Recent content by DrGreg

For what it's worth, when metrication was being introduced in the UK, many decades ago, we were told A litre of water's A pint and three quarters and Two and a quarter pounds of jam Weigh about a kilogram

In an electronic document, you don't need a page number, you need a link that you can click.

Here is a spacetime diagram of a rod accelerating along its own length. The green area is the rod. This is drawn under the assumption of constant proper acceleration and a Born rigid rod. On the diagram below I have superimposed some snapshots of the rod at various times, using the definition...

I thought it was the Citroën 2CV that many said was a true lemon?

Today I learned that the Mercator projection isn't what I thought it was. When I was a child and teenager, I was told that the Mercator projection was what you got by putting a light source at the centre of a hollow transparent globe, and wrapped a piece of paper around the equator to form a...

Yes, but according to Wikipedia, the U.S. system is different from the European system. Europe U.S. Russia 2B #0 2М B #1 M HB #2 TM H #3 T 2H #4 2T

Something similar happened in a pencil shop.

I'll probably join some time next month.

past infinitive = "(to) have" + past participle

While "she has written..." is the present perfect tense, which differs from the past tense as described in post #1, "she should have written..." is not. It is composed from the past tense "should" of the modal auxiliary verb "shall" combined with the past infinitive "(to) have written"...

To be pedantic the phrase should really be "proper fraction of the cost".

Opinion is divided.

Former UK prime minister Boris Johnson was yesterday turned away from a polling station when he could not prove his identity. It was his own government that two years ago introduced legislation requiring voters to show photo ID. BBC: Boris Johnson turned away from polling station after...

The subtraction makes no sense. It's as if you are trying to subtract 3 cats from 5 dogs and don't understand why an answer of 2 is wrong. It makes no sense to subtract ##Y_\mu## from ##X^\mu## no matter what ##\mathbf{X}## and ##\mathbf{Y}## are. You did, but that's irrelevant to why the...

At least it didn't take you a degree.