Skip to main content

How the Moon causes tides in the oceans on both sides of the Earth at the same time.

moon tides


Tides are cyclical changes in sea level, caused by the influence of the moon's gravitational force on Earth. At any point in the world, the tides occur twice a day, in cycles of 12 hours and 25 minutes, half the time it takes for each point on Earth to pass in the area closest to the moon. At any given moment, the tide occurs in two separate regions of the earth. One is on the closest side to the moon, the other on the opposite side, the farthest from the moon. The tide can be equated with a kind of ellipse of water revolving around the solid earth, whose long axis is always parallel to the axis connecting the center of the earth to the moon.

There is a misconception that the gravity of the moon is the one that "draws" water. But in fact, changes in the surface of the oceans occur as a result of another physical phenomenon, which explains why the tide is also occurring on the side of the Earth far from the Moon, a fact that the moon's gravity does not explain.

Every point on earth "feels" the moon's gravity with a different intensity?

The closest point of the moon to the surface of the earth will feel the strongest gravity, while the opposite point, the farthest, will feel the weakest force.

It is the lack of uniformity of the gravitational force acting on the Earth that causes the tide phenomenon, which is explained by the tidal force. The tidal force operates at a different intensity on every point on earth. It is calculated by the average gravitational force of the moon (which is felt in the center of the earth) by the force of gravity that is felt at each point. Since the nearest point to the moon has a gravitational force greater than average, it will "stretch" toward the moon. However, at the farthest point, where the gravitational force acting on it is smaller than the average, the force calculation thus gives a negative result, and indeed this point is stretched far from the moon. The space around the Earth, located at 90 degrees to the axis connecting the center of the earth and the Moon, acts roughly equal to the average gravity, canceling each other. Therefore, this area, which stands at the axis of the earth and the moon, seemingly acts as the gravitational force of the Earth alone, and is "pressed" to its center.

These are minor changes, but with the vast surface area of ​​the oceans, and the ability of the water to move relatively easily, make these changes stand out and create the tidal cycles that characterize it.


Why don`t we see tidal cycles in the lakes as well? 

The power of the tide does indeed work on lakes, and indeed on every other body on earth. But the limited surface area of ​​the water in the lakes does not allow them a range of motion wide enough to create significant level differences between their two banks. In the Great Lakes in Michigan, which are among the world's largest lakes, tidal cycles occur, causing a few centimeters of surface change, but light winds are enough to make waves higher, and the tide is not actually felt.

All the oceans are interconnected, and according to logic, we would expect the altitude differences generated during the tidal cycles to be identical at each point along the beaches around them. But the actual situation is not the same, and in each coastline on the Earth there are different levels of change. The factors influencing the range of change are the volume of water near the coast and the geography of that region. In shallow and open bays, there will be bigger level changes, such as in the Gulf of Fundy in eastern Canada, where tidal waves generate changes of more than 16 meters, the largest in the world.

The tidal force affacets not only the oceans, but also on the atmosphere and, to a certain extent, on the Earth itself, which sometimes causes earthquakes, or perhaps we should say: moon quakes.

Comments

Popular posts from this blog

Moon’s gamma-ray glow from NASA’s Fermi Gamma-ray Space Telescope

Steadily improving view of the Moon’s gamma-ray glow from NASA’s Fermi Gamma-ray Space Telescope. Each 5-by-5-degree image is centered on the Moon and shows gamma rays with energies above 31 million electron volts, or tens of millions of times that of visible light. 
At these energies, the Moon is actually brighter than the Sun. Brighter colors indicate greater numbers of gamma rays. This image sequence shows how longer exposure, ranging from two to 128 months (10.7 years), improved the view.
If our eyes could see high-energy radiation called gamma rays, the Moon would appear brighter than the Sun! That’s how NASA’s Fermi Gamma-ray Space Telescope has seen our neighbor in space for the past decade.

