Category: Education

Darkness!

Chris Impey writes about his specialty in observational cosmology.

This has nothing to do with life, nothing that we are dealing with in our daily affairs, and has nothing to do with our dear dogs. BUT! This is incredibly interesting! Incredibly and beautifully interesting!

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The most powerful space telescope ever built will look back in time to the Dark Ages of the universe

Hubble took pictures of the oldest galaxies it could – seen here – but the James Webb Space Telescope can go back much farther in time. NASA

Chris Impey, University of Arizona

Some have called NASA’s James Webb Space Telescope the “telescope that ate astronomy.” It is the most powerful space telescope ever built and a complex piece of mechanical origami that has pushed the limits of human engineering. On Dec. 18, 2021, after years of delays and billions of dollars in cost overruns, the telescope is scheduled to launch into orbit and usher in the next era of astronomy.

I’m an astronomer with a specialty in observational cosmology – I’ve been studying distant galaxies for 30 years. Some of the biggest unanswered questions about the universe relate to its early years just after the Big Bang. When did the first stars and galaxies form? Which came first, and why? I am incredibly excited that astronomers may soon uncover the story of how galaxies started because James Webb was built specifically to answer these very questions.

A graphic showing the progression of the Universe through time.
The Universe went through a period of time known as the Dark Ages before stars or galaxies emitted any light. Space Telescope Institute

The ‘Dark Ages’ of the universe

Excellent evidence shows that the universe started with an event called the Big Bang 13.8 billion years ago, which left it in an ultra-hot, ultra-dense state. The universe immediately began expanding after the Big Bang, cooling as it did so. One second after the Big Bang, the universe was a hundred trillion miles across with an average temperature of an incredible 18 billion F (10 billion C). Around 400,000 years after the Big Bang, the universe was 10 million light years across and the temperature had cooled to 5,500 F (3,000 C). If anyone had been there to see it at this point, the universe would have been glowing dull red like a giant heat lamp.

Throughout this time, space was filled with a smooth soup of high energy particles, radiation, hydrogen and helium. There was no structure. As the expanding universe became bigger and colder, the soup thinned out and everything faded to black. This was the start of what astronomers call the Dark Ages of the universe.

The soup of the Dark Ages was not perfectly uniform and due to gravity, tiny areas of gas began to clump together and become more dense. The smooth universe became lumpy and these small clumps of denser gas were seeds for the eventual formation of stars, galaxies and everything else in the universe.

Although there was nothing to see, the Dark Ages were an important phase in the evolution of the universe.

A diagram showing different wavelengths of light compared to size of normal objects.
Light from the early universe is in the infrared wavelength – meaning longer than red light – when it reaches Earth. Inductiveload/NASA via Wikimedia Commons, CC BY-SA

Looking for the first light

The Dark Ages ended when gravity formed the first stars and galaxies that eventually began to emit the first light. Although astronomers don’t know when first light happened, the best guess is that it was several hundred million years after the Big Bang. Astronomers also don’t know whether stars or galaxies formed first.

Current theories based on how gravity forms structure in a universe dominated by dark matter suggest that small objects – like stars and star clusters – likely formed first and then later grew into dwarf galaxies and then larger galaxies like the Milky Way. These first stars in the universe were extreme objects compared to stars of today. They were a million times brighter but they lived very short lives. They burned hot and bright and when they died, they left behind black holes up to a hundred times the Sun’s mass, which might have acted as the seeds for galaxy formation.

Astronomers would love to study this fascinating and important era of the universe, but detecting first light is incredibly challenging. Compared to massive, bright galaxies of today, the first objects were very small and due to the constant expansion of the universe, they’re now tens of billions of light years away from Earth. Also, the earliest stars were surrounded by gas left over from their formation and this gas acted like fog that absorbed most of the light. It took several hundred million years for radiation to blast away the fog. This early light is very faint by the time it gets to Earth.

But this is not the only challenge.

As the universe expands, it continuously stretches the wavelength of light traveling through it. This is called redshift because it shifts light of shorter wavelengths – like blue or white light – to longer wavelengths like red or infrared light. Though not a perfect analogy, it is similar to how when a car drives past you, the pitch of any sounds it is making drops noticeably. Similar to how a pitch of a sound drops if the source is moving away from you, the wavelength of light stretches due to the expansion of the universe.

By the time light emitted by an early star or galaxy 13 billion years ago reaches any telescope on Earth, it has been stretched by a factor of 10 by the expansion of the universe. It arrives as infrared light, meaning it has a wavelength longer than that of red light. To see first light, you have to be looking for infrared light.

Telescope as a time machine

Enter the James Webb Space Telescope.

Telescopes are like time machines. If an object is 10,000 light-years away, that means the light takes 10,000 years to reach Earth. So the further out in space astronomers look, the further back in time we are looking.

