The definition of Half-Life

StickFigs

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half-life (plural half-lives)

noun

1. physics time taken to lose half of radioactivity: the time a radioactive substance takes to lose half its radioactivity through decay.
Symbol T½


2. physiology time taken to lose half of drug: the time it takes for half a given amount of a substance such as a drug to be removed from living tissue through natural biological activity

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I just recently found out that Half-Life was an actual word by just HAPPENING to see it in my science book.
 
ya its kind of like when a math teacher mentions matrix or matrices...suddenly people pay attention because its like the movie the matrix....those students are retarded
 
we have a half life chemistry club at school. one day they brought it up in the morning announcements and i wasnt really paying attention...i was like...'WTF we have a halflife club!?!?!!'
 
No, and I just was flipping through the science book, I'm not a retarded "matrix" student.
 
Originally posted by l337vegeta
we have a half life chemistry club at school. one day they brought it up in the morning announcements and i wasnt really paying attention...i was like...'WTF we have a halflife club!?!?!!'


LMAO OMG I WA ROLLING FOR A MINUTE OR 2 THER. ahh thx for the laff
 
Originally posted by Estevan
LMAO OMG I WA ROLLING FOR A MINUTE OR 2 THER. ahh thx for the laff

WTF? WTF!??!?!

*im-friggin-plodes*
 
Yeah. It's a scientific term.

Also:

Blue Shift is a term with relation to stars in Astronomy.

Opposing Force as in Newton's Law, for every action there is a an equal and opposite reaction.

It's kind of cool how all of the Half Life titles have been scientific puns.
 
Originally posted by RhapSidious
Yeah. It's a scientific term.

Also:

Blue Shift is a term with relation to stars in Astronomy.

Opposing Force as in Newton's Law, for every action there is a an equal and opposite reaction.

It's kind of cool how all of the Half Life titles have been scientific puns.


They delayed it a whole year to think up names? FOR SHAME VALVE!
 
Scientific puns?

Half-Life 3: G-Man, the Sphincter Spasm
 
I first noticed when we took it in math. and i was like .. what the hell is half-life doing here?
 
Does Half-Life 2 have a subtitle, with a little scientific joke in it? Hrmm..
 
i definitely know its a word cos its one of the most frickin boring parts of my physics course.


PS. the name in the game was taken directly from the first meaning you gave.
 
HL2 = Half-Life squared

so it's like half the life of a radioactive element times itself...

:p ok that was dumb, someone else think of something better
 
If that's the case, wouldn't quarter life be a better name?
 
I don't know physics (and I wish I did, makes me wanna switch majors) but why use a half-life instead of the full time it takes for a radioactive element to decay? What's so significant about the half way mark?
 
Half Life is NOT the time it takes for a substance to half its radioactivity. It's the time it takes for the object to half its MASS. Ask yer local science-teacher and you'll see.
 
Radioactive decay is logarithmic. The radioactivity halves every X years. It isn't a loss of mass.

The halflife of uranium 235 is 713,000,000 years. If you have 2 samples, 1 that has just been created, and one that is 713,000,000 years old, the older one will be putting out a count approximately half of that of the new sample.
 
Originally posted by Kyle2
HL2 = Half-Life squared

so it's like half the life of a radioactive element times itself...

:p ok that was dumb, someone else think of something better
Actually, the symbol used to represent HL is "lambda", a letter from the greek alphabet, which is commonly used in physics and maths equations etc. HL2 is actually lambda^2 (lambda squared). Just look at how the HL2 logo is layed out :)

There are certain common uses of the lambda symbol in physics, but I'm no scientist so don't ask me :) It's been discussed around here though, so someone around here knows more about it.
 
Originally posted by RhapSidious
Yeah. It's a scientific term.
Also:
Blue Shift is a term with relation to stars in Astronomy.
Opposing Force as in Newton's Law, for every action there is a an equal and opposite reaction.
It's kind of cool how all of the Half Life titles have been scientific puns.

