resistors limit current

That statement is too general, resistors can be said to resist current. In some applications resistors can be used to limit current - a typical example is in series with an LED and a constant-voltage power supply.

resistors allow all voltage to pass through them

That is only true under specific circumstances, namely when the current is zero (or too close to zero to measure the effect on voltage)

The voltage across a resistor V is given by V = IR where I is current and R is resistance. For some narrow ranges of voltage, current and temperature, this resistance can be assumed to be nearly constant for resistors.

I don't understand is why the 555 timer only is looking at the voltage given off by C1, and why the voltage coming through R1 from VCC doesn't trigger the threshold itself.

Before the power supply is first connected, the capacitor is "uncharged", there is no voltage difference between the two sides of the capacity. this means that pins 6&7 are at 0 volts (relative to ground & pin 1)

When the power supply is connected, current flows through the resistor R1, "charging" the capacitor. As the charge grows, the voltage across the capacitor rises, so the voltage at pins 6&7 rises.

The operation of this "one-shot" circuit is explained here

Voltage doesn't really "come through" resistors. Or at least, I believe that's not a useful way to think about this sort of electronics.

Voltage isn't moving. The only things moving around are charge-carriers (e.g. electrons and holes). We call the movement of charge carriers current and measure it in units called Amps.

resistors limit current

That statement is too general, resistors can be said to resist current. In some applications resistors can be used to limit current - a typical example is in series with an LED and a constant-voltage power supply.

resistors allow all voltage to pass through them

That is only true under specific circumstances, namely when the current is zero (or too close to zero to measure the effect on voltage)

The voltage across a resistor V is given by V = IR where I is current and R is resistance. For some narrow ranges of voltage, current and temperature, this resistance can be assumed to be nearly constant for resistors.

I don't understand is why the 555 timer only is looking at the voltage given off by C1, and why the voltage coming through R1 from VCC doesn't trigger the threshold itself.

Before the power supply is first connected, the capacitor is "uncharged", there is no voltage difference between the two sides of the capacity. this means that pins 6&7 are at 0 volts (relative to ground & pin 1)

When the power supply is connected, current flows through the resistor R1, "charging" the capacitor. As the charge grows, the voltage across the capacitor rises, so the voltage at pins 6&7 rises.

The operation of this "one-shot" circuit is explained here

Voltage, Charge, Current, Connected, Motion, etc

Voltage doesn't really "come through" resistors. Or at least, I believe that's not a useful way to think about this sort of electronics.

Voltage isn't moving. The only things moving around are charge-carriers (e.g. electrons and holes). We call the movement of charge carriers current and measure it in units called Amps.

Consider this circuit

^{simulate this circuit – Schematic created using CircuitLab}

Even though there is a conducting path from pin 6 to Vcc, Pin 6 does not see Vcc, it sees the voltage at the junction between pin 6, the LED and the resistor. This voltage is held by the LED at close to whatever it's nominal forward voltage is, perhaps 2V say. This is almost regardless of the exact value of Vcc within some reasonable range.

resistors limit current

That statement is too general, resistors can be said to resist current. In some applications resistors can be used to limit current - a typical example is in series with an LED and a constant-voltage power supply.

resistors allow all voltage to pass through them

That is only true under specific circumstances, namely when the current is zero (or too close to zero to measure the effect on voltage)

The voltage across a resistor V is given by V = IR where I is current and R is resistance. For some narrow ranges of voltage, current and temperature, this resistance can be assumed to be nearly constant for resistors.

I don't understand is why the 555 timer only is looking at the voltage given off by C1, and why the voltage coming through R1 from VCC doesn't trigger the threshold itself.

Before the power supply is first connected, the capacitor is "uncharged", there is no voltage difference between the two sides of the capacity. this means that pins 6&7 are at 0 volts (relative to ground & pin 1)

When the power supply is connected, current flows through the resistor R1, "charging" the capacitor. As the charge grows, the voltage across the capacitor rises, so the voltage at pins 6&7 rises.

The operation of this "one-shot" circuit is explained here

resistors limit current

That statement is too general, resistors can be said to resist current. In some applications resistors can be used to limit current - a typical example is in series with an LED and a constant-voltage power supply.

resistors allow all voltage to pass through them

That is only true under specific circumstances, namely when the current is zero (or too close to zero to measure the effect on voltage)

The voltage across a resistor V is given by V = IR where I is current and R is resistance. For some narrow ranges of voltage, current and temperature, this resistance can be assumed to be nearly constant for resistors.

I don't understand is why the 555 timer only is looking at the voltage given off by C1, and why the voltage coming through R1 from VCC doesn't trigger the threshold itself.

Before the power supply is first connected, the capacitor is "uncharged", there is no voltage difference between the two sides of the capacity. this means that pins 6&7 are at 0 volts (relative to ground & pin 1)

When the power supply is connected, current flows through the resistor R1, "charging" the capacitor. As the charge grows, the voltage across the capacitor rises, so the voltage at pins 6&7 rises.

The operation of this "one-shot" circuit is explained here

Voltage doesn't really "come through" resistors. Or at least, I believe that's not a useful way to think about this sort of electronics.

Voltage isn't moving. The only things moving around are charge-carriers (e.g. electrons and holes). We call the movement of charge carriers current and measure it in units called Amps.

resistors limit current

That statement is too general, resistors can be said to resist current. In some applications resistors can be used to limit current - a typical example is in series with an LED and a constant-voltage power supply.

resistors allow all voltage to pass through them

That is only true under specific circumstances, namely when the current is zero (or too close to zero to measure the effect on voltage)

The voltage across a resistor V is given by V = IR where I is current and R is resistance. For some narrow ranges of voltage, current and temperature, this resistance can be assumed to be nearly constant for resistors.

I don't understand is why the 555 timer only is looking at the voltage given off by C1, and why the voltage coming through R1 from VCC doesn't trigger the threshold itself.

Before the power supply is first connected, the capacitor is "uncharged", there is no voltage difference between the two sides of the capacity. this means that pins 6&7 are at 0 volts (relative to ground & pin 1)

When the power supply is connected, current flows through the resistor R1, "charging" the capacitor. As the charge grows, the voltage across the capacitor rises, so the voltage at pins 6&7 rises.

resistors limit current

That statement is too general, resistors can be said to resist current. In some applications resistors can be used to limit current - a typical example is in series with an LED and a constant-voltage power supply.

resistors allow all voltage to pass through them

That is only true under specific circumstances, namely when the current is zero (or too close to zero to measure the effect on voltage)

The voltage across a resistor V is given by V = IR where I is current and R is resistance. For some narrow ranges of voltage, current and temperature, this resistance can be assumed to be nearly constant for resistors.

I don't understand is why the 555 timer only is looking at the voltage given off by C1, and why the voltage coming through R1 from VCC doesn't trigger the threshold itself.

Before the power supply is first connected, the capacitor is "uncharged", there is no voltage difference between the two sides of the capacity. this means that pins 6&7 are at 0 volts (relative to ground & pin 1)

When the power supply is connected, current flows through the resistor R1, "charging" the capacitor. As the charge grows, the voltage across the capacitor rises, so the voltage at pins 6&7 rises.

The operation of this "one-shot" circuit is explained here