The Conversation it had to be shared.
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Stonehenge may have aligned with the Moon as well as the Sun
When it comes to its connection to the sky, Stonehenge is best known for its solar alignments. Every midsummer’s night tens of thousands of people gather at Stonehenge to celebrate and witness the rising Sun in alignment with the Heel stone standing outside of the circle. Six months later a smaller crowd congregates around the Heel stone to witness the midwinter Sun setting within the stone circle.
But a hypothesis has been around for 60 years that part of Stonehenge also aligns with moonrise and moonset at what is called a major lunar standstill. Although a correlation between the layout of certain stones and the major lunar standstill has been known about for several decades, no one has systematically observed and recorded the phenomenon at Stonehenge.
This is what we are aiming to do in a project bringing together archaeologists, astronomers and photographers from English Heritage, Oxford, Leicester and Bournemouth universities as well as the Royal Astronomical Society.
There is now an abundance of archaeological evidence that indicates the solar alignment was part of the architectural design of Stonehenge. Around 2500 BC, the people who put up the large stones and dug an avenue into the chalk seemed to want to cement the solstice axis into the architecture of Stonehenge.
Archaeological evidence from nearby Durrington Walls, the place where scientists believe the ancient people who visited Stonehenge stayed, indicates that of the two solstices it was the midwinter one that drew the largest crowd.
But Stonehenge includes other elements, such as 56 pits arranged in a circle, an earthwork bank and ditch, and other smaller features such as the four station stones. These are four sarsen stones, a form of silicified sandstone common in Wiltshire, that were carefully placed to form an almost exact rectangle encompassing the stone circle.
Only two of these stones are still there, and they pale in comparison to their larger counterparts as they are only a few feet high. So what could their purpose be?
Only two of the station stones are still there. Drone Explorer/Shutterstock
Lunar standstill
The rectangle that they form is not just any rectangle. The shorter sides are parallel to the main axis of the stone circle and this may be a clue as to their purpose. The longer sides of the rectangle skirt the outside of the stone circle.
It is these longer sides that are thought to align with the major lunar standstill. If you marked the position of moonrise (or set) over the course of a month you would see that it moves between two points on the horizon. These southern and northern limits of moonrise (or set) change on a cycle of 18.6 years between a minimum and a maximum range – the so-called minor and major lunar standstills, respectively.
The major lunar standstill is a period of about one and a half to two years when the northernmost and southernmost moonrises (or sets) are furthest apart. When this happens the Moon rises (and sets) outside the range of sunrises and sets, which may have imbued this celestial phenomenon with meaning and significance.
The range of Moonrise positions on the horizon during minor and major lunar standstills. Fabio Silva, CC BY-NC
The strongest evidence we have for people marking the major lunar standstill comes from the US southwest. The Great House of Chimney Rock, a multi-level complex built by the ancestral Pueblo people in the San Juan National Forest, Colorado, more than 1,000 years ago.
It lies on a ridge that ends at a natural formation of twin rock pillars – an area that has cultural significance to more than 26 native American tribal nations. From the vantage point of the Great House, the Sun will never rise in the gap between the pillars.
However, during a major standstill the Moon does rise between them in awe-inspiring fashion. Excavations unearthed preserved wood that meant researchers could date to the year episodes of construction of the Great House.
Of six cutting dates, four correspond to major lunar standstill years between the years AD1018 and AD1093, indicating that the site was renewed, maintained or expanded on consecutive major standstills.
Returning to southern England, archaeologists think there is a connection between the major lunar standstill and the earliest construction phase of Stonehenge (3000-2500 BC), before the sarsen stones were brought in.
Several sets of cremated human remains from this phase of construction were found in the southeastern part of the monument in the general direction of the southernmost major standstill moonrise, where three timber posts were also set into the bank. It is possible that there was an early connection between the site of Stonehenge and the Moon, which was later emphasised when the station stone rectangle was built.
The major lunar standstill hypothesis, however, raises more questions than it answers. We don’t know if the lunar alignments of the station stones were symbolic or whether people were meant to observe the Moon through them. Neither do we know which phases of the Moon would be more dramatic to witness.
A search for answers
In our upcoming work, we will be trying to answer the questions the major lunar standstill hypothesis raises. It’s unclear whether the Moon would have been strong enough to cast shadows and how they would have interacted with the other stones. We will also need to check whether the alignments can still be seen today or if they are blocked by woods, traffic and other features.
The Moon will align with the station stone rectangle twice a month from about February 2024 to November 2025, giving us plenty of opportunities to observe this phenomenon in different seasons and phases of the Moon.
To bring our research to life, English Heritage will livestream the southernmost Moonrise in June 2024, and host a series of events throughout the year, including talks, a pop-up planetarium, stargazing and storytelling sessions.
Across the Atlantic, our partners at the US Forest Service are developing educational materials about the major lunar standstill at Chimney Rock National Monument. This collaboration will result in events showcasing and debating the lunar alignments at both Stonehenge and at Chimney Rock.
I came across this post yesterday and thought that it would make a good article for today. But the truth is that I, and I expect many other readers, do not understand the article.
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Employees Heartbroken When They See Someone Tied To ‘Do Not Abandon Animals’ Sign
Outside the front door of the Harbor Humane Society sits a sign. “Do not abandon an animal here,” the sign reads. “Wait until business hours. No fee for bringing an animal to HHS. For the sake of the animal, please be humane.” An older, outdated version of the same sign sits at the back of the shelter, too, near some picnic tables where employees can take a break. When they arrived at work one morning recently, there were no animals waiting for them out front.
Harbor Humane Society
Sadly, the same could not be said for the sign in the back.
Tied to the base of the “do not abandon animals” sign was a tiny dog who had been abandoned there the night before. Security footage showed the dog, later named Trixie, had been tied to the sign around 9 p.m. and wasn’t found until 7:30 a.m. the next morning, meaning she’d waited there for 11 hours.
Harbor Humane Society
“Our team member was just about to unarm the building (had just arrived to start their morning shift) when she noticed the dog tied to the signpost near our intake door located toward the back side of the shelter,” Jen Nuernberg, director of marketing and strategic initiatives at Harbor Humane Society, told The Dodo. “Initially, she was nervous and scared, barking at her. But once she crouched down and gave her some time, she quickly warmed up and crawled right into her lap. She has been very friendly ever since!”
Harbor Humane Society
Trixie was terrified out there all alone, wondering why she’d ended up there. As soon as she met her rescuer, though, all was well. She was rushed inside and eventually met the rest of the staff members, who were just as heartbroken by the situation. Thankfully, Trixie seemed to be pretty healthy, just a little confused — as was everyone at the shelter.
“When someone abandons an animal without any information, we are just left to guess,” Jen Self Aulgur, executive director at Harbor Humane Society, told The Dodo. “So we can assume she is about 3 to 4 years old, but we don’t know her story, her name, her likes, her favorite treats or toys. This is all information we try to get on animals when they are surrendered to the shelter.”
Harbor Humane Society
The shelter employees are still hoping someone might come forward to give them some information about Trixie before she’s adopted, just to make sure she’s getting the best care possible.
“This pup deserves to have her story and history known,” Self Aulgur said. “We do not want to shame or get you in trouble — we just want to help this poor pup.”
Harbor Humane Society
Trixie is safe now and will be available for adoption in about a week or so. Until then, she’s getting as many kisses and cuddles as the staff can give her while she dreams of her loving forever family.
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Let me add my wishes to the Harbor Humane Society in hoping that very soon Trixie will be adopted by that loving family.
Learning from Dogs 