A large golden colored disc with a sensor in the middle and scientists standing below.
The James Webb Space Telescope was specifically designed to detect the oldest galaxies in the universe. NASA/JPL-Caltech, CC BY-SA

Engineers optimized James Webb for specifically detecting the faint infrared light of the earliest stars or galaxies. Compared to the Hubble Space Telescope, James Webb has a 15 times wider field of view on its camera, collects six times more light and its sensors are tuned to be most sensitive to infrared light.

The strategy will be to stare deeply at one patch of sky for a long time, collecting as much light and information from the most distant and oldest galaxies as possible. With this data, it may be possible to answer when and how the Dark Ages ended, but there are many other important discoveries to be made. For example, unraveling this story may also help explain the nature of dark matter, the mysterious form of matter that makes up about 80% of the mass of the universe.

James Webb is the most technically difficult mission NASA has ever attempted. But I think the scientific questions it may help answer will be worth every ounce of effort. I and other astronomers are waiting excitedly for the data to start coming back sometime in 2022.

Chris Impey, University Distinguished Professor of Astronomy, University of Arizona

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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The dark ages of the universe that lasted for millions of years until gravity started to form some order out of the ‘soup’.

I don’t know about you but the winter nights, when the sky is clear, have me waiting outside for the dogs to come in looking up at the night sky just lost in the sheer wonder of it all.

The very best of luck to NASA on December 18th!

Is there more to licking paws?

I am speaking of dogs!

Speaking for myself I haven’t ever given any notice to a dog licking its paws. Jeannie, however, would spot if a dog was over-licking, (you know what I mean), and would find out the cause.

This comes to the fore because The Dodo published a post in May, 2020, that I reckoned was worth republishing.

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Why Does My Dog Always Lick Her Paws?

Here’s how to tell when it’s a problem.

By DANIELLE ESPOSITO , Published on May 5th, 2020

You’ve seen your dog do it a thousand times — that cute paw licking that can quickly turn to “Hey! Stop that!” once it becomes a total obsession.

In general, paw licking is normal behavior for many dogs. They do it after they eat; they do it after they’ve been playing outside; they even sometimes do it before taking a nap. While all these are expected, you should start to take it more seriously if you’re noticing a sudden increase in licking, raw or irritated spots between their toes, or even loss of fur.

When it crosses the line between normal grooming and excessive paw licking, it’s probably time to try to figure out the root of the problem — so we chatted with one of our favorite veterinarians to get some expert advice.

Allergies

“There are a number of reasons why dogs lick their paws, but one of the most common reasons is allergies,” Dr. Alex Blutinger, a veterinarian from BluePearl Pet Hospital in New York City, told The Dodo.

“This behavior can be caused by environmental allergies, food allergies and even fleas or ticks,” he said. 

Dr. Blutinger said many everyday substances can also cause an allergic reaction, including things like pollen, grass that’s been treated with insecticide, certain plastics or rubber materials on food bowls, and even certain medications or shampoos.

“There are other caustic chemicals that dogs encounter in their environment,” he said, “[like] deicing salts to melt ice.”

This means that if you’ve noticed your dog is licking her paws more than usual, she’s likely experiencing allergies. If that’s what you suspect, it’s a good idea to chat with your vet about how to help her feel better.

Trauma to the Paws

Aside from allergies, excessive paw licking — which includes paw chewing — can also be caused by various types of injuries.

According to Dr. Blutinger, some of these types of trauma can include burns from walking on hot surfaces like cement or blacktop, splinters, broken nails, injured bones or ligaments, or even insect bites.

It’s a good idea to inspect your dog’s paws to see if you can find any physical trauma, and consult your vet if you think it’s something that may need extra attention.

Gastrointestinal Issues

“Interestingly, dogs that have gastrointestinal disorders (like pancreatitis) have also been shown to lick their paws,” Dr. Blutinger said.

He added that certain hormonal imbalances like hypothyroidism and Cushing’s disease can also cause dogs to lick their paws — which means a trip to the vet is definitely in order to sort out your pup’s health!

Anxiety

Finally, sensitive dogs can also display anxiety by licking their paws, in the same way some people bite their nails as a sign of nervousness. If you think this is the case, it might be a good idea to figure out why your dog is feeling anxious and find ways to help her feel better.

So while paw licking is generally normal for most dogs, if you worry it’s becoming obsessive, and you can’t figure out an obvious cause, it’s a good idea to check with your vet to make sure your dog doesn’t need extra care.

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I call that very sound advice.

Out of interest have any readers of this post had a case of excessive licking with their dogs?

Furry life saver!

The story of Rhys the dog!

I have known Keith Edmunds from a long time ago and we chat from time to time. Keith has his own company Tiger Computing, Linux specialists, (We provide managed cloud services and Linux support services for high-tech businesses), and we had a business connection many moons ago. But in an effort to stay connected with friends in the old country I have subscribed for quite some time to Keith’s newsletter. Although Keith clearly is speaking to potential clients his newsletter is quite readable for non-technical peeps such as myself.

