Gear

We just learned about the Motor or engine that makes things move.

One very important part of most engines is the Gear.

Gears are wheels that have teeth on the end, and usually a hole in the middle.
The teeth on the end can match up with other gears that also have teeth.
So when one gear moves, it also turns the other gear.

If there is a big wide gear that is moving very slow, it can be hooked to a small gear that will spin very fast.
Or it can be hooked to a gear that is sideways, to change the direction of the movement.

Gears are in everything from car motors to clocks to bicycles.
Pretty much everything with moving parts uses at least one gear to help control the movement made by the energy!

The teeth on gears are called "cogs", and gears are sometimes called cogwheels.
Sometimes people will even refer to themselves as a "cog in the machine" meaning that they are just one part of a bigger machine that makes things work.



(from: wikipedia - gear)


Kid Facts - Blast from the past: Rockets - Star Tracker

Motor

We just started learning about Machines.

One of the most important things about a machine is the Motor, also sometimes called the engine.

The motor is the thing that takes some type of energy and turns it into movement.
Like a car's engine takes in gas, and then the engine burns the gas to turn it into movement that makes the car go.

Electrical motors can take electricity from a plug or a battery and use that to move something like a toy or a fan.

There are even types of motors that use steam, air, liquids or coils like toys that you wind up and they walk around.

Anything that takes in energy and then makes something move is a motor.
Really you can even think of our human bodies like engines that take in food and make our muscles move!


(from: wikipedia - steam engine)


Kid Facts - Blast from the past: Accelerometer

Machines

We've learned a lot about the science of forensics that detectives use to solve crimes.

Another type of science is the study of Machines, which are the things that make the world move.

This could be anything from a car that is driving down the street to a windmill that takes wind power and turns it into energy.

There are many types of machines in the world, and there are lots of jobs for people who work with machines.
One type of job for working with machines is a mechanical engineer.

These people help figure out how to build machines and how to use them to build the things we need in our lives.

Another types of job is a machine operator, like the people who use the machine to do work.
This could be someone driving a big bulldozer, or someone working in a big building using a machine to cut or lift things.

Sometimes our machines break down and we need people to fix them.
There are lots of people working those jobs too, like a mechanic that looks at a car when it isn't working any more and has to figure out how to get it running again.

There are so many machines in our world that we need a lot of smart people to help make them work!


(from: wikipedia - mechanical engineering)


Kid Facts - Blast from the past: Altimeter

Fire Investigation

We just learned about how Tire Skid Marks can help show what happened in a car accident.

Another type of forensic science is Fire Investigation.

After a big fire happens, the forensic scientists will go into the burned building or car, and look for evidence.
They look for things to tell them what may have started the fire.

There are lots of accidents that can start fires, like stoves or electrical plugs, or even magnifying glasses.

But sometimes bad people start fires either to hurt someone or to burn down a building they don't like.
When someone starts a fire like that on purpose it is called arson.

The scientists can tell from the different kinds of chemicals in the burned building or from the way the flame burned how it started and maybe even tell if it was an accident or on purpose.


(from: wikipedia - arson)


Kid Facts - Blast from the past: GNC - Guidance, Navigation, and Control

Tire Skid Marks

We just learned about the Forensic Podiatry.

Another part of forensic science is Tire Skid Marks.

These are the marks left on roads from tires.
Sometimes cars can leave these marks if they are going really fast, taking a sharp turn, stopping very fast, or if there is an accident.

The marks on the road usually look like one of three kinds:

- acceleration marks: These are when someone goes from slow to really fast and the tires are just spinning.

- braking marks: These are when someone hits the brakes and their tires lock up and slide.

- yaw marks: If the car slides sideways either on a turn or because they hit something.

When there is a car accident, the police can look at the skid marks to figure out how the crash happened.


(from: wikipedia - skid mark)


Kid Facts - Blast from the past: Gimbaled Thrust

Forensic Podiatry

We just learned about the Forensic Epidemiology, trying to prove what causes things like diseases or accidents.

Another part of forensics is Forensic Podiatry.

Podiatry is the study of feet, so this means looking at a person's foot to figure out evidence.
This might be checking to see if a footprint matches their bare feet, or it might be looking at a shoe footprint and trying to find out if that person's foot fits into that shoe.


(from: wikipedia - foot)


Kid Facts - Blast from the past: Rocket Thrust Vectoring

Forensic Epidemiology

We just learned about Forensic Entomology, looking at evidence of bugs!

Another part of detective science is Forensic Epidemiology.

