Mini-Hub - 3 things you didn't know
The old saying is "You learn something new every day", and that may be true. But do you remember it? Well here are 3 things you'll learn today, and hopefully remember.
Where are the hottest and the coldest places in the universe?
Have you ever burnt yourself on the stove whilst cooking your favourite meal, or gotten Brain-Freeze whilst eating freezing cold Ice-Cream and then thought to yourself; "Where are the hottest and coldest places in the whole universe?" Of course not. This isn't a question we usually trouble ourselves with, but where are these places?
Surely the cold, dark depths of deep space are amongst coldest places. They have no heat sources for trillions upon trillions of miles in every direction...But you would be wrong.
The coldest possible temperature of something is -273.15°C, known as absolute zero, but we cannot actually reach this temperature. When we do, the molecules of the object or gas now no longer move, at all, meaning no energy can be transferred and no heat is produced. Because this requires the molecules to stop completely we never will reach -273.5°C entirely, but we can reach a very few billions of a centigrade above absolute zero. So where is the coldest thing in the universe? A glacier on a barren asteroid in deep space? My ex-girlfriend's heart? Close, but no.
A laboratory in Brighton, England has created a gas that is just a billionth of a centigrade above absolute zero. So cold we cannot get colder, ever and life cannot exist there.
But, where is the hottest place in the whole universe? Well the hottest natural temperature recorded on Earth was a staggering 54°C in the USA, but that isn't even close.
The surface of the sun reaches 5000°C and the centre reaches an incredibly hot 15,000,000°C but these still are not even close to how hot the hottest thing in the universe is.
At the centre of a thermo-nuclear explosion it reaches, for a tiny amount of time, 350,000,000°C and this, again, is not even close to the hottest.
When particles were fired towards each other in the Large Hadron Collider in Switzerland the particles had so much energy that for a time so small it was barely measurable their temperature was an unimaginable 1,000,000,000,000,000,000°C.
So both the hottest and coldest temperatures ever reached were both man-made on Earth.
You live very slightly in the past.
When somebody shouts to you "You live in the past!" Well, they're not actually far wrong. You do.
But why? You may ask. Well, the answer is because everything takes time.
When an event occurs such as a flash of light, the light has to travel from it's point of origin to the retina of your eye.
So for example, if you flick the light switch on in your house it sends an electrical current to the light-bulb at close to the speed of light. This switches the light on, and the light emitted travels from the bulb and then reflects off of your retina. Light travels at an approximate speed of over 299,000 metres per second, so it hits your retina almost immediately.
Once the light has reflected from your retina, it causes an electrical impulse to travel to your brain, again at close to the speed of light. At this point your brain interprets the electrical impulse received from your retina and then it waits. Now, your brain only waits an incredibly short amount of time, a few milliseconds, but it is measurable and often noticeable. The end result is that you actually notice the flash of light from the bulb a staggering 0.4 seconds after it started producing light.
Since light travels at 299,000 metres a second you can have fun with this. The time light takes to get from the sun to Earth is a total of 8 minutes, which means when you look up into the sky and see the sun what you're seeing is the Sun 8 minutes ago, you're looking back in time. The same applies to stars, due to their distance when you look up at the night sky you're actually seeing the universe as it was thousands of years ago as that light has taken thousands of years to reach Earth.
This also means that, if you were able to travel faster than the speed of light then time travel back in time would technically be possible, but you cannot exceed the speed of light.
How many continents are there?
Now this isn't so much a fact as it is a point to consider. You may find this a ridiculous question to ask since everybody knows the answer, but how many continents are there?
The universal answer is 7. Europe, Africa, Asia, South America, North America, Australasia and Antarctica. But are there really 7?
For that matter, what is a continent? If you said a large land-mass separated by a large body of water, such as an Ocean then you're both right and wrong. Most continents, i.e. Antarctica, North/South America, Africa and Australasia are all separated but Asia and Europe are connected. Look closely at the border between them, and see the distinct lack of Ocean.
So surely there should be a total of 6 continents as Europe and Asia would be combined to make Eurasia. So what is a continent? Well it's a large landmass separated from another large landmass by a large body of water, and how many continents are there? Well you choose, 6 or 7. The choice is yours.
As a little bit of additional information, North and South America are separated by the Panama Canal.