Gamma-ray observations are not sensitive enough to clearly see the shape of the Moon’s disk or any surface features. Instead, Fermi’s Large Area Telescope (LAT) detects a prominent glow centered on the Moon’s position in the sky.

Scientists have been analyzing the Moon’s gamma-ray glow as a way…

Two T-38s traveling faster than the speed of sound (shock waves visible)

To get the image, NASA utilized a Super King Air turboprop airplane flying at an indicated airspeed of about 160 miles per hour at 30,000 feet. 

The two supersonic jets, separated by about 30 feet front to back and 10 feet vertically, were listed below the King Air by about 2,000 feet when it shot the images. 
The shock waves were photographable because of the modification in air density. "The density modification triggers a modification in the index of refraction," Banks states. A spoon will look distorted when you see it immersed in a glass of water. 
It turns out that images of shockwaves triggered by flying faster than the speed of sound are amazing to see, even without the sound. 

NASA photographed 2 T-38 airplanes flying at merely faster than the speed of sound over California. The King Air has ports on its stomach that can be opened or closed, and the photography equipment was placed in among those ports so it might shoot downwards. 
The turboprop doing the shooting was st…

A new automated system that is capable of producing organs from stem cells

Organoids: mini organs in a petri dish for disease research and new curesA new automated system developed at the University of Washington is capable of efficiently producing mini organs from stem cells, and thereby has the potential to accelerate biomedical science and research.

Normally, when a researcher wants to test medications or treatments on cells from a particular tissue - for example, a liver - he should first grow the cells in the laboratory in a petri dish. The cells grow on the bottom of the dish and form a thin two-dimensional tissue that does not reflect what happens in the complex three-dimensional tissue that exists in the body. In recent years, researchers have been able to make stem cells develop into three-dimensional structures more like those in the body, called mini-organs. Researchers are able to test different treatments for the mini-organs, and to be more confident that they actually reflect what happens in the living body.

But there is one big problem: produci…

Stanford Prison Experiment Response bias, Are the conclusions valid?

Stanford Prison ExperimentAlmost 50 years after the Stanford Prison Experiment (zimbardo), which is considered one of the milestones in behavioral psychology, it turns out that much of it was fake. Conclusions about stanford prison experiment.
"How we went about testing these questions and what we found in the stanford experiment (philip zimbardo) may astound you. Our planned two-week investigation into the psychology of prison life had to be ended after only six days because of what the situation was doing to the college students who participated. In only a few days, Inour prison experiment guards became sadistic and our prisoners became depressed and showed signs of extreme stress".
This is how Philip Zimbardo summed up the experiment. In 1971, it was one of the most recognized psychological experiments in the world. Its findings were extensively covered in the media and influenced the perception of many in terms of the role of prisons, the source of criminal behavior and th…

NASA researching how climate change is adding to more regular forest fires

On July 7th, 2019 the skies around Anchorage Alaska were thick with smoke. Across the Cook Inlet, the Swan Lake Fire had spread over nearly 79,000 acres and was still growing. This was just one of over 400 fires that burned in Alaska so far in 2019.

Climate change and forest fires In the Arctic, fires can help rejuvenate ecosystems and make way for new growth. However, Arctic and boreal regions are warming at a faster rate than anywhere else on Earth, and hotter and drier summers are leading to accelerated fire cycles and more intense burns.

Elizabeth Hoy: Fires in boreal forests are different than in other areas of the world, such as those in the western United States. One of the main differences is they have these really thick organic soils layers and these soil layers burn.

And so you’re not just getting fires in the trees or in the canopy, you’re getting fires below the tree itself, like in that soil layer and that is really when you get a lot of these carbon emissions.

Researchi…

A new scientific review of 6,000 genetically modified corn studies in the last 21 years

Genetically modified crops have been criticized by environmental organizations for many years, although many studies have proven their safety. A new scientific review of about 6,000 genetically modified corn studies in the last 21 years shows that not only are genetically modified crops helping the environment, but they are also safer than 'natural' corn crops.

