What Would Happen to Earth In This Scenario

  • Thread starter thequestioner
  • Start date
  • Tags
    Earth
In summary: So I guess the coin would just disintegrate.In summary, if a coin sized object were to collide with Earth at the speed of light, it could potentially cause a massive explosion or even create a black hole due to the immense energy released. However, it is unlikely to actually reach the center of the Earth and would most likely disintegrate before causing significant damage. A city sized object traveling at the same speed would have an even larger amount of energy, but it would still not be enough to completely destroy the Earth.
  • #1
thequestioner
2
0
What would happen if a coin sized object traveling at the speed of light were to collide with earth? What about a city sized object?
 
Physics news on Phys.org
  • #2
thequestioner said:
What would happen if a coin sized object traveling at the speed of light were to collide with earth? What about a city sized object?
I think more interesting question would be what would happen to a coin traveling at the speed of light. :)
 
  • #3
Coins have mass and therefore cannot travel at c
 
  • #4
Please rephrase your question so that it is physically meaningful. Objects with mass cannot travel at the speed of light.
 
  • #5
A coin sized object slightly slower than light can release energy comparable to a thermonuclear bomb. See the relativistic xkcd-baseball for a description. With those numbers, the released energy is about 4 MT TNT-equivalent.
 
  • #6
agreed, objects with mass cannot travel at the speed of light. So I'm going to assume the OP'er meant to say traveling at almost the speed of light.

In this case, ummm, If the coin was traveling pretty fast, as mfb said, it could give off a massive explosion. If it was going even faster, it might potentially blow up the earth. If it was going really fast, then it might just become a black hole due to so much energy being in such a small space. I'm not sure on the exact physics of black holes though. I still need to learn general relativity.
 
  • #7
At 0.9c a 5.6 gram quarter dollar coin from the US would have about 1.5 megatons of TNT worth of kinetic energy, or about 6.5x1015 joules.

At 0.99999c the same coin would have about 1.1x1018 joules of energy, or around 250 megatons of energy.

BruceW said:
In this case, ummm, If the coin was traveling pretty fast, as mfb said, it could give off a massive explosion. If it was going even faster, it might potentially blow up the earth. If it was going really fast, then it might just become a black hole due to so much energy being in such a small space. I'm not sure on the exact physics of black holes though. I still need to learn general relativity.

No object would ever collapse into a black hole, as in it's rest frame the object is not moving and has no additional mass or energy. As far as I understand very few people use relativistic mass anymore and use momentum instead.
 
  • #8
Wrt the city sized object; taking a spherical 5km radius asteroid with a density of 5g/ml traveling at .9c the kinetic energy is a mind boggling 9.54259E+30J. That's close to the total amount of solar energy output in a day. It's still only 1% of the gravitational binding energy of Earth though so presuming that all of the energy entered the system (i.e. part of the mass didn't simply shoot out of the other side of the planet) whilst the surface would be heated to incandescence and most likely the shape and orbit of the planet warped it wouldn't be totally destroyed by any means.
 
  • #9
Drakkith said:
No object would ever collapse into a black hole, as in it's rest frame the object is not moving and has no additional mass or energy.

As we are talking about a coin hitting Earth there is additional mass and energy. I don't know if the coin may form a black hole in this situation but if this happens it would cross Earth within 32 ms and than escape into space. I even don't know what this would mean to Earth.
 
  • #10
DrStupid said:
As we are talking about a coin hitting Earth there is additional mass and energy. I don't know if the coin may form a black hole in this situation but if this happens it would cross Earth within 32 ms and than escape into space. I even don't know what this would mean to Earth.
I'm not sure how we'd work this out for sure but I'm betting the coin would fully disintegrate long before it made it through the Earth. Assuming the veracity of the baseball link above this would be a safe bet.
 
  • #11
Ryan_m_b said:
I'm betting the coin would fully disintegrate long before it made it through the Earth

A black hole couldn't disintegrate. Therefore it seems to be an important question whether formation of a black hole is possible and if yes how it would happen in detail.
 
  • #12
In theory, it can form a black hole in a collision with Earth (but not as free object in space), as the center of mass energy density (which does not depend on the reference frame) can become large enough there. However, a black hole with a size of several millimeters would have a mass equivalent to the earth. The coin would probably need an energy which exceeds the mass of Earth (times c^2), and I think it needs several orders of magnitude more as it collides just with a small fraction of earth.
 

1. What would happen if Earth's atmosphere suddenly disappeared?

If Earth's atmosphere suddenly disappeared, all living organisms would die due to lack of oxygen. The atmosphere protects us from harmful radiation, regulates the Earth's temperature, and provides the necessary gases for respiration.

2. What would happen if the Earth's rotation slowed down or stopped?

If the Earth's rotation slowed down or stopped, the length of a day would change significantly, resulting in extreme weather patterns and disruptions to ecosystems. The Earth's magnetic field would also weaken, leaving us vulnerable to solar radiation.

3. What would happen if the Earth's magnetic poles flipped?

If the Earth's magnetic poles flipped, there would be temporary disruptions to communication and navigation systems due to changes in the magnetic field. However, this process occurs gradually and does not pose a threat to life on Earth.

4. What would happen if a large asteroid hit Earth?

If a large asteroid were to hit Earth, it could potentially cause mass extinction, depending on its size and impact location. The impact would release a large amount of energy, triggering earthquakes, tsunamis, and changes in the Earth's climate.

5. What would happen if the Earth's temperature continues to rise due to climate change?

If the Earth's temperature continues to rise due to climate change, we can expect more frequent and severe natural disasters, loss of biodiversity, and disruptions to food and water supply. It is crucial to take action to reduce carbon emissions and mitigate the effects of climate change.

Similar threads

B Untraditional Space Travel
    • Other Physics Topics
Replies
32
Views
4K
I What happens when an explosion occurs on the surface of the moon?
    • Other Physics Topics
Replies
5
Views
410
B What if a needle hits Jupiter at nearly speed of light?
    • Other Physics Topics
Replies
14
Views
2K
B Is one side of the Earth faster at night and slower at daytime?
    • Other Physics Topics
Replies
10
Views
8K
I Yuri Milner Breakthrough Starshot - Nano Craft hitting Earth
    • Other Physics Topics
Replies
2
Views
1K
I Image for increase in gravitational potential energy in radial field
    • Other Physics Topics
Replies
6
Views
914
I Earth Spinning: What Would Happen If You Were Left Behind?
    • Other Physics Topics
Replies
10
Views
1K
I Move the Earth Away from the Sun
    • Other Physics Topics
Replies
17
Views
2K
Gravitational Field: What Would Happen?
    • Other Physics Topics
Replies
8
Views
1K
I What Could Cause the Earth's Rotation to Dramatically Slow Down?
    • Astronomy and Astrophysics
2
Replies
39
Views
3K

Hot Threads

Recent Insights

Back
Top