# Arjun Artro

Senior Members

38

1. ## Curvature of space time

I've been thinking about gravity and its curving effect on spacetime. It seems very strange to me that a massive object can warp space and time around it. I have a few questions: 1. Would a magnetic field as strong as the gravity around a black hole bend the spacetime around it? If so, it's the bending effect same as that of gravity? 2. If gravity is a curvature in spacetime, and not a force, why doesn't the centre of an object experience the same curvature? (for eg, Fg=0 at the centre of the earth)as I thought it is because the forces cancel out each other at the centre.
2. ## Speed of light as it enters vacuum from a dense medium.

Thank you for the information.
3. ## Speed of light as it enters vacuum from a dense medium.

We know that light slows down inside a dense medium like glass, water, etc. But the moment the light beam gets out of the dense medium to vacuum, it regains the original speed c instantaneously. I know that waves doesn't require acceleration to travel in a particular speed but as light also behaves in particle nature ,shouldn't it obey the laws of particles too ?
4. ## Are dimensions real?

That's all what I am saying here. It exists only in math. And objects like tesseract or 4d hypercube can only be modelled with certain assumptions and I don't we cannot visualize it because we live in a 3d world but because such objects only exist in math.
5. ## Are dimensions real?

Okay that's for locating an object. And I agree that dimensions are needed for that just like the latitude and longitude of the earth. But we never use the terms like "a latitude object" , a "longitude object" like we call 2d object, 3d object etc. I might be wrong, but imagine this- suppose there is another world which is 2 dimensional. And the projection of a 2d surface is a "line" right? Suppose there are two lines - red and blue. How would you know that one is red and the other is blue if those lines only have length and no width (even if it is negligible, width cannot be equal to zero) . Am I right?
6. ## Are dimensions real?

I wanted to learn about 4d space and got curious why I cannot visualize it so I searched in the internet for some answers. I am not satisfied by how it is explained, especially the flatlander's theory. First of all, how can a 1d or 2d object exist? Lets take 1d for an example. Its called 1d because it only has length and no width. How can you see a line that has no width, even the slightest width and the slightest height? Okay, 3 dimensions might be needed to do the math but in reality , are dimensions real? And our theory about 4d, 9d and 25d might be just helping quantum physics and string theories but I dont think it's actually there.
7. ## Arjun Artro

Being silent doesn't always mean you're a coward ; sometimes it is a brilliant art of observation.>art.magnifique

8. ## No need for dark energy

Okay let's assume that space is expanding when gravity is not strong enough to pull objects together. But why does gravity lose its grip with time? It's been billions of years since big bang and there's no other force that push objects away . So there must be some sort of energy that overpowers gravity.
9. ## Complete information about Black hole

Google it.. This is a discussion forum. Or this may help- http://en.wikipedia.org/wiki/Black_hole
10. ## Lucid Dreaming-The science behind it

still no scientific base? How does things align so quickly to perfect these dreams ? If dreams are stories made up by mind from bits of what we've seen at some point of life, how do we remember those dreams the next morning or so?
11. ## Lucid Dreaming-The science behind it

Lucid dreaming is a technique by which we can control our dreams with practise and certain sound waves. I've tried it and have once succeeded in doing it. I've read that dreams just last for about 2 seconds and that it is made up by our sub conscious. If so, how can these people or even myself control these scenes and stuff that show up just for a couple of seconds? What is the science behind this? And does dreams have solid scientific base? Does anyone have a clear idea about this?
12. ## Did God create the universe?

"Nothing" in his statement means absolute nothing. Not even space. Space and time makes something. And we can't find anything that hasn't been recorded in space or time or both.
13. ## Speed of light

does that mean when the speed of bullet is .9c+v, speed of the light emitted from flashlight is c+c=c?
14. ## Speed of light

Why is it still c?
15. ## Speed of light

Imagine a spaceship traveling at 99% speed of light. Inside the capsule there is a gun. when it fires, space time will be warped so that the time around the bullet is reduced to such an extent that it doesn't break the speed limit. But what if instead of a gun, a flashlight was lit? Would it emit light like usual?
16. ## How can the universe be infinite in size?

Infinity is just a word to cover up or hide all the loopholes these "experts " make when making theories. The Big Bang is an assumption. As no one is able to "prove " it wrong, it has taken its place in science to a very big extent. Nothing observable by our senses can be finite. In other words, we make these scales and we measure it. What if we're wrong somewhere? We humans never admit it. .
17. ## "Real" Dreams

you said 2 persons. i*2 is not a real number. For i to be made real, it needs to be seen by i number of persons, which in turn are imaginary people.
18. ## Is it possible transfer human subconscious into a robot?

Human mind is still a mistery. Scientists believe that the mind is just a collective form of all the senses, memory etc. But we all feel there is something that isn't just that. Senses that aren't related to our surroundings and the things we know. If the brain is all that makes the mind, we simply can't put a mind into a robot. Our brain is so complex , made better and better every moment, for thousands of years. Whatever technology we can make is also made by the same brain. So we'll have to wait for maybe another 4 or 5 hundred years to solve this mystery.who knows!
19. ## Did God create the universe?

We can find what happened at the time of the big bang, but only for values of time > 0. For any other values of time including t=0, it is impossible to find what there was because the phenomenon hasn't left any trails or clues for us to move on with. From a dead body we can find how he looked like, what kinda food he ate etc but we cannot find out what all things went through his mind , even at the time of death. , as it doesn't leave any trails behind. We just get the outline and not the complete picture. Same is the case with the universe and all those stuffs.
20. ## How gravity can attract light?

Helium floats not because it interacts different with gravity, but because its density is much lighter than that of other gases that comprises the atmosphere. It is just like oil floating on water.
21. ## How did planets end up orbiting the sun?

If stars attract everything,and that too with a very high gravitational force, objects like planets would've fallen into the star. But how did they start orbiting the stars?
22. ## Arjun Artro

I've seen people earning numerous Likes and Comments simply by asking users- Hit like if you don't want somethin bad happen to your dear ones, comment if you love your mom and all. . . Wat's the point? The Like button is supposed to be clicked if you really like the post. And look what these people do- you Like messi? Hit LIKE. Like ronaldo? Thn comment 7. It's time to stop this trend right? DO IT.

23. ## static electricity

It depends on how you are making static electricity. If u're making static electricity by rubbing it, it will stay in that object. But different factors like humidity, etc. But you can charge a capacitor and keep it too. Plastics ( i don't know which type) can store static electricity for very long time.But we can't discharge it whenever we need. It will be useless.
24. ## digital or analog?

The world is neither digital nor analog. These two terms are man made and is just for the sake of understanding things. It doesn't mean the universe is digital or analog.
25. ## What exactly is Gravity?

So... does light move inwards even after crossing the event horizon? I think it shouldn't. If there's any movement inside the black hole, that means, there's an existence of dimension , leading to the existence of time. But inside a black hole, time is non existent. ???
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