This is the science of looking at someone who is sick or injured, making a guess as to why it happened, and then trying to prove that the guess was right or wrong.

A lot of times people get sick or injured, and we think we know what caused it.
If someone has really bad breathing problems, detectives can look around for bad chemicals in the house, and then do some tests to see if that was really what caused their problems or if maybe they were a smoker or something else.

When a person gets into a car crash and then has neck problems, the science of epidemiology helps prove whether or not their neck problems were because of the car crash or if they would have had the same neck problems from something else.

This type of science is very important, because if scientists can prove that something is bad and causes sickness or injury, then things like bad chemicals can be made illegal, cars can be changed to have better safety, medicines and surgeries can be proven to be good or bad.

(from: wikipedia - forensic epidemiology)


Kid Facts - Blast from the past: Fire Arrow

Forensic Entomology

We just learned about how Forensic Dentistry can help use teeth to solve crimes.

Another type of science used by detectives is Forensic Entomology.

Entomology is the study of bugs!

Bugs can be pretty scary and gross, but sometimes they can actually help solve crimes that no one else can figure out.
When someone dies, and a detective has to figure out how it happened, they can look at all different types of bugs.

When a scientist is in a laboratory looking at the body of someone who died, they can sometimes find clues of different types of insects that touched the body.
This can help them figure out how long it's been since the person died, and even sometimes it can tell them where the person was at when they died.
This can be very useful in solving crimes!

Studying bugs can also help scientists figure out if there is a problem with bugs in an area.
Like if someone complains that there are fleas in their house, scientists can come by and help figure out where they are coming from, how they got in there, and how to get rid of them.

Forensic entomology also helps figure how helpful insects like bees are being killed, like if there is a type of chemical somewhere that is causing problems for them.

Bugs are not always pretty, but studying the science of bugs can help solve mysteries!


(from: wikipedia - forensic entomology)


Kid Facts - Blast from the past: Specific Impulse

Forensic Dentistry

We just learned about how scientists can use Forensic Botany to figure out what kind of plants were around during a crime.

Another part of forensic science is Forensic Dentistry.

Sometimes after a crime has been committed, scientists will look at teeth to figure out what really happened.

If there was a fight between two people and one person bit the other person, they can look at the bite mark and try to match it up to the other person's teeth!

There also might be a skeleton that was found from a long time ago, and people aren't sure who it was.
If that person ever went to the dentist and had molds made of their teeth or x-rays of them, they can try to match it up and see who it was.

The teeth can also tell a scientist how old a person was when they died.
This can even be helpful for people that died hundreds of years ago, when people are digging out ancient pyramids, castles or finding cavemen!


(from: wikipedia - forensic dentistry)


Kid Facts - Blast from the past: Rocket Engine Thrust

Forensic Botany

We just learned about the Species Test to test blood to see what kind of animal it belongs to.

Another type of forensic science is Forensic Botany.

This is the study of the plants around a place where a crime was committed.
If the police look at a person's shoes or clothes, sometimes they can find tiny pieces of plants that are on them.
It could be just a seed, or a piece of a leaf, or even a tiny bit of pollen from a flower.

If the forensic scientists find evidence of a type of plant, they can figure out what season a crime happened, like fall winter spring summer.
They can also sometimes figure out the place where it happened, like if a type of flower or plant only grows in one area.
Scientists can also look at the plants and figure out how long ago it was that someone was near those plants, because the plants get brown and decay.

Sometimes the pollen, seeds or bits of plants on our clothes are so small that a criminal wouldn't see it and think they got away with a crime, but the forensic scientists look closely and figure it out!



(from: wikipedia - botany)


Kid Facts - Blast from the past: Rocket Engine

Species Test

We just learned about Forensic Anthropology, the study of a body to see who it is after someone has died.

Another test in forensic science is the Uhlenhuth Test or Species Test.

Way back in 1901 a scientist named Paul Uhlenhuth figured out how to test blood to see if it belonged to a human, or a different type or "species" of animal.

This was important because if a detective found a stain of blood somewhere, people could just lie and say that it was from a cow or a chicken or another animal.

If the blood was from a human, then it was a big deal, especially if someone had been hurt!
Once detectives could use this Uhlenhuth test to see what type of blood they found, people couldn't hide out and lie if someone found a blood stain as evidence of a crime.

One of the most important things about forensic science is finding clues or evidence, and testing to see if people are telling the truth.


(from: wikipedia - blood test)


Kid Facts - Blast from the past: Combustion Chamber

Forensic Anthropology

We just learned about how scientists can look at guns with Forensic Firearm Examination to see who committed a crime.