At the end of September this year Keith’s newsletter was a little different. Here it is:

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Rhys the dog saved my wife’s life last week.

She was alone in the house. She put some flatbread in a pan on the hob, then went to check something on her PC. And forgot about the flatbread.

The flatbread got hotter, started smoking, and then the smoke alarm went off. That would be a clue for most of us that something may be amiss.

But my wife is deaf. She can’t hear the smoke alarm.

That’s when Rhys, the Hearing Dog, leapt into action. He found her and butted her hard with his nose. “What is it?”, she asked him. He squatted down on all fours, the signal that the smoke alarm is going off. He only makes that move for the smoke alarm so it’s clear what the problem is.

My wife ran to the kitchen, turned off the hob and opened windows to disperse the smoke. Without Rhys alerting her there would have been a fire. The consequences of that can only (fortunately) be imagined.

So here’s how it works. Rhys is trained to notify my wife when he hears certain sounds. He notified her when he heard one, and corrective action was taken.

Here at Tiger Computing we have sophisticated monitoring systems that keep an eye on our clients’ Linux systems. They’re configured to alert our support staff if things start going wrong, and the support staff can take corrective action.

Our monitoring probably won’t save your life. But it might save your bacon.

Until next week –
Keith

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It is a delightful account of yet another aspect of dogs. Dogs can undertake many things and some of our dogs are really clever. Rhys is an example of how highly trained dogs can be.

I spoke to Keith and asked permission to republish this, gladly and readily given, and whether Keith had any photographs of Rhys.

Rhys and Mrs. Edmunds

Beautiful!

Who wants to kiss a dog!

Well Jeannie does for sure.

All our six dogs are beautifully friendly but there’s one dog that just loves to be kissed and returns the favour just as much. That is Oliver!

Oliver

I don’t have a photograph of Oliver and Jean kissing and that’s me being lazy rather than anything else.

Now for whatever deep-seated reason I won’t give Oliver or any of the other dogs a tongue-to-tongue kiss but I am envious of Jean and Oliver; they both love it!

All of which serves as a preamble to an article from The Dodo on dogs’ mouths! Here it is, and it is quite a lengthy one, so settle yourself down and quietly read it completely:

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Are Dogs’ Mouths Cleaner Than Humans’?

For everyone who kisses their pup on the mouth 😘

By LAUREN TAYLOR, Published on the 24th September, 2021

If anyone has ever shamed you for letting your dog give you a kiss, you might have told them that dogs’ mouths are cleaner than humans’ mouths. But is that actually true, or is it just something obsessed dog parents made up to justify letting their dogs lick them?

The truth is that dogs’ mouths actually aren’t cleaner than human mouths — but they’re not really dirtier either. We just have different germs.

The Dodo spoke to Dr. Jonathan Roberts, a remote veterinarian with DoggieDesigner.com, to find out everything you need to know about dog saliva.

Why dogs’ mouths aren’t cleaner than human mouths.

Your dog’s mouth isn’t exactly clean. Just like people have bacteria living in our mouths, dogs do too.

“Multiple studies have discovered that dogs have many unique and potentially dangerous bacteria and other parasites lurking in their mouths,” Dr. Roberts told The Dodo. “Around 600 different species of bacteria have been discovered in both canine and human mouths.”

The type and amount of bacteria living in a dog’s mouth depends on the level of periodontal (dental) disease present, which is determined by a number of factors, including:

  • Diet
  • Breed (smaller dogs tend to be at greater risk because they have smaller teeth and mouths, leading to more food getting stuck, and they have less bone mass, leading to tooth loss)
  • Frequency of teeth brushing
  • Frequency of professional dental cleaning by a vet

What diseases can you get from dog saliva?

There are lots of bacteria in a dog’s mouth that are different from what humans have in our mouths. Some of these are harmless, but some could make you sick.

Some of the bacteria found in dogs’ mouths that can be dangerous to people include:

  • E. coli, Clostridia, Salmonella and Campylobacter — “[These are] bacteria that can cause severe gastrointestinal illness in people,” Dr. Roberts said. “Dogs are often carriers of these bacteria, yet they do not become ill from them. They usually get these bacteria in their mouths through licking their anuses or ingesting other animals’ feces. Another common source of these illness-causing bacteria is from ingesting raw food.”
  • Pasteurella — This can cause skin infections that can travel to your lymph nodes and cause severe disease, such as cellulitis or meningitis.
  • Capnocytophaga canimorsus — “[This] enters the wounds in skin after being licked by a dog’s tongue,” Dr. Roberts said. “Mostly only immune-compromised people are susceptible to this disease that develops into septicemia [blood poisoning].”
  • Giardia and Cryptosporidium — These are actually protozoa, not bacteria, but they can still make you sick by your dog licking your face and can cause gastrointestinal illnesses.
  • Parasites — If your dog has parasites, such as worms, and licks his anus and then your face, you could contract the parasite.

