Bullets

I had quite a horrible mental breakdown over the weekend, a proper mental breakdown and not some blog hyperbole, and as a result I've decided to keep myself a bit more busy over the coming weeks. This should hopefully extend to this blog too.

With all that said, off to yet another post of inane pedantic drivel...

In a somewhat similar vein to my last post, the subject of movie physics, I plan to talk about bullet sparks.

Simply put, they're a load of bullshit. Bullets don't spark like what you see in some films and most TV shows. The reason for this is very simple, they're made out of copper-clad lead or lead alloys and not steel.

It's why some hammers, used in chemical industry or other places where a spark could be very fatal, are made out of lead (or copper alloys) and not steel.

Bullets do get hot when they strike solid objects. The worst case would be if all of a bullet's kinetic energy were instantly converted to thermal energy when a bullet struck its target and all the thermal energy remained inside the bullet. This is highly unlikely but easy to calculate. I say easy...

A .45 cal handgun bullet (it's a big enough bullet, in between (ish) a standard 9mm and Dirty Harry's
.44 mag), has a mass of 0.015 kg and a muzzle velocity of around 288 m/s. Kinetic energy is calculated from the mass and the magnitude of the velocity of an object using the following equation...

KE = ½mv2

KE = kinetic energy m = mass v = velocity

Using the above equation and the values I supplied we find that such a bullet has a kinetic energy of 619 J. And if all that kinetic energy is converted into thermal energy the temperature rise is calculated as 324° Celsius.

If the bullet starts at room temperature (24° C) it will end up at 348° C. The melting point of lead is 328° C.

So, in this highly unlikely event that all the kinetic energy turns to heat, in a hope to generate a spark, the lead would melt. And molten lead looks like silver. In fact molten lead is used in films as a substitute for molten silver.

All worked out on the basis that the shot was at point blank range.

Of course bullets don't get that hot and most of the kinetic energy is lost on it's short travel.

Unlike last weeks post, where I made the point that lasers in films work how they do because otherwise they'd be boring, sparking bullets are just shit.

Subtlety can be far more dramatic­

Laserface

Lasers in most people's minds probably look and act like those found in such films like Star Wars. Multi coloured fun beams of death. Of course, real lasers don't work like that, especially in space.

First, imagine you're in a big space dog fight with all the homo-erotic undertones of Top Gun. You spot a boggy in the distance and line up your shot. You fire but - SHIT - you missed because you didn't aim far enough in front of the enemy and by the time your laser gets to it's target it's behind them.

You see this happen all the time in films. It's pretty stupid though seeing as lasers are made of light (light amplification by stimulated emission of radiation, to be exact) which is pretty damn fast. Really fucking fast in fact - Around 300 million meters a second.

So, when you take into account that in these space battles ships are usually only a couple of kilometers away it would only take a millionth of a second or less to reach it's destination.

It's been proven that the human mind cannot precive two events that happen within around 3 thousandths of a second of each other as separate events . So you'd never have to wait for your laser to hit, it'll all look like it happened at once, in your mind.

Now, let's say your enemy has super amazingly quick reactions and can hit some gay hyper drive system once he spots your lasers. WRONG. He won't be able to see the laser until some light from the firing gun has reached his eyes and by that time he'll have died a horrible death.

Add to all that the fact that all lasers in space would be invisible because, seeing as space is a vacuum, there is nothing for them to bounce off of and become visible.
Lasers you see at gigs and other such events have a load of smoke, dry ice and other such particles in the air to react with. This creates the long colourful laser beams you see at your discotheques.

The thing I think is the funniest though, when you cast this hyper analytical no fun geek logic to cinematic space epics, is that with all their amazing technological insights and breakthroughs that are but the fevered dreams of a mad man to us, they haven't developed a space ship with a perfectly mirrored hull, that would simply reflect the lasers and hence make them invulnerable to such attacks.

This isn't a post criticising these types of films for not being realistic, god forbid. If these films applied the laws of physics with such a stringent attitude, they'd be fucking shit and boring. They're unrealistic on purpose and with good reason. I just think the idea of laser combat in space, when broken down, kinda funny and redundant.

Looks shit hot though.

- Thanks to Steven Poole and his awesome book Trigger happy for the 'inspiration' for the above post -

Prion disease no.1

Jesus, even when I come up with a way to make my life easier I some how manage to fuck it up. Procrastination or out right laziness, either way this post should have come days ago.