Another part of forensic science is Forensic Anthropology.

This is the science of looking at the bones of a person and trying to figure out what happened.
Sometimes this is used in archeology for bones that are hundreds or thousands of years old.
Other times it can be used by police when they find some bones, to try and figure out who the person was.

Scientists can look at teeth to see how old the person was, or the length of their arm or leg bones, or even the size of their skull.

They can even look at the hip bones of a person to see if they were a man or a woman.
Sometimes this helps solve a crime if they find an old skeleton, and they don't know who the person was when they were alive.
If they figure out who it was, they can look for marks on the bones, to maybe tell how they died.
They can also look at the teeth, and sometimes match them up with x-rays from a dentist office to see if they can figure out who it was.

It might seem a little scary or creepy, but by using science with old bones we can solve crimes and make sure the bad guys don't get away!



(from: wikipedia - forensic anthropology)


Kid Facts - Blast from the past: Rocket Propellant Tank

Forensic Firearm Examination

We just learned about Ballistic Fingerprints.

Another type of science is Forensic Firearm Examination.

When guns are made, they are each given a special different code number called a "serial number".
No two guns have the same number, and when someone buys a gun they keep track of who owns which gun with which serial number.

This is done so that if a gun is used for a crime, the police can look at the serial number on the gun and figure out who owns the gun.

The serial number is printed right into the metal of the gun.
Sometimes people try to scrape off the metal where the serial number is, but police can use special electromagnets and chemicals to tell what the serial number was even if it has been scraped off.

Some guns these days are also being made to mark the serial number of the gun on the bullet when it is fired.
That way each bullet can be tracked down to who fired it if a crime is committed.



(from: wikipedia - forensic firearm examination)


Kid Facts - Blast from the past: Rocket Engine Nozzle

Ballistic Fingerprints

We just learned about the Toxicology.

Another part of forensics is the study of Ballistic Fingerprints.

When someone uses a gun to shoot someone else, and they run away before the police can arrest them, there are ways that scientists can look at the bullets to try and figure out which gun they came from.

When a bullet is shot out of a gun, it spins around inside the gun's barrel.
This is a special thing called rifling, and it helps the bullet go straighter.
The way the bullet is spun around inside the gun leaves marks on the metal bullet.

If the police find the bullet that was used to shoot someone, and they find the gun that they think was used, they can test shooting another bullet out of that same gun and see if the marks on the bullets match.

They put both bullets under a microscope and if the lines match up, then they can use that as evidence to put a bad person in jail.




(from: wikipedia - forensic firearm examination)


Kid Facts - Blast from the past: Gas Rocket Propellants

Toxicology

We just learned about the Fingerprints.

Another part of forensic science is Toxicology.

Long ago when someone died and it was a mystery, it was very hard to tell what happened.
If a bad person had killed someone by using poison, there was no good way to prove it so they could be sent to jail.

In 1832, a scientist named James Marsh came up with a test that could be used to show if a poison called arsenic was used to kill someone.
Arsenic did not have a smell or a strong taste, so people would sometimes sneak it into someone's food to poison them.
With the Marsh test, they would take some liquid from the body of the person that was poisioned.
Either some blood, or saliva (or spit) from their mouth, or urine from their bladder.
That liquid would be put into a bottle with some other chemicals, then burned up with some other gases, and then if it left a silvery black stain after being burned, it was proof that arsenic was used.

After Marsh proved to everyone that this test worked, it was used by police all over the world to put people in jail for trying to poison other people!

Because this worked so well, people worked on coming up with other ways to test for chemicals in a person's body.
These days scientists can test hair, blood, saliva, sweat or even food that is in the intestines that was not totally digested yet.

Toxicology helps the police prove what the truth is, using the evidence that is in the body!


(from: wikipedia - marsh test)


Kid Facts - Blast from the past: Liquid Rocket Propellants

Fingerprints

Let's keep learning about Forensics, the science of a detective!

Another part of forensic science is Fingerprints.

Everyone's fingers have tiny little ridges that are made over years and years of touching things.

The skin on the hand is the epidermis, and the fingerprints are called epidermal ridges.
These little ridges stick up, and have oils on them that is made by the skin.
When a person touches something, the oil from the ridges leaves a mark.

A good way to test it is to touch a mirror or a piece of glass, and it should show the finger print.

Detectives figured out that using a little brush with some ink on it, they could find fingerprints on windows, desks, or anything a person touches.
To match up the fingerprints, they take a persons finger and get ink on it, then make a mark on a piece of paper.
If the paper mark matches the one they found, then it is for sure a match, as no two people have the same fingerprints.