So what is the risk of getting sick from your dog licking you? Even with all those germs, if you’re healthy and don’t have a compromised immune system, the risk is luckily pretty low.

“Most human immune systems will neutralize these parasites before they can cause illness,” Dr. Roberts said. “Those with weakened immune systems, such as persons going through chemotherapy, persons with HIV, very young and very old people should be more careful around pets.”

Ultimately, it’s up to you to determine if it’s a risk you want to take.

But to be safe, you can follow these steps to avoid getting sick from dog saliva:

  • Keep your dog up to date on his deworming medications and flea and tick medications.
  • Get checked out by a doctor if you get bitten or scratched by a dog.
  • Don’t let a dog lick your wounds.
  • Frequently wash items that your dog’s mouth touches, like toys and food and water bowls.
  • Don’t let your dog lick you if you’re immunocompromised, and don’t let him lick others who are immunocompromised.

Does dog saliva heal wounds?

It’s an old belief that dog saliva heals wounds. But is it actually true?

“There may be some truth to this after all,” Dr. Roberts said. “The action of licking helps to remove debris and necrotic tissue from the wound.”

Dog saliva also contains proteins that can be beneficial in healing.

“Mammal saliva contains a protein called histatin,” Dr. Roberts said. “This protein is able to kill bacteria before they can cause infection.”

Histatins have antimicrobial and antifungal properties and are part of the immune system. They have been found to play a role in wound closure.

But while it’s possible that dog saliva could help to heal a paper cut, you shouldn’t let your dog lick all of your cuts and scrapes — there are much better ways to take care of your injuries, and you always run the risk of infecting your wound instead of making it better.

“I would still not allow my dog to lick my wounds,” Dr. Roberts said. “We have excellent wound care products on the market these days that not only do a better job of keeping wounds clean but also come without the risk of introducing nasty infections or potential parasites.”

How to keep your dog’s mouth clean

If you do let your dog give you occasional kisses (and even if you don’t), you should try to keep his mouth as clean as possible since it’s also important for his health.

You can do this by regularly brushing his teeth and by providing toys that help clean his teeth.

Try this dog toothpaste from Chewy for $4.99.

“The most important way to keep your dog’s mouth clean and healthy is (just like humans) through regular teeth brushing and dental cleaning by a professional,” Dr. Roberts said. “Start introducing your dog to teeth brushing from a young age and aim to brush at least twice a week.”

You can also let your dog chew on dental treats to clean his teeth in between brushing. (These treats received The Dodo’s Paw of Approval, and you can get them from Amazon for $4.98.)

So dogs’ mouths aren’t actually cleaner than people’s, and you shouldn’t let your dog lick your wounds. But if you keep your dog’s mouth and teeth clean, a kiss from your pup every now and then should be fine (if it’s something you’re comfortable with).

We independently pick all the products we recommend because we love them and think you will too. If you buy a product from a link on our site, we may earn a commission.

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I suggest that if you want to purchase any of the products described above then you go directly to The Dodo website and place your order via The Dodo.

Overall I find this a very useful article and I am grateful to The Dodo for allowing me to republish it.

Oh dear, I meant deer!

A timely reminder from The Conversation.

We live in a rural part of Southern Oregon. The number of deer hit on our roads is appalling. Not infrequently when out cycling I come across a deer that seems uninjured. Often I get off my bike and stroke the animal, or drag it from the centre of the road to the shoulder. But it is dead.

Once recently the deer was still warm. What surprises me is that they are always dead. There never seems to be a deer that has been wounded. Probably just as well as I wouldn’t want to leave the animal.

We feed the deer at home on a daily basis and there is a young stag that has become familiar with me and starts eating the COB (corn, oats and barley mixed together) even before I have finished setting out the six piles of food. They are very dear creatures.

So this article has to be shared with you!

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Fall means more deer on the road: 4 ways time of day, month and year raise your risk of crashes

Deer cross roads whenever they wish, but some time periods are higher risk than others. Josh Edelson/AFP via Getty Images

Tom Langen, Clarkson University

Autumn is here, and that means the risk of hitting deer on rural roads and highways is rising, especially around dusk and during a full moon.

Deer cause over 1 million motor vehicle accidents in the U.S. each year, resulting in more than US$1 billion in property damage, about 200 human deaths and 29,000 serious injuries. Property damage insurance claims average around $2,600 per accident, and the overall average cost, including severe injuries or death, is over $6,000.

While avoiding deer – as well as moose, elk and other hoofed animals, known as ungulates – can seem impossible if you’re driving in rural areas, there are certain times and places that are most hazardous, and so warrant extra caution.

Transportation agencies, working with scientists, have been developing ways to predict where deer and other ungulates enter roads so they can post warning signs or install fencing or wildlife passages under or over the roadway. Just as important is knowing when these accidents occur.

