# Search results

1. ### The speed of light in a vacuum?

Why does light appear 2 hav a different speed in a medium? Tiny spacetime warps caused by the matter (just 2 throw a guess at it)?
2. ### Relativity of Simultaneity

Its not a specific answer to your question, but draw the situation in a spacetime diagram and im sure itll work out. Do the 2 people with the flashlights turn on their flashlights at the same time in their frame or the cars?
3. ### Relativity of Simultaneity

Everything became clear when i read this page. http://www.mth.uct.ac.za/omei/gr/chap1/node4.html I was just thinking of it as space and time contracting and expanding as opposed 2 different observers taking different space and time slices of spacetime.
4. ### The Future is written?

I remember the "by applying to C a treatment depending on the scanned-out information" bit now! Does that mean their talk about a Quantum Internet is a load of BS? Considerin the isp guys would hav 2 phone ya up and tell you how 2 treat each qubit. (This has become more about QM than SR now!)
5. ### The Future is written?

I know SR forbids ftl travel for an object with mass. Iv only just come to grips with SR so im really just speculating but i cant see how one would deduce that information also cant b sent ftl or even instantaneous. My understanding of QM is limited to the concepts and the basic 1s at that...
6. ### The Future is written?

Lets say we mastered near lightspeed travel and instantaneous communication using quantum teleportation. Then we send the spaceship off to someplace 1 lightyear away. It turns around and for a brief moment travels twords earth at near lightspeed. During this moment the spaceship asks earth how...
7. ### Confused about time dilation

Class! They're both right is an answer i should hav assumed. "they each measure the other's clocks as running slowly compared to their own" was what i thought there was a problem with. Thanks
8. ### What's gravity from the Quantum point of view

Im just a noob but from my understanding there is no gravity in QM, the theory just ignores it, and thats been the biggest problem in physics for ages. Im confused about u sayin there arnt any forces or spacetime in QM. I think your wrong on that point (but then again what do i no!). Also...
9. ### Confused about time dilation

Iv been reading the fabric of the cosmos and its my 1st and only source on theoretical physics. I reckon i understand str from it, i can work spacetime diagrams and lorentz transforms but my understanding must b wrong somewhere. Str says the faster an object moves the slower time flows for...