My teacher told me that vacuum contains nothing.my question is that space is vacuum and energy. Plus energy doesn't need a medium to travel through. so why doesn't energy go and occupy vacuum? If it has already then if vacuum a type of energy?
2 Answers
Vacuum is specifically empty space devoid of matter existing at exactly 0 K units but no place in the universe exists that is total vacuum.
As the universe expands, the very work of that expansion converts to energy giving empty space a standard temperature of approximately 2.5 K units.
That standard temperature indicates that in spite of the lack of physical "stuff", there is a modicum of energy everywhere.
There are certainly not massive bodies everywhere but there is most certainly measurable energy in every region of the universe. A total vacuum would exist only at 0 K units but no such place in the cosmos exists where the temperature is actually 0 K units.
We have measured an amazing amount of the universe, going quite close to the dawn of time; the standard temperature in deep space is not vacuum and does not indicate vacuum.
The lowest temperatures ever recorded were not in deep space but were produced right here on Earth, just a few minidegrees higher than 0 K units.
Almost all scientists with interest in the situation are 100% certain that absolute zero, absolute vacuum, cannot possibly be attained.
Information from
http://www.smithsonianmag.com/science-nature/the-coldest-place-in-the-universe-8121922/?no-ist
was used as research for this answer.
I might always be wrong.
Your hypothesis that space is energy is not sustainable.
See explanation below.
Explanation:
In Physics Vacuum is understood as
- A region containing no matter; free space
- A region in which matter, specially gas is present at a low pressure . If the gas is totally absent it is called a perfect vacuum.
Your teacher was referring to the first definition.
Now lets understand what you meant by energy. Energy as used by you is electromagnetic energy or light, when in visible region, as we call it.
Gravitational field, lines of electric field or of magnetic field would be crossing and present in the vacuum space under consideration But these do not constitute energy unless these interact with matter.
We know from the second postulate of Special Theory of Relativity propounded by Einstein that
The speed of light in a vacuum is the same for all observers, regardless of the motion of the light source.
Assuming that vacuum under consideration is filled with energy. And we consider a finite vacuum space. For an observer in the vacuum the energy moves with speed of light. Therefore, it must leave that vacuum space at one time, as measured by the observer in the vacuum, or the other. This implies that energy can not fill vacuum.
Thus can conclude:
Either the basis of Special Theory of Relatively is not correct
or
Assumption that space is energy is not supported.
or
As postulated by you that energy can occupy space is not sustainable.
