Do we really need Dark Matter?
As the scientist said, universe is expanding at accelerating rate. “Something” is to blame for this. Gravitational pull of “something”. So we call that “Something” “Dark Matter” and “Dark Energy”. We can’t see it, we don’t know what it is, yet we can see effects of it.
One personal example and logic made me doubt about Universe’s expansion acceleration. But firsts things first.
How can we determine exact position of something? We need several reference points and measurements of each. Method is called “Triangulation”. We need at least three observation points for this. That is why your mobile device need to “catch” at least 3 GPS satellites to determine your location. This is something we do not have considering universe. We have only one observation point. Well, we have more – displacement of various observation satellites in Earth’s orbit, but distance between them is too small to triangulate something billions of light years away with precision. Even if we measure it from one point of Earth’s orbit, then 6 months later from another point on the far side of the Sun. So far we can say that we have only one observation point, and we are missing two to triangulate.
I am sure that even sparrows know by now that Time and Space does not exist in reality as separate values. They are just our understanding/perception of the Space-Time that exists. Gravity distorts Space-Time. In our perception, gravity SLOWS time. That has been proven as the clocks works different in Earth’s orbit from the ones on the ground. Acceleration has part in it also.
Real life example that I was referring to at the beginning: When standing near pyramid in Egypt, cars and people in the distance appears to go faster then they are. That is because pyramid has huge mass and it distorts Space-Time, no matter how little, but it does. It slows time, more the nearer to it you are.
Imagine yourself sitting on a huge stone of a Keops’ pyramid, having a lemonade. You are observing a car very far away. Car is tiny to our eyes, and it’s not going from left to right, but in opposite direction, maybe some slight angle to the left. Over time, you will notice that car is further away, and that it moved slightly to the left. Imagine your mobile phone of new generation have Doppler measuring device. You can calculate with great imprecision that car is moving away. Measuring time and it’s offset to the left, can give you some idea of it’s speed. Well, in reality, not quite.
As car is moving away, it is also moving away from the gravity of the pyramid. As gravity slows time, and you are sitting on it’s source, it will look like that car is actually accelerating. What is worse, your imprecise Doppler tool on your phone may confirm it.
Now, we are looking at a distant galaxy (click on image to enlarge).
As we see, we have large gravity source at our Milky Way’s spiral arms, and huge gaps with no gravity sources in between, adding ultra-huge void that contains no gravity sources until we get to our observation object. So, our line of sight passes through several ripples of distortion & no-distorion of Space-Time, following by the ultra-huge space of unaltered space-time fabric.
Questions arises: Can objects appear to be accelerating due to huge chunks of masses that stands in our line of sight? Do we really need to put “Something” that has “some gravitational pull” in between to justify acceleration? How can we measure with precision without proper triangulation, also given the ripples in space-time, can we really determine anything with precision?
Just remember: What we see that is billions of light years away, it is billions of years old information.