My former students Victor Colino-Rabanal, Nimanthi Abeyrathna and I have analyzed over 86,000 deer-vehicle collisions involving white-tailed deer in New York state using police records over a three-year period. Here’s what our research and other studies show about timing and risk:

Time of day, month and year matters

The risk of hitting a deer varies by time of day, day of the week, the monthly lunar cycle and seasons of the year.

These accident cycles are partly a function of driver behavior – they are highest when traffic is heavy, drivers are least alert and driving conditions are poorest for spotting animals. They are also affected by deer behavior. Not infrequently, deer-vehicle accidents involve multiple vehicles, as startled drivers swerve to miss a deer and collide with a vehicle in another lane, or they slam on the breaks and are rear-ended by the vehicle behind.

Car on road during the start of leaf colors with road sign reading: Caution: High Hit Area
A sign warns of deer traffic on Route 16 in Franklin County, Maine. Education Images/Universal Images Group via Getty Images

In analyzing thousands of deer-vehicle collisions, we found that these accidents occur most frequently at dusk and dawn, when deer are most active and drivers’ ability to spot them is poorest. Only about 20% of accidents occur during daylight hours. Deer-vehicle accidents are eight times more frequent per hour of dusk than daylight, and four times more frequent at dusk than after nightfall.

During the week, accidents occur most frequently on days that have the most drivers on the road at dawn or dusk, so they are associated with work commuter driving patterns and social factors such as Friday “date night” traffic.

Over the span of a month, the most deer-vehicle accidents occur during the full moon, and at the time of night that the moon is brightest. Deer move greater distances from cover and are more likely to enter roadways when there is more illumination at night. The pattern holds for deer and other ungulates in both North America and Europe.

Over a year, by far the highest numbers of deer-vehicle accidents are in autumn, and particularly during the rut, when bucks search and compete to mate with does. In New York state, the peak number of deer-vehicle accidents occurs in the last week of October and first weeks of November. There are over four times as many deer-vehicle accidents during that period than during spring. Moose-vehicle accidents show a similar pattern.

That high-risk period is also when daylight saving time ends – it happens on Nov. 7, 2021, in the U.S. Shifting the clock one hour back means more commuters are on the road during the high-risk dusk hours. The result is more cars driving at the peak time of day and during the peak time of the year for deer-vehicle accidents.

Overall, given that most U.S. states and more than 70 countries have seasonal “daylight saving” clock shifts, elevated ungulate-vehicle accident rates caused by clock shift may be a widespread problem.

[Over 100,000 readers rely on The Conversation’s newsletter to understand the world. Sign up today.]

There is a longstanding debate about the benefit of a daylight saving clock shift, given how it disrupts humans’ circadian rhythms, causing short-term stress and fatigue. Risk of deer-vehicle accidents may be another reason to reconsider whether clock shifts are worthwhile.

Deer still cross roads at any time

It’s important to remember that deer-vehicle accidents can occur at any time of day or night, on any day of the year – and that deer can show up in urban areas as well as rural ones.

The insurance company State Farm found that on average, U.S. drivers have a 1 in 116 chance of hitting an animal, with much higher rates in states such as West Virginia, Montana and Pennsylvania. Over the 12 months ending in June 2020, State Farm counted 1.9 million insurance claims for collisions with wildlife nationwide. Around 90% of those involved deer.

Where deer or other ungulates are likely to be present, drivers should always be alert and cautious, especially at dawn, dusk, on bright moonlit nights and during the fall rut.

Tom Langen, Professor of Biology, Clarkson University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Nothing else to say but we drivers need to slow down and extra vigilant. Driving safely means always allowing for the unexpected and never following the vehicle in front too close. The minimum safe distance is one vehicle length for every 10 miles per hour in speed!

Canine Behavior.

Canine Behavior Friends from the start

In this month’s Science magazine, on page 1213, there is a short piece under the heading of In Other Journals.

I share it with you.

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Canine Behavior Friends from the start

By Sacha Vignieri.

Dogs, unlike wolves, are highly responsive to human voice, gestures, and eye contact.
CREDIT: ISTOCK.COM/HNIJJAR007

The closest relative to dogs, “man’s best friend,” is the wolf, a wily predator that generally avoids human interaction. For decades, researchers and dog owners have wondered how the leap to domestication occurred.

The main hypothesis invoked very early selection for wolves that “liked”—or least tolerated—humans, and the connection strengthened from there.

However, there is still some debate about whether the degree to which dogs interact and communicate with humans is a learned trait.

Two recent studies appear to close the book on this learning hypothesis. Bray et al. looked at about 400 puppies and found that at this young age and without much human interaction, they were adept at following human gestures and positively responded to high-pitched “puppy talk.” Further, there was variation in these responses with an association between relatedness and social communication skills, which supports a genetic driver.

