|
Post by Twoddle on Jun 29, 2008 20:16:15 GMT
Tone,
My car has a left-side mirror that tips to let the driver see the kerb clearly when reverse gear is selected. I hoped it would assist the Contessa when parking, but it's largely a waste of technology because: (a) She doesn't park the vehicle if reversing is required, and (b) I've never known her to use the outside mirrors.
As she says: "I don't need to reverse; I have a man for that sort of thing."
|
|
|
Post by Bertie on Jun 29, 2008 20:47:31 GMT
I had thought that there was some actual mathematical explanation, but it appears from the answers thus far given by this learned panel, that it is considered merely an optical illusion. I do not notice it so much in a car travelling at high speed, it is much more 'evident' when driving a large vehicle, and thus, almost by default, overhauling another with only a small differential in speed.
|
|
|
Post by Tone on Jun 29, 2008 21:04:43 GMT
>that it is considered merely an optical illusion.<
I think that the explanations given would make that more of a "mental" illusion.
Tone
|
|
|
Post by Verbivore on Jun 29, 2008 23:59:48 GMT
[...] My car has a left-side mirror that tips to let the driver see the kerb clearly when reverse gear is selected. I hoped it would assist the Contessa when parking, but it's largely a waste of technology because: (a) She doesn't park the vehicle if reversing is required, and (b) I've never known her to use the outside mirrors. As she says: "I don't need to reverse; I have a man for that sort of thing." Well, Twod, at least be grateful the Contessa doesn't park like so many I see (and occasionally suffer car-bruises from!): parking by feel! And it seems the smaller the car, the greater the parking incompetence of its driver. (All my cars have flat mirrors; convex ones were, for a long time, illegal in my state of Oz. Still should be. If a mirror is large enough, well enough designed, and optimally positioned, there should be no need for the dangerous and misleading convex nonsense. That used also to be the opinion of Daimler-Benz, the inventors of the car and car safety - though I don't know the company's present view.)
|
|
|
Post by Geoff on Jun 30, 2008 2:58:30 GMT
You're right, it took me almost 12 months before I felt confident using the convex side mirrors on my present car. This, obviously, is the first car I've had with such mirrors.
|
|
|
Post by Tone on Jun 30, 2008 20:33:55 GMT
> it took me almost 12 months before I felt confident using the convex side mirrors on my present car. This, obviously, is the first car I've had with such mirrors.<
Um ... how about, change them, then!
Vv, > parking by feel<
We tend to use the term "parking by ear"!
Tone
|
|
|
Post by Twoddle on Jun 30, 2008 20:49:19 GMT
Vv, > parking by feel<We tend to use the term "parking by ear"! Tone It's parking by insurance excess and no-claim-discount as far as the "collidee" is concerned (as I know from bitter - and I do mean bitter, that being the over-riding emotion - experience).
|
|
|
Post by Tone on Jun 30, 2008 20:53:38 GMT
>(as I know from bitter - and I do mean bitter, that being the over-riding emotion - experience).<Yes, bitter will do it, as will any alcohol in excess! (And I thought that you claimed not to like beer!) Tone
|
|
|
Post by Twoddle on Jun 30, 2008 21:01:09 GMT
>(as I know from bitter - and I do mean bitter, that being the over-riding emotion - experience).<Yes, bitter will do it, as will any alcohol in excess! (And I thought that you claimed not to like beer!) Tone I leave all the imbibing of alcohol to my offspring, Tone. They manage my share very easily.
|
|
|
Post by Geoff on Jun 30, 2008 21:33:13 GMT
Um ... how about, change them, then! Ignorance, Tone. I didn't know you could and, obviously, never thought to ask. I just accepted them as standard, knowing that convex mirrors were fitted to modern cars.
|
|
|
Post by Rajesh Valluri AKA Raj on Jul 1, 2008 4:27:55 GMT
Its definitely not doppler effect in this case. The speed of the vehicles should be in the magnitude of that of the electromagnetic waves. That's why we are able to observe doppler effect in clestical objects because they are infact moving at such speeds. The few cases where we do get to observe this effect is the sound waves. The speed of sound is comparable to that of some vehicles. I use comparable in a loose way here, and I know some of you might question that assumption. Anyway, doppler effect is indeed observed when you hear a train approaching, its horn becomes shriller and the one that's leaving has the opposite effect.
|
|
|
Post by Trevor on Jul 1, 2008 7:52:33 GMT
Bill Bailey touches on the doppler effect in his ramble on foreign sirens here.
|
|