6 ms·
Timeline of a Car Crash
- tjic 17y agoFrom time to time I stop and think about how blindingly FAST computers are. It's easy enough to click "refresh" on a web server running on your desktop and wait half a second for a refresh...but then when you ponder that not only might you be executing a few THOUSAND or TENS OF THOUSANDS of lines of your own code, but you're executing a few hundred SQL queries, each of which is doing mind-bendingly complex stuff over in the SQL server ... running the same CPU ... it just boggles the mind. I remember when I was amazed at how many computations my overclocked Apple IIe (running at 2.5 MHz !!!) could do in an eyeblink.
- yan 17y agoI had a similar realization when it dawned on me that my computer performed about twenty instructions before the light from my monitor arrived at my cornea... (edit: light travels about a foot in a nanosecond, or 6 inches per clock cycle in a standard 2ghz pc. multiple simple additions can be done in a single clock cycle; multiple by number of cores)
- maukdaddy 17y agoWow that's an amazing way of looking at the computing power and speed of modern processors. Maybe Intel should start marketing processor functionality this way!
- ars 17y agoTthe speed of light is starting to impact how fast cores can be. They need to take it into account when routing signals on the core. And it's one reason asynchronous cores work a lot better, since at high hz it's impossible to keep the entire core synchronized.
- yan 17y agoAs I understand it, it has been an issue and a major reason for actual cores being as small as they are. The time a signal takes to propagate from one section of the core to another is significant.
- anamax 17y agoChip sizes are a function of yield and performance. Core sizes are designed to optimize performance for a given chip size. (Yes, there's a circular dependence but yield is a huge factor in chip size.) That said, it's been at least a process generation since a given clock signal could be used to synch events on the opposite sides of a core, let alone a (high performance) chip. This is due to both increasing clock frequency and the fact that propagation speed has gone down as feature size decreased.
- baddox 17y agoElectric current in copper does not travel anywhere near the speed of light. In fact, motherboards using fiber optic buses instead of copper buses may be one solution to the problem you're talking about.
- joeyo 17y agoAnd when you consider how much longer it takes for you perceive, the light it gets even more ridiculous!
- spoiledtechie 17y agoExtremely interesting stuff here. Was impressed with how fast the computer reacts compared to how long it takes a person to be aware they were just hit. Amazing.
- mynameishere 17y ago1000 ms - infinity: Occupant stops being aware of collision.
- kirse 17y agoLink to full original content that was used for this blog-rip: http://www.drive.com.au/Editorial/ArticleDetail.aspx?ArticleID=56781 http://www.drive.com.au/Editorial/ArticleDetail.aspx?Article...
- keltecp11 17y agoI would love to see it with Illustrations. Excellent Posting, well done.
- showerst 17y agoI was thinking of doing one, but the few stock images of car cutaways I could find (http://www.khulsey.com/stockimages.html http://www.khulsey.com/stockimages.html) are $1500 =(.
- nopassrecover 17y agoOuch - nice images though.
- CrLf 17y agoInteresting, but the occupant is probably already aware of the collision before the two cars touch.
- icey 17y agoA) Not always B) I think they're just making the point that all this occurs before the brain can register what's going on to begin with.
- helveticaman 17y agoI'm just glad to see Ford doing engineering.
- csbrooks 17y agoAlso: A videogame running at 60 fps has to calculate everything associated with rendering a frame, and get the image on the screen, in 16.6ms.
- teuobk 17y agoAirbag systems are fascinating. They sit around for years, perhaps decades, deciding over and over again whether or not a crash is occurring. Then, when a collision does occur, they have to make a decision -- the right decision -- and take action within a few milliseconds. A false-negative could exacerbate the injuries of the passengers. A false-positive could cause a fatal crash. No room for error. Amazing stuff.
- modoc 17y agoYour comment reminded me of the Neal Stephenson short story Jipi and the Paranoid Chip: http://www.vanemden.com/books/neals/jipi.html http://www.vanemden.com/books/neals/jipi.html Worth a read, and very apropos.
- furyg3 17y agoHilariously appropriate! I enjoyed that a lot, thanks.
- vaksel 17y agoWhen I had my car accident, front end collision, which then spun the car around to hit the side, the front air bag didn't deploy, but the side one did.
- baddox 17y agoWhy is unlocking the doors so late on the list? I would think that instructing the doors to begin unlocking could be done relatively early in the process. Perhaps they meant at that point the doors were completely unlocked.
- mhb 17y agoMaybe the doors are stronger when locked.