Category: PSA

PSA: Jellyfish

1. Jellyfishes are made up of more than 95% water.

Their bodies are soft and lack a skeletal structure or outer shell. They are delicate and easily damanged. Jellyfishes require water to help support their body and if removed from their aquatic surroundings, they collapse and die.

2. Jellyfish are radially symmetrical.

Jellyfish are symmetrical about a central axis that runs through the length of their body, from the top of their bell to the ends of their tentacles. They have a top and a bottom but they lack a left and right side and as a result differ from many other types of animals (such as mammals, reptiles, fish, birds, and arthropods) which exhibit bilateral symmetry.

3. Jellyfishes have no brain, no blood, and no nervous system.

Their senses are primitive and consist of a neural net, eye spots that can sense light from dark, and chemosensory pits that help them identify potential prey.

4. Some Jellyfish are immortal 

Turritopsis nutricula, is a hydrozoan whose medusa, or jellyfish, form can revert to the polyp stage after becoming sexually mature. It is the only known case of a metazoan capable of reverting completely to a sexually immature, colonial stage after having reached sexual maturity as a solitary stage. It does this through the cell development process of transdifferentiation. Cell transdifferentiation is when the jellyfish “alters the differentiated state of the cell and transforms it into a new cell”. In this process the medusa of the immortal jellyfish is transformed into the polyps of a new polyp colony.

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PSA: Brain Power

PSA: Space

10 Things You Didn’t Know About Space

There is still so little known about outer space by modern science, but of that little we do know, there are some extraordinarily amazing things. This is a list of the top 10 cool facts about Space.

10. Lightweight

Fact: If you put Saturn in water it would float

The density of Saturn is so low that if you were to put it in a giant glass of water it would float. The actual density of Saturn is 0.687 g/cm3 while the density of water is 0.998 g/cm3. At the equator Saturn has a radius of 60,268 ± 4 km – which means you would need an extremely large glass of water to test this out.

9. Constantly Moving

Fact: We are moving through space at the rate of 530km a second

Our Galaxy – the Milky Way is spinning at a rate of 225 kilometers per second. In addition, the galaxy is travelling through space at the rate of 305 kilometers per second. This means that we are traveling at a total speed of 530 kilometers (330 miles) per second. That means that in one minute you are about 19 thousand kilometers away from where you were. Scientists do not all agree on the speed with which the Milky Way is travelling – estimates range from 130 – 1,000 km/s. It should be said that Einstein’s theory of relativity, the velocity of any object through space is not meaningful.

8. Farewell old friend!

Fact: The moon is drifting away from Earth

Every year the moon moves about 3.8cm further away from the Earth. This is caused by tidal effects. Consequently, the earth is slowing in rotation by about 0.002 seconds per day per century. Scientists do not know how the moon was created, but the generally accepted theory suggests that a large Mars sized object hit the earth causing the Moon to splinter off.

7. Ancient Light

Fact: The light hitting the earth right now is 30 thousand years old

The energy in the sunlight we see today started out in the core of the Sun 30,000 years ago – it spent most of this time passing through the dense atoms that make the sun and just 8 minutes to reach us once it had left the Sun! The temperature at the core of the sun is 13,600,000 kelvins. All of the energy produced by fusion in the core must travel through many successive layers to the solar photosphere before it escapes into space as sunlight or kinetic energy of particles.

6. Solar Diet

Fact: The Sun loses up to a billion kilograms a second due to solar winds

Solar winds are charged particles that are ejected from the upper surface of the sun due to the high temperature of the corona and the high kinetic energy particles gain through a process that is not well understood at this time. Also, did you know that 1 pinhead of the sun’s energy is enough to kill a person at a distance of 160 kilometers?

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PSA: Water

The Surprisingly Strange Physics of Water

1. Race to the bottom

A logical person might assume that it would take longer for hot water to plunge down the temperature scale to 32 degrees Fahrenheit (0 degrees Celsius) and freeze than would cold water. But oddly enough, this is not always the case. As was first observed by a Tanzanian high school student, Erasto Mpemba, in 1963, hot water actually freezes faster than cold water when the two bodies of water are exposed to the same subzero surroundings.

