Weird things you never knew

Hattigol

Last night, the current Mrs H said to me that a flame doesn't create a shadow. 

B*llocks I suggested back to her.

True enough, after a brief experiment with a candle and a torch, I got to eat some delicious humble pie as she was correct.

Anyone else discovered anything weird that they hadn't known previously?

rogd

Try folding a piece of paper 8 times.

dano

Intersting.

We've  been discussing shadows at home recently with my daughter who is into science and maths 

Shadows don't exist. 

Think about it, a shadow is just where the light can't get to. Light doesnt actually  create a shadow. Not having light on the wall behind the object creates a shadow.

You can see it, but it has no physical properties (and no electromagnetic properties like the light).

munckee

That we are so far from the sun that we can’t feel it’s warmth. 

The radiation speeds up the molecules in our atmosphere and the friction from the moving molecules gives us our warmth. 

Sassafras

I still don't know the things I never knew.

Sassafras

I learnt only recently that the male duck billed platypus has got a venomous claw on one of its back legs and that being an egg laying mammal that bears milk, it can make its own custard.
I think the custard making is limited to the female platypus.

dazzajl

In a photograph a shadow will normally have more substance than the object casting it but the platypus being the only animal that can make it’s own custard one has to be the best fact of them
all. 

Sassafras

dazzajl said:

In a photograph a shadow will normally have more substance than the object casting it but the platypus being the only animal that can make it’s own custard one has to be the best fact of them
all. 

I think humans can make custard too by buying a packet of Birds.

HAL9000

That ‘ye’ (as in Ye Olde Shoppe) was pronounced ‘the’.

Danny1969

Did you know we can't measure the speed of light, only the round trip of it. So we have no idea if the reflected returns at the same speed the light left the source, we just assume it does. 

If you get 2 pieces of metal that have been made with completely flat surfaces they will stick together like magnets, even though aren't magnetic at all. Precise metal blocks used to calibrate micrometers will do this for example. 

PhilW1

Danny1969 said:

If you get 2 pieces of metal that have been made with completely flat surfaces they will stick together like magnets, even though aren't magnetic at all. Precise metal blocks used to calibrate micrometers will do this for example. 

We do this all the time in my toolroom wringing different size gauge blocks together  , it’s called “Sticktion” ( might be a brummie thing!)

Dominic

HAL9000 said:

That ‘ye’ (as in Ye Olde Shoppe) was pronounced ‘the’.

And was actually a letter in our Alphabet until it was dropped........it looked like a Y and an E joined together ,rather like the Greek ae .It was called a Toth or a Thorn depending on what part of the country you came from.
It became reserved for religious use in the plural form.

goldtop

That the wonkily attached tag on the end of a tape measure - the stupid wobbly bit that seems to add vagueness to every measurement - is actually there by design to make measurements more accurate. Who knew!

ICBM

Danny1969 said:

Did you know we can't measure the speed of light, only the round trip of it. So we have no idea if the reflected returns at the same speed the light left the source, we just assume it does.

Not true - the very first measurement of the speed of light was one-way only. It was done using the difference in the predicted positions of the moons of Jupiter compared to the observed positions when the planet is on the same or opposite sides of the Sun from the Earth. The time it takes for the light to reach Jupiter from the Sun is irrelevant, it's only time it takes to reach Earth from Jupiter that matters.

https://en.wikipedia.org/wiki/Rømer's_determination_of_the_speed_of_light

OK, the result he got wasn't very accurate by modern standards, but the principle is correct and it's possible to do better with modern observations.

EricTheWeary

HAL9000 said:

That ‘ye’ (as in Ye Olde Shoppe) was pronounced ‘the’.

There was the letter Thorn in old English which was the th sound. It still exists in the Icelandic alphabet. As we started printing things in English we had mostly German printing sets that omitted the letter Thorn and Y was used to represent it. Hand writing it as a Y on something like a shop sign is a bit arse backwards as they could have used a Thorn but the original letter shape had fallen out of use. 
It takes about 1,000 years for a language to become unrecognisable. So the version of English in use when the Thorn was originally used would be unrecognisable to us today; Shakespeare for example is still modern English and that seems odd enough. 

Kittyfrisk

Most humans peel bananas the 'wrong' way round, opening the stalk end, instead of using it as a built in handle.

viz

Kittyfrisk said:

Most humans peel bananas the 'wrong' way round, opening the stalk end, instead of using it as a built in handle…

… and holding it like a champagne flute. Cheers!

Kittyfrisk

Quoting on here adds parentheses to the original statement. Who knew? 

Funkfingers

Vivian Stanshall was wrong to have the Rawlinson End character, Reg Smeaton, assert that there is no proper name for the back of the knee. 

mrkb

goldtop said:

That the wonkily attached tag on the end of a tape measure - the stupid wobbly bit that seems to add vagueness to every measurement - is actually there by design to make measurements more accurate. Who knew!

Yep - it compensates for the thickness of the L shaped tag to account for the different use case when hanging it off the end of the wood or pushing it into the corner of the room.  

Funkfingers

A pipefitter taught me to measure tube from the ten and, then, subtract that from the apparent measurement.