Kevin SC Jul 27, 2010:

It is clear that the writer wants to exemplify that his technology can handle a very wide range of frequencies starting with sismic waves (very low frequencies) all the way up to radio waves (high to ultra high frequencies). When he says "de l'ordre du Herz" he clearly means of about a herz or so. So for him the frequency range is from about 1Hz to about 10 Giga. An order of magnitude is an approximation whereas here he's being highly specific. He's spelling it out for us.

Tony M Jul 27, 2010:

Thanks... So glad if it helps!

I'm often accused of being too long-winded, but sometimes it takes a lot of words to explain things ;-)

Louisa Tchaicha (asker) Jul 27, 2010:

Thank you Tony for your explanation, it is very clear :)

Tony M Jul 27, 2010:

The trouble with... ...saying "in the Hz range" is that if you fial to specify some kind of number, it tends to naturally lead to an interpretation of 'hertz, as against some other unit of measurement...' — what is actually crucial here is the number of hertz involved, and not the actual unit of measurement per se. Consider that the writer might well have said "From 1 (Hz) to 10 giga Hz" — the first (Hz) is really needed to avoid its being misread as '1–10 GHz'.

Tony M Jul 27, 2010:

No, that doesn't work in EN That's the whole problem — although it works in FR, because it uses the def. article and so 'du' Hz is OK, in EN it doesn't work, as we would naturally use the indef. article — of the order of a Hz; however, we don't usually say 'a hertz' in EN, since it isn't an everyday unit like a foot or a metre; so it feels much more natural to say '1 Hz' instead of 'a Hz' (and even more so if you use the abbreviation!) I don't think you should be slavishly worried about the fact that a figure is not used in the original, I feel sure the writer would have done so if it had been the most natural way of expressing it in FR; and after all, they didn't shy from using 10 Gig — let's not forget that when you get up into the gigahertz region, one can legitimately talk about a band of frequencies, whereas is sounds a little odd to talk about the '1 Hz frequency band' (though of course it is techncially perfectly valid to do so!)

We must not lose sight of the fact that we are simply talking about 'orders of magnitude' here...

The most natural-sounding way around it might be to say 'of the order of a hertz or so'

Louisa Tchaicha (asker) Jul 27, 2010:

yes I do know that Hz is the same unit of measurement as GHz, my problem is just with using the "1" :(

How about "in the Hz range for seismology and..no never mind

Tony M Jul 27, 2010:

Oh dear! :-( The whole point is, 'hertz' is the unit of measurement (exactly the same in both cases!), while G is simply the multiplier, giga, = 1,000 million.

So the contrast is perfectly valid between 1 and 10,000 million Hz — all they're doing is expressing what a vast range of values their wonderful invention can cover!

I agree it's best to avoid using a figure, but we are only talking 'orders of magnitude' here, so it would be OK — but mediamatrix has come up with a suggestion in his peer comment to my answer which avoids quoting a specific figure (and thereby being obliged to use the abbreviation).

Louisa Tchaicha (asker) Jul 27, 2010:

I'm not sure about putting 1Hz as there is no 1 in the source text, I understood that the waves processed were like Wendy Leech said measured in Hz rather than GHz