Showing posts with label Forensics. Show all posts
Showing posts with label Forensics. Show all posts

Thursday, April 25, 2019

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

Thursday, April 18, 2019

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

Thursday, April 11, 2019

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

Thursday, March 28, 2019

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