Recent content by sophiecentaur

If Eureka can, anybody can.

What accuracy is needed for the measurement? Hopefully the deer is dead by this stage.

I think there must be more to this jack than it appears. Those conductors are going to wipe across other (the wrong) conductors as the jack is inserted. IMO, the live and neutral in the receptacle must be lifted away from the rings on the jack or the could be an Earth-Neutral contact on the way...

In many ways that would be true; you can be much more 'adventurous' than you can with static optics and get an almost parallel sided output. But moving parts?? I wouldn't go there' The context of this thread is still unknown. It strikes me that the OP got himself a laser and waved it about on a...

How far, though? You would want it to be compact, I assume. OP didn’t say the focal length. I didn’t understand it ‘not working at all’. Maybe the fan out dispersed the energy too much.

I hope your confidence is justified with all those students. You delivered the message ok but did 'they all' get it? I guess it would depend on the students' potentials and it would be nice to think that they did.

OK; that's the definition of a Plano Convex lens but you need a concave lens to spread the beam. There are hundreds of links showing ray traces of all common shapes of lenses and reflectors. Do a bit of research with terms like basic lens and ray diagram. It has taken 29 posts to get down to the...

And they were an exclusive 'general public' who could actually understand his message. Can anyone assume that they had really thought out the issues of causality? N3 was too brief to include this and a whole paragraph would never have got the message across. This poor guy at the interview is...

. . . . and you were careful not to do your diagram whilst riding on a bus or with a mouse. There is little excuse for not using a free drawing app (not a painting app), which makes lines straight and level. A quick tiffle with contrast and brightness would render that photo as good as new.

The terms were introduced a long time ago and were chosen (probably) to be acceptable to the public at the time. The notion was (and still is) a difficult one as 'another force' suddenly comes out of nowhere. It is obviously a confusing and counterintuitive notion. There are many others which...

That was what attracted me to the thread because contributors seemed to assume that considering cause and effect would have to be a given requirement to do a Physics degree (or even a lower qualification). Let's face it, if it were a trivial matter then it couldn't support the amount of...

Just any old concave lens will not do. I saw several versions of the same on eBay thing so they are clearly for a particular purpose. is this the sort of thing they delivered? (eBay ad) But seriously, why not go for a cheap laser level? A fan-out will reduce / eliminate the risk of eye...

That's a very simplistic / optimistic remark. Iin my experience, many PhDs get their doctorates by just repeating the ideas of their supervisor. Of course, we had some brilliant exceptions but a significant number were disasters waiting to happen; no ability to relate the book to a practical...

Yes I read some of those discussions but the reason for the disbelief was due to a deep intuition ("it just could never work") and failure to go through all the appropriate steps- including chasing 'signs' and sticking to them. This is a typical result of trying to establish what's really...

You have my sympathy BUT why spend that sort of money on an initial project? Edmund Optics supply high end users. Why not look through my fave eBay or the local second hand market? If you have calculated the focal length you need for your lens then a used camera lens could well do the trick. I...