Einstein's Relativity Theories

Poulgorm

Is there any book / article out there that explains his theories in a manner I can understand?

I can't get my head around this space time thing and gravity explained as ripples on this space-time grid (or whatever).

Maybe, people like me were never meant to grasp it

Morbert

Poulgorm wrote: »

Is there any book / article out there that explains his theories in a manner I can understand?

I can't get my head around this space time thing and gravity explained as ripples on this space-time grid (or whatever).

Maybe, people like me were never meant to grasp it

"The Fabric of the Cosmos" by Brian Greene is a good place to start.

Justin1982

The best introduction by a long shot for Special Relativity is "University Physcis" by Young and Freedman. Its introduces the theory using a lot of words, diagrams and simple maths. The maths really is so well explained and of Secondary school level. Its actually a really simple theory. A lot of books way way way over complicate it.
If you try to read verbiose books with no maths then the power of the theory will never be understood.

For general relativity, I'm not sure that there is an easy way to understand the theory. You kind of need to understand the central equation to fully appreciate the theory and understand what the theory really is saying.
But I hear that Carrolls book on General Relativity is excellent.

Personally I read Ray D'Inverno's "Introducing Einsteins Relativity" for General Rel. You could get that book, skip all the introductory maths and Special relativity and just read the 2 or three chapters leading up to the Central Equation of General Relativity. They are mainly words with very little maths. You might not understand the maths fully but one can get a very good idea what is going on. Thats what I'd do.

Lbeard

Justin1982 wrote: »

A lot of books way way way over complicate it.

I don't think it's a case of over complication, more bad descriptions that keep getting used again and again. Or sometimes it's just plain bad writing.

If you try to read verbiose books with no maths then the power of the theory will never be understood.

If you were given a million quid to sponsor a few well written books, what would they be like? Obscure, symbolic, with lots of Gothcha!!'s or more verbose.

Lbeard

Something I really can't grasp is the Twins Paradox. I can understand in terms of a twin holding another over a black hole, but when I think about linear motion I can't get it. The stationary twin seems to be experiencing acceleration relative to the accelerating twin. Any descriptions I've read have confused me more.

One of a few books I have on the go at the minute is Einstein's book relativity.

Morbert

Lbeard wrote: »

Something I really can't grasp is the Twins Paradox. I can understand in terms of a twin holding another over a black hole, but when I think about linear motion I can't get it. The stationary twin seems to be experiencing acceleration relative to the accelerating twin. Any descriptions I've read have confused me more.

It is true that, from the perspective of each twin, the other is accelerating. However, only one twin experiences an accelerating force, and both twins agree that it is the twin in the spaceship that experiences the force.

If I'm on a road and you drive off in your car, we both say the other is accelerating, but we both agree that only you feel an accelerating force.

Lbeard

Morbert wrote: »

If I'm on a road and you drive off in your car, we both say the other is accelerating, but we both agree that only you feel an accelerating force.

I get it now. It's just the descriptions in some of the books are so confusing. I was trying to visualise the wrong thing.

If I think of the person in the car as a wave, it all makes sense. At least I think it makes sense. I've been thinking, the Arrow Paradox, that if objects were not waves, and if Heisenberg's uncertainty principle were not true, bodies would be rigid and unable to either move or be accelerated.

Arse Biscuits!

Gravity, think of it like this:

You have a sheet held up by 4 people, one in each corner, pulling it so that it is flat and even in a square between them. You get a basket ball, and place it on the sheet. What happens? The sheet dents in around the basketball and makes a dip. Now get a ping pong ball. Place the ping pong ball on the edge of the dip of the basketball on the sheet. What happens? The ping pong ball rolls towards the basketball along the dip. If you give the ping pong ball a little momentum in a direction entering the dip, it will circle the basketball until it reaches the centre where it will stop.

Now think of the above objects like this: The sheet represents space-time, the basketball represents a massive object (lets say Earth), the dip in the sheet represents the distortion of space time by the massive object & the ping pong ball represents a smaller object (lets say the moon). So the massive object distorts space-time and the little object rolls along the dip towards the centre of the massive object. This is gravity & space-time explained basically.

Voltex

Arse Biscuits! wrote: »

Gravity, think of it like this:

You have a sheet held up by 4 people, one in each corner, pulling it so that it is flat and even in a square between them. You get a basket ball, and place it on the sheet. What happens? The sheet dents in around the basketball and makes a dip. Now get a ping pong ball. Place the ping pong ball on the edge of the dip of the basketball on the sheet. What happens? The ping pong ball rolls towards the basketball along the dip. If you give the ping pong ball a little momentum in a direction entering the dip, it will circle the basketball until it reaches the centre where it will stop.

Now think of the above objects like this: The sheet represents space-time, the basketball represents a massive object (lets say Earth), the dip in the sheet represents the distortion of space time by the massive object & the ping pong ball represents a smaller object (lets say the moon). So the massive object distorts space-time and the little object rolls along the dip towards the centre of the massive object. This is gravity & space-time explained basically.

Im just sitting here laughing at your name..."arse biscuits"...classic.
BTW...your space-time example is very good

ecowise2

Does theory also mean 'principle' and 'law' ?

Voltex

There's some great videos on YouTube that explains and sorts through the math very easily.
This is one of the better ones.