Expand your coin collection with a range of historical denominations struck by the Royal Mint,

whether they're related to changes in the British monarchy or times of conflict.

Each denomination has a fascinating story to tell, from the shilling and the six pence

to the guinea and the sovereign. There is so much for you to discover with the Royal Mint.

Search RoyalMint.com to discover some of the most popular denominations to circulate before

decimalization today.

Give us a result that we haven't been able to find because we were looking for something small.

As far as I can see right now, there are teams who exhausted themselves in the late 20th century.

Has macho now been retired or is it absolutely absolutely but it's a very nice story because it's

it's a very neat story to explain how science works. Back in the 1980s, everybody thought dark

matter must be this non-barionic, cold dark matter, weekly, interacting, massive particle and

that's where the physicist started to work on and they had all these theories and they tried to

look for it. But then it signs you always have to think yes but what if? What if dark matter is

actually something else or what if dark matter might be these wind particles but there might be

other types of dark matter too. We can't exclude it. So we need to look for other types of dark matter

too. You need to be sure that some other explanation cannot be the whole or part of the truth.

So what they started to do was looking through this gravitational lensing at the existence of

of dark, massive objects in the outer parts of galaxies. And the only way you can do that is by

looking at the way such a dark, invisible object would bend and amplify the light of an individual

star. And it's a very rare event. So if you want to be successful in that, you have to study

hundreds of millions of stars and you have to use electronic detectors and big telescopes and

computer algorithms to study all these measurement data. And that's what two teams in the 1990s

...