Geek alert: 'How The Universe Works' on Discovery tonight

[tridim]

One of the best shows on the subject that I've seen, the CGI is absolutely incredible.

Relax, Sarah Palin had nothing to do with it.

[CherokeeDem]

1. You are so right...

CGI is great and I adore Dr. Michio Kaku...love his SciFi Science series on the Science Channel. And Steven Hawking next...good geek night!

[david13]

2. I may try it, just based on your recommendation. However, I think

you may have the whole thing confused with Elgar.
The first question I do have to ask, as well, is, does the universe work? It is my observation that it just sits there. As the world turns.
dc

[Physbin]

3. Wups they made a mistake with E=mc2

The Big Bang part of How the Universe Works would have been
better if one physicist hadn’t made a basic mistake. E=mc2
does NOT mean that “energy” can be converted to “matter.” It
means that mass (not the same as matter) and energy are the
same thing, and that one of them never shows up without the
other. There is thus no “conversion” between mass and energy,
as they are separately conserved and never change value over
time. E=mc2 by itself doesn't even guarantee conservation--
all it guarantees is that if mass OR energy is conserved, then
the other is also. This is in fact the case, but it has to be
known separately at this stage of special relativity.

“Matter,” however, isn’t defined very well, and Einstein’s
equation says nothing about it, per se, since the “m” in the
equation stands for “mass,” NOT matter. 

All that E=mc2 tells us, is that WHEN something we regard as
“matter” (like particles) is created out of “energy” (like
light or kinetic energy), THEN the mass and energy will change
together in the process, IF they do change. And if one does
not change (which is the case in isolated systems) then the
other won't, either. Matter is not conserved, but mass and
energy ARE.

To put it another way: given the fact of mass and energy
conservation, even when there is indeed an energy-to-MATTER
conversion (as after the Big Bang), the total MASS doesn’t
change during this process, since (like energy) mass is
conserved. Energy has mass, and if some turns into matter, the
total mass doesn't change, because the new matter has the same
mass as the energy that it is made from.

You can illustrate this all nicely by the annihilation of an
electron and a positron. Before they annihilate, they have a
combined mass/energy of 1022 KeV. After they turn into two
gamma rays, the system containing the two gamma rays still has
a mass of 1022 KeV (a system of two gamma rays going in
opposite directions actually has a rest mass, and this is it).
So even though matter has changed to energy, the mass never
changes at all through the process, because the energy never
changes. The same is true going the opposed direction, as
after the Big Bang, when energy is changed to matter. Through
it all, mass never changes.

I can certainly understand why your show didn’t try to explain
all this, but it would have been better to have left E=mc2 out
of the show, since it doesn't address how new matter particles
can come out of the energy of the Big Bang, and doesn't even
promise THAT they can. It might happen, or it might not. The
mass of the universe doesn't change even if it does happen,
and given the fact of energy conservation, E=mc2 at best just
says that the new particles have the same energy and mass as
before. When all there existed in the universe was energy,
with no matter, the energy had all the mass.

Even some physicists get lost in the explanation of energy
turning into "matter," if they don’t think very
carefully. That happened in this show, where the physicist
totally confused matter and mass!

Phys-bin