Recent content by karl22

Hi everybody I just wanted to ask are all the galaxies in the universe visible by the light they send? In the other words are all the galaxies optically visible ?How do scientists predict the number of galaxies and do they understand the existence of other galaxies(very far galaxies) by...

OK thank you so much for the answer I got what I was looking for.

OK thank you so much for the answer But my my question is that if you throw your hands to one side so fast then pull you hands to your side again but slowly this time won't you move ?

Thanks a lot foe the answers. If this is the case then when the gas rocket of the astronaut becomes broken or it doesn't work anymore and the astronaut is left alone in the space without being able to stick to anything how could he move and change his location?? Is it even possible ?

Hi As you may know according to third law of Newton every action has a reaction.But my problem is that as we may know there is the need of friction for moving that you lean on something that you become able to move But as I have heard NASA has developed some gas-powered rocket maneuvering...