Salomons et al. compared dog and wolf puppies and found no difference in general cognitive responses, but much greater responsiveness to human gestures and eye contact, in dog puppies. Importantly, this happened even though the dog pups had received less actual human interaction than did the wolf pups.

These studies confirm that dogs’ interest in communication with humans is an evolved trait unique to their lineage.

Curr. Biol.31, 3132, 3137 (2021).

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That is fascinating. Dogs have evolved this trait on their own, so to speak. It further underlines the precious nature of the relationship between dogs and humans.

Brandy et moi! Taken 6th April, 2018.

Yet more of the big question.

Time!

I wasn’t going to publish a post for today but then yesterday I read this article on The Conversation and wanted to share it with you. In fact it shares much of what I posted on the 1st, The Big Question. Because time and infinity are beautifully connected.

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What is time – and why does it move forward?

By Thomas Kitching, Lecturer in Astrophysics, UCL

Imagine time running backwards. People would grow younger instead of older and, after a long life of gradual rejuvenation – unlearning everything they know – they would end as a twinkle in their parents’ eyes. That’s time as represented in a novel by science fiction writer Philip K Dick but, surprisingly, time’s direction is also an issue that cosmologists are grappling with.

While we take for granted that time has a given direction, physicists don’t: most natural laws are “time reversible” which means they would work just as well if time was defined as running backwards. So why does time always move forward? And will it always do so?

Does time have a beginning?

Any universal concept of time must ultimately be based on the evolution of the cosmos itself. When you look up at the universe you’re seeing events that happened in the past – it takes light time to reach us. In fact, even the simplest observation can help us understand cosmological time: for example the fact that the night sky is dark. If the universe had an infinite past and was infinite in extent, the night sky would be completely bright – filled with the light from an infinite number of stars in a cosmos that had always existed.

For a long time scientists, including Albert Einstein, thought that the universe was static and infinite. Observations have since shown that it is in fact expanding, and at an accelerating rate. This means that it must have originated from a more compact state that we call the Big Bang, implying that time does have a beginning. In fact, if we look for light that is old enough we can even see the relic radiation from Big Bang – the cosmic microwave background. Realising this was a first step in determining the age of the universe (see below).

But there is a snag, Einstein’s special theory of relativity, shows that time is … relative: the faster you move relative to me, the slower time will pass for you relative to my perception of time. So in our universe of expanding galaxies, spinning stars and swirling planets, experiences of time vary: everything’s past, present and future is relative. 

So is there a universal time that we could all agree on?

The universe’s timeline. Design Alex Mittelmann, Coldcreation/wikimedia, CC BY-SA

It turns out that because the universe is on average the same everywhere, and on average looks the same in every direction, there does exist a “cosmic time”. To measure it, all we have to do is measure the properties of the cosmic microwave background. Cosmologists have used this to determine the age of the universe; its cosmic age. It turns out that the universe is 13.799 billion years old. 

Time’s arrow

So we know time most likely started during the Big Bang. But there is one nagging question that remains: what exactly is time? 

To unpack this question, we have to look at the basic properties of space and time. In the dimension of space, you can move forwards and backwards; commuters experience this everyday. But time is different, it has a direction, you always move forward, never in reverse. So why is the dimension of time irreversible? This is one of the major unsolved problems in physics. 

To explain why time itself is irreversible, we need to find processes in nature that are also irreversible. One of the few such concepts in physics (and life!) is that things tend to become less “tidy” as time passes. We describe this using a physical property called entropy that encodes how ordered something is.

Imagine a box of gas in which all the particles were initially placed in one corner (an ordered state). Over time they would naturally seek to fill the entire box (a disordered state) – and to put the particles back into an ordered state would require energy. This is irreversible. It’s like cracking an egg to make an omelette – once it spreads out and fills the frying pan, it will never go back to being egg-shaped. It’s the same with the universe: as it evolves, the overall entropy increases.

Unfortunately that’s not going to clean up itself. Alex Dinovitser/wikimediaCC BY-SA

It turns out entropy is a pretty good way to explain time’s arrow. And while it may seem like the universe is becoming more ordered rather than less – going from a wild sea of relatively uniformly spread out hot gas in its early stages to stars, planets, humans and articles about time – it’s nevertheless possible that it is increasing in disorder. That’s because the gravity associated with large masses may be pulling matter into seemingly ordered states – with the increase in disorder that we think must have taken place being somehow hidden away in the gravitational fields. So disorder could be increasing even though we don’t see it.

But given nature’s tendency to prefer disorder, why did the universe start off in such an ordered state in the first place? This is still considered a mystery. Some researchers argue that the Big Bang may not even have been the beginning, there may in fact be “parallel universes” where time runs in different directions

Will time end?

Time had a beginning but whether it will have an end depends on the nature of the dark energy that is causing it to expand at an accelerating rate. The rate of this expansion may eventually tear the universe apart, forcing it to end in a Big Rip; alternatively dark energy may decay, reversing the Big Bang and ending the Universe in a Big Crunch; or the Universe may simply expand forever.