And no one knows why.

One possibility is that the Mpemba effect results from a heat circulation process called convection. In a container of water, warmer water rises to the top, pushing the colder water beneath it and creating a “hot top.” Scientists speculate that convection could somehow accelerate the cooling process, allowing hotter water to freeze faster than cooler water, despite how much more mercury it has to cover to get to the freezing point.

2. Levitating liquid

When a drop of water lands on a surface much hotter than its boiling point, it can skitter across the surface for much longer than you’d expect. Called the Leidenfrost effect, this occurs because, when the bottom layer of the drop vaporizes, the gaseous water molecules in that layer have nowhere to escape, so their presence insulates the rest of the droplet and prevents it from touching the hot surface below. The droplet thus survives for several seconds without boiling away.

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PSA: Humans + World

PSA: Titivillus!

Titivillus was a demon said to work on behalf of Belphegor, Lucifer or Satan to introduce errors into the work of scribes in the middle.

No worry kids, Titivillus has been alive and well in the blogosphere as well!

PSA: Your Ego

PSA: The Social Media

PSA: The Brain

  • Your brain consists of about 100 billion neurons.
  • Your brain is about 2% of your total body weight but uses 20% of your body’s energy.
  • Because your brain shuts off the visual cortex signal very briefly every time your eyes move, you’re blind for 2 hours a day.
  • 70,000 is the number of thoughts that it is estimated the human brain produces on an average day.
  • The human brain is the fattest organ in the body and may consists of at least 60% fat.
  • The brain is made up of about 75% water.
  • 3 = the weight of your brain in pounds.
  • 4 to 6 = the number of minutes your brain can survive without oxygen before it starts to die.
  • 8 to 10 = the number of seconds you have before losing consciousness due to blood loss.
  • 10 to 23 = the number of watts of power your grain generates when you’re awake (that’s enough to turn on a light bulb!)
  • 20 = the percentages of oxygen and blood flow going to the brain
  • 100,000 = the number of miles of blood vessels in your brain
  • 1,000 to 10,000 = the number of synapses for each neuron in your brain
  • Each person has about the same number of brain cells at birth as in adulthood, but those cells grow, reaching maximum size at about age six.
  • A newborn’s brain triples its size in the first year of life (no wonder babies have such big heads!).
  • The sense of touch is the first sense to develop in a fetus, with the lips and cheeks experiencing this sensation at eight weeks.
  • Keep exercising your brain, because mental activity stimulates the creation of new neurons throughout your whole life.
  • Think positive because when you do, you’ll keep the doctor away: Studies show that 50-70% of visits to the doctor for physical ailments can be traced to psychological reasons.
  • Eat well, and it’ll have positive effects on your brain, because a study of one million New York students showed that those who ate lunches without additives such as artificial flavours, preservatives and dyes performed 14% better in IQ tests.
  • New connections are created each and every time you remember something or have a new thought.
  • Stronger, more intense emotional connections are linked to memories prompted by scent.
  • Memories triggered by scent (like cologne) have a stronger emotional connection, and therefore appear more intense than other memory triggers.
  • Cherish your sleep because that’s probably the best time for your brain to file away all the memories of the day.
  • It’s not your brain that’s hurting when you get a headache – without pain receptors, your brain can’t feel any pain.
  • Your brain knows when you tickle yourself, which is why you don’t bend over laughing.
  • Supertasters have a super power that enables them to sometimes taste flavours that others can’t detect; they have more taste buds and a brain that’s more sensitive to tastes of foods and drinks.
  • When you sleep, you’re virtually paralyzed because your brain creates a hormone to prevent you from acting out your dreams.
  • About 12% of people dream in black and white.
  • It’s not true that humans only use 10% of their brains; each part of the brain has a purpose.
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