Đây là bộ sách tiếng anh về chuyên ngành vật lý gồm các lý thuyết căn bản và lý liên quan đến công nghệ nano ,công nghệ vật liệu ,công nghệ vi điện tử,vật lý bán dẫn. Bộ sách này thích hợp cho những ai đam mê theo đuổi ngành vật lý và muốn tìm hiểu thế giới vũ trụ và hoạt độn ra sao.
[...]... said, “to talk of many things” Lewis Carroll, Through the Looking Glass of atoms, stars and galaxies, and what a black hole means; and whether Einstein’s space can bend enough for time machines This book is meant for all those people—which is pretty much everyone I know—who are curious about such exotic sounding concepts as black holes, space warps, the Big Bang, time travel and parallel universes... solid three-dimensional object rather than a flat two-dimensional one, like a disc, due to the way light shining on the ball provides shading Even without this, we know from experience what a ball looks like and how it behaves So, when we watch a football match on television we know that the circular object being kicked is a three-dimensional football and not just a flat disc that looks like a ball and is... constructive comments and suggestions: Julie Al- Khalili, Reya Al- Khalili, Richard Wilson, Johnjoe MacFadden, Greg Knowles, Simon Doran, James Christley, Ray Mackintosh, John Miller and James Curry I am sure that errors still remain, for which I hold sole responsibility I must also thank Bill Gelletly for making the suggestion that got the whole project started, Kate Jones for some constructive lunch -time discussions... If this weren’t the case, and the eyes were fixed on either side of their heads then, although they would have the advantage of being able to see in both directions at the same time, they would be missing a vital skill Being able to look at the same object with both eyes would enable them, as it does us, to judge 9 BLACK HOLES, WORMHOLES & TIME MACHINES Figure 1.3 Two-dimensional beings living in 2Dworld... future! Although I will come back to this later, the idea of time slowing down when you travel at high speeds is something that xix BLACK HOLES, WORMHOLES & TIME MACHINES has actually been checked and confirmed many times in different experiments to extremely high degrees of accuracy For example, scientists have synchronized two high precision atomic clocks, then placed one of them on a jet aircraft and. .. strictly in a straight line 5 BLACK HOLES, WORMHOLES & TIME MACHINES What if you are on a ship on the ocean? You now require two numbers (co-ordinates) to locate your position These will be the latitude and longitude with respect to some reference point, say the nearest port or internationally fixed co-ordinates The ship therefore moves in two dimensions For a submarine, on the other hand, you need three numbers... me from the publishers for final corrections and changes, I had to completely revise the chapter on cosmology Due to recent astronomical discoveries, many of the ideas about the size and shape of the Universe had changed during the few short months since I had written that chapter Jim Al- Khalili Portsmouth, England, July 1999 xi ACKNOWLEDGMENTS Looking back over the second half of 1998 when the bulk of... obvious for all solid objects A sphere, for instance, needs only one number to define its size: its radius But it is still three-dimensional because it is a solid object embedded in 3D space We see around us shapes that are either one-, two- or threedimensional, never four-dimensional because such objects cannot be accommodated in our three-dimensional space In fact, we cannot even imagine what a four-dimensional... of the ball and despite the television picture itself being a 2D projection of the 3D reality When we look at a 3D object we only ever see the twodimensional surface facing us Our brains then take into account 11 BLACK HOLES, WORMHOLES & TIME MACHINES past experience of such an object plus the way light interacts with that surface to build up a model in our minds of the whole threedimensional shape... has been bent instead 2Dworld and 2D’ers Since it is impossible for us to imagine a higher dimension into which we could curve our 3D world, I will employ a useful trick We simply make do without one of our spatial dimensions, say the dimension of depth, and then we can deal with an imaginary 2D world (let’s be bold and original and call it 2Dworld) Such flat, two-dimensional worlds have been discussed . Falling into a black hole • To see a black hole • Not so black after all • White holes vii BLACK HOLES, WORMHOLES & TIME MACHINES TIME 5 TIMES ARE CHANGING. without much success) for a sort of Stephen Hawking-meets-Terry Pratchett. ix BLACK HOLES, WORMHOLES & TIME MACHINES Many scientists would argue that difficult