But would any of these future scenarios end time? Well, according to the strange rules of quantum mechanics, tiny random particles can momentarily pop out of a vacuum – something seen constantly in particle physics experiments. Some have argued that dark energy could cause such “quantum fluctuations” giving rise to a new Big Bang, ending our time line and starting a new one. While this is extremely speculative and highly unlikely, what we do know is that only when we understand dark energy will we know the fate of the universe.

So what is the most likely outcome? Only time will tell.

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Let me explain, in part, entropy. Because while I and many others sort of understand it, the principle behind entropy is much more detailed.

It is explained pretty well on WikiPedia, from which I reproduce the first paragraph.

Entropy is a scientific concept, as well as a measurable physical property that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynamics, where it was first recognized, to the microscopic description of nature in statistical physics, and to the principles of information theory. It has found far-ranging applications in chemistry and physics, in biological systems and their relation to life, in cosmologyeconomicssociologyweather scienceclimate change, and information systems including the transmission of information in telecommunication.[1]

There’s a little bit more to read … 😉

Again, I am going to finish with sharing that image from Unsplash.

Imagine the universe is constant whichever direction one looks in, to 1 in 10,000. That is truly amazing!

Dogs’ Teeth!

Another helpful article.

Of course when I want a photograph of the teeth of one of our dogs then none is available. So this photo of Sweeney kissing Jean taken in 2018 will have to do.

But the question of dental care and attention for dogs is yet something else we dog owners need to know. That is why a recent article in The Dodo is a great share for you all today.

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How To Tell If Your Dog Needs Dental Work

And what it means if he has dragon breath 🐉

By SAM HOWELL

Published on the 7th September, 2021

You probably think that if your dog needs dental work, you’ll be able to tell by looking at his teeth — right?

Turns out, that’s not always the case.

The Dodo spoke with Allyne Moon, a registered vet technician with Free Animal Doctor in California, who explained what you need to know about dental work for dogs — and why it’s so important to get regular check-ups.

How to tell if your dog needs dental work

Your dog’s dental health is super important, so you need to be able to identify when your pup’s pearly whites might need some work.

“Pet parents should check their dogs’ teeth regularly,” Moon told The Dodo.

During those check-ins on his chompers, you should know what to do and what to look for.

“Look all the way at the back teeth by gently pulling the corner of the lip back,” Moon explained. “If the teeth appear discolored, [if the] gums are very red [or ‘angry’], [if] any blood or [pus or] discharge is present or if teeth are loose, they should seek a consultation with their veterinarian.”

If your pup’s breath is so bad that it almost makes you wish you didn’t have a sense of smell, that’s also a pretty solid indication that your dog needs dental work.

“If your dog’s breath smells bad, even if the teeth look OK, it is also an indication to have your pet evaluated by your veterinarian,” Moon said.

Signs your dog needs dental work

Some general symptoms that might mean your pup needs dental work include:

  • Having bad breath
  • Experiencing excessive drooling
  • Pawing or rubbing his mouth (more than usual)
  • Getting lumps on his face under his eyes
  • Dropping food when eating
  • Eating less
  • Appearing like his mouth is in pain
  • Refusing to let you look in his mouth

If you’re noticing any of these signs, you should give your vet a call.

Common dog dental problems

According to Moon, your dog can be at higher risk for certain dental problems based on his size.

“In my experience, the most common dental problems in … small breed dogs [are] heavy dental tartar, calculus and crowded [or] diseased teeth,” Moon said. “Large breed dogs [can have] broken teeth, requiring … root canal, endodontic therapy or extraction.”

Now, that doesn’t mean that tartar buildup only happens in small dog breeds, or that big dogs are the only pups who have broken teeth.

These problems can happen in any dog, no matter his size or breed.

If your pup is experiencing any of these things, or any of the symptoms above, it’s crucial to bring him directly to the vet ASAP.

“I would absolutely NEVER take your pet to a ‘nonanesthetic pet dentist’ [or] run out [to] a grooming shop,” Moon said. “At best, these people only provide a cosmetic service. At [worst], you’ll be spending a lot of money for something that gives you a false sense of confidence and can ruin your pet’s health … If your pet is lucky, the only thing they will waste is your money.”

How to stay on top of your dog’s dental care

“Unfortunately, once your dog’s teeth have reached the stage of significant tartar buildup, foul breath or loose [or] broken teeth, there’s nothing a pet parent can do at home to help beyond scheduling an appointment with their veterinarian,” Moon said.

However, there are things you can do to try to prevent things from getting to that point.

The best way to keep your dog’s teeth clean at home

According to Moon, it’s key to use an appropriate dog toothpaste.

