How do the scientists know?

Question

...how long the Sun will last for? They say a couple or few billion years which is like forever but how do they know that it won't burn out or blow up tomorrow, next week or next year?

Answer 1

They know the mass and type of star that the Sun is. From that they can extrapolate.

Answer 2

We can tell the mass of the sun by the strength of it's gravitational pull.

We can tell the amount of mass converted or utilized in making energy it burns off every year by the heat and light it produces.

So, we know how much fuel it has (the mass) and how fast it is burning that fuel.

But everyone Could possibly be wrong and the solar system could cease to exist tomorrow...but I have too many things to worry about that I CAN do something about. And I would much rather think that the sun will last a few billion years than burning up tomorrow.

Answer 3

The sun is made up of mainly hydrogen and helium. The sun gives out radiation by converting hydrogen to helium in a process called nuclear fusion. By spectral analysis and other methods we can find that the sun still contains more than half of its mass of hydrogen which will take a few billion years to burn up.

Secondly, the gravitational force between the elements required to keep sun at its present state is very large. For this to occur, there must be a lot of matter in a specific area, and the sun goes according to this rule. So the high gravitational force between the atoms keeps it in the steady state without allowing it to blow up for a few billion years.

Answer 4

The person that said the sun is a chemical reaction is incorrect. The core of the sun is a big fusion reactor. Hydrogen nuclei are fused into Helium nuclei. Some small amount of mass is lost to energy in the process, governed by Einstein's famous equation, e=mc^2.

Answer 5

Like many problems in science, there is no way to be exact on the lifetime of the sun. However, spectograph readings of the sun can determine what and how it is 'burning' its fuel, and can determine how much of that fuel is left. Comparing our sun with other suns in different stages of their 'life span' can give us an good idea of where our sun fits in and thereby give an idea of how long it will last.

Answer 6

It's estimate based on how much materials the sun have that it can burn. Not a future prediction. If nothing crazy like that happens sun will burn for amount of time they predict.

Answer 7

The Sun is a chemical reaction. Since we know the chemical components envolved and how the reaction works, it is easier to predict how long the Sun will last.

Since we've started to track the Sun's activity it is noticeble its reduce, so we can easily measure the speed of this reduction of activity.

Answer 8

Virial theorem.