anonymous asked:

coolest physics thing that u know??

The coolest physics thing that I know keeps changing over time. But here is one that is extremely fascinating ( and also exaggerated for the effect ; but true! ):

Person living at the top of a skyscraper experiences time faster than one at the bottom

It is a known fact that the higher you are in the earth’s ** atmosphere, the lesser the effect of gravity is.

But the lesser the effect of gravity is, the faster the time ticks.

By how much you ask? Even if you live on the top floor of the Burj Khalifa  your entire life, you would have aged more only by a few milliseconds than your friends at the bottom. 

( Sure, doesn’t seem like much, but hell would break loose if we don’t consider this on the bigger scale of things )

This is known as Gravitational time dilation and is at the foundations of General Theory of Relativity. (More about this in an upcoming post)

Have a great day and thanks for asking!

EDIT: ** Lets just say hypothetically the earth is not spinning( just to ignore special relativistic effects) and we are looking at only the effects of height.

The famous image of Einstein’s desk, exactly how he left it, mere hours after his death

Before his passing Einstein had refused the surgery for the internal bleeding that subsequently took his life; saying: “I want to go when I want. It is tasteless to prolong life artificially. I have done my share, it is time to go. I will do it elegantly”.

As can be seen here with the mountains of shuffled paper and scribbles on the blackboard, Einstein certainly did do his part and worked until the very end.



Strange is our situation here on Earth. Each of us comes for a short visit, not knowing why, yet sometimes seeming to divine a purpose. From the standpoint of daily life, however, there is one thing we do know: that man is here for the sake of other men - above all for those upon whose smiles and well-being our own happiness depends.

The most beautiful thing we can experience is the mysterious. It is the source of all true art and science.

Happy 138th birthday to Albert Einstein, one of the brilliant fathers of modern physics and the founder of physical cosmology and relativity. 

Kányádi Sándor: Relativitás

- Megállt az idő - mondják,
akik megálltak.

- Rohan az idő - mondják,
akik rohannak.

A várakozónak: végtelen;
a rabnak: mozdulatlan;
a bölcsnek: mély;
az alkotónak: kevés;
emennek: boldog;
amannak: boldogtalan;
kecsegtető és kilátástalan,
satöbbi, satöbbi … csupa
érzelmi hozzáállás.

Einstein fölfedezése nem sokat
változtatott a közfelfogáson.


If The Universe Is Expanding, Then Why Aren’t We?

“You might then ask, at what distance does the expansion start to take over? That happens when you average over a volume so large that the density of matter inside the volume has a gravitational self-attraction weaker than the expansion’s pull. From atomic nuclei up, the larger the volume you average over, the smaller the average density. But it is only somewhere beyond the scales of galaxy clusters that expansion takes over. On very short distances, when the nuclear and electromagnetic forces aren’t neutralized, these also act against the pull of gravity. This safely prevents atoms and molecules from being torn apart by the universe’s expansion.”

The Universe is expanding. The farther away a galaxy is, the faster it appears to be receding from us. The standard story tells us that space itself is expanding, and that’s the cause, but it’s only natural to wonder if perhaps space is static, and everything else within it isn’t shrinking instead? Many laypersons choose to go this route, and question the entire field of cosmology as a result. But is this fair? Or is this a road to not only ruin, but to physical inconsistencies? Could we flip the story on its head, and do some sort of test to see if atoms, the planet, or some other ‘local’ entity is shrinking, instead? Or, using the principle of relativity, could we declare that all frames are equally valid, and choose a frame where space isn’t expanding, after all?

These are all interesting thoughts, but there’s only one correct, valid, and consistent way to view the Universe. Sabine Hossenfelder has the explanation!

The fact that we live at the bottom of a deep gravity well, on the surface of a gas covered planet going around a nuclear fireball 90 million miles away and think this to be normal is obviously some indication of how skewed our perspective tends to be.
—  Douglas Adams, The Salmon of Doubt: Hitchhiking the Galaxy One Last Time
Space fact #5

If you and I are in separate space ships both traveling fast, there’s literally no possible way to determine if I am staying still and you are moving, or if you are staying still and I am moving, or if we are both moving. Also, from your perspective time will flow normally for you and slower for me, but from my perspective time will flow normally for me and slow for you.

Basically, everything, including time, is completely relative.

What we don’t know about black holes:

Of all the places in the entire universe, there is probably nowhere more mysterious than the inner workings of a black hole. This is because the two most accurate theories humans have ever created disagree about what happens in the center of one.

When a large star runs out of fuel, it no longer has the energy to resist its own gravity and starts pulling in on itself. If nothing stops the collapse before a certain point, the gravity will become so strong that not even light can escape. At this point, the star becomes a black hole; a massive celestial body that has the ability to tear apart stars.

For the most part, we have a good idea for what happens in the space around a black hole. Einstein’s theory of General Relativity tells us that black holes, as well as other massive objects, bend the fabric of space and time, leading to strange events such as time dilation. But the main point of controversy isn’t what happens around a black hole, but what happens in the very middle; the singularity.

General Relativity states that if a piece of matter falls into a black hole, it gets crushed into a single point in the center. Here, any information about what fell in is completely obliterated. However, quantum mechanics tells a different story. It is a well known rule in quantum physics that quantum information can’t be destroyed, and there must be some ambiguity to a particle’s position. Clearly, something is off here.

There are a lot of different theories that attempt to solve this riddle, often involving extra dimensions or new particles beyond the Standard Model, but none of them seem to be currently testable. But it’s possible that someday, someone will give us a new, testable theory, and it will give us insight into the inner working of black holes, and maybe even the first few moments of the Big Bang.