“The onset of many dental problems can be delayed by having pet parents brush their dogs’ teeth with a pet-approved enzymatic toothpaste,” Moon explained. “The beauty of an enzymatic toothpaste is it works without scrubbing.”

This is great if your pup can’t stand it when you try to get in there with a toothbrush.

“If all you can do is get the enzymatic paste on the gums and teeth, that is fine,” Moon said. “People have gotten good results by just smearing the paste onto their dog’s gums and teeth.”

It’s also important to know what should — and shouldn’t — be in your dog’s toothpaste.

“Whatever product people use, it should be labeled for dogs, work by using enzymes, NOT have fluoride in it and come in a flavor your pet enjoys,” Moon explained.

(Ed: Two entries for products listed on Amazon removed. Please go here if you need to see the details.)

Between regular at-home dental care and cleanings at your vet’s office, there’s so much you can do to keep your pup’s teeth pearly white — and smelling good.

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And I will close with another photograph, this time of Brandy, but again with his mouth tightly closed!

Hope people found this useful!

A beautiful photograph

Of a hummingbird!

Thursday was a chaotic day for me and I only got to my desk at 3pm. Then I found that I didn’t have any posts to share about dogs.

I was mulling what to do and then came across this article on Treehugger and wanted to share it with you.

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Hummingbirds Are Able to Smell Danger

Vultures aren’t the only birds who recognize odors, study finds.

By Mary Jo DiLonardo September 9, 2021

Mary Jo DiLonardo
Tongho58 / Getty Images

Glittery and graceful, hummingbirds hover and flit in midair as they gather nectar. But it’s not just their athleticism that helps them source food. 

New research finds that these tiny birds have a great sense of smell that helps them detect potential danger when they are hunting for nectar.

“In the last 10-15 years, researchers have just now begun to realize the importance of smell in birds in general. For a very long time, it has been known that some birds, such as vultures, have a keen sense of smell and use it to find food,” study co-author Erin Wilson Rankin, an associate entomology professor at the University of California Riverside, tells Treehugger.

“However, the role of olfaction in most birds has only been recently recognized. That may be in part because many birds do not appear to use odor to help them locate food.”

In earlier studies, researchers were unable to show that hummingbirds preferred the smell of flowers that contained nectar. Also, flowers that have been pollinated by birds don’t have strong aromas, like those that have been pollinated by insects. That’s why scientists didn’t believe that birds had the ability to smell odors.

But with this new study, researchers believe otherwise.

For their experiment, Rankin and her colleagues observed more than 100 hummingbirds in the wild and in aviaries. The birds were given the choice between feeders that contained just sugar water, or sugar water with the addition of one of several chemicals with a scent that meant there was an insect present. The feeders otherwise looked exactly the same.

The scents included one deposited on flowers by European honeybees, a chemical produced by Argentine ants, and formic acid, which is released defensively by some formica ants and can injure birds and mammals.

“If a bird has any exposed skin on their legs, formic acid can hurt, and if they get it in their eyes, it isn’t pleasant,” Rankin said in a statement. “It’s also extremely volatile.”

In the experiments, the hummingbirds avoided the feeders with the sugar water that contained the ant-derived chemicals. They didn’t react to the sugar water with the honeybee scent, even though it’s been known to keep other bees from visiting flowers.

To make sure the bees weren’t avoiding the feeders due to a fear of a new smell, the researchers performed an extra test with sugar water and ethyl butyrate, which is a common additive in human food.

“It smells like Juicy Fruit gum, which is not a smell known in nature,” Rankin said. “I did not enjoy it. The birds did not care about it though and didn’t go out of their way to avoid it.”

The results were published in the journal Behavioral Ecology and Sociobiology.

Avoiding Danger 

For hummingbirds, recognizing smells isn’t just about finding a meal. They use their sense of smell much differently than vultures. These birds use the massive olfactory bulb in their brain like an “airborne bloodhound” to detect decaying carcasses.

Instead, hummingbirds use their excellent vision to locate flowers from which they collect nectar.

“Flowers, while specific species may be patchy in distribution, are much more common and numerous than the animal carcasses that vultures rely on. Thus, it is not surprising that vultures use their sense of smell to find carcasses which they then scavenge,” Rankin explains.

Hummingbirds use their ability to smell in a different way.

“Rather than using odors to find flowers, they will avoid flowers or feeders that have specific insect odors on them, such as formic acid or an Argentine ant aggregation pheromone. A hummingbird can use the chemical cues associated with ants to help them determine if the hummingbird should feed from there, or avoid it because it’s already occupied by ants, which can drink the nectar first or potentially harm them,” Rankin says.

“Ants are also very hard for hummingbirds to see until they are up close, so being able to smell them even when they are hidden deep in a flower could be advantageous. By avoiding defensive chemicals, hummingbirds can avoid interactions with ants and focus on feeding at safer food resources.”

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As long as I shall live I will never stop being amazed at what science discovers and then reports. And the photograph is gorgeous!