Redefining The Kilogram

Veritasium takes you through the history of the kilogram standard, a block of metal locked in a basement that defines the most important international standard that we have. 

Unfortunately, the mass of the current standard is changing thanks to … well, something not entirely known. Atomic evaporation maybe? What is definitely true is that a new kg standard is needed.

The replacement candidate is a nearly perfect sphere of a single isotope of crystalized silicon. It is the world’s roundest object! If this sphere were the Earth, the highest mountain and the lowest valley would only be a few meters apart.

An awesome chemistry and physics lesson from Derek!

Source: youtube.com

Can You Boomerang A Football/Soccer Ball?

Sure you can. You just need a 75-foot tall Roberto Carlos. Let Michael from Vsauce tell you what Newtonian physics has to do with one of the greatest goals ever scored, and just how hard you’d have to kick a ball to have it return to where it started from.

(by Copa90)

Source: youtube.com

So what IS the Cosmic Microwave Background, anyway? A few hundred thousand years after the Big Bang, things cooled down enough (to about 2,700 ˚C) that neutral matter like hydrogen and helium began to condense from a sea of charged protons and electrons. This released photons that have been propagating through space since that very moment. Of course, we know that the universe is expanding, right? Those photons are expanding along with it. We are detecting them at a distance in light years almost equal to the age of the universe itself, as they have been stretched and cooled to just above absolute zero (a few degrees Kelvin).  Why “microwave”? The photon wavelengths have expanded so much during the expansion of the universe that they now sit in the microwave range, like extending a Slinky into a single, straight wire! Check out this cool feature from Space.com to find out even more about the CMB, including how pigeon poop helped us figure out it even existed.
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So what IS the Cosmic Microwave Background, anyway?

A few hundred thousand years after the Big Bang, things cooled down enough (to about 2,700 ˚C) that neutral matter like hydrogen and helium began to condense from a sea of charged protons and electrons. This released photons that have been propagating through space since that very moment.

Of course, we know that the universe is expanding, right? Those photons are expanding along with it. We are detecting them at a distance in light years almost equal to the age of the universe itself, as they have been stretched and cooled to just above absolute zero (a few degrees Kelvin). 

Why “microwave”? The photon wavelengths have expanded so much during the expansion of the universe that they now sit in the microwave range, like extending a Slinky into a single, straight wire!

Check out this cool feature from Space.com to find out even more about the CMB, including how pigeon poop helped us figure out it even existed.

Planck-in’ on Billions and Billions I’m amazed that in 2013, we can still be smacked upside the head and reminded of how little we know about our universe. Even the most basic things about it. Like, how old it is. The European Space Agency’s Planck space telescope has collected 15.5 months worth of data on the Cosmic Microwave Background, or CMB (What’s that? Click here), and today they released the most detailed map ever of those oldest remnants of the Big Bang. It says that our universe is almost perfect. Almost.  The highlights from this new map include the finding that the universe is almost certainly 13.81 billion years old, about 100 million years older than previous estimates. And we got better estimates for the stuffness of stuff: 4.9 percent normal matter, 26.8 percent dark matter, and 68.3 percent dark energy. The universe is expanding, which is the whole reason that the CMB even exists, but this new map says it’s expanding slower than we thought.  The coolest part, though? The “almost perfect” part. The radiation that became the CMB was just sort of randomly splattered out, like we’d expect (and the randomness of the dots on the map above show that). But those little fluctuations aren’t the same everywhere! The universe appears to be slightly lopsided, and even rather cold in one part. The ESA folks say we may need “new physics” to explain why. Nice to know you cosmologists of the future will have something to work on :) Of course, all of this just goes for the observable universe. The rest, whatever it may be (or not be), has NO EDGE. Just like Hank Green reminds us. Phil Plait has tons more dirty details behind the Planck news at Bad Astronomy.
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Planck-in’ on Billions and Billions

I’m amazed that in 2013, we can still be smacked upside the head and reminded of how little we know about our universe. Even the most basic things about it. Like, how old it is.

