Convert rad [rd] to petagray [PGy] Online | Free radiation-absorbed-dose Converter

Rad [rd]: A Legacy Unit of Absorbed Radiation Dose

The rad (short for radiation absorbed dose) is a legacy unit used to measure the amount of ionizing radiation energy absorbed per unit mass of material. It was widely used before the adoption of the gray (Gy) in the International System of Units (SI).

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  1 rad = 0.01 gray (Gy)

  
  
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  This means that 1 rad corresponds to the absorption of 0.01 joules of radiation energy per kilogram of matter.

  
  

The rad was commonly used in medical, industrial, and scientific settings to quantify radiation doses. Although now largely replaced by the gray for consistency and international standardization, the rad is still sometimes referenced in older research, medical records, and certain fields.

The rad and its subunits (like the millirad) helped establish the groundwork for understanding radiation exposure and effects before the transition to the more precise and universally accepted gray unit.

Petagray [PGy]: An Unimaginably High Radiation Dose

The petagray (PGy) is a unit of absorbed radiation dose equal to 1,000 trillion grays (10¹⁵ Gy)—that’s one quadrillion grays. This is an extraordinarily vast amount of radiation energy absorbed per kilogram of matter, far beyond any natural or engineered radiation exposure known to humanity.

The petagray is purely theoretical and only relevant in extreme astrophysical phenomena or fundamental physics simulations, such as:

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  Modeling the intense radiation environments near supermassive black holes or during the most energetic cosmic events.

  
  
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  Exploring theoretical limits of matter-radiation interactions at cosmic or quantum scales.

  
  
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  Simulating conditions immediately following high-energy particle collisions or gamma-ray bursts.

  
  

At doses this high, all conventional matter would be utterly destroyed or transformed, and the concept of dose loses practical meaning.

The petagray highlights the vast scope of radiation measurement, showing how the gray unit can be scaled to express energy absorption at levels far beyond any earthly or practical scenario, emphasizing its role as a universal scientific measure across all scales.