Holy shite, I never noticed that before! That is so cool.
 
lambda is the cosmological constant

Lambda must be a variable, e.g. Lambda(x, t) could be a density dependent on space/time. More specifically, Lambda(x, t) = C.f(x,t), where C is some constant relating the force Lambda to the local density of `something'.


Redshift is a measure of how far away an object is from Earth. An object with a higher redshift is further away, and, since the speed of light is finite (large, albeit, but not infinitely so), the further away an object is, the further back in time we observe it (think about that for a minute). So, the Initial Redshift simply sets the physical size of the simulation.

The opposite of a red-shift is a blue-shift. Red light is lower in energy; blue light is higher. Things rushing away from us as space expands would leave light from distant objects moving more slowly relative to us if not for special relativistic effects. With the effects, the energy of the light is reduced.
 
Originally posted by FISKER_Q
Wow old news this is so exiting.
Indeed... Still, with people joining all the time, there's a whole new batch of people that have the right to talk about stuff we've already discussed. After all, it's not like you can expect new members to read through every thread, and without new threads about old news, there might be a lot of people who would never be made aware of things like this (see the "never noticed that before" type posts).
 
Originally posted by Ares
I don't know physics (and I wish I did, makes me wanna switch majors) but why use a half-life instead of the full time it takes for a radioactive element to decay? What's so significant about the half way mark?

Because you can't predict the full time.

Dont ask me why, I haven't gotten to that course yet.
 
Wait a second... if Half-Life is half the life of an atom... then Half-Life Squared (HL2) is MORE than an atom should be able to live.... does this mean up until this sequal Gordon has been preserved? OMG CONSPIRACY!
 
i bet it has something to do with the stuff that gordon pushed in the beam in the beginning of HL
 
Tsk Tsk, no the symbol lambda is used to represent the decay constant of a radioactive material. It however can be used (by dividing ln2 by it) to find the Half-Life.
 
Black Mesa is a place in Oklahoma.
It doesn't mean anything else...Black is a color, and Mesa is a large geological formation, a natural pillar.
 
Originally posted by vetebulle
Because you can't predict the full time.

Dont ask me why, I haven't gotten to that course yet.
You're probably on the right track. Think about it - if every X amount of time, something halves, then it's just going to get infinitely smaller without ever reaching 0 (it's logarithmic).
 
Originally posted by Logic
Indeed... Still, with people joining all the time, there's a whole new batch of people that have the right to talk about stuff we've already discussed. After all, it's not like you can expect new members to read through every thread, and without new threads about old news, there might be a lot of people who would never be made aware of things like this (see the "never noticed that before" type posts).

I don't think this has been mentioned a lot of times here.

I did once. Where someone emailed Gabe(i think) where he challenged us to find out what the equations were. In that movie. I wrote i couldn't see it clearly. But i thought it was the equation of a half life.

I'm more refering to the age of the information. I learned a lot of years back what some Danish terms we're called in English. And he spoke about half-life and redshift. But not blueshift.
 
Red shift and blue shift are the same thing. It's a doppler effect. Say you were moving at close to light speed. Everything in front of you would be red-shifted, everything behind you would be blue-shifted. The wavelengths of light expand or contract depending on whether you're approaching them or moving away from them. (I think I got that about right, correct me if not.)
 
even a Half-Life web site has a definition clearly at the top, how ironic!
 
I think people would have made this thread sooner if they didn't think everybody knew this already. :)
 
Originally posted by Crusader
Tsk Tsk, no the symbol lambda is used to represent the decay constant of a radioactive material. It however can be used (by dividing ln2 by it) to find the Half-Life.

Lambda is also the symbol for wavelength.
 
i was at work yesterday(work as a nuclear operator for usn) and got to thinkin' its ironic that half-life (the game) uses the lambda symbol, while the actual half life (physics term) uses t sub 1/2. *sigh* throwing away acuraccies just so it looks cool i suppose. Lambda typically means Decay Constant, which i suppose would have sounded cooler than half life anyways so just wtf were they thinking?
 
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