Hubble Time Age Estimate
1/H0 timescale in Julian Gyr, not actual cosmological age without expansion history. Model only, not an ephemeris, measured stellar identity or observational guarantee.
Description
Hubble time is the reciprocal of the Hubble parameter after unit conversion.
Hubble time is the reciprocal of the Hubble parameter after unit conversion.1
It is a characteristic timescale rather than the age from a full cosmological history. Use Hubble Time Age Estimate to evaluate the supplied inputs under the model explained below.
When to use Hubble Time Age Estimate
Use Hubble Time Age Estimate to evaluate the supplied inputs under the model explained below. Establish the units, measurement scope and model assumptions before entering values.
How to use Hubble Time Age Estimate and understand its results
- Establish the units, measurement scope and model assumptions before entering values.
- Enter Hubble km per second per mpc using the field table and validation rules below, then run the tool.
- Read Hubble time gyr; interpret the units, signs, ordering and unknown-value placeholders described below.
- Correct reported input errors and rerun. Apply successful results according to their specific meanings and check the assumptions before using them in a decision.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| hubbleKmPerSecondPerMpc | Hubble km per second per mpc | number | Required; constraints below |
Enter a positive Hubble parameter in km/s/Mpc. Convert one Mpc to 3.0856775814913673e19 km, divide by the parameter and by 365.25×86400×1e9 to return Gyr. No matter, radiation or expansion history is integrated.
HubbleTimeGyr=(3.0856775814913673e19/H0)/(365.25×86400×1e9) Use the field order, units and branch conditions described above.
| Output field | Meaning | Value type |
|---|---|---|
| hubbleTimeGyr | Hubble time gyr | number |
{
"input": {
"hubbleKmPerSecondPerMpc": 70
},
"output": {
"hubbleTimeGyr": 13.96846030972556
}
}Limitations and assumptions
It is a characteristic timescale rather than the age from a full cosmological history. Apply the exact scope and assumptions explained above.
All listed fields require explicit values. Unexpected fields, incorrect types, nonfinite numbers and sparse arrays fail validation. Domain-specific bounds, alignments and supported tokens are explained above; extremely large inputs or outputs can also be rejected. Input errors differ from successful false results, empty match lists and unknown-evidence placeholders.
Alternative or Complementary methods
Use Approximate Lookback Time From z for a related task: Lookback time measures elapsed model time between emission and observation.
Use Hubble Law Distance From Velocity for a related task: The linear Hubble relation compares recession velocity with an assumed Hubble parameter.
References
-
Hubble Time Age Estimate — tool.io
Similar or alternative tools
- Approximate Lookback Time From z
Lookback time measures elapsed model time between emission and observation.
- Hubble Law Distance From Velocity
The linear Hubble relation compares recession velocity with an assumed Hubble parameter.