Aug 07

Explain it like I’m Five: What is the Higgs Boson?

ELI5: The Higgs Boson

If you’ve been watching TV lately, you’ve probably seen a lot of news about a particle called the Higgs boson and how important it is for physics.

First, a little bit of background info:

Physicists believe that the entire universe is made of up of only a handful of different particles. So everything from lightning bolts to your fingertips are made up of at least one of those particles (usually a couple of them). This is called the Standard Model. Scientists are proud to say that they’ve discovered all of these particles except for one.

Yep, you’ve guessed it. Except for the Higgs boson.

At this point, you may be thinking: “How did they know the Higgs boson existed if they hadn’t found it yet?”

Well, to explain this, let’s use a really basic example. Imagine our solar system in your head. Before our planet Neptune was discovered, scientists still knew it existed. All they had to do was watch the neighboring planet Uranus and see how it moved. They noticed that its orbit was a little strange at some points. Based on this, they knew some other planet was there affecting Uranus.

Similarly, physicists watch particles and see how the mass (this is almost like “weight”) works. They realized that there has to be some other particle helping out with this, so they predicted that the Higgs boson exists.

 

Scientists know that all of the matter just doesn’t stay put. There is something that happens when the stuff around it gets “excited” and they believe this to be the Higgs boson.

So what is the big deal about finding this particle anyway? Well, scientists already assume that Higgs boson exists, so discovering it just proves all of the theories that have been in the works for the past few decades. Now the main problem is what would be happen if scientists prove that the Higgs boson doesn’t actually exist. Simply put, this will pretty much destroy most of our knowledge of universe. Let’s just hope that this doesn’t happen!

As of July 2012, physicists at one of the biggest labs in the world are about 99% sure they’ve found it. Even though that sounds really good, physicists are extremely precise and will continue testing until they’re completely sure.

 

Check out our top 5 favorite links explaining the Higgs boson:

 

  1. John Ellis, explains what is the Higgs boson 
  2. The Higgs boson is explained in a fun way using drawings and animation
  3. CNN offers a quirky explanation of the Higgs boson using Justin Beiber
  4. Ian Sample offers a not-so high tech explanation of the Higgs boson
  5. Follow this complex flow chart to find out what particle are you?

 

 

Jul 16

Explain it like I’m Five: How do scientists theorize what is at the center of the Earth?

Let’s look at a simpler question. If you don’t know what your friend’s bed is made of, what do you do? Easy–jump on it! If it doesn’t shake very much, it’s just a normal bed. If it shakes a lot, you know the bed is filled with water.

 

These are examples of waves. With the normal bed, the waves are really slow and short, while a water bed’s waves last for much, much longer.

 

We can’t jump on the earth hard enough to produce waves but we already have something that does produce giant waves. What shakes the earth enough to produce waves (both on land and water)? Well an earthquake does. When an earthquake occurs on one part of the world, the wave is so powerful that it goes through the Earth and is felt on the opposite side (not by people, but by sensitive equipment). Scientists measure how long it takes for this wave to be felt on the opposite side and see how powerful the wave is.

 

 

Doing this, there are 2 main possibilities:

1. If it takes a really long time to get to the other side and if the wave is not very powerful, scientists know that something solid is in the center.

 

2. If it doesn’t take a long time and if the wave is still powerful, we can tell that there’s something that’s slightly liquid in the center.

 

 

Using this, scientists have determined the earth is made of different kinds of “liquids”. One part of the Earth’s inside is like a milkshake. It can still flow like a liquid, but it’s not as smooth as water.

The part below that is very very liquid and it flows like water does.

The section in the very center is a solid ball. This is called the inner core.

 

Every time an earthquake occurs, scientists all across the world use it to find out how these waves travel and that helps us see what’s on the inside of the Earth.

Jul 05

What Does Bieber and the Higgs Boson Have to do With Each Other? Find Out as CNN Explains The Higgs Boson Particle

Check out their simplified and funny explanation of the Higgs Boson particle here.

Jun 30

Explain it like I’m Five: How do astronomers measure things so far away?

Discovery of Close Stars

When you shift your body side to side, the things closest to you look like they are moving the most. The things further away don’t look like they are moving much.

We compare how much this star shifted with closer and other known stars.

To figure out how far away stars are, we do something similar, but instead of moving our body we have to wait for the earth to move in its orbit. The fancy term for shifting your body from side to side or for waiting for the earth to orbit is “parallax”. Using parallax and a p

rocess which is of similar to how our GPS works, we find the location and distance of these new stars.Discovery of Far Stars:

For stars really far away we can’t move our body far enough side to side. Therefore we have to use a different method based on our observations of color and brightness. Now I’m sure that you’ve observed that fire of different temperatures is a different color. The same goes for stars, so we can figure out how hot a star is by its color. Now the hotter the star the brighter it is, but if a really hot star based on color doesn’t seem very bright in our observations we can assume it is very far away.

Now to Discover Planets:

Since we now know how to find stars, we use those stars to find far-away planets. We look at the stars and see if they wobble. If they do, they have planets.

