Here’s looking at you

Video: Life on an Eyeball Planet? It’s Possible

By: SciShow Space

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Notes:

Eyeball planets are a nickname for planets that are tidally locked to their parent star., meaning the same side always faces the star. This name comes from the way the side facing the star would be a baked desert, the side facing away from the star would be a frozen wasteland, and there could be concentric circles of in between zones.

An example of a tidally locked celestial body is our own Moon.

This concept is pretty inhospitable to life, however it’s possible that a Eyeball planet orbiting a Red Dwarf, with a strong magnetic field, in the habitable zone, and with water and an atmosphere, could support life with temperatures between 50 and -50 celcius.

For these planets, life could exist in the area between the two sides. However, it would need to be able to deal with very little light, and very strong winds. Also, there would be no day/night cycle, something on which almost all life on Earth has some kind of reliance.

Reach out to an old friend.

Video: Loneliness

By: Kurzgesagt

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Notes:

46% of all Americans report feeling lonely

Loneliness can be thought of as analogous to hunger for social interaction. It’s an evolutionary product where humans who were part of social groups were much more likely to survive than those living alone.

The enlightenment and industrial revolution stressed the importance of the individual and deemphasized the importance of social groups.

In the modern world we move away from the social groups of our childhood and have more troubles forming strong bonds as adults.

Chronic loneliness is extremely unhealthy, more so than obesity or smoking.

Lord of the Rings

Video: Has Saturn Had More than One Ring System?

By: SciShow Space

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Notes:

Data from Cassini shows that Saturn may be losing it’s rings at a rate of 5k to 25k kilograms per second. This phenomenon is called ring rain and at that rate the rings will be gone within a 100 million years.

It’s also theorized that perhaps the rings are less than 100 million years old. This is troublesome because many theories about how they formed require them to be much older.

It’s possible that we’re seeing a cyclical behavior where the larger planets destroy and recreate ring systems.

Even after the rings have disappeared, Saturn will still have some rings that are the result of other processes.

Pancakes and Walnuts

Video: MU69 is Flat, and No One Knows Why

By: SciShow Space

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Notes: 

MU69 is made of two bodies that are pancake and walnut shaped instead of spheres. This was unexpected as it doesn’t confirm with the current theory that planets were created by matter collecting in the protoplanetary disk and creating larger and larger spheres.

Data from Gaia shows that the Andromeda galaxy is set to collide with the Milky Way in about 4.5 billion years, which is 600 million years longer than the previous estimate.

It’s unlikely the two galaxies will have a direct head on collision as previously thought. They’ll go a bit past each other before circling back to form a single galaxy.

Hungry Hungry Hormones.

Video: The Real Reason It’s So Hard to Lose Weight

By: SciShow

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Notes:

There are mechanisms in the body that push back against weight loss.

When you lose weight, your fat cells produce less leptin. Having less leptin causes your hypothalamus to interpret this as starvation and it increases your desire to eat more and have your body run more efficiently.

Ghrelin levels (signaling hunger) rise and Amylin levels (signaling fullness) go down. The result is the brain increases your appetite.

The brain responds to these changes by making the act of eating feel more pleasurable and rewarding.

Restricting calories causes muscles to rely more on glucose from the food you’re consuming for energy than from the stored fat. They also become more efficient.

Many of these hormones don’t return to normal levels when you stop calorie restricting. They can stay altered for years. Even regaining the weight don’t shift the body out of this mode. Dieting can permanently decrease your resting metabolic rate even if you gain the weight again.

How much energy you use at any point in your life actually varies depending on if you’ve ever been heavier or skinnier.

Thoughts: From an evolutionary standpoint, this is all amazing. The fact that our body can detect a caloric reduction and respond by making everything run more efficiently is an amazing adaptation. And for many people in the modern world this is still a lifesaving mechanism. But for the people in the world with easy access to Coca-Cola and McDonald’s its making it harder to stay at a healthy weight. Technological progress is outpacing evolution.

Balloons would never be the same.

Video: The Impossible Element Hiding in the Sun

By: SciShow Space

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Notes:

The first periodic table didn’t include space for the noble gases – since they don’t react with anything they’re very hard to detect through chemistry.

Helium was discovered in space due to a solar eclipse in the 1860s before it was discovered on Earth in 1895 through radioactive decay of Uranium.

By looking at light through a prism, scientists discovered that you can distinguish different types of light by looking at its spectrum.

Light generated by burning different element has a unique collection of dark lines. This is due to each element absorbing light at specific wavelengths. This is governed by quantum mechanics. Atoms absorb photons at different wavelengths, and this behavior is unique to each element.

The solar eclipse allowed scientists to get a spectrum that included Helium from the Sun’s corona by blocking out the main spectrum.

We use spectroscopy to learn about composition of all kinds of things that emit or reflect light. We can even study the atmospheres of planets orbiting other stars.

Nothing was wrong with that name until that sitcom from the 2000’s came along and made my In-Laws think they finally understood me.

Video: What’s Wrong With the Big Bang Theory?

By: PBS Space Time

 

Notes: From the CMB we can see that the temperature of the Universe is every direction is very consistent, even among areas of the Universe that are outside each other’s particle horizons. The best current explanation of this is that the Universe must have started out very small so everything had enough time to mix around, before undergoing a rapid phase of massive inflation – going from the size of a subatomic particle to roughly the size of a grain of sand. At that point it switched to expanding at the current rate of expansion we still observe today.

The current limitations of the Big Bang theory do not explain the origin of the Universe. They explain what has happened after that.

Before the Universe was 400,000 years old it was too hot and dense for atoms to exist. Photons would be emitted and instantly absorbed. So it’s impossible for us to see back further in time than this – there’s nothing to see.

At the initial stages of the Big Bang, temperatures were so hot that the Higgs field didn’t exist to give particles mass. (Editorial: Does this help explain why the Universe didn’t just collapse back on itself as a black hole? Without the Higgs field and mass, there wasn’t anything for gravity to operate on). Also, we can actually create these conditions within the Large Hadron Collider.