The researchers found that the crop of genetically modified corn was 10 percent higher than the corresponding non-modified corn crop. The concentration of nutrients in the different species was the same, meaning that a farmer who sows genetically modified corn in his fields will receive a healthy and nutritious crop in 10 percent more of the "natural" species. The farmer will not have to expand his fields, invade protected forests or hit the environment to increase the crop - he can simply use genetically modified varieties to achieve the same goal. Thus, the use of genetically engineered corn helps preserve na…

A new study suggests, breastfeeding for 3 months is associated with reduced ovarian cancer risk.

Breastfeeding Benefits and RecommendationsThe World Health Organization (WHO) recommends breastfeeding exclusivly for up to six months of age and combined with solid foods thereafter. According to WHO, only 38 percent of infants across the world receive breast milk for their first six months of life. The recommendation is designed to save lives and protect against infectious diseases, diseases of the gastrointestinal tract, diseases of the respiratory tract (asthma) and metabolic diseases (such as obesity). 

According to the data, more than 20 million babies are born each year at a low weight (under 2.5 kg) and are at higher risk for developmental delay and disease.The advantage of breastfeeding is not only medical. Comparative analysis concluded that breastfeeding reduces infant hospitalizations in childhood, increases intelligence, and increases the fertility and income of the infant in adult life. Therefore, if all infants were to be breastfed for at least a full-year, that alone is…

Researchers developed a way to deal with cancerous tumors that are resistant to immunotherapy

Researchers from the US and Israel found a way to deal with tumors that developed a resistance to immunotherapy
In recent years, the field of cancer treatment with immunotherapy has made headlines. Medications of this type activate the immune system and mobilize it against the cancerous growth, thus helping the body to destroy the malignant cells on its own. But many cancerous tumors manage not only to passively evade the immune system, but also to display proteins on their cell membrane that "cheat" the immune system and make it think the cell is normal.

In order to deal with them, a specific type of immunotherapy called checkpoint inhibitors has been developed, which prevents communication between the tumor and the immune system, thus preventing it from delaying its activity. These medications are not directed directly at the tumor, but rather prevent it from evading the immune system. Their use requires initial mobilization of the immune system in the cancerous environment,…

Findings from an archaeological site in Jordan indicate that dogs lived with humans 11,500 years ago

The transition from hunter-gatherer societies to farmers' societies
The people who lived 11,500 years ago in the area that is today northeast of Jordan apparently did not know this, but they were in the midst of one of the most important changes in human history: the transition from hunter-gatherer societies to farmers' societies. This is the change that led to the development of cities and then kingdoms, and ultimately to all human civilizations. These people already lived in permanent settlements, and began to use more and more plants and animals in their environment. And they had something else: dogs. 

In a new article, researchers from Denmark and the United Kingdom suggest that dog domestication have contributed to the expansion of resources available to people of the period, and that the dogs mainly helped to hunt relatively small prey, such as rabbits.
Those whose remains were found at a site known as Shubayqa 6 lived in basalt stone structures, with a stone floor, which …

NASA picture of the sunrise of the Columbia shuttle a few days before the disaster

Sunrise from Columbia Space Shuttle
Sixteen years after the shuttle disaster, in which seven astronauts, were killed, NASA released a picture of the sunrise from the window of the crew of the shuttle a few days before the disaster.
The US space agency NASA released a picture of the sunrise at the end of the week, as it was taken from the Columbia Space Shuttle on its last space flight, which ended with the deaths of seven astronauts, including the first Israeli astronaut Ilan Ramon.
The space shuttle Columbia disaster occurred on February 1, 2003, when the shuttle returned to Earth from a 16-day space trip. The photograph was taken on January 22, 2003. NASA did not say which of the seven crew members photographed the amazing picture of the sunrise from the crew cabin.
A NASA commission of inquiry established after the disaster determined that the cause of the failure was apparently air bubbles created by the insulating foam that covered the external fuel tank and increased its volume. In…