Customer Reviews

NOVA - Magnetic Storm

5 star:		(8)
4 star:		(3)
3 star:		(2)
2 star:		(1)
1 star:		(0)

 

 

This DVD leads us through time to examine the strength of the Earth¡¦s magnetic field through various perspectives, from potteries to volcano rocks. It also briefly describes the consequences of Earth without the protection of the magnetic field, how Earth generates the magnetic field, and when the next reversal of magnetic field occurs.

I find that the information on the DVD is not detailed enough. However, the PBS website (http://www.pbs.org/wgbh/nova/magnetic/) gives me a better understanding of the Earth¡¦s magnetic field.

This is an entertaining, informative, and even-handed look at the Earth's magnetic field, how it has changed over time, what it is doing now, and what it all might mean.

The computer graphics used are interesting and effective, but the most interesting part was the (previously unknown to me) magnetic history stored in volcanic rock. Some of the conclusions they draw from this work can really make you think.

Although documentary DVDs are usually not very cost effective, giving you a (if you're lucky) 1-hour program for the price of a 2-hour blockbuster movie, this one is worth a try. And as the Earth's magnetic field continues to change (it's clearly in the midst of a fast-moving decline right now), this could be a good source of entertaining info to review later.

This film probes the problem of the Earth's magnetic field. The nature of the Earth's magnetic field provides a shield to protect us getting bursted from cosmic rays and radiation. Scientists have found that the Earth's magnetic field is rapidly weakening, and even reversing in some future. Yes, compass will point to south someday. The film only focuses on the reversing of the Earth's magnetic field; however, it does not cover much of the details about the damages to our people and our earth during this reversing phenomena. It does not mention any government special project groups working on solution or prevention to this magnetic storm. Strong contents on telling how the Earth's magnetic field works and the reversing fact, but weak on covering the consequences from the reversing cause.

Unlike NOVA's Elegant Universe, this DVD only gives a 55 min. show and does not provide extra feartures and educational softcopy materials. I recommend you may get a copy from your local library, watch it and decide your purchase.

I had seen part of the Magenetic Storm months ago on KQED. It is an amazing story about magnetic polarity of the earths core. It also gives you an better uderstanding of global warming, in directly. Very educational!

I found this DVD by incident. Since there are not so many DVD's about this topic, I just bought it out of curiosity and am happy I have done that.

This film discusses about the fading of the magnetic field of the Earth. It turns out to be a reversal: the north and south poles will flip every 200,000 years in average. Fading is just part of the process, not the result. and we are just being in this process. The reason, however, is not well explained in this film. They just said scientists put many factors into consideration and form many equations to have been solved by a super computer. If you are a hard-core technical fan, this is what will disappoint you.

Despite of this, the other parts are quite abundant, entertaining and educational. This topic can be related to the dying of the Mars, ancient potteries, lava rocks from volcanoes and even the Royal Navy's logs. In addition, the importance of the magnetic field is also emphasized.

Overall, this film is well made and it is relaxing to watch.

This is a magnificent documentary program, which let us know what could happen if the magnetic shield of the Earth dissapears. I'm a physicist and a high school teacher, so i use the program to introduce to my students to the study of the solar wind on Earth, and the liquid core of the Earth. They were surprised because they didn't think that the Earth's core produce the magnetic shield that protect us from the solar radiation.
The program shows a very interesting experiment that recreates the earth, the core and the efects. Besides there are interviews with scientists that have been working with the polarity of the magnetic field produced by the Earth's core. Definitely a superb program for all ages.

NOVA - Magnetic Storm (2003) was another good science special on the Earth's magnetic field which has been determined to be rapidly weakening based on it's current rate of change. The field may weaken to very low levels in the 21st century and then actually reverse resulting in a change in direction indicated on a compus. Also, during the very weak phase just prior to reversal, a significantly increased incidence of cancers may result in our children's lifetime which will be a problem. This is a much less serious scenario than the fictional story discussed in the sci-fi film "The Core", but still serious enough to warrant our attention.

The special discussed in some detail the ongoing transient in the Earth's liquid iron core which has been modeled by numerical integration (via time history analysis) on the super computer to weaken and reverse with time. The period appears to average out at about 200,000 years with a low of less than 100,000 years to a maximum of perhaps 1,000,000 years. Since 700,000 years have passed since the last one we are probably past due.

The reasons given for field reversals appear to have something to do with changes in liquid flow in the iron core due to convection coupled with other perhaps electrodynamic effects within the core. Some great computer graphics were exhibited demonstrating how the magnetic field is predicted to change which I wish more information had been provided on. I have done some numerical integration on the digital computer in thermal work and orbital mechanics and feel that greater detail could have been provided (on at least an intuitive level) on what is happening in the liquid core of the Earth. The film definitely deserves four stars but felt it required far more detail on exactly what is causing the periodic time history in the direction of the magnetic field of the Earth indicated by the geologic record.

The electromagnetic field of earth explains why earth's atmosphere has remained stable while Mars has lost most of it's atmosphere. It also surprises in that our North and South Poles switch places over a relatively short cosmic period of time - 200,000 years, and that we are now experiencing a rapid change with the predicted reversal in 300 years. This is a fascinating detective story that started with data from Mars showing that it had an atmosphere and water at one time, but why did it disappear? Rocks on mars showed it had a magnetic core about 4 billion years ago, but that it solidified and Mars electromagnetic field disappeared with the water and atmosphere.

From this the mystery of whether Earth will lose its field or not is solved using surprising sources. Clues from ancient clay-fired pottery, volcanic rocks, 300 year old ship logs, and many other pieces of data are put into NASA and Government computers for 6 months of processing to find that we will not lose our life-saving shield for hundreds and thousands of years, but it will continue to shift. Why it shifts is not answered, nor what happens with weather, global warming. They think there will be more "Northern" lights displays all over the world and a slightly higher incidence of cancers during the shift.

A marvelous collection of current research on the Earth's magnetic field. The only video I have that other science teachers keep borrowing and borrowing. It starts with reasonable questions about the possible disappearance or change of our magnetic field and clearly and logically follows the chain of research up to what we know in the current day. The use of ancient pottery, Hawaiian lava, the Royal Navy, and other compelling evidence ends with a clear and understandable picture of our current understanding. The final questions and possible futures it ends with have been starting points for some great discussions. In a decade or two research might make this show outdated, but it is currently wonderful.

We watched this video as part of an earth sciences study with my girls (9 years old, 12 years old). I was hoping it would be accessible and not overly technical ... and it is! The girls (and their parents) enjoyed and learned from this episode just fine. Like someone else mentioned, I was happy to hear that it wasn't a huge doomsday, magnetic field reversal scare video. Just a nice overview perfect for a supplement or review to a study of our magnetosphere.