The Royal Institution
Fay Dowker tells the story of general relativity and its interactions with Newtonian physics, from Galileo to cutting edge research on the granularity of spacetime.
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Watch the Q&A that follows this talk here: https://www.youtube.com/watch?v=IyBGWd6IddU
Fay Dowker is Professor of Theoretical Physics at Imperial College London and works on the problem of quantum gravity. Her research is based on the hypothesis that spacetime is fundamentally granular or atomic, and she has done numerous public lectures.
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No such thing as pulling an object to move it. It's always pushing on the object to move it. You got to get behind an object to move it to move it forward.
Time is the GUT. We measure everything as a measurement of time. Time is not linear, it's omni-directional.
Gravity has two main parts: UP and DOWN.
"The inverse Lorentz transformation used in
relativity is false, it does not define a division operation and using it produces incorrect
results, which are called paradoxes, because they contradict common sense. There is a
mathematically correct inverse Lorentz transform that can be derived by assuming a linear
algebra with a multiplicative group structure in which a mathematical division operation
is defined, and in this mathematical structure the traditional inverse Lorentz
transformation is known as the adjoint or dual Lorentz transformation"
Harry Ricker III
Special Relativity Is Irksome
http://www.naturalphilosophy.org/site/harryricker/2015/07/09/special-relativity-is-irksome/
Two balls of the same size, one made of wood and the other made of iron, released together, fall together and hit the ground at the same time, this appears natural if there is no gravitational force, BUT, which is then the cause that make them to accelerate?
Total BS. Einsteins GR replaces Newton's Laws? Newton was a real physicist. Newton had the honesty to admit he didn't know what the force of gravity was conducted by. Einstein made up "spacetime" to refute him for fame.
One of Einsteins quote if you can't explain it to a fourth grader you probably do not understand it yourself. this could apply to Einstein himself.
These comments are such rubbish, people should think a bit before they post.
Mass and Spacetime have equality of gender: one bosses the other because mass always forces spacetime to curve and the curved spacetime makes mass to follow it wherever it wants to!!!…. i.e, Mass says: I shall curve you…. Spacetime says: but I shall make you follow me in my curves!!
I really felt SPACETIME flying faster than speed of light at my BOTTOM during meditation exercise !! Thus, my bottom taught me a lesson!!
Me having difficulty in understanding how a curved surface forces an object to go inward particularly in the absence of a pushing or pulling force. And when we come on the earth How this is related to an event when an object fells down from a bed to the floor. Why??
I found that the meditation part was helpful. Remember that it isn't meant to confirm the theory, it's meant to support the conjecture that General Relativity is more in line with experience–which isn't exactly an empirical claim anyway. However there is plenty of good evidence which shows that our active or fast thinking mechanisms often make broad generalizations about what we are experience–if a little reflective thinking can get me to focus just on what I'm experiencing and not my interpretation of what I'm experiencing, then great.
both are imagined and silly
Great talk.
One correction I thought Einstein happiest thought was his thought experiment where he managed a man falling in an elevator and deduced he would not know the difference between gravity and deceleration/acceleration.
VERY INTERESTING ABOUT THE ELECTROMAGNETIC WAVES IN THE WARPED SPACETIME. IN THE EVENT HORIZON OF BLACK HOLES ELECTROMAGNETIC RADIATION IS EMITTED(HAWKING RADIATION) I AIWAYS THOUGHT NOTHING COULD ESCAPE A BLACK HOLE, NOT EVEN LIGHT. BUT YET HAWKING RADIATION CAN. MY QUESTION IS HOW CAN THIS RADIATION ESCAPE WITH SUCH A HIGH WARPING OF SPACETIME CAUSED BY THE MASS OF THE BLACK HOLE.?
My subjective reaction: There is something intuitively correct about the idea of new grains of space time popping into existence. It is a pleasing and somehow liberating idea.
but how do we explain the spinning of the planets in the spacetime curvature. is thr a friction too ?
Newton can not explain Mercury's observed orbit exactly. GR can. This is because gravity is not really a force. The Earth is not being "pulled" by the sun by some "force". The Earth follows a straight path through space. It's path however is "bent" by the sun, which causes its orbit.
You nailed it thank you, best explanation of free fall I've heard!
between 17:15 and 17:25 there is too many 'tch' sounds, is that an audio anomaly or she was doing it ?
Man is constantly seeking to understand how the universe works. After working out a mathematical model that works and explains a lot a paradox arises which causes us to develop the next model. Did you notice that you have to use gravity on the trampoline to understand the bowling ball explanation of gravity between objects? Can there be a better illustration of gravity?
