Can we see the Earth in the past

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In summary, the conversation discusses the possibility of using laser interferometry to detect space-time disturbances caused by the Earth's movement through it. This is based on the idea that matter modulates space-time, and the question is how long this modulation lasts. However, gravitational waves, which are the disturbances created by a moving mass, are very difficult to detect and may not provide much information about the past. The conversation also considers the possibility of using a clock or measuring device to detect these disturbances, but it would only be able to "see" as far back as when it was launched into space. The conversation ends with a discussion about whether space-time gets modulated by matter and how long this modulation stays.
  • #1
leonstavros
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If matter modulates space-time then the Earth modulates space-time as it travels through it. If it does then can we send a spaceship to the location of Earths wake and measure the disturbance. How? By using laser interferometry. If we arrange a laser transmitter to shine through Earths wake and arrange a laser receiver on the other side of the wake we can detect space-time disturbances. Those disturbances can be de-modulated and then reproduced as images of Earth. The entire process hangs on whether space-time is modulated by matter and how long the disturbance lasts.

What do you think?
 
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  • #2
If by "Earth's wake" you mean the gravitational waves produced by the Earth-Sun system, then these waves are really puny...I'm not sure how accurate of a machine you would need to measure that. If you just mean Earth's disturbance of Space-time, we could measure that here on Earth...as Gravity. o_O
 
  • #3
Gravity waves are very weak making them exquisitely difficult to detect [see LIGO]. Only compact objects, like binary neutron stars [e.g., Hulse, et al], have yielded any observable effects.
 
  • #4
The Earth's wake is a disturbance of space-time that means space is affected and time is affected. The question is do we have instruments that can detect such changes? Perhaps at some point we can design a clock that can detect nano-changes in space-time then move the clock around to collect data points at which time a picture can be formed.

If the physics allow it then it's just a matter of technology catching up.
 
  • #5
It sounds like you're talking about gravity waves, which are the space-time disturbances created by a moving mass. Like Matterwave and Chronos said, these waves are very difficult to detect, and we haven't been able to detect the strongest of them until just recently. Unfortunately, it doesn't seem to provide much information as to what that object was like in the past.

As an analogy, this is sort of like dropping a rock into a pond and studying the ripples that it creates. Then by looking at only the ripples, trying to guess the composition of the rock. We may be able to infer a few things: whether it's a large or small rock, heavy or light, dropped straight in or at an angle, etc.
 
  • #6
Gravitational waves propagate through spacetime at the speed of light, so even if it were possible to accurately detect the waves and infer images, you would only be able to "see" as far into the Earth's past as when your detector was launched into space and started recording.
 
  • #7
imaloonru said:
It sounds like you're talking about gravity waves, which are the space-time disturbances created by a moving mass. Like Matterwave and Chronos said, these waves are very difficult to detect, and we haven't been able to detect the strongest of them until just recently. Unfortunately, it doesn't seem to provide much information as to what that object was like in the past.

As an analogy, this is sort of like dropping a rock into a pond and studying the ripples that it creates. Then by looking at only the ripples, trying to guess the composition of the rock. We may be able to infer a few things: whether it's a large or small rock, heavy or light, dropped straight in or at an angle, etc.

I'm saying that matter effects space-time at a quantum level. As the Earth moves through space-time it's not like a boat moving through water pushing the water out of the way and leaving a disturbance behind like a ships wake turbulence. Rather, all space that was occupied by Earth has been "changed" by Earths matter. The question is how much change and how long does the change stay. Does space-time get modulated by matter and does this modulation stay till some other matter changes it?
 
  • #8
GRB 080319B said:
Gravitational waves propagate through spacetime at the speed of light, so even if it were possible to accurately detect the waves and infer images, you would only be able to "see" as far into the Earth's past as when your detector was launched into space and started recording.

That depends on whether or not space-time gets modulated by matter and how long the modulation stays. It would be similar to a cosmic ray going through a cloud chamber only in a cloud chamber the track doesn't stay too long. If Earths "track" stayed a while then a measuring device could be send at any point of Earth's passing and detect the "track".
 

1. Can we see the Earth in the past?

Yes, it is possible to see the Earth in the past through various scientific methods and technologies such as satellite imagery, geological records, and astronomical observations. However, the further back in time we go, the more difficult it becomes to obtain clear and accurate images.

2. How far back in time can we see the Earth?

The farthest back in time that we can currently see the Earth is around 13.8 billion years, which is the estimated age of the universe. This is based on observations of the cosmic microwave background radiation, which is the residual heat from the Big Bang.

3. How do we see the Earth in the past?

One of the main ways we see the Earth in the past is through the study of geological records, such as sedimentary rocks and ice cores, which can provide information about past climates and environments. We can also use satellite imagery and remote sensing to study changes in land use and natural phenomena over time.

4. What can we learn from seeing the Earth in the past?

Studying the Earth in the past can provide valuable insights into the planet's history, including how it has changed over time and how it has been affected by natural processes and human activities. It can also help us understand the origins of life and how it has evolved over millions of years.

5. Are there any limitations to seeing the Earth in the past?

While we have made significant advancements in our ability to see the Earth in the past, there are still limitations to what we can observe and understand. For example, the further back in time we go, the less accurate and detailed our observations become. Additionally, some events and phenomena may not have left a clear record for us to study.

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