The discovery of gravitational waves wins the 2017 Nobel Prize in Physics

“Gravitational waves are allowing us to open a completely new window on the cosmos,” - Massimiliano Razzano, member of the Virgo team

“The theory describes geometry of space and time. When gravitational wave propagates, it changes [this] geometry,” - Ivanov Pavel, Doctor of Physical and Mathematical Sciences

Gravitational waves are ripples in the curvature of spacetime that are generated in certain gravitational interactions and propagate as waves outward from their source at the speed of light.


Gravitational Waves Win 2017 Nobel Prize In Physics, The Ultimate Fusion Of Theory And Experiment

“The 2017 Nobel Prize in Physics may have gone to three individuals who made an outstanding contribution to the scientific enterprise, but it’s a story about so much more than that. It’s about all the men and women over more than 100 years who’ve contributed, theoretically and experimentally and observationally, to our understanding of the precise workings of the Universe. Science is much more than a method; it’s the accumulated knowledge of the entire human enterprise, gathered and synthesized together for the betterment of everyone. While the most prestigious award has now gone to gravitational waves, the science of this phenomenon is only in its earliest stages. The best is yet to come.”

It’s official at long last: the 2017 Nobel Prize in Physics has been awarded to three individuals most responsible for the development and eventual direct detection of gravitational waves. Congratulations to Rainer Weiss, Kip Thorne, and Barry Barish, whose respective contributions to the experimental setup of gravitational wave detectors, theoretical predictions about which astrophysical events produce which signals, and the design-and-building of the modern LIGO interferometers helped make it all possible. The story of directly detecting gravitational waves is so much more, however, than the story of just these three individuals, or even than the story of their collaborators. Instead, it’s the ultimate culmination of a century of theoretical, experimental, and instrumentational work, dating back to Einstein himself. It’s a story that includes physics titans Howard Robertson, Richard Feynman, and Joseph Weber. It includes Russell Hulse and Joseph Taylor, who won a Nobel decades earlier for the indirect detection of gravitational waves. And it’s the story of over 1,000 men and women who contributed to LIGO and VIRGO, bringing us into the era of gravitational wave astronomy.

The 2017 Nobel Prize in Physics may only go to three individuals, but it’s the ultimate fusion of theory and experiment. And yes, the best is yet to come! 

seidlalex  asked:

If a black hole got an object with a huge mass in it then why is the hole in only one direction?

I’m assuming you’re referring to pictures like this one

which imply that black holes are a hole in one of our three spatial directions, and stuff can only enter through a ‘plane.’ In reality, black holes are spherical, meaning any object can enter from any angle and go into the black hole; the hole goes in all directions, as shown by this image:

However, this image that accurately shows what a black hole would look like to us, it doesn’t show us the extreme warping of space around a black hole, which is where the misconception arises: from scientists trying to depict the warping of space and time around a black hole. It’s very hard to visualize the warping of three dimensional space, and even harder to create a two dimensional image depicting a three dimensional warping, so they essentially remove one dimension - think of it as a cross section. This way of illustrating it shows how dramatically curved space and time are around a black hole, but they also imply that a black hole goes “down” in one of our directions, and that matter can only enter one way, which is false. Sorry if I did a poor job of explaining - let me know if you have any more questions!

the-endlessquestions  asked:

Does time actually exist? I personally dont think that it really exists...

Time, as described by Einstein’s theories of relativity, certainly does exist. The duration of time between two events is just as real as the distance in space between two objects, and according to Einstein, these two qualities are actually tied together. This is where the concept of space-time comes from, and it has some profound consequences.

Not only does time exist, but it can be stretched, bent, and warped. The flow of time can change depending on how fast you are moving, and how close you are to a massive object. The same can be said for space, too, but I don’t think anyone is debating how ‘real’ space is.

Now, the human perception of time may not be entirely real. Our brains aren’t perfect clocks, so we’re bound to be a little bit off. Not to mention, one can make the argument that all of human perception is an illusion, but I digress. That being said, our perception of time is a decent approximation.


Is Time Travel Possible, According To Science?

“You can witness the evolution and destruction of humanity; the end of the Earth and Sun; the dissociation of our galaxy; the heat death of the Universe itself. So long as you have enough power in your space ship, you can travel as far into the future as you like.”

Have you ever wondered about time travel? Perhaps you have your destination in the far future, and want to see how it all turns out? Maybe you want to return to the past, and alter the future or present by your actions there? Or maybe you want to freeze time altogether? If you want to know whether it’s possible, the physics of relativity holds the answer. Special relativity allows us to control our motion through time by manipulating our motion through space. The more we move through space, the less we move through time, allowing us to travel as far as we want into the future, limited only by our energy available for space travel. But going to the past requires some specific solutions to general relativity, which may (or may not) describe our physical Universe.

What’s the status of traveling through time? Come get the scientific story (with a brand new podcast) today!

anonymous asked:

can you explain a bit about the curvature of spacetime or how it's curved?

Thanks for asking!! It’s a little difficult ti picture curved space, so I highly recommend this video, it’s phenomenal at helping you understand how gravity arises from space and time being warped//curved by matter.

I think the above video does a phenomenal job at explaining gravity in terms of warping space and time; definitely watch it. The heavier an object, the more it warps space-time; this means that time gets slowed down with heavier objects, since the space and time become more warped. You may have heard that time flows slower on the earth than it does further up from its surface; time flows faster for astronauts since they experience less of earth’s gravity (since they are further away).

Originally posted by 1ucasvb

This visualization was the best one I could find? but tbh it’s still hard for pretty much everybody, including the world’s best physicists, to visualize and wrap their head around. Let me know if you have any other questions or need a clarification!! Also, you might want to check out the relativity/general relativity tag on my blog if you want to see some of the other posts i’ve made.