There are special names for some types of shapes on the fingerprints, like arch, loop, and whorl.







(from: wikipedia - fingerprint)


Kid Facts - Blast from the past: Solid Rocket Propellants

Forensics

We just learned about the Falcon Heavy rocket engine made by SpaceX.
From rocket fuel to navigation systems to the history of rockets, we've learned a whole lot about rockets!

Let's move on to something new, called Forensics!

This is the science of figuring out things that happened, by looking around for clues.
The word "forensic" comes from the Latin language and means "of or before the forum".
In the old days when someone did something bad, they would have to come before a group of people called a forum and tell them what happened.

When detectives and police officers are working to solve crimes, they use forensic science to look around at the place where the crime happened and see if they can figure out what really happened.

This can be things like fingerprints, talking to people who saw the crime, or even looking at what kind of animals are in the area!

Famous detectives from books like Sherlock Holmes were experts in forensics and could figure out any crime that happened!


(from: wikipedia - forensic science)


Kid Facts - Blast from the past: Rocket Propellant

Falcon Heavy

We just learned about the Falcon rocket.

Another SpaceX rocket is the Falcon Heavy.

This rocket is a lot more powerful than just one Falcon rocket, and it is being made to hopefully some day take people into outer space, to the Moon or even to Mars!

It is made from three "Falcon 9" rockets strapped together.
The one in the middle is the core main rocket, and the two on the outside are booster rockets.

This rocket can carry a lot of weight, about 141,000 pounds into outer space!
On the first of the Falcon Heavy rocket launch, the owner Elon Musk sent his car into space, a shiny red Tesla Roadster, and they also put a fake person inside in a space suit, and nicknamed him "Starman".

When the space craft makes it up into space, the Falcon 9 rockets actually fall off the main spacecraft and fall back to earth.
They don't crash into the ocean though, they actually use guidance systems to come back down to the ground and land safely on a launch pad so they can be used again!





(from: wikipedia - falcon heavy)



Falcon Heavy boosters landing - SciNews


Kid Facts - Blast from the past: Rockets

Falcon

We just learned about the Space Shuttle.

Another famous rocket is the Falcon made by SpaceX in 2008.

In 2002 the SpaceX company was started by Elon Musk as a way to try and build rockets to go to outer space and even someday Mars!

The big difference with SpaceX is that it was a business that was in charge, instead of a people that worked for the government like USA or Russia.

These rockets were two stage, and made to use liquid rocket fuel.
Elon Musk said that the name of the Falcon rocket came from the Millennium Falcon from Star Wars!



(from: wikipedia - falcon 1)


Kid Facts - Blast from the past: Speleoseismite

Space Shuttle

We just learned about the Ariane rocket.

Another famous rocket is the Space Shuttle, made in the USA in 1981.

This was a kind of airplane made for doing work in outer space, and then bringing people home.
The space shuttle had two big rockets to help it launch called "Solid Rocket Boosters" or SRBs.
These are the tall skinny white rockets on either side of the shuttle.

These SRBs used solid rocket propellant, together weighed about 2.6 million pounds, were about 150 feet long, and 12 feet wide.
When the shuttle was launched, these rockets helped bring it to 28 miles up into the sky, at a speed of over 3,000 miles per hour.
They used gimbaled thrust like we learned about, to tilt the engine nozzle and steer the rocket, and they used gyroscopes to make sure they were going the right way.
After these rockets ran out of fuel, they would let go of the shuttle and fall to earth with a parachute.
When they made it down to earth, they were found and fixed up and reused over and over again.

The Space Shuttle main engine, called the SSME uses liquid fuel, and has three rocket engines with nozzles at the bottom of the space shuttle.
These engine nozzles also used gimbaled thrust, just like the SRBs.
It holds its fuel in a giant fuel tank called the Space Shuttle external tank (ET).
The ETs weighed over 70,000 pounds, was over 150 feet long, and 27 feet wide.

During launch, the SSME would burn the fuel in the fuel tank for about eight minutes, and then it would drop off the ET which would fall into the ocean and never be reused.

After it was coming back from space it used small thrusters called the Reaction Control System or RCS to help steer it down, and then it mostly flew down to earth like a glider.

The space shuttle flew 135 missions into space, from 1981 to 2011.







(from: wikipedia - space shuttle)


Space Shuttle Launch Audio - play LOUD (no music) HD 1080p - indiegun


Kid Facts - Blast from the past: Seismite