Why might they wobble? Well, imagine a father spinning around while swinging his daughter through the air. His daughter is “orbiting” around him but because of the forces at work he’ll wobble a bit as his daughter’s mass pulls him in different directions. Things work in a similar way with planets orbiting stars. The gravity from the mass of the star swings the planet around but the mass of the planet creates a slight wobble on the star because of its mass pulling in different directions as it orbits. This wobble is very slight because stars are hundreds of thousands of times more massive than planets but our astronomy equipment keeps improving so that we can detect these slight differences (we will discover the most massive planets first because they create more of a wobble).

Another way to find planets is by checking the brightness of the closet star (kind of like what we said earlier). When scientists are looking at a star, sometimes it will look slightly dimmer than it’s supposed to. This tells us that there is something blocking our view of the star and that usually that means a planet is in orbit.

Our friend at XKCD drew this awesome picture of all the planets we have discovered by using these methods.

 

Jun 28

ELI5: Why is it colder on mountains–when you’re closer to the sun?

This is a question that has always bothered me. Valleys, like Death Valley in California, tend to be really hot. But the tops of mountains (closer to the sun!!) are snowy and very cold.

Colder on the mountain top

And what about that whole thing, with “heat rising?” I know for a fact that my basement (lower) is always colder than my attic (higher). So why are mountaintops always colder than valleys, even though mountains are closer to the sun?

 

THREE REASONS

1. Ain’t no mountain high enough

Mountains are not as close to the sun as you might think. Even though mountains seem very tall to us, we are so far away from the sun that moving from the ground to a mountain doesn’t put us that much closer to the sun. Even if you’re on Mt. Everest, 8.8km high, the sun is still 140 MILLION kilometers away. Think about it this way. You’re climbing a rope that’s 140m high (longer than a soccer field!), and you move .0000088 cm closer. Not going to make much of a difference in the weather, is it?

 

2Lower pressure at higher altitudes

At higher altitudes there is less atmospheric pressure. What’s atmospheric pressure? It’s how much stuff is pushing on you. Think about it like this, when you’re at a low altitude, like at sea level, there’s a lot more stuff in the air (“atmosphere”) to push down on you. When you’re at a high altitude, you’re above a lot of air and so there’s less stuff pushing on you.

Pressure and temperature have a direct relationship. A higher pressure is like shaking up a soda bottle, you’re pushing the molecules of soda together more and more and so they heat up by rubbing together. At a high altitude, there’s less pressure, so the molecules are rubbing together less and stay at a cooler temperature.


3. Heating of the Earth

Here is something that might surprise you: the sun doesn’t heat the air, the sun heats the earth. The sun heats things by sending waves of energy down to the earth. These waves of energy pass through the air, and then hit the ground, and start heating it up! Now think about standing on a mountain, is there a lot of earth around there? No, a mountaintop is a small surface that can’t give off that much heat. But if you’re in a valley close to sea level, there’s the ground you’re standing on, plus all the mountains and hills around you that can give off heat. So mountaintops don’t get heated by the earth as much.

To sum up, mountains aren’t as tall as you think. But, mountaintops do have less atmospheric pressure, so the molecules just chill and don’t give off much energy. And because there’s less earth on mountaintops, there’s less earth giving off heat, and mountaintops become very cold places.

Have any questions? Leave them in the comments!

Micaela Deitch is a Content Developer for OpenSesame, the world’s largest elearning marketplace. She enjoys learning and learning about elearning.

Jun 16

Explain it like I’m Five: How does Carbon dating work?

In order to Carbon date something, it must be “organic”, which means it was once living or part of something that was once living.

Before we talk about Carbon dating, we have to know a bit about radioactivity.

·      All elements are at least a little bit radioactive

·      Elements with more or less neutrons than normal are unstable and become more radioactive

·      Living things contain an especially radioactive type of Carbon that has more neutrons than normal called Carbon-14.

·      Carbon with the normal amount of neutrons is called Carbon-12 and is more stable and is also found in living things.

Radioactive material decays and becomes smaller by releasing particles and changing into other elements. One
way of measuring this decay is called the “half-life”. This is the amount of time for the radioactive substance to reduce to half its original amount.

Carbon-14 and Carbon-12 are both floating around the atmosphere. This creates a ratio of the two amounts.The ratio is always the same around the world at any point in time, but the amount of Carbon-14 in the world slowly decreases over time, because of those particles being released.

 

Plants get their carbon from the atmosphere and animals get their carbon from plants and other animals. Because of this, all creatures have the same Carbon-12 and Carbon-14 ratio as the atmosphere and it’s the same as the time period they lived. Once the creature dies, the amount of carbon is set. This is what’s important. All that’s left is to measure this ratio of Carbon-14 to Carbon-12. This is then compared to a table of ratios to determine the time.

In order to create this table, scientists look to tree-rings. Every tree stump has rings to indicate its age and some trees are thousands of years old. Scientists measure the amount of Carbon-14 on those old rings and create the table, so we know almost exactly how much Carbon-14 was around at that time. For example, the number associated with Carbon-14 from tree rings in the year 1200 is about 800, while for the year 1800, it’s about 200. As you can see, the amount of Carbon-14 is going down with time.