Now, I'm going to be real lazy and just outline a bit about a disease that effects the most interesting organ in the body - the brain. At this point I feel I should detail why I find the brain so fascinating but, as I said, I'm going to be lazy and leave that for some other time.

The disease is called Fatal Familial Insomnia. It's a super rare autosomal (a non-sex chromosome) dominant inherited prion disease. A prion is a infectious agent born form mutated protein. Another example of a prion disease would be Creutzfeldt–Jakob disease (CJD) also know as 'mad-cow disease'.

In Fatal Familial Insomnia the thalamus part of the brain gets pretty badly fucked up and degenerates in a spectacular fashion. The thalamus is responsible for many functions but it plays a key role in sleep and wakefulness.
As the disease goes to town on this part of the brain the patient's progression into complete sleeplessness is untreatable, and ultimately fatal.

Doesn't sound like a nice way to go if you, like me, love your sleep. Also, as your body is deprived of sleep some truly horrible and strange things begin to happen. I'll go into that in a second...

The gene responsible has been found in only 50 families world wide since the disease was discovered by an Italian doctor, Ignazio Roiter, in 1974. He found a family where two women had appeared to die from insomnia. When Ignazio (legend name) looked back through the family medical records he found a history of insomnia related death. When another member of the family fell ill in 1984 Ignazio studied the patients deterioration and after his inevitable and no doubt horrible death the patients brain was flown to the US for study.

As I said before, the body deprived of sleep doesn't just give up and die, it goes pretty mental. Here's how the disease presents.

The age of onset of symptoms varies a bit, between 30 to 60 – average of 50. It seems though that the disease will usually onset in the later years – after childbirth.
You might think, given the description of the disease, death comes relatively quickly. In fact, it takes between 7 and 36 months.

It breaks down into four stages.

In the fist stage you begin to suffer from increasing insomnia. This leads to panic attacks, paranoia and new phobias. This will last for around 4 months.

Next, comes the insomnia induced hallucinations as your panic attacks become much more noticeable. This lasts around 5 months.

Then comes the complete inability to sleep, followed by rapid loss of weight. This lasts for about 3 months. (I need to look into this more as a 'complete inability to sleep' can not last for 3 weeks let alone 3 months)

Finally you succumb to dementia during which the you become unresponsive or mute over the course of 6 months. This is the final progression of the disease, and you will subsequently die.

All in all a pretty horrible way to go.

Now, like I said this is an insanely rare disease and the chances of you having it are are so small they're up there with me featuring on the cover of a Men's Health magazine.

An out

I'm still working on taking out and putting back in RX-7 engines. It's fucking hard, painful work.
Nuts and bolts in these impossible positions, all requiring the force of 100 men, each who have the strength of 10 men, to loosen. When I do get it lose, because I'm putting my whole body into it, my hand flies into some sharp metal or plastic. That can fucking smart. It's up there with standing on a plug in your bear feet or stubbing your toe on the bed.

Also, a lot of shit falls into my eyes when I'm under the car. Rust and dust mostly. One time I opened up the clutch inspection plate and there was a load of spider eggs inside. Thankfully they didn't fall into my eyes...or any part of my face. Squirming and freaking out underneath a car that's an inch away from your face and is precariously balanced is not an option. Unless being horribly crushed is also an option.

Anyway, to the point of this post...

To stop this blog from going completely dark I'm going to get a wee bit lazy and write about some quick simple things. Mainly interesting medical conditions and diseases.

I hope some will be worth a read and I should be able to post a couple of times a week..

Also, I might write a bit about big brother seeing as I've decided to watch it this year. Although after 4 episodes it seems to be a war of attrition I'm not going to win.

Bah...

Seems like I have to go back to work on removing RX-7 engines with the old man. This will eat up my time and it looks like the next post won't be with us for a few more days at least.

That is unless my brand new medical condition I just found out I had a few days ago stops me from doing the work. In a way I hope it doesn't because if it does, well, this condition will be with me until I'm 40 I was told by the doctor.

That's preety shitty. And to have something stop me from doing just about anything "rough" for the next 15 years would really piss me off.

Anyway, in short, the blog will be hit with another delay.

Edit - It's just been brought to my attention that I made it sound like I have a very serious problem. It's not that bad but it's a fucking nuisance. You all don't need the details.