[Diogo_Afonso_Leitao (OP)]

Hello, my name is Diogo and this is my first post here in the naked scientists forum! So, i was wondering
why did scientists come up with the idea of dark energy and dark matter and what is the difference between them.
Thanks for attention!

[Bill S]

Hi Diogo, welcome.

Very briefly, dark matter was suggested as an explanation for things such as the speed of rotation of galaxies, which didn't seem quite "right".

Dark energy was proposed when it was discovered that the expansion of the Universe is accelerating.  Something had to be "pushing" it.

It might be worth keeping an eye on the thread "The nature of dark matter"; the chances are some of your questions will be answered there, and that will avoid repetition.  If not; keep asking; our experts sometimes need prodding. []

[Diogo_Afonso_Leitao (OP)]

Hi Diogo, welcome.

Very briefly, dark matter was suggested as an explanation for things such as the speed of rotation of galaxies, which didn't seem quite "right".

Dark energy was proposed when it was discovered that the expansion of the Universe is accelerating.  Something had to be "pushing" it.

It might be worth keeping an eye on the thread "The nature of dark matter"; the chances are some of your questions will be answered there, and that will avoid repetition.  If not; keep asking; our experts sometimes need prodding. []

Thank you very much Bill!

[PmbPhy]

Hello, my name is Diogo and this is my first post here in the naked scientists forum! So, i was wondering
why did scientists come up with the idea of dark energy and dark matter and what is the difference between them.
Thanks for attention!

Welcome to the forum.

Dark matter is the source of matter that is responsible for the anomalous rotation curves of galaxies while dark energy is the source of the repulsive gravitational field that is responsible for the accelerating expansion of the universe. Nobody knows what they're composed of yet.

[F'dscience]

All these fifty years of conscious brooding have brought me no nearer to the answer to the question, 'What are light quanta?' Nowadays every Tom, D i c k and Harry thinks he knows it, but he is mistaken. -Albert Einstein 1953

nowadays everything energy, everything quantum.

do you really know what is energy? not even einstein.

what is ENERGY?

coal? fuel? oxygen? wind? sunlight? any matters?

NO. matter is not energy. matter is the carrier/source/container of energy.

a rock at rest only has its thermal energy.

if you threw it away, your hand put a force on the rock pushing it moving at a speed v, the moving rock will have 1/2mvv energy added on it. we call it kinetic energy.

if the flying rock hits a wall, that energy becomes the impact force that hits the wall, makes atoms on the wall vibrate faster/hotter, atoms thermal energy.

so, energy is nothing but vibrating force/moving force.

energy is always vibrating/moving, within and between matters. matter is always moving/vibrating due to the existence of energy.

nothing is ever at rest, keep moving, changing, involving, reforming, transforming.

somehow, LIFE woke up?

[puppypower]

Hello, my name is Diogo and this is my first post here in the naked scientists forum! So, i was wondering
why did scientists come up with the idea of dark energy and dark matter and what is the difference between them.
Thanks for attention!

Welcome to the forum.

Dark matter is the source of matter that is responsible for the anomalous rotation curves of galaxies while dark energy is the source of the repulsive gravitational field that is responsible for the accelerating expansion of the universe. Nobody knows what they're composed of yet.

Is dark matter the same thing as relativistic mass? If you had a mass M moving at the speed of light, the kinetic energy becomes much higher than 1/2MC2.  Relativistic mass is a math function that adds mass; M*, to the kinetic energy equation, so the kinetic energy will add up based on forces required; 1/2 (M*+M) C2. Is M* dark matter?

If this was the case, one would expect to find the main source of dark matter or relativistic mass at the perimeter of galaxies since this is where the average velocity is highest and more M* needs to be added to close the relativistic energy balance.

Relativistic mass is not the same as rest mass. Both rest mass and relativistic mass can impact space-time. This is reflected in general and special relativity. However, only rest mass can generate pressure; via gravity. The result of relativistic mass or dark matter is energy would red/blue shift due to space-time changes, but without new exotic phases of matter appearing due to no induced pressures.