Question

In: Physics

This question came about from a side discussion that arose on this: Does GR provide a...

This question came about from a side discussion that arose on this: Does GR provide a maximum electric field limit?

Can we change our choice of coordinate system completely independent of physical motion, and still refer to coordinate dependent components as observations? For example if we have an inertial coordinate system in which we measure the electric field to be E, and now I want to boost the coordinate system to a different inertial coordinate system and state what the electric field E' is in this new coordinate system, do I need to physically accelerate to justify this change in coordinate system (and therefore need to worry about effect such as Unruh, etc. during "changing" the coordinate system)?

Solutions

Expert Solution

This is a common confusion students have with coordinate systems when first learning SR. They hear us say things like "the time according to observer Bob" or "in the reference frame of Alice" or "boost to the rest frame of Charlie". To be clear, these are short hand. Something isn't literally/physically "in" one frame and not "in" another frame. When we refer to the coordinate system "of" an observer, or something "in" someone's frame, it is usually short hand for discussing values according to the instantaneous co-moving inertial coordinate system.

So do not take such short hand literally.

A coordinate system is just a systematic labeling of spacetime points. We can choose any coordinate system we want. As an example that will hopefully get past this intuition barrier, choose a coordinate system in which you are at rest. Now change the coordinate system by adding a constant (shifting the origin). You don't need to physically move to use this new coordinate system.

In short, nature doesn't care how we label spacetime points. So we should be able to explain the physics independent of choice of coordinate systems. This is indeed possible, so you can really use whatever coordinate system you choose. A particular choice may be simplier to work with based on your motion, but no choice is more mathematically correct than any other.

As should be apparent from the other question you asked, the Motion Mountain book is not reliable. Just searching in Google brings up the phrase crackpot in link titles on the first page of results. Please stick with reputable sources.


Related Solutions

This question arose in a seminar today about the solar wind... This is my vagueish understanding...
This question arose in a seminar today about the solar wind... This is my vagueish understanding of the problem - please correct if you see errors! The 'classical' picture of atmospheric electricity is that the Earth as a whole is neutral, but that thunderstorms maintain a voltage of around +300kV at the electrosphere with respect to the Earth's surface, with a current of around 1 kA slowly discharging around 500 kC of total charge separation. The solar wind is supposed...
Discussion question #1 – Draw two graphs side-by-side that show the market equilibrium price for soy...
Discussion question #1 – Draw two graphs side-by-side that show the market equilibrium price for soy beans as $3 per pound. The second graph is for Sally the soy bean farmer whose profit maximizing output is 80 pounds of soybeans. Show on your graph Sally making a profit of $140 at the market price of $3. Label all curves you draw and clearly indicate the profit region. 1. Is the above scenario a short-run or long-run equilibrium? 2. If it...
1. How does TLS provide authentication? Does it provide mutual authentication (both client and server-side)? Is...
1. How does TLS provide authentication? Does it provide mutual authentication (both client and server-side)? Is that required? 2.What is the purpose of padding, Message Authentication Code (MAC), handshake protocol, change cyber suite (CCS) protocol? 3.How does TLS provide: confidentiality, availability, integrity, non-repudiation?
Side PanelExpand side panel Breadcrumb: 5-1 Discussion: Sentencing and "Reasonableness"    Previous Next  After reading about the...
Side PanelExpand side panel Breadcrumb: 5-1 Discussion: Sentencing and "Reasonableness"    Previous Next  After reading about the Sentencing Reform Act of 1984 and the subsequent adjustments ordered by the Supreme Court, consider how these changes impact an individual judge's view of a "reasonable sentence." Then, in a post to the discussion board, answer these questions: Describe how you would tell a "reasonable" sentence from an unreasonable one—what are the hallmarks of a reasonable sentence? How does a forensic psychologist's sentencing evaluation...
Question for Discussion ---------- 2. Examine the role demand-side factors play in shaping the pattern of...
Question for Discussion ---------- 2. Examine the role demand-side factors play in shaping the pattern of world trade. 3. Why do demand-side factors sometimes lead to the geographical concentration of manufacturing industries in particular countries or regions?
Investing Activities Where does the primary investing cash outflow come from? Does it provide information about...
Investing Activities Where does the primary investing cash outflow come from? Does it provide information about " operational investment"
This is the question from US History 1 ( DISCUSSION) need about 250-300 words 1. Could...
This is the question from US History 1 ( DISCUSSION) need about 250-300 words 1. Could the Civil War have been avoided? Was western expansion inevitable? How did one event contribute to the other?
Create a discussion question about Endocrine System and submit a thorough response to this question.
Create a discussion question about Endocrine System and submit a thorough response to this question.
Create a discussion question about the Immune System and submit a thorough response to this question....
Create a discussion question about the Immune System and submit a thorough response to this question. "create a discussion question about Immune System."
This is a discussion board question. Explain the concept and provide an example if needed (ex....
This is a discussion board question. Explain the concept and provide an example if needed (ex. journal entry, depreciation calculation, t-account, statement). Solvency analysis focuses on the ability to accompany to pay its liabilities. It is usually assessed using the following: 1.     Current position analysis 2.     Accounts receivable analysis 3.     Inventory analysis 4.     The ratio of fixed assets to long-term liabilities 5.     The ration of liabilities to stockholders’ equity 6.     The number of times interest charges are earned
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT