pmourad

I agree with both of you, @Baryon and @Studiot. I am not a scientist, just an enthusiast on astrophysics and I've been reading about Einstein's relativity and even though the first image did help me understand the idea, it also made me wonder. As a matter of fact, here's another question if you don't mind. In the first image, the earth is "sitting" on top of this fabric, therefore bending it. Now that I know that this fabric is all around the earth, the fabric on top of the earth, would it be bending the fabric towards the earth or would it be bending it upwards?

Most images about general relativity and curvature of space time are show as the image below, where space-time is portrait as a "fabric". We see a grid that bends where earth is placed. I wonder though, if this fabric should be portrait in 3D as well. In the image below earth is "sitting" over this fabric, but isn't this fabric all around earth? If this is so, then space-time is being bent not only below earth, but all around it (view last image to see what I mean).

Hi. I am an astrophysics enthusiast and I would like to learn more, on my own at my own pace. I'm not pursuing any degree, I simply enjoy it and want to know more. I have very little knowledge in both physics and math. Since I chose to follow an artistic plan in high school, I saw almost no physics and the basics of algebra. Therefore, I believe learning math and physics would be an important steps before enrolling in astrophysics courses. So far, I've read (and enjoyed) the following books: "Seven brief lessons on physics" by Carlo Rovelli "Theory of everything" by Stephen Hawking (this one was a little challenging) "The order of time" by Carlo Rovelli "Astrophysics for people in a hurry" by Neil D. Tyson I wonder if you could recommend any courses, books or videos on things I should learn before diving into astrophysics. Thanks in advance, Paula.

My point is that if what we are seeing is the past, then it's a different conception of "past" as we, humans, know it. Our own past, what we did yesterday, las week, last year, happened then and therefore we cannot see it in the present. It was an action that took place in a moment of our lives and ended, doesn't continue. Taking that into account, if today (the present) we look at the sky and are able to see the past, then there are "two pasts": our humanly past (the one that ends) and a universe's past, the one that we can still see. I hope I was able to explain myself (I find it hard myself to explain my question)

I have been thinking about the “past” in the universe and what the past mean to us, and I came across a thought that I would like to share and hopefully get some feedback and discussion. When reading books on astrophysics, they all mention that the universe is expanding, and probably has been expanding for some time now. That means if there is a star close to us today, tomorrow that star will be farther away, because the universe is expanding. Let’s imagine that from earth in the year 2019 we can see the Star “X”. Then, in the year 3000 the universe has continue to expand and therefore Star “X” is farther away from us but we can still see it. 10.000 years later, as the universe has continued to expand, Star “X” is so far away from earth that we cannot see it anymore, but we know it is there. We would talk about the Star “X” as something that happened in “the past”; but it can’t really be in the past because it still exists, therefore the Star “X” still IS, in the present. The difference I see with our “humanly” past, is that our past is over, it’s a moment that happens and ends, doesn’t continue. We cannot see it, hear it, measure it; we can only remember it. Our past has an end. But is there a past in the universe? The expansion we know of today, if it is a result of the big bang, doesn’t it mean that it is still happening and therefore it is not in the past? I drew a little sketch of my example because I think that it might help to explain myself :)

Hello forum, This is probably a rather unusual question, but I hope you can shed some light. I'm a physics and astrophysics amateur and rookie and I find it absolutely amazing. I would very much like to contribute to this science area as a multimedia graphic designer (that's my profession); and I would like to know if there is any demand or need for design in the field. Thank you in advance.