Beautiful lecture
Excellent lecture Professor Fowker. Very easy to follow and the material is very relevant and important to the story of spacetime
but space time is a mathematical model yes? Minkowski came up with it to display events from Einstein's special relativity
I love listening to her,
I wonder what spacetime is like in eternity.
I disagree with the ending. If we had better communication that we're still fighting over (thanks ATT, Verizon, Xfinity-Comcast, etc.) we would have instant communication limited only by the speed of light, not the companies we pay to manage, and not in OUR interest but their stock holders interest. Ask ATT how they "throttled" the California Fire Fighters cell service because of…..MONEY! We as a country are a disgrace to humanity.
Excellent meditation!
All objects with mass, curve spacetime, not just massive ones.
One might imagine that it would be possible to "patch" Newtonian Gravitation by introducing a simple propagation delay at exactly the speed of light. This fails utterly. No stable orbit is possible as one can see by considering the simplest case and how the "retarded" force is "off-center" and so introduces a torque that causes the objects to spin into each other. No simple patch can work. Something as radical as General Relativity is required because nothing simpler can possibly work.
The British…. personally I'd like to see more explanation by way of hard math. I understand it I just enjoy hearing different lecturers wax eloquent about their thingys along with a bit of understated British wit. Kai to the Uploader!! My deepest accord's
The audience is having a good laugh at least.
She doesn't explain things very well. And why does she call it Gena-Relativity?
this theory frustrates me.
For starters, we use "gravity" to add momentum to probes. We sling shot them.
How?
By making exact calculations and expert timing…… by way of treating time a constant.
There was no contradiction between Newtonian gravity and SR. There was just an aspect of it that had no explanation yet. It just indicated that gravity did not travel. This did not challenge the Newtonian effects of gravity.
Sitting in a chair there is no force pushing you up against gravity, there is only a blockage stopping movement. If there was a force pushing you up, you would be weightless or at least lighter.
Next there was a jump in logic describing four dimensional time which prevented giving an explanation of it.
The lecture was clear and succinct until GR. After that there were lots of stutters and pauses.
I am not convinced that this is not the king in his altogether. It may solve many problems, but I have yet to be convinced by any explanation. There are always jumps in the logical sequence of explanation. The fact that GR can accurately describe some things does not make it right. Just the same that believers in GR think Newtonian explanations produce the right results but are just an illusion. There are no jumps in Newtonian logic, so I will stick with that. I await a satisfactory explanation of gravity. I understand time. History shows that the complicated solutions are usually wrong. For example, the earth being the centre of the solar system with complicated planetary motions ensuing is not sensible, when compared with the sun being the centre.
I was hoping to hear someone smart enough to call this theory out. Nope, I get another acolyte, who never questioned the fundamental thought, their equations, and how much damage it has done to Science. Many careers have been wasted by this Alice in Wonderland concept. Einstein's last genius contribution was E=mc² and everything after that was pure hubris. He wanted to shine higher than Newton and ultimately failed.
Gravity is the concatenated or compounded unused attractive/magnetic force we currently attribute to electrons. We know this because Mass is intimately involved. All we now need is the experiment to prove this and to make the journey to Stockholm to collect the prize. The creator of the successful experiment may be smarter than Einstein.
Needless to say it won't be Cox, Krauss or Tyson or any other unquestioning minion. Theoretical Physics has almost become a religious movement with stained-glass windows (computer-derived pictures of multiverses), the rabid aversion to commonsense (the fundamental force of Science), the claims of special knowledge (too many, latest was no free thought) which ennoble their holders with infallibility hence the ludicrous attack on philosophy.
Ultimately the universe we are aware of is absolutely linear, automatic and understandable if we give ourselves enough time. Space never ends, time is a very helpful but abstract concept.
ps: The first one who mentions perihelions can excuse themselves, not even bright enough to apply Cartesian Geometry.
What if Enstien was wrong?
I very keenly listened to the lecture. Very good lecture. One question which I have been keen to know the answer of , never lucky so far, is this. Why is space-time wrapped near the massive objects? If it is not gravity, what is this that makes the lighter bodies to be trapped in pits of space-time created by massive objects? Why is not the space-time raised up causing to repel the other objects,instead of creating a pit and trap other masses? Dr. Dowker is requested to help. One more question that I have is related to your explanation of letting fall two different masses. You said, they start falling without gravity? What makes them move without force? Should we throw away Newton's second law of motion as well? Thanks. Once again well done with your theories and lecture.
I can't finish ,,, she is so mind-numbingly repetitive.