The European Space Agency’s Planck space telescope has collected 15.5 months worth of data on the Cosmic Microwave Background, or CMB (What’s that? Click here), and today they released the most detailed map ever of those oldest remnants of the Big Bang. It says that our universe is almost perfect. Almost. 

The highlights from this new map include the finding that the universe is almost certainly 13.81 billion years old, about 100 million years older than previous estimates. And we got better estimates for the stuffness of stuff: 4.9 percent normal matter, 26.8 percent dark matter, and 68.3 percent dark energy. The universe is expanding, which is the whole reason that the CMB even exists, but this new map says it’s expanding slower than we thought. 

The coolest part, though? The “almost perfect” part. The radiation that became the CMB was just sort of randomly splattered out, like we’d expect (and the randomness of the dots on the map above show that). But those little fluctuations aren’t the same everywhere! The universe appears to be slightly lopsided, and even rather cold in one part. The ESA folks say we may need “new physics” to explain why. Nice to know you cosmologists of the future will have something to work on :)

Of course, all of this just goes for the observable universe. The rest, whatever it may be (or not be), has NO EDGE. Just like Hank Green reminds us. Phil Plait has tons more dirty details behind the Planck news at Bad Astronomy.

Why Is The Sky Blue…Or Red…Or Any Color At All?

New episode of It’s Okay To Be Smart is up! I tackle one of the oldest questions in the book:

Why is the sky blue (or any other color)? It’s a question that you’d think kids have been asking for thousands of years, but it might not be that old at all. The ancient Greek poet Homer never used a word for blue in The Odyssey or The Iliad, because blue is one of the last colors that cultures pick out a word for.

In this episode, I’ll tell you not only why the sky is blue, but why it’s red at sunset. It turns out, those colors are all part of the same sunbeam. And when you’re looking at a blue sky, you could be sharing a special moment with someone thousands of miles away. Next time a kid (or the kid inside you) wants to know why the sky is blue, you’ll have science to back you up!

Subscribe to It’s Okay To Be Smart on YouTube.

Creating Order From Chaos

This is a little different from the video we saw earlier, where the rainy wooshing of a table full of ball bearings perfectly demonstrates how systems tend toward chaos, simply because there are more ways in which they can take random positions than ordered ones.

In this time-lapse video, a random input (a table vibrating at 20 Hz) allows two intertwined chains to separate. Randomness rears its head here by allowing the two chains to take on multiple arrangements. But because they are limited in a key way (being connected to the rest of their chain), an interesting thing happens. They end up separating from each other rather than becoming even more tangled.

Long molecules like DNA can be randomly unwound in the same way (think heat!). This is still the power of randomness, it’s only the outcome that’s different.

(via io9)

Source: io9.com

freshphotons: Surface Tension. Curious how this sorcery happens? You bet you are. An insect like a wasp or a water strider can rest atop the water, held up by surface tension. This means that the cohesive force of the water molecules sticking to each other is stronger than the force of the bug being pushed down by gravity. This works because it spreads its weight out over a large surface area (like snowshoes). That creates a slight indentation in the top of the water, changing the direction that the light coming down is refracted and re-directing it slightly sideways (that’s where the bright halos around the dark areas come from). And what’s the absence of light?  A shadow. All those words in picture form:
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freshphotons:

Surface Tension.

Curious how this sorcery happens? You bet you are.

An insect like a wasp or a water strider can rest atop the water, held up by surface tension. This means that the cohesive force of the water molecules sticking to each other is stronger than the force of the bug being pushed down by gravity. This works because it spreads its weight out over a large surface area (like snowshoes).

That creates a slight indentation in the top of the water, changing the direction that the light coming down is refracted and re-directing it slightly sideways (that’s where the bright halos around the dark areas come from). And what’s the absence of light? 

